Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 04/17/2026 has been entered.
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Amendment
Applicant's arguments and remarks filed on 04/17/2026 have been fully considered.
Claim 21 is new.
Claims 8 and 14 previously canceled.
Claims 1-7, 9-13, and 15-20 are pending.
Response to Arguments
Applicant's arguments filed 04/17/2026 have been fully considered but they are not persuasive.
Regarding Applicant’s Arguments That Gang Does Not Teach the Frequency Distance and Signal Pattern Limitations (Claims 1 and 13). The Applicant argues that “Gang does not describe comparing frequencies of signals received from multiple reflectors and generating a ‘distance measuring signal pattern,'” that “the use of FFT, as described by Gang, is limited to extracting peak values for distance estimation and does not involve generating or matching a distance measuring signal pattern based on frequency differences,” and that “a combination with Gang does not teach or suggest ‘determining … a frequency distance between the target reflector signal and each of the one or more reference reflector signals … and generating … a distance measuring signal pattern …'” (RCE Remarks, pp. 10–11).
The Examiner respectfully notes that the rejection does not rely on Gang (‘155) alone for the “frequency distance” and “distance measuring signal pattern” limitations. The rejection explicitly acknowledges that Gang (‘155) does not explicitly teach these limitations and relies on Doemens (‘237) to supply them. Applicant’s argument attacks each reference in isolation rather than addressing the combination as articulated in the rejection. In response to Applicant’s arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986). Nevertheless, the Examiner notes that Gang (‘155)’s system does involve frequency-domain analysis of reflector signals. Gang (‘155) teaches a millimeter wave radar ([0070]) that processes echo signals from multiple reflectors using Fast Fourier Transform ([0019], [0093]). In an FMCW radar system — which millimeter wave radars of the type described by Gang (‘155) commonly are — the FFT of the beat signal produces peaks at beat frequencies that are directly proportional to the range of each reflecting object. The positions of these FFT peaks in the frequency domain correspond to distinct beat frequencies for each reflector. The difference between the FFT peak positions for two different reflectors is therefore inherently a frequency difference. Gang (‘155)’s determination of “the difference in the distance between the signal peaks corresponding to each of the echo signals” ([0019]–[0020]) encompasses determining differences in the frequency-domain representation of these signals. Accordingly, Gang (‘155)’s FFT-based peak difference analysis teaches a form of frequency comparison, even though Gang (‘155) does not use the terminology “frequency distance.” The explicit frequency-based distance measurement and structured multi-frequency data organization are supplied by Doemens (‘237), as detailed in the rejection.
Regarding Applicant’s Arguments That Doemens Fails to Overcome the Deficiencies of Gang (Claims 1, 13, and 17). The Applicant argues that Doemens (‘237)’ characteristic switching frequencies (fs1, fs2, fs3) are employed “only for signal separation” and that Doemens (‘237) “derives distance values from phase measurements, not from frequency distances between reflector signals.” Applicant further argues that Doemens (‘237) “fails to teach or suggest ‘determining … a frequency distance between the target reflector signal and each of the one or more reference reflector signals'” and “generating … a distance measuring signal pattern … [that] comprises a matrix that is based on the determined frequency distances.” (RCE Remarks, pp. 10–11).
The Examiner respectfully disagrees for the following reasons:
(a) Doemens (‘237) teaches frequency distances between reflector signals. Each active reflector unit in Doemens (‘237) modulates the received radar signal at a characteristic frequency — fs1, fs2, or fs3 — such that “the radar signals reflected by the active reflector units 24, 25, 26 to the radar sensor 2 do not spectrally overlap in the selected spectral useful band” ([0105]). These characteristic frequencies become part of the reflected signal received by the radar sensor ([0107]–[0108]). The reflected signals from different reflector units therefore exist at different, identifiable frequencies. The difference between these signal frequencies (e.g., the difference between fs1 and fs2) is, by definition, a difference in signal frequency between reflector signals — which is precisely what the claims define as a “frequency distance.” The claims recite “a frequency distance between the target reflector signal and each of the one or more reference reflector signals, wherein the frequency distance comprises a difference in signal frequency between the target reflector signal and each of the one or more reference reflector signals.” The claims do not require that the frequency difference itself serve as the sole or direct means of distance calculation. They require that the radar sensor determine a frequency distance — i.e., ascertain the frequency-domain spacing between signals from different reflectors. Doemens (‘237)’ radar sensor does exactly this when it separates the spectral components at fs1, fs2, and fs3 through bandpass filtering ([0108]).
Applicant’s argument that Doemens (‘237) uses the characteristic frequencies “only for signal separation” does not negate the fact that Doemens (‘237) teaches determining frequency differences between reflector signals. A reference is not limited to the specific purpose for which it employs a technique; the teaching exists regardless of purpose. See In re Heck, 699 F.2d 1331, 1332–33, 216 USPQ 1038, 1039 (Fed. Cir. 1983) (“The question under 35 U.S.C. 103 is not merely what the references expressly teach but what they would have suggested to one of ordinary skill in the art.”).
(b) Phase measurement and frequency-based measurement are not distinct categories. Applicant attempts to characterize Doemens (‘237)’ distance determination as purely “phase-based” rather than “frequency-based.” This distinction is technically unfounded. Doemens (‘237) itself establishes the mathematical relationship between phase and frequency: the phase difference between transmitted and received signals is Δφ = 2π × f_HF × τ ([0092]), where f_HF is the radar frequency and τ is the propagation time. Phase measurements are inherently frequency-dependent. Moreover, Doemens (‘237) explicitly teaches that the radar sensor “carries out a measurement at at least two different radar frequencies and, by evaluating the phase differences from the transmitted and the received radar signal at the different radar frequencies, forms a measure for the distance” ([0044]). The distance measure is formed by evaluating how phase varies across different frequencies — this is a frequency-based distance measurement. Absolute distance measurement in Doemens (‘237) requires “at least two phase values, which are determined at at least two different radar frequencies” ([0094]). The difference in phase values between two measurement frequencies for a given reflector provides a frequency-dependent distance measure. The collection of such frequency-dependent distance measures across multiple reflectors provides a structured dataset of frequency-based distances.
(c) Doemens (‘237) teaches structured, multi-frequency, multi-reflector measurement data. Doemens (‘237) teaches that “the signal phase values for each measurement path between radar sensor 2 and the relevant active reflector unit 24, 25 or 26 are determined for a plurality of radar signal frequencies” and “these signal phase values are then converted to range values” ([0112]). This describes a measurement dataset organized by two dimensions: (1) measurement path (i.e., which reflector unit — 24, 25, or 26) and (2) radar signal frequency. A dataset organized along two dimensions is a matrix. Doemens (‘237) further teaches that “at least two measured values are determined for different transmission paths and these measured values are combined in a geometric equation system in order to determine the spatial position” ([0066]). The systematic organization of frequency-dependent measurements across multiple reflector paths into an equation system constitutes generating a structured signal pattern — a matrix — based on frequency-derived distance information.
Combined with Gang (‘155)’s database of reflector distances populated during initial calibration ([0016], [0131]), the combination teaches generating a distance measuring signal pattern comprising a matrix based on the determined frequency distances of the one or more reference reflector signals.
Regarding Applicant’s arguments that the combination lacks a reasonable expectation of success and requires impermissible hindsight (Claims 1 and 13). The Applicant argues that “the combination of Gang and Doemens does not provide a reasonable expectation of success” because Gang “does not disclose or suggest determining frequency differences between reflector signals or generating any form of distance measuring signal pattern” and Doemens (‘237) “employs them only for signal separation and derives distance values from phase measurements,” and that “combining Gang and Doemens would not yield the claimed invention and would require impermissible hindsight reconstruction using the present application as a blueprint.” (RCE Remarks, p. 11).
In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971).
The Examiner respectfully disagrees with the argument. The combination involves applying a known radar measurement technique (Doemens (‘237)’ multi-frequency, frequency-identified distance measurement for lifting device positioning) to a known radar positioning system (Gang (‘155)’s elevator radar system with multiple reflectors) to yield predictable results (improved reflector identification and distance measurement through frequency-domain analysis). Both Gang (‘155) and Doemens (‘237) are directed to radar-based position measurement systems for lifting devices — Gang (‘155) for elevators and Doemens (‘237) for cranes/hoists — and both use radar sensors with multiple reflectors to determine position. One of ordinary skill in radar signal processing would recognize that Doemens (‘237)’ techniques for frequency-based reflector identification and multi-frequency distance measurement are directly applicable to Gang (‘155)’s FMCW-type millimeter wave radar system. The predictable result is a system that uses frequency-domain analysis to more precisely identify and measure distances between reflectors in the elevator hoistway. This falls squarely within the rationale of KSR International Co. v. Teleflex Inc., 550 U.S. 398 (2007), which held that combining known elements according to known methods to yield predictable results supports an obviousness determination.
The fact that the prior art combination produces the same result as the claimed invention does not establish that the combination was derived through hindsight. Rather, it establishes that the claimed invention would have been obvious. Here, the combination relies solely on teachings present in the prior art references, which are in the same field of endeavor, and involves applying known radar signal processing techniques to known radar positioning systems.
Regarding Applicant’s arguments directed to Claim 17 — Doemens and Kech. The Applicant argues that Doemens (‘237) “fails to teach or suggest ‘generating … a distance measuring signal pattern, wherein the distance measuring signal pattern comprises a matrix that is determined based on the initial frequency of the first signal compared with the second frequency of the second signal,’ as recited in claim 17.” Applicant further argues that Kech (‘054) “does not describe generating a distance measuring signal pattern that comprises a matrix” and “nowhere does Kech describe comparing the initial frequency of a first signal with the frequency of a second signal in generating a matrix or signal pattern.” Applicant concludes that “combining Doemens and Kech would not result in the claimed subject matter and would require significant modification unsupported by either reference or impermissible hindsight reconstruction.” (RCE Remarks, pp. 12–13).
In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971).
The Examiner respectfully notes that Applicant’s argument conflates the respective roles of the three references in the rejection. The rejection of claim 17 relies on Gang (‘155) in view of Doemens (‘237) and further in view of Kech (‘054). Kech (‘054) is relied upon solely for the electromechanical actuation of a reflector between positions ([0016]–[0017], [0056]) — Kech (‘054) is not relied upon for the “distance measuring signal pattern” or “matrix” limitations. The frequency comparison and matrix limitations are addressed by Gang (‘155) in view of Doemens (‘237), as set forth in the analysis of claim 1. Applicant’s arguments that Kech (‘054) does not teach the matrix or frequency comparison limitations are therefore inapposite, as Kech (‘054) is not relied upon for those teachings.
Regarding Doemens (‘237)’ alleged failure to teach the claim 17 “matrix” limitation, the Examiner maintains the position set forth above. Doemens (‘237) teaches structured multi-frequency measurement data organized by reflector path and radar frequency ([0066], [0112]), which constitutes a matrix. When a reflector is moved between a first position and a second position (as taught by Kech (‘054)), the radar sensor receives signals at different frequencies from the same reflector at different positions. Comparing these frequencies and organizing the resulting data into a structured pattern is the natural and predictable result of applying Doemens (‘237)’ multi-frequency measurement methodology to a system with a mechanically repositionable reflector as taught by Kech (‘054), within the context of Gang (‘155)’s elevator radar system. The motivation to combine remains as stated in the rejection.
Claim Objections
Claim 9 objected to because of the following informalities: ". Appropriate correction is required.
Claim 16 objected to because of the following informalities: the claim recites “The method of claim 15”, however claim 15 is directed to a system claim. Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim 2 rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. The claim recites “actuating, by the radar sensor, an electromechanical device coupled to the reflector to move the reflector between at least two positions during elevator operation”. The claim does not clearly identify whether “the reflector” means the target reflector, the main reflector, one reference reflector, and of the reference reflectors, or some additional reflector.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1–7, 9–13, 15, and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Gang et al. (CN 111847155A) in view of Doemens et al. (EP 1087237A2).
Regarding Claim 1, Gang (‘155) in view of Doemens (‘237) teaches:
Gang (‘155) teaches: A method for training a radar sensor to determine positioning of an elevator car within an elevator system, the method comprising: ([0010]-[0011]: “A method for determining the position of an elevator car, the method comprising: Obtain the switching times of the reflector switch of the ranging radar installed on the outer surface of the elevator car from the initial position, and determine the reflector identification of the target reflector corresponding to the current time of the ranging radar according to the switching times; the reflector Are arranged on the side wall of the elevator hoistway at intervals”; [0070]: “the ranging radar 102 is installed on the outside of the elevator car, and a plurality of reflectors are successively arranged on the elevator shaft wall on the same side as the ranging radar 102”). The “training” of the radar sensor is broadly taught by the initial calibration/configuration procedure of Gang’s system upon first power-on.
Gang (‘155) teaches: emitting, by the radar sensor, electromagnetic waves comprising a transmission signal; ([0080]: “the ranging radar 102 can transmit lightning signals to the target reflector and receive the echoes reflected from the target reflector”; [0070]: “the ranging radar 102 may be a millimeter wave radar”).
Gang (‘155) teaches: receiving, by the radar sensor, a target reflector signal and one or more reference reflector signal, wherein the target reflector signal comprises a reflected electromagnetic wave from a target reflector, wherein the one or more reference reflector signals comprise a reflected electromagnetic wave from one or more reference reflectors; ([0097]-[0098]: “when the ranging radar receives echo signals from multiple reflectors, obtain the signal strength of the echo signals of each reflector respectively”; [0082]: “the reference distance is the vertical distance between the target reflector and the reference reflector, and the reference reflector is the reflector closest to the pit or top of the elevator hoistway”). Gang teaches that the radar receives echo signals (reflected electromagnetic waves) from multiple reflectors including both a target reflector and reference reflectors arranged along the hoistway.
Gang (‘155) teaches: calibrating, by the radar sensor, the target reflector signal; ([0093]: “the distance between adjacent reflectors can be calculated based on the echo signal received by the ranging radar when the elevator or ranging radar is first powered on. Specifically, the distance between each adjacent reflector can be obtained by the ranging radar. The echo signal is processed by Fast Fourier Transform”). The initial power-on procedure involving FFT processing of echo signals to determine signal peaks constitutes calibrating the target reflector signal.
Gang (‘155) teaches: calibrating, by the radar sensor, the one or more reference reflector signals; ([0093]-[0096]: “the echo signals of adjacent reflectors are obtained, and the echo signals are processed by fast Fourier transform to obtain the signal peaks corresponding to each echo signal”). The same FFT-based signal processing calibration is performed for each reflector signal including the reference reflector signals.
Gang (‘155) teaches: comparing, by the radar sensor, frequencies of the target reflector signal and the one or more reference reflector signals; ([0093]-[0094]: “From the distance-amplitude change graph, the corresponding echo signal is determined The signal peak value is the signal strength when the radar signal is completely transmitted to any reflector. From the distance-amplitude change graph, it is determined that when the signal strengths from two adjacent reflectors are maximum, the relative distances between the ranging radar and the two reflectors are recorded as the first relative distance d11 and the second relative distance d12, respectively.”; [0019]: “performing fast Fourier transform processing on the echo signals to obtain signal peaks corresponding to each of the echo signals”). In FMCW radar systems (such as the millimeter wave radar of Gang), the FFT of the mixed signal produces frequency peaks that correspond to the range of each reflector, and comparing the positions of these peaks inherently involves comparing the frequencies (beat frequencies) associated with each reflector.
Gang (‘155) does not explicitly teach: determining, by the radar sensor, for each of the one or more reference reflector signals, a frequency distance between the target reflector signal and each of the one or more reference reflector signals, wherein the frequency distance comprises a difference in signal frequency between the target reflector signal and each of the one or more reference reflector signals. However, Doemens (‘237) teaches a radar-based measurement system for determining the position of load-carrying devices in lifting equipment using multiple active reflector units ([0044]: “A radar sensor expediently carries out a measurement at at least two different radar frequencies and, by evaluating the phase differences from the transmitted and the received radar signal at the different radar frequencies, forms a measure for the distance and/or the change in distance between the radar sensor and an active reflector unit.”). Doemens further teaches that each active reflector unit modulates the radar signal at a characteristic frequency so that the signal from each reflector can be identified and separated ([0047]: “Each active reflector unit advantageously modulates the radar signal received by it in a manner characteristic of the relevant active reflector unit”; [0105]: “the amplifier 8 of each active reflector unit 24, 25, 26 is switched on and off with a characteristic clock fs 1, fs 2 or fs 3. This clock characteristic for each active reflector unit 24, 25, 26 is to be selected such that the radar signals reflected by the active reflector units 24, 25, 26 to the radar sensor 2 do not spectrally overlap in the selected spectral useful band”). Doemens teaches that these characteristic frequency components are separated by bandpass filtering and the phase of each separated signal is evaluated at multiple radar frequencies to determine distance ([0107]-[0108]: “The radar signals received there and reflected by the active reflector units 24, 25, 26 are mixed down into baseband by the mixer 13 of the radar sensor 2. In addition to frequency components around 0 HZ, signal components result at the switching frequency fs 1, fs 2 or fs 3 characteristic of the active reflector units 24, 25, 26 and their multiples”; “The spectral components can be selected by band-pass filtering and the radar signal components of all active reflector units 24, 25, 26 can be separated from one another”). This teaches determining, for each reflector signal, a frequency-based measure (a frequency distance) that corresponds to the distance between the radar sensor and each reflector, and the differences between these frequency-based measures for different reflectors directly yield frequency distances between reflector signals.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to combine the elevator car position determination system of Gang (‘155) with the frequency-based radar distance measurement techniques of Doemens (‘237), specifically to explicitly determine, for each reference reflector signal, a frequency distance (difference in signal frequency) between the target reflector signal and each reference reflector signal. One would have been motivated to do so because Gang already uses millimeter wave radar and FFT-based signal peak analysis to determine distances between reflectors, and Doemens teaches that evaluating phase differences at different radar frequencies provides a precise measure for distance between a radar sensor and each reflector in a lifting device positioning system ([0044], [0094]). Applying Doemens’ multi-frequency, frequency-difference-based distance analysis to Gang’s multi-reflector elevator system would provide an explicit and mathematically precise way to determine the spacing between reflectors using frequency domain analysis, improving measurement accuracy. There is a reasonable expectation of success because both Gang and Doemens are directed to radar-based position measurement systems for lifting devices (elevator and crane, respectively), both use radar sensors with multiple reflectors, and Doemens explicitly teaches FMCW radar evaluation methods ([0063], [0089], [0094]) which are directly applicable to Gang’s millimeter wave radar system.
Gang (‘155) teaches: generating, by the radar sensor, a distance measuring signal pattern, Partially, Gang teaches storing distances between adjacent reflectors in a database ([0016]: “Query a preset database according to the reflector identification to obtain multiple distances between the target reflector and the reference reflector; the preset database stores the distances between two adjacent reflectors”; [0131]: “query a preset database according to the reflector identification to obtain multiple distances between the target reflector and the reference reflector; the preset database stores two adjacent The spacing of the reflector plate”). This database of distance relationships among reflectors constitutes a structured pattern of distance measurements.
Gang (‘155) does not explicitly teach, but Doemens (‘237) teaches wherein the distance measuring signal pattern comprises a matrix that is based on the determined frequency distance of the one or more reference reflector signals. Doemens teaches generating structured measurement data based on frequency analysis across multiple reflectors and multiple measurement frequencies. Doemens teaches that signal phase values for each measurement path between the radar sensor and each active reflector unit are determined for a plurality of radar signal frequencies, and these values are then converted to range values ([0112]: “During a measurement, the signal phase values for each measurement path between radar sensor 2 and the relevant active reflector unit 24, 25 or 26 are determined for a plurality of radar signal frequencies. In the manner described above, these signal phase values are then converted to range values.”). Doemens further teaches combining at least two measured values from different transmission paths in a geometric equation system to determine position ([0066]: “at least two measured values are determined for different transmission paths and these measured values are combined in a geometric equation system in order to determine the spatial position of the load-receiving means”). The organized collection of phase/frequency measurements across multiple reflectors and multiple frequencies, combined in an equation system, inherently constitutes a matrix-based signal pattern. Additionally, the spectral components at the characteristic frequencies fs1, fs2, fs3 for the three reflector units ([0105]) naturally organize into a structured frequency-distance matrix.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to combine the multi-reflector distance database of Gang (‘155) with the structured multi-frequency, multi-reflector measurement data organization of Doemens (‘237) to generate a distance measuring signal pattern comprising a matrix based on the determined frequency distances of the one or more reference reflector signals. One would have been motivated to do so because Gang already stores reflector distances in a structured database for later matching, and Doemens teaches that organizing frequency-domain measurements (phase values at multiple frequencies) across multiple reflector paths into a structured system is an effective technique for accurately determining and tracking position in a lifting device ([0066], [0112]). Applying this multi-frequency, multi-reflector structured measurement approach to the frequency distances between reflectors in Gang’s system would create a unique and reliable identification pattern for the reflector configuration, improving the robustness and accuracy of the position determination system. There is a reasonable expectation of success because both references use radar-based distance measurement in lifting devices, both process signals from multiple reflectors, and organizing measured frequency differences into a matrix/table structure is a routine data organization step in multi-variable signal processing.
Regarding Claim 2, Gang (‘155) in view of Doemens (‘237) teaches the method of claim 1.
Gang (‘155) teaches: wherein the target reflector signal comprises a signal from reflection of electromagnetic waves emitted by the radar sensor by a main reflector. ([0079]-[0080]: “Obtain the current measurement distance obtained by the ranging radar, and obtain the relative height between the ranging radar and the target reflector according to the measurement distance; the measured distance is the distance between the ranging radar and the target reflector”; “the ranging radar 102 can transmit lightning signals to the target reflector and receive the echoes reflected from the target reflector.”). The target reflector from which echo signals are received constitutes the “main reflector.”
Regarding Claim 3, Gang (‘155) in view of Doemens (‘237) teaches the method of claim 2.
Gang (‘155) teaches: wherein the target reflector signal is associated with a static location corresponding to the main reflector. ([0070]: “a plurality of reflectors are successively arranged on the elevator shaft wall on the same side as the ranging radar 102… each reflector is marked as R1, R2…Rn in turn according to its installation position”). The reflectors are physically fixed to the elevator shaft wall at static locations.
Regarding Claim 4, Gang (‘155) in view of Doemens (‘237) teaches the method of claim 1.
Gang (‘155) teaches: wherein calibrating the target reflector signal comprises: emitting, by the radar sensor, electromagnetic waves comprising a transmission signal; ([0080]: “the ranging radar 102 can transmit lightning signals to the target reflector”; [0093]: “the distance between adjacent reflectors can be calculated based on the echo signal received by the ranging radar when the elevator or ranging radar is first powered on”).
Gang (‘155) teaches: and monitoring, by the radar sensor, for the target reflector signal from a reflection of the electromagnetic waves by a main reflector. ([0080]: “receive the echoes reflected from the target reflector”; [0093]: “The echo signal is processed by Fast Fourier Transform… of the echo signal from the adjacent reflector to obtain a distance-amplitude change graph”).
Regarding Claim 5, Gang (‘155) in view of Doemens (‘237) teaches the method of claim 1.
Gang (‘155) teaches: wherein the one or more reference reflector signals comprise one or more signals from reflection of electromagnetic waves emitted by the radar sensor by one or more corresponding reference reflectors. ([0082]: “the reference distance is the vertical distance between the target reflector and the reference reflector, and the reference reflector is the reflector closest to the pit or top of the elevator hoistway”; [0098]: “when the ranging radar receives echo signals from multiple reflectors, obtain the signal strength of the echo signals of each reflector respectively”).
Regarding Claim 6, Gang (‘155) in view of Doemens (‘237) teaches the method of claim 5.
Gang (‘155) teaches: wherein the one or more reference reflector signals are associated with static locations corresponding to the one or more reference reflectors. ([0070]: “a plurality of reflectors are successively arranged on the elevator shaft wall on the same side as the ranging radar 102… the distance between any adjacent reflectors can be denoted as d”). The reference reflectors are fixed at known static locations along the elevator shaft wall.
Regarding Claim 7, Gang (‘155) in view of Doemens (‘237) teaches the method of claim 1.
Gang (‘155) teaches: wherein calibrating the one or more reference reflector signals comprises: emitting, by the radar sensor, electromagnetic waves comprising a transmission signal; ([0093]: “the distance between adjacent reflectors can be calculated based on the echo signal received by the ranging radar when the elevator or ranging radar is first powered on”).
Gang (‘155) teaches: and monitoring, by the radar sensor, for the one or more reference reflector signals from reflections of the electromagnetic waves by one or more corresponding reference reflectors. ([0093]: “Specifically, the distance between each adjacent reflector can be obtained by the ranging radar. The echo signal is processed by Fast Fourier Transform… of the echo signal from the adjacent reflector”; [0096]: “the echo signals of adjacent reflectors are obtained, and the echo signals are processed by fast Fourier transform to obtain the signal peaks corresponding to each echo signal”).
Regarding Claim 9, Gang (‘155) in view of Doemens (‘237) teaches the method of claim 1.
Gang (‘155) teaches: further comprising: receiving a location determination request; ([0047]-[0048]: “A computer device includes a memory and a processor, the memory stores a computer program, and the processor implements the following steps when executing the computer program: Obtain the switching times of the reflector switch of the ranging radar installed on the outer surface of the elevator car from the initial position”). The execution of the computer program to determine position constitutes receiving a location determination request.
Gang (‘155) teaches: emitting electromagnetic waves comprising a transmission signal in response to the location determination request; ([0080]: “the ranging radar 102 can transmit lightning signals to the target reflector”).
Gang (‘155) teaches: monitoring for signals from reflection of the electromagnetic waves by a main reflector and one or more reference reflectors; ([0098]: “when the ranging radar receives echo signals from multiple reflectors, obtain the signal strength of the echo signals of each reflector respectively”).
Gang (‘155) teaches: recording signals detectable by the radar sensor, wherein the signals comprise reflection of the electromagnetic waves by a main reflector and one or more reference reflectors; ([0093]: “the relative distances between the ranging radar and the two reflectors are recorded as the first relative distance d11 and the second relative distance d12, respectively”).
Gang (‘155) teaches determining signal peak differences for adjacent reflectors using FFT processing ([0019]-[0020]: “performing fast Fourier transform processing on the echo signals to obtain signal peaks corresponding to each of the echo signals; The difference in the distance between the signal peaks corresponding to each of the echo signals is obtained as the distance between the two adjacent reflectors.”). However, Gang does not explicitly teach: calculating, iteratively for each recorded signal, frequency differences F(n−1)n=fn−1−fn over frequency domains f1, f2, . . . fn, wherein n=2 to N, where N comprises a total number of recorded signal peaks corresponding to the main reflector and the one or more reference reflectors, searching for a match of the distance measuring signal pattern to the calculated frequency differences. However, Doemens (‘237) teaches iterative frequency analysis across multiple measurement frequencies and multiple reflector units. Specifically, Doemens teaches that the radar sensor carries out measurements at multiple radar frequencies and evaluates phase differences at each frequency ([0094]: “For absolute distance measurement, at least two phase values, which are determined at at least two different radar frequencies, must be evaluated.”), and that signal phase values for each measurement path between the radar sensor and each active reflector unit are determined for a plurality of radar signal frequencies ([0112]). The spectral components at each characteristic reflector frequency are separated and evaluated iteratively ([0105]-[0108]).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to apply Doemens’ iterative multi-frequency analysis to Gang’s multi-reflector signal peak processing in order to calculate frequency differences iteratively across recorded signal peaks. One would have been motivated to do so because iteratively calculating frequency differences across all recorded signal peaks at multiple frequency domains provides a systematic and comprehensive approach to identifying reflector configurations, improving upon Gang’s pairwise peak-difference approach. The motivation to combine and reasonable expectation of success remain as stated in claim 1.
Gang (‘155) teaches matching reflector identification through database comparison ([0016]: “Query a preset database according to the reflector identification to obtain multiple distances between the target reflector and the reference reflector”). However, Gang does not explicitly teach: searching for a match of the distance measuring signal pattern to the calculated frequency differences. Doemens (‘237) teaches that the measured phase/frequency values across multiple reflectors are used to determine the position of the load-carrying device by solving a geometric equation system ([0066], [0082], [0112]), which inherently involves matching measured frequency-based values against expected patterns to determine position. It would have been obvious to apply Doemens’ frequency-based pattern matching approach to search for a match of the distance measuring signal pattern against calculated frequency differences, because Doemens teaches that organized frequency-domain measurements across multiple reflectors effectively determine position in lifting equipment. The motivation to combine and reasonable expectation of success remain as stated in claim 1.
Gang (‘155) teaches: determining a match to the distance measuring signal pattern; ([0099]-[00100]: “Determine the reflector with the highest signal strength from among the reflectors; Generate a control instruction according to the reflector with the largest signal strength, and send the control instruction to the ranging radar; the control instruction is used to trigger the ranging radar to identify the reflector with the largest signal strength as the target reflector.”).
Gang (‘155) teaches: identifying the target reflector signal based on the match; ([00100]: “the control instruction is used to trigger the ranging radar to identify the reflector with the largest signal strength as the target reflector”).
Gang (‘155) teaches: and determining a distance based on the target reflector signal. ([0079]-[0080]: “Obtain the current measurement distance obtained by the ranging radar, and obtain the relative height between the ranging radar and the target reflector according to the measurement distance; the measured distance is the distance between the ranging radar and the target reflector.”).
Regarding Claim 10, Gang (‘155) in view of Doemens (‘237) teaches the method of claim 9.
Gang (‘155) teaches: wherein the location determination request comprises a request for the radar sensor to determine a height of the elevator car. ([0079]: “obtain the relative height between the ranging radar and the target reflector according to the measurement distance”; [0084]: “Determine the current position of the elevator car according to the relative height and the reference distance.”).
Regarding Claim 11, Gang (‘155) in view of Doemens (‘237) teaches the method of claim 9.
Gang (‘155) teaches organizing distance/signal data in a structured database ([0131]: “query a preset database according to the reflector identification to obtain multiple distances between the target reflector and the reference reflector; the preset database stores two adjacent The spacing of the reflector plate; add multiple spacings to obtain the reference distance corresponding to the reflector plate mark.”). However, Gang does not explicitly teach: further comprising: populating to a matrix row, for each frequency domain, the frequency differences for each recorded signal from a signal of a given frequency domain. However, Doemens (‘237) teaches organizing frequency-domain measurement data in a structured manner across multiple frequency domains and multiple reflector paths. Specifically, Doemens teaches that signal phase values for each measurement path are determined for a plurality of radar signal frequencies and converted to range values ([0112]), and that these measurements across different transmission paths are combined in a geometric equation system ([0066]). This teaches populating measurement data in a structured, per-frequency-domain format across multiple reflector signals.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to organize the frequency differences from Gang’s reflector echo signals into matrix rows indexed by frequency domain, as taught by Doemens’ multi-frequency, multi-reflector measurement organization. One would have been motivated to do so because organizing frequency difference data into a matrix row structure enables systematic comparison and efficient pattern matching across all frequency domains, and Doemens demonstrates that structured multi-frequency measurements are essential for accurate position determination in lifting devices ([0094], [0112]). The motivation to combine and reasonable expectation of success remain as stated in claim 1.
Regarding Claim 12, Gang (‘155) in view of Doemens (‘237) teaches the method of claim 9.
Gang (‘155) teaches matching measured distances to stored reference distances ([0016]: “Query a preset database according to the reflector identification to obtain multiple distances between the target reflector and the reference reflector”). However, Gang does not explicitly teach: further comprising matching frequency distances of the distance measuring signal pattern to the calculated frequency differences by frequency domain. However, Doemens (‘237) teaches that measurements at different radar frequencies provide complementary distance information — differential distance measurement at one frequency and absolute distance at multiple frequencies ([0093]-[0095]) — and that the measurements across frequency domains are matched and combined to determine position ([0066], [0112]). This teaches matching frequency-based distance measurements on a per-frequency-domain basis.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to apply Doemens’ per-frequency-domain measurement matching to Gang’s reflector identification process to match frequency distances of the distance measuring signal pattern to calculated frequency differences by frequency domain. One would have been motivated to do so because per-frequency-domain matching provides finer-grained and more reliable pattern matching than bulk distance comparison alone, and Doemens teaches that evaluating at multiple frequencies is essential for accurate absolute distance determination ([0094]). The motivation to combine and reasonable expectation of success remain as stated in claim 1.
Regarding Claim 13, Gang (‘155) in view of Doemens (‘237) teaches:
Gang (‘155) teaches: A system for training a radar sensor to determine positioning of an elevator car within an elevator system, the system comprising: (See claim 1 analysis; [0047]: “A computer device includes a memory and a processor, the memory stores a computer program”).
Gang (‘155) teaches: a memory device having executable instructions stored therein; ([0047]: “A computer device includes a memory and a processor, the memory stores a computer program”).
Gang (‘155) teaches: and a processor, in response to the executable instructions, configured to: ([0047]: “the processor implements the following steps when executing the computer program”; [0155]: “a computer device is also provided, including a memory and a processor, and a computer program is stored in the memory, and the processor implements the steps in the foregoing method embodiments when executing the computer program.”).
Gang (‘155) teaches: generate electromagnetic waves comprising a transmission signal; (See claim 1 analysis for “emitting” limitation).
Gang (‘155) teaches: receive a target reflector signal and one or more reference reflector signal, wherein the target reflector signal comprises a reflected electromagnetic wave from a target reflector, wherein the one or more reference reflector signals comprise a reflected electromagnetic wave from one or more reference reflectors; (See claim 1 analysis for “receiving” limitation).
Gang (‘155) teaches: calibrate the target reflector signal; (See claim 1 analysis for “calibrating the target reflector signal” limitation).
Gang (‘155) teaches: calibrate the one or more reference reflector signals; (See claim 1 analysis for “calibrating the one or more reference reflector signals” limitation).
Gang (‘155) teaches: compare frequencies of the target reflector signal and the one or more reference reflector signals; (See claim 1 analysis for “comparing” limitation).
Gang (‘155) does not explicitly teach: determine, for each of the one or more reference reflector signals, a frequency distance between the target reflector signal and each of the one or more reference reflector signals, wherein the frequency distance comprises a difference in signal frequency between the target reflector signal and each of the one or more reference reflector signals. Doemens (‘237) teaches this element. (See claim 1 analysis for “determining” limitation. The same deficiency analysis, Doemens citations, obviousness rationale, motivation to combine, and reasonable expectation of success apply.)
Gang (‘155) does not explicitly teach: and generate a distance measuring signal pattern, wherein the distance measuring signal pattern comprises a matrix that is based on the determined frequency distances of the one or more reference reflector signals. Doemens (‘237) teaches this element. (See claim 1 analysis for “generating” limitation. The same deficiency analysis, Doemens citations, obviousness rationale, motivation to combine, and reasonable expectation of success apply.)
Regarding Claim 15, Gang (‘155) in view of Doemens (‘237) teaches the system of claim 13.
Gang (‘155) teaches: wherein the processor is further configured to: (See claim 13 analysis).
The remaining limitations of claim 15 are substantively identical to those of claim 9 but recited in system form. The analysis for each limitation of claim 15 — receive a location determination request; emit electromagnetic waves comprising a transmission signal in response to the location determination request; monitor for signals from reflection of the electromagnetic waves by a main reflector and one or more reference reflectors; record signals detectable by the radar sensor, wherein the signals comprise reflection of the electromagnetic waves by a main reflector and one or more reference reflectors; calculate, iteratively for each recorded signal, frequency differences F(n−1)n=fn−1−fn over frequency domains f1, f2, . . . fn, wherein n=2 to N, where N comprises a total number of recorded signal peaks corresponding to the main reflector and the one or more reference reflectors, searching for a match of the distance measuring signal pattern to the calculated frequency differences; search for a match of the distance measuring signal pattern to the calculated frequency differences; determine a match to the distance measuring signal pattern; identify the target reflector signal based on the match; and determine a distance based on the target reflector signal — follows the same analysis, citations, and obviousness rationale as provided for corresponding limitations in claim 9 above.
Regarding Claim 16, Gang (‘155) in view of Doemens (‘237) teaches the system of claim 15.
Note: Claim 16 recites “The method of claim 15” but claim 15 depends from system claim 13. This appears to be a typographical error and is treated as “The system of claim 15.”
Gang (‘155) does not explicitly teach: wherein the processor is further configured to: populate to a matrix row, for each frequency domain, the frequency differences for each recorded signal from a signal of a given frequency domain. Doemens (‘237) teaches this element. (See claim 11 analysis. The same deficiency analysis, Doemens citations, obviousness rationale, motivation to combine, and reasonable expectation of success apply.)
Claims 17-21 are rejected under 35 U.S.C. 103 as being unpatentable over Gang et al. (CN 111847155A) in view of Doemens et al. (EP 1087237A2) and further in view of Kech (US 2015/0029054 A1).
Regarding Claim 17, Gang (‘155) in view of Doemens (‘237) and Kech (‘054) teaches:
Gang (‘155) teaches: A method for calibrating signal frequency signature by a radar sensor in an elevator system, the method comprising: ([0070]: “the ranging radar 102 is installed on the outside of the elevator car, and a plurality of reflectors are successively arranged on the elevator shaft wall”; [0093]: “the distance between adjacent reflectors can be calculated based on the echo signal received by the ranging radar when the elevator or ranging radar is first powered on”). The initial power-on procedure teaches calibrating signal characteristics of the radar sensor in an elevator system.
Gang (‘155) teaches: emitting, by the radar sensor, electromagnetic waves comprising a transmission signal to perform a calibration procedure with a reflector configured in a first position; ([0093]: “the distance between adjacent reflectors can be calculated based on the echo signal received by the ranging radar when the elevator or ranging radar is first powered on. Specifically, the distance between each adjacent reflector can be obtained by the ranging radar.”; [0080]: “the ranging radar 102 can transmit lightning signals to the target reflector”). When the radar is first powered on and the elevator car is at a given position, the reflectors are at fixed positions relative to the radar, and the radar emits signals to perform its initial calibration.
Gang (‘155) teaches: receiving, by the radar sensor, a first signal comprising a reflection of the electromagnetic waves by the reflector, wherein the first signal comprises an initial frequency; ([0093]: “The echo signal is processed by Fast Fourier Transform… of the echo signal from the adjacent reflector to obtain a distance-amplitude change graph… the corresponding echo signal is determined The signal peak value”). The echo signal from a reflector at a first position has a characteristic frequency (beat frequency/signal peak in the FFT spectrum).
Gang (‘155) teaches: recording, by the radar sensor, the first signal corresponding to the first position of the reflector; ([0093]: “the relative distances between the ranging radar and the two reflectors are recorded as the first relative distance d11 and the second relative distance d12, respectively”).
Gang (‘155) does not explicitly teach: actuating, by the radar sensor, an electromechanical device coupled to the reflector causing the reflector to move to a second position. However, Kech (‘054) teaches a radar-based measurement device, Fig. 1, comprising a security device with a reflector (7) and an adjusting device (9), wherein a drive (11) — designed as an electric motor ([0055]) — acts on the adjusting device to move the reflector between at least a first position (I) in which it reflects electromagnetic waves and a second position (II) ([0016]: “the security device comprises a reflector and an adjusting device, and is suitably designed to move the reflector at least between a first position, in which it reflects the electromagnetic waves, and a second position”). Critically, Kech teaches that the drive is connected to the electronics of the radar-based measurement device, and the reflector moves upon request by the electronics ([0017]: “the drive is connected to the electronics of the radar-based fill level measurement device, and the reflector moves from the second position into the first position upon request by the electronics”; [0056]: “the drive 11 is connected to the electronics 13 of the radar-based fill level measurement device 1, and pivots the reflector 7 out of the second position II and into the first position I upon request by the electronics 13, such that a functions check can be carried out in an automated manner”). This teaches actuating, by the radar sensor (via its electronics), an electromechanical device (drive 11 / adjusting device 9) coupled to the reflector (7) causing the reflector to move to a different position.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to modify Gang’s elevator radar system to include Kech’s electromechanical drive and adjusting device coupled to a reflector. Kech teaches that such a drive enables automated verification and calibration of radar-based measurement devices without manual intervention ([0035]-[0036]), and that the drive connected to the electronics allows “an entirely automated process for verifying the proper functioning of the radar-based fill level measurement device” ([0036]). One of ordinary skill in the art would be motivated to apply this automated reflector-positioning capability to Gang’s elevator radar system to enable controlled, repeatable calibration without requiring the elevator car to be in motion. Both Gang and Kech are in the same field of radar-based distance/level measurement systems that use reflectors, and there is a reasonable expectation of success because Kech’s drive mechanism operates by simply changing the physical position of a reflector relative to the radar sensor, which directly changes the reflected signal characteristics in an entirely predictable manner.
Gang (‘155) teaches: receiving, by the radar sensor, a second signal comprising a reflection of the electromagnetic waves by the reflector configured in the second position, wherein the second signal comprises a second frequency; ([0093]-[0094]: “when the signal strengths from two adjacent reflectors are maximum, the relative distances between the ranging radar and the two reflectors are recorded as the first relative distance d11 and the second relative distance d12, respectively.”). When the reflector is at a different position (second position), the reflected signal has a different characteristic frequency. Kech similarly teaches that reflections differ between the first position and the second position ([0016]).
Gang (‘155) teaches: recording, by the radar sensor, the second signal corresponding to the second position of the reflector; ([0093]: “the relative distances between the ranging radar and the two reflectors are recorded as the first relative distance d11 and the second relative distance d12”).
Gang (‘155) teaches determining peak differences from FFT-processed echo signals ([0093]-[0094]: “The difference between the first relative distance and the second relative distance is obtained, and the distance between two adjacent reflectors is obtained.”; [0019]-[0020]: “performing fast Fourier transform processing on the echo signals to obtain signal peaks corresponding to each of the echo signals; The difference in the distance between the signal peaks corresponding to each of the echo signals is obtained”).
Gang (‘155) does not explicitly teach: comparing, by the radar sensor, the initial frequency of the first signal with the second frequency of the second signal as a frequency comparison. However, Doemens (‘237) teaches that in radar-based position measurement for lifting devices, the phase difference between transmitted and received signals at different radar frequencies is evaluated to determine distance, and that measurements at least two different radar frequencies form a measure for distance ([0044], [0094]). It would have been obvious to characterize Gang’s signal peak difference comparison as a frequency comparison because, as taught by Doemens, in FMCW radar systems (which Doemens explicitly describes at [0063], [0089], [0094]) the position of FFT peaks directly corresponds to beat frequency, and comparing peaks inherently involves comparing frequencies. The motivation to combine and reasonable expectation of success remain as stated in claim 1.
Gang (‘155) does not explicitly teach: generating, by the radar sensor, a distance measuring signal pattern, wherein the distance measuring signal pattern comprises a matrix that is determined based on the initial frequency of the first signal compared with the second frequency of the second signal. However, Doemens (‘237) teaches generating structured frequency-based measurement data across multiple frequencies and reflectors ([0066], [0112]). (See claim 1 analysis for “generating a distance measuring signal pattern” limitation. The same deficiency analysis, Doemens citations, obviousness rationale, motivation to combine, and reasonable expectation of success apply.)
Gang (‘155) teaches determining differences between signal peaks to identify reflectors ([0019]-[0020]: “The difference in the distance between the signal peaks corresponding to each of the echo signals is obtained as the distance between the two adjacent reflectors.”; [0096]: “after the reflector mark is determined, the reference distance corresponding to the reflector mark is determined according to the distance between adjacent reflector plates, and the position of the elevator car is further determined.”).
Gang (‘155) does not explicitly teach: determining, by the radar sensor, a reference frequency difference usable by the radar sensor to identify signals corresponding to the reflector from amongst a plurality of signals as a frequency-based identification. However, Doemens (‘237) teaches using frequency-based identification to distinguish among multiple reflector units — each active reflector unit modulates at a characteristic frequency (fs1, fs2, fs3) that is spectrally separated, allowing the radar sensor to identify and separate signals from each reflector unit ([0047], [0105]-[0108]). It would have been obvious to apply Doemens’ frequency-based reflector identification to Gang’s peak-difference-based reflector identification to determine a reference frequency difference for identifying reflector signals, for the same reasons stated in claim 1.
Regarding Claim 18, Gang (‘155) in view of Doemens (‘237) and Kech (‘054) teaches the method of claim 17.
Gang (‘155) teaches comparing signal peak differences from FFT-processed echo signals ([0093]-[0094]: “The difference between the first relative distance and the second relative distance is obtained”; [0019]-[0020]: “performing fast Fourier transform processing on the echo signals to obtain signal peaks corresponding to each of the echo signals; The difference in the distance between the signal peaks corresponding to each of the echo signals is obtained”). However, Gang does not explicitly teach: wherein comparing the first signal with the second signal further comprises comparing an initial frequency associated with the first signal to a second frequency associated with the second signal. However, Doemens (‘237) teaches that in FMCW radar for lifting device positioning, comparing signal measurements inherently involves comparing their phase/frequency characteristics at different radar frequencies ([0044], [0094]). It would have been obvious to characterize Gang’s signal peak comparison as a frequency comparison for the same reasons stated in claim 1.
Regarding Claim 19, Gang (‘155) in view of Doemens (‘237) and Kech (‘054) teaches the method of claim 17.
Gang (‘155) does not explicitly teach: wherein actuating the electromechanical device causes an adjustment of a height of the reflector. However, Kech (‘054) teaches that the drive can move the reflector linearly ([0026]: “the drive is suitably designed to move the reflector linearly”; [0051]: “A corresponding approach is also possible with a linear movement of the reflector in a plane which is perpendicular to the beam path of the antenna”). As applied to Gang’s elevator system where reflectors are arranged vertically along the hoistway wall ([0070]), actuating the electromechanical device to linearly move the reflector results in an adjustment of the height of the reflector. The motivation to combine Kech with Gang and the reasonable expectation of success are the same as stated for claim 17.
Regarding Claim 20, Gang (‘155) in view of Doemens (‘237) and Kech (‘054) teaches the method of claim 17.
Gang (‘155) does not explicitly teach: further comprising: actuating the electromechanical device causing the reflector to move to the first position. However, Kech (‘054) explicitly teaches moving the reflector back to the first position: ([0056]: “the drive 11 is connected to the electronics 13 of the radar-based fill level measurement device 1, and pivots the reflector 7 out of the second position II and into the first position I upon request by the electronics 13”; [0049]: “the reflector is continuously moved into and back out of the beam path of the antenna”). The motivation to combine and reasonable expectation of success remain as stated for claim 17.
Gang (‘155) teaches: receiving a third signal comprising a reflection of the electromagnetic waves by the reflector configured in the first position; ([0093]: The radar receives echo signals from reflectors. Receiving a signal from the reflector returned to the first position yields a third signal.)
Gang (‘155) teaches: recording the third signal corresponding to the first position of the reflector; ([0093]: Recording echo signal data is taught throughout Gang’s system.)
Gang (‘155) teaches comparing echo signals from reflectors at different positions ([0093]-[0094]). However, Gang does not explicitly teach: comparing the second signal with the third signal as a frequency comparison. However, Doemens (‘237) teaches frequency-based signal comparison in FMCW radar for lifting device position measurement ([0044], [0094]). It would have been obvious to compare the second and third signals by their frequencies for the same reasons stated in claim 1.
Gang (‘155) does not explicitly teach: and confirming the reference frequency difference based on a comparison of the second signal with the third signal. Kech (‘054) teaches comparing reflected signal parameters across multiple measurement cycles to verify proper functioning of the radar ([0036]: “it is also possible to improve the quality of the measurements which are carried out. By way of example, it is possible for the measurement device to automatically determine a degree of contamination of the measurement device by means of comparing the signal reflected by the reflector with earlier measurement values”; [0050]: “a change in the amplitude relative to the position of the reflector can be analyzed, by way of example, and a momentary malfunction or a failure of the measurement device which can be expected at a later point in time can be determined by a comparison with earlier measurements”).
It would have been obvious to confirm the reference frequency difference by comparing the third signal (reflector returned to first position) with the second signal, as Kech teaches comparing current reflected signals with earlier measurement values to verify measurement accuracy. The motivation to combine and reasonable expectation of success remain as stated for claim 17.
Regarding Claim 21, Gang (‘155) in view of Doemens (‘237) and Kech (‘054) teaches the method of claim 1.
Gang (‘155) does not explicitly teach: actuating, by the radar sensor, an electromechanical device coupled to the reflector to move the reflector between at least two positions during elevator operation, wherein an oscillating frequency signature is generated in the reflected signal based on the actuating.
Kech (‘054) teaches: (Fig. 1) a radar-based measurement device having a security device (5) comprising a reflector (7) and an adjusting device (9), wherein the security device has a drive (11) which acts on the adjusting device to move the reflector between at least two positions ([0016]: “the security device comprises a reflector and an adjusting device, and is suitably designed to move the reflector at least between a first position, in which it reflects the electromagnetic waves, and a second position … wherein the security device has a drive which acts on the adjusting device”). The drive is designed as an electric motor ([0045]: “The electromagnetic drive can be designed as a step motor, by way of example.”; [0040]: “The drive of the security device can have an electric, electromagnetic, or pneumatic design, by way of example.”), constituting an electromechanical device. Kech (‘054) teaches that the drive is connected to the electronics of the radar-based measurement device and moves the reflector upon request by the electronics ([0017]: “the drive is connected to the electronics of the radar-based fill level measurement device, and the reflector moves from the second position into the first position upon request by the electronics”; [0056]: “the drive 11 is connected to the electronics 13 of the radar-based fill level measurement device 1, and pivots the reflector 7 out of the second position II and into the first position I upon request by the electronics 13, such that a functions check can be carried out in an automated manner”).
Kech (‘054) teaches: continuous oscillatory movement of the reflector during operation. Kech (‘054) discloses that ([0049]: “the reflector is continuously moved into and back out of the beam path of the antenna. Such a continuous movement can either take place upon request, or permanently, and can be implemented both in configurations with a rotary movement and a linear movement of the reflector”). Kech (‘054) further teaches that ([0028]: “the drive is suitably controlled to move the reflector continuously, and preferably permanently”), and that ([0065]: “in all manner of rotary movements, either a continuous movement of the reflector 7 can occur, such that it is possible for a verification of the functional capability of the radar-based fill level measurement device 1 to be carried out periodically every time the first position I is reached, or a movement can be initiated upon regular or non-regular requests by the electronics 13”). When the reflector is continuously moved into and back out of the radar beam path, the amplitude of the reflected signal from the reflector continuously grows larger until it reaches a maximum and then drops continuously as noted in ([0044-0049]: “When the reflector undergoes a rotary movement, a continuous movement can occur, by way of example, wherein the reflector is rotated in a plane perpendicular to the beam path, such that a continuous transition thereby occurs between the first and the second position”; [0049]: “the reflector is pivoted into the beam path of the antenna and then pivoted back out. The amplitude of the signal reflected to the signal antenna in this case is continuously larger, until it reaches a maximum, and then drops continuously”). In an FMCW radar system such as Gang (‘155)’s millimeter wave radar, this continuous back-and-forth movement of the reflector between two positions produces a periodic variation in the effective reflective cross-section and range to the reflector, which results in a periodic (oscillating) modulation of the reflected signal characteristics - i.e., an oscillating frequency signature.
Doemens (‘237) teaches, as additional confirmation, that periodic modulation of reflected radar signals produces characteristic spectral components detectable by the radar sensor. Doemens (‘237) teaches that each active reflector unit modulates the radar signal with a characteristic switching frequency, and that these modulated signals create identifiable spectral components ([0105]: “In order to be able to separate the radar signals reflected by the active reflector units 24, 25, 26 in the radar sensor 2, the amplifier 8 of each active reflector unit 24, 25, 26 is switched on and off with a characteristic clock fs 1, fs 2 or fs 3”; [0107-0108]: “The radar signals received there and reflected by the active reflector units 24, 25, 26 are mixed down into baseband by the mixer 13 of the radar sensor 2. In addition to frequency components around 0 HZ, signal components result at the switching frequency fs 1, fs 2 or fs 3 characteristic of the active reflector units 24, 25, 26 and their multiples”; “The spectral components can be selected by band-pass filtering and the radar signal components of all active reflector units 24, 25, 26 can be separated from one another”). Doemens (‘237) thus establishes the principle that periodically modulating a reflected radar signal — whether by electronically switching an amplifier or by any other periodic modulation — produces a detectable, characteristic frequency signature in the received signal.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to incorporate Kech (‘054)’s electromechanical reflector actuation mechanism into Gang (‘155)’s elevator radar system, wherein the reflector is continuously oscillated between positions during elevator operation, such that the oscillating movement generates an oscillating frequency signature in the reflected signal. One would have been motivated to do so because Kech (‘054) teaches that continuous, permanent reflector movement enables automated, ongoing verification of radar measurement device functionality without manual intervention ([0028], [0049], [0065]), and that the drive connected to the electronics creates ([0036] “an entirely automated process for verifying the proper functioning of the radar-based fill level measurement device”). Doemens (‘237) further teaches that characteristic periodic modulation of reflected signals provides a reliable mechanism for identifying and separating signals from intended reflectors in lifting device positioning systems ([0089], [0105]). Applying this continuous oscillatory reflector actuation technique during elevator operation would enable the radar to continuously verify the presence and identity of the intended reflector. There is a reasonable expectation of success because Kech (‘054)’s continuous reflector movement inherently produces a periodic signal variation that is straightforwardly detectable using standard radar signal processing techniques available in Gang (‘155)’s millimeter wave radar system, and Doemens (‘237) demonstrates that such periodic modulation produces clearly identifiable spectral signatures ([0107-0108]).
Gang (‘155) does not explicitly teach: distinguishing, by the radar sensor, the reflected signal corresponding to the reflector from noise or obstruction signals based on a detection of the oscillating frequency signature, wherein the noise or obstruction signals comprise substantially static frequencies.
Doemens (‘237) teaches that modulation-based frequency signatures enable reflector signals to be distinguished from environmental interference. Doemens (‘237) teaches that the time delay of active reflector units is selected so that interference from the environment is attenuated ([0089]: “The time delay is to be selected to be so great that other interference signal components, for example caused by reflections on objects in the measurement range, are substantially attenuated by the propagation attenuation in the free space.”). Doemens (‘237) similarly teaches that interference echoes from the environment can be suppressed by filtering based on the characteristic modulation frequency ([0087]: “Interference echoes can be suppressed by suitable bandpass filtering with subsequent demodulation; when different modulation frequencies are used at different active reflector units 3, the radar signal components of different active reflector units 3 can be separated from one another in radar sensor 2.”). Doemens (‘237) further teaches that the characteristic modulation frequencies of the active reflector units are selected such that their reflected signals do not spectrally overlap, enabling separation by bandpass filtering ([0105]: “This clock characteristic for each active reflector unit 24, 25, 26 is to be selected such that the radar signals reflected by the active reflector units 24, 25, 26 to the radar sensor 2 do not spectrally overlap in the selected spectral useful band”; [0108]: “The spectral components can be selected by band-pass filtering and the radar signal components of all active reflector units 24, 25, 26 can be separated from one another”). The interference signals from static objects in the measurement environment, which lack any modulation, appear at substantially static (unmodulated) frequencies in the baseband spectrum, centered around 0 Hz ([0107]: “In addition to frequency components around 0 HZ, signal components result at the switching frequency fs 1, fs 2 or fs 3”), while the modulated reflector signals appear at the characteristic modulation frequencies and their multiples. Bandpass filtering selects the modulated reflector signal components and rejects the static interference. This directly teaches distinguishing intended reflector signals from noise/obstruction signals based on the presence of a characteristic modulation frequency signature, where noise and obstruction signals lack such modulation and thus comprise substantially static frequencies.
Kech (‘054) additionally teaches that signal characteristics are compared across measurement cycles to detect changes indicative of contamination or malfunction ([0036]: “it is possible for the measurement device to automatically determine a degree of contamination of the measurement device by means of comparing the signal reflected by the reflector with earlier measurement values, in order to initiate maintenance of the system or to recommend different maintenance intervals”; [0050]: “a change in the amplitude relative to the position of the reflector can be analyzed, by way of example, and a momentary malfunction or a failure of the measurement device which can be expected at a later point in time can be determined by a comparison with earlier measurements”). This teaches that the radar system actively discriminates between expected signal characteristics from the known reflector and anomalous or static signals.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to apply Doemens (‘237)’ principle of frequency-signature-based signal discrimination to the mechanically oscillated reflector of Kech (‘054) (as incorporated into Gang (‘155)’s elevator system) to distinguish the reflected signal corresponding to the intended reflector from noise or obstruction signals. One would have been motivated to do so because in an elevator shaft, the radar sensor encounters reflections from structural elements, cables, guide rails, and other stationary objects that produce static (unmodulated) reflections, and using the oscillating frequency signature produced by the mechanically actuated reflector to discriminate intended reflections from environmental clutter would improve the reliability and accuracy of the position measurement system. Doemens (‘237) establishes that this type of frequency-based discrimination — where interference from static objects is suppressed by filtering based on the characteristic modulation frequency of the intended reflector — is effective and practical in radar-based lifting device positioning systems ([0087], [0089], [0105]). There is a reasonable expectation of success because static objects produce reflections at substantially constant frequencies (no modulation), while the mechanically oscillated reflector produces a time-varying (oscillating) frequency signature, and detecting this distinction through bandpass filtering or spectral analysis is a routine signal processing operation within the capability of the radar systems described by Gang (‘155), Doemens (‘237), and Kech (‘054).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to REMASH R GUYAH whose telephone number is (571)270-0115. The examiner can normally be reached M-F 7:30-4:30.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Resha H Desai can be reached at (571) 270-7792. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/REMASH R GUYAH/ Examiner, Art Unit 3648
/RESHA DESAI/Supervisory Patent Examiner, Art Unit 3648
Prosecution Insights