DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
Claims 1-20 are pending.
Claims 1-20 are rejected, grounds follow.
THIS OFFICE ACTION IS FINAL, see additional information at the conclusion of this action.
Response to Arguments
Applicant’s arguments, see Remarks page 5, filed 26 August 2025, with respect to the rejection(s) of claim(s) 1, 4, 6-7, and 12-13 under 35 USC 102 in view of Lepka et al., US 9,496,817 have been fully considered and are persuasive. Examiner agrees that the amendment to claims 1 and 7 is not disclosed by the Lepka reference. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made over Lepka in view of Well-Known Practice (as exemplified by Wikipedia article Proportional-integral-derivative controller) see below for detailed rejection.
Applicant’s arguments, see Remarks Page 5, with respect to the rejection(s) of claim(s) 14 under 35 USC 103 have been fully considered and are persuasive. Examiner agrees that none of the references of record appear to clearly articulate the amended limitations of Claim 14 (or the limitations of dependent claim 20, which contains substantively similar subject matter); Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Desrus, US 5,525,881.
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.
Claim(s) 1, 4, 6, 7, 12 and 13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lepka et al., US 9,496,817 in view of Well-Known Practice (as exemplified by the Wikipedia article “Proportional-Integral-Derivative Control” (2022).
Regarding Claim 1, Lepka teaches:
An electric drive system (see fig. 1, “electric motor system 100”, col. 2, line 44) comprising: a motor (fig. 1, 102 Motor) having a rotor (fig. 1, 109 Rotor) and a stator, (fig. 1, 110 Stator)
the stator having a plurality of windings; (Col. 2, line 55 “Windings are disposed within motor 102. For example, stator windings may be provided to create a magnetic field in stator 110.”)
and a controller (Fig. 1, 101, Motor Control Circuit) programmed to control a winding current such that the motor produces torque and power, (see e.g. Col. 4 lines 26-50: “by being provided with maximum temperatures and estimated temperatures of components… improving efficiency, managing torque, managing power, managing speed,” etc.)
the controller further programmed to reduce a motor operating limit (see fig. 7, 504; e.g. “reduce application of power”) in response to an estimate of a temperature of the windings (Col. 9, line 31 “By comparing the estimated winding temperature and the estimated motor mass temperature to…) exceeding a threshold, (ibid. “…respective maximum and limitation values” see e.g. fig. 2 “maximum winding temperature register 374, winding temperature limitation register 334” col. 3 line 48)
wherein the estimate is output by a dynamic model (see col. 15 line 20-47; motor winding temperature may be estimated by a 1st order dynamic model) having rotor speed as an input. (ibid. “the winding resistance can be modeled according the estimated winding temperature… a second input power calculation option can be used to calculate the power losses from the motor input power minus calculated mechanical power from the speed and torque current component I.sub.q (current component orthogonal to rotor flux). A model with a two-equation first-order system characterizing simplified winding and magnetic circuits can be used.”)
Lepka differs from the claimed invention in that:
Lepka does not clearly articulate a degree of reduction of the operating limit is based on a rate of change of the estimate of the temperature of the windings.
However, adjusting a degree of a control output based on a rate of change of the estimate of the measured input is a well-known type of control commonly referred to in the art as “Derivative Control” (see “Proportional-integral-derivative controller”, page 2 “Term D is a best estimate of the future trend of the SP – PV error, based on its current rate of change. It is sometimes called “anticipatory control”, as it is effectively seeking to reduce the effect [of the error] by exerting a control influence generated by the rate of error change. Nb “error” in this context is the deviation between a setpoint or limit (SP) and the present process variable (PV), see page 1, not a fault condition.).
Wikipedia, “Proportional-integral-derivative controller” is analogous art because it is representative of the background knowledge regarding control theory applications that one of ordinary skill in the art of controllers would have had prior to the effective filing date of the application.
Accordingly, Examiner finds 1) the prior art contained a “base” device (method, or product) upon which the claimed invention can be seen as an “improvement” – the teachings of Lepka, which differ from the claimed device by adjusting the degree of reduction in the operating limit based on the rate of change in the monitored temperature estimate; 2) the prior art contained a known technique that is applicable to the base device (method, or product) – the well-known practice as exemplified by Wikipedia “Proportional-integral-derivative controller” which teaches adjusting the degree of change in a controlled value may be based on the rate of change in the monitored process variable; 3) one of ordinary skill in the art before the effective filing date of the application would have recognized that applying the known technique would have yielded predictable results and resulted in an improved system at least because derivative control is known to be effective at anticipating (e.g. “anticipatory control” see Wikipedia, page 2) the future state of the system, and because Lepka suggests knowledge of trends (i.e. rate of change) in the temperature estimate can be used to take pre-emptive action. (see Lepka, Col. 4, line 41 “Knowledge of trends of estimated temperatures of electric motor components can be used to take preemptive action”); and accordingly the improvement would have been obvious to one having ordinary skill in the art before the effective filing date of the application (see MPEP 2143.I.D).
Regarding Claim 4, Lepka in view of Well-Known-Practice as exemplified by Wikipedia teaches all of the limitations of parent claim 1,
Lepka further teaches:
wherein the temperature of the windings is a temperature of a center section of the winding. (Lepka models internal component temperatures, see e.g. Col. 11, lines 14-22 “The difference between electrical power applied to the motor and mechanical power provided by the motor can be used to determine power dissipated by the motor, which heats the motor. Heat flow from the motor windings, through other motor components, to the ambient environment can be modeled on an ongoing basis to provide a mathematically derived dynamic internal temperature measurement of the motor in response to actual motor operation.”)
Regarding Claim 6, Lepka in view of Well-Known-Practice as exemplified by Wikipedia teaches all of the limitations of parent claim 1,
Lepka further teaches:
wherein the motor operating limit is a maximum rotor speed. (Fault handler block (See fig. 3) sends a max angular velocity signal to the motor control block responsive to the fault handler temperature monitoring. See Col. 3, line 59: “Motor control block 301 receives a requested angular velocity signal ω.sub.(EST), a maximum angular velocity signal ω.sub.MAX, a maximum current signal I.sub.MAX, and a fault state request signal from outputs 396 of fault handler block 380.”)
Regarding Claim 7, Lepka teaches:
A method (see fig. 7) of operating a motor (see fig. 1; Motor 102) of an electric drive system, (see fig. 1, “electric motor system 100”, col. 2, line 44) comprising: adjusting, with a controller, (fig. 101, Motor Control Circuit) a winding current (Col. 2, line 55 “Windings are disposed within motor 102. For example, stator windings may be provided to create a magnetic field in stator 110.”) such that the motor produces torque; (see e.g. Col. 4 lines 26-50: “by being provided with maximum temperatures and estimated temperatures of components… improving efficiency, managing torque, managing power, managing speed,” etc.)
and reducing an operating limit of the motor (see fig. 7, 504; e.g. “reduce application of power”) in response to an estimated center section (Lepka models internal component temperatures, see e.g. Col. 11, lines 14-22 “The difference between electrical power applied to the motor and mechanical power provided by the motor can be used to determine power dissipated by the motor, which heats the motor. Heat flow from the motor windings, through other motor components, to the ambient environment can be modeled on an ongoing basis to provide a mathematically derived dynamic internal temperature measurement of the motor in response to actual motor operation.”) winding temperature (Col. 9, line 31 “By comparing the estimated winding temperature and the estimated motor mass temperature to…) exceeding a first threshold, (ibid. “…respective maximum and limitation values” see e.g. fig. 2 “maximum winding temperature register 374, winding temperature limitation register 334” col. 3 line 48)
wherein the center section winding temperature is estimated by the controller using a first dynamic model (see col. 15 line 20-47; motor winding temperature may be estimated by a 1st order dynamic model) based on a rotor speed. (ibid. “the winding resistance can be modeled according the estimated winding temperature… a second input power calculation option can be used to calculate the power losses from the motor input power minus calculated mechanical power from the speed and torque current component I.sub.q (current component orthogonal to rotor flux). A model with a two-equation first-order system characterizing simplified winding and magnetic circuits can be used.”)
Lepka differs from the claimed invention in that:
Lepka does not clearly articulate a degree of reduction of the operating limit is based on a rate of change of the estimate of the temperature of the windings.
However, adjusting a degree of a control output based on a rate of change of the estimate of the measured input is a well-known type of control commonly referred to in the art as “Derivative Control” (see “Proportional-integral-derivative controller”, page 2 “Term D is a best estimate of the future trend of the SP – PV error, based on its current rate of change. It is sometimes called “anticipatory control”, as it is effectively seeking to reduce the effect [of the error] by exerting a control influence generated by the rate of error change. Nb “error” in this context is the deviation between a setpoint or limit (SP) and the present process variable (PV), see page 1, not a fault condition.).
Wikipedia, “Proportional-integral-derivative controller” is analogous art because it is representative of the background knowledge regarding control theory applications that one of ordinary skill in the art of controllers would have had prior to the effective filing date of the application.
Accordingly, Examiner finds 1) the prior art contained a “base” device (method, or product) upon which the claimed invention can be seen as an “improvement” – the teachings of Lepka, which differ from the claimed device by adjusting the degree of reduction in the operating limit based on the rate of change in the monitored temperature estimate; 2) the prior art contained a known technique that is applicable to the base device (method, or product) – the well-known practice as exemplified by Wikipedia “Proportional-integral-derivative controller” which teaches adjusting the degree of change in a controlled value may be based on the rate of change in the monitored process variable; 3) one of ordinary skill in the art before the effective filing date of the application would have recognized that applying the known technique would have yielded predictable results and resulted in an improved system at least because derivative control is known to be effective at anticipating (e.g. “anticipatory control” see Wikipedia, page 2) the future state of the system, and because Lepka suggests knowledge of trends (i.e. rate of change) in the temperature estimate can be used to take pre-emptive action. (see Lepka, Col. 4, line 41 “Knowledge of trends of estimated temperatures of electric motor components can be used to take preemptive action”); and accordingly the improvement would have been obvious to one having ordinary skill in the art before the effective filing date of the application (see MPEP 2143.I.D).
Regarding Claim 12, Lepka in view of Well-Known-Practice as exemplified by Wikipedia teaches all of the limitations of parent claim 7,
Lepka further teaches:
wherein the motor operating limit is a maximum rotor speed. (Fault handler block (See fig. 3) sends a max angular velocity signal to the motor control block responsive to the fault handler temperature monitoring. See Col. 3, line 59: “Motor control block 301 receives a requested angular velocity signal ω.sub.(EST), a maximum angular velocity signal ω.sub.MAX, a maximum current signal I.sub.MAX, and a fault state request signal from outputs 396 of fault handler block 380.”)
Regarding Claim 13, Lepka in view of Well-Known-Practice as exemplified by Wikipedia teaches all of the limitations of parent claim 12,
Lepka further teaches:
operating at least one instrumented test vehicle to record data including measured motor center section winding temperature and measured rotor speed; and computing model constants based on the recorded data. (col. 6 line 36 et seq.: “By using temperature measuring instrumentation to measure the temperatures of motor components during operation in a laboratory, parameter values characteristic of an electric motor can be empirically determined. The empirically determined values can be adjusted to compensate for any measurement shortcomings by selecting values that best dynamically track measurements during motor operation over time. As such electric motors are mass-produced, characteristics of individual specimens of a electric motor tend to conform to the characteristics of the tested specimen, allowing static parameter values of the thermal model to be programmed at a factory where a product incorporating the electric motor system is manufactured.”)
Claim(s) 2, 3, and 8-10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lepka in view Well-Known Practice (as Exemplified by Wikipedia), further in view of Thyagarajan et al., US Pg-Pub 2024/0235454.
Regarding Claim 2, Lepka in view of Well-Known-Practice as exemplified by Wikipedia teaches all of the limitations of parent claim 1,
Lepka differs from the claimed invention in that:
Lepka does not appear to clearly articulate: the inputs of the dynamic model further include an oil flow rate through the motor.
However, Thyagarajan teaches a model for estimating electric motor winding temperature (fig. 1, “Winding Temperature Estimation System [0019] FIG. 1 is a functional block diagram of an example system 100 for estimating winding temperature of an electric machine (such as an electric motor)”) which includes oil flow rate ([0030] “The motor sensor data 116 may include current operating parameters of a motor… Example motor operating parameters include, but are not limited to, an oil inlet temperature, a rotor oil flow, a stator oil flow, a speed of the motor, a torque of the motor, a direct current (DC) bus voltage of the motor, a quadrature(q)-axis voltage of the motor, a direct(d)-axis voltage of the motor, a q-axis current of the motor or a d-axis current of the motor.”) as an input to the estimation model.
Lepka and Thyagarajan are analogous art because they are from the same field of endeavor of electric motor control and contain overlapping structural and functional similarities; each estimates motor winding temperature via indirect measurement of other parameters of the motor; each controls operational limits of the motor based on the estimated winding temperature)
Accordingly, Examiner finds 1) the prior art contained a “base” device (method, or product) upon which the claimed invention can be seen as an “improvement” – the dynamic model of Lepka, upon which the inclusion of oil flow rate as an input to the dynamic model can be seen as an “improvement”; 2) the prior art contained a “comparable” device (method, or product that is not the same as the base device) which has been improved in the same way as the claimed invention – the winding temperature estimation model of Thyagarajan which also includes oil flow rate (and oil temperature) as an input to the estimation model; 3) one of ordinary skill in the could have applied the known “improvement” technique in the same way to the “base” device (method, or product) and the results would have been predictable to one having ordinary skill in the art before the effective filing date of the application at least because Thyagarajan teaches that oil flow rate is a relevant parameter to consider for estimating motor winding temperature ([0095] “For example, in one implementation a rolling mean of the voltage of the q-axis of the motor may have a strongest impact on the temperature estimation output, a stator flow may have a second strongest impact on the temperature estimation output, a rolling mean of the oil temperature may have a third strongest impact on the temperature estimation output, etc.”) and accordingly the improvement would have been obvious to one having ordinary skill in the art before the effective filing date of the application (see MPEP 2143.I.C).
Regarding Claim 3, Lepka in view of Well-Known Practice as exemplified by Wikipedia, further in view of Thyagarajan teaches all of the limitations of parent claim 2,
Lepka further teaches:
wherein the inputs of the dynamic model further include the winding current, (col. 8 line 55 “FOC block 371 provides a stator current signal I.sub.s, comprising a direct stator current component I.sub.sd and a quadrature stator current component I.sub.sq, to power losses calculation block 372.” Nb. power losses are an input to the estimation model, see fig. 7) an ambient temperature, (see col. 10, line 7 “Thermal potential 415 represents the ambient temperature, represented as T.sub.A.”)
And Thyagarajan further teaches:
[wherein the inputs include] a sump temperature. ([0030] “The motor sensor data 116 may include current operating parameters of a motor… Example motor operating parameters include, but are not limited to, an oil inlet temperature”)
Accordingly, Examiner finds 1) the prior art contained a “base” device (method, or product) upon which the claimed invention can be seen as an “improvement” – the dynamic model of Lepka, upon which the inclusion of oil flow rate as an input to the dynamic model can be seen as an “improvement”; 2) the prior art contained a “comparable” device (method, or product that is not the same as the base device) which has been improved in the same way as the claimed invention – the winding temperature estimation model of Thyagarajan which also includes oil flow rate (and oil temperature) as an input to the estimation model; 3) one of ordinary skill in the could have applied the known “improvement” technique in the same way to the “base” device (method, or product) and the results would have been predictable to one having ordinary skill in the art before the effective filing date of the application at least because Thyagarajan teaches that oil flow rate is a relevant parameter to consider for estimating motor winding temperature ([0095] “For example, in one implementation a rolling mean of the voltage of the q-axis of the motor may have a strongest impact on the temperature estimation output, a stator flow may have a second strongest impact on the temperature estimation output, a rolling mean of the oil temperature may have a third strongest impact on the temperature estimation output, etc.”) and accordingly the improvement would have been obvious to one having ordinary skill in the art before the effective filing date of the application (see MPEP 2143.I.C).
Regarding Claim 8, Lepka in view of Well-Known Practice as exemplified by Wikipedia teaches all of the limitations of parent claim 7,
Lepka differs from the claimed invention in that:
Lepka does not clearly articulate the inputs of the first dynamic model further include an oil flow rate through the motor.
However, Thyagarajan teaches a model for estimating electric motor winding temperature (fig. 1, “Winding Temperature Estimation System [0019] FIG. 1 is a functional block diagram of an example system 100 for estimating winding temperature of an electric machine (such as an electric motor)”) which includes oil flow rate ([0030] “The motor sensor data 116 may include current operating parameters of a motor… Example motor operating parameters include, but are not limited to, an oil inlet temperature, a rotor oil flow, a stator oil flow, a speed of the motor, a torque of the motor, a direct current (DC) bus voltage of the motor, a quadrature(q)-axis voltage of the motor, a direct(d)-axis voltage of the motor, a q-axis current of the motor or a d-axis current of the motor.”) as an input to the estimation model.
Lepka and Thyagarajan are analogous art because they are from the same field of endeavor of electric motor control and contain overlapping structural and functional similarities; each estimates motor winding temperature via indirect measurement of other parameters of the motor; each controls operational limits of the motor based on the estimated winding temperature)
Accordingly, Examiner finds 1) the prior art contained a “base” device (method, or product) upon which the claimed invention can be seen as an “improvement” – the dynamic model of Lepka, upon which the inclusion of oil flow rate as an input to the dynamic model can be seen as an “improvement”; 2) the prior art contained a “comparable” device (method, or product that is not the same as the base device) which has been improved in the same way as the claimed invention – the winding temperature estimation model of Thyagarajan which also includes oil flow rate (and oil temperature) as an input to the estimation model; 3) one of ordinary skill in the could have applied the known “improvement” technique in the same way to the “base” device (method, or product) and the results would have been predictable to one having ordinary skill in the art before the effective filing date of the application at least because Thyagarajan teaches that oil flow rate is a relevant parameter to consider for estimating motor winding temperature ([0095] “For example, in one implementation a rolling mean of the voltage of the q-axis of the motor may have a strongest impact on the temperature estimation output, a stator flow may have a second strongest impact on the temperature estimation output, a rolling mean of the oil temperature may have a third strongest impact on the temperature estimation output, etc.”) and accordingly the improvement would have been obvious to one having ordinary skill in the art before the effective filing date of the application (see MPEP 2143.I.C).
Regarding Claim 9, Lepka in view of Well-Known Practice as exemplified by Wikipedia, further in view of Thyagarajan teaches all of the limitations of parent claim 8,
Lepka further teaches:
wherein the inputs of the first dynamic model further include the winding current, (col. 8 line 55 “FOC block 371 provides a stator current signal I.sub.s, comprising a direct stator current component I.sub.sd and a quadrature stator current component I.sub.sq, to power losses calculation block 372.” Nb. power losses are an input to the estimation model, see fig. 7) an ambient temperature, (see col. 10, line 7 “Thermal potential 415 represents the ambient temperature, represented as T.sub.A.”)
And Thyagarajan further teaches:
[wherein the inputs include] a sump temperature. ([0030] “The motor sensor data 116 may include current operating parameters of a motor… Example motor operating parameters include, but are not limited to, an oil inlet temperature”)
Accordingly, Examiner finds 1) the prior art contained a “base” device (method, or product) upon which the claimed invention can be seen as an “improvement” – the dynamic model of Lepka, upon which the inclusion of oil flow rate as an input to the dynamic model can be seen as an “improvement”; 2) the prior art contained a “comparable” device (method, or product that is not the same as the base device) which has been improved in the same way as the claimed invention – the winding temperature estimation model of Thyagarajan which also includes oil flow rate (and oil temperature) as an input to the estimation model; 3) one of ordinary skill in the could have applied the known “improvement” technique in the same way to the “base” device (method, or product) and the results would have been predictable to one having ordinary skill in the art before the effective filing date of the application at least because Thyagarajan teaches that oil flow rate is a relevant parameter to consider for estimating motor winding temperature ([0095] “For example, in one implementation a rolling mean of the voltage of the q-axis of the motor may have a strongest impact on the temperature estimation output, a stator flow may have a second strongest impact on the temperature estimation output, a rolling mean of the oil temperature may have a third strongest impact on the temperature estimation output, etc.”) and accordingly the improvement would have been obvious to one having ordinary skill in the art before the effective filing date of the application (see MPEP 2143.I.C).
Regarding Claim 10, Lepka in view of Well-Known Practice as Exemplified by Wikipedia, further in view of Thyagarajan teaches all of the limitations of parent claim 9,
Lepka in view of Thyagarajan differs from the claimed invention in that:
Neither reference clearly articulates estimating, with the controller, an end winding temperature using a second dynamic model based on the oil flow rate, the winding current, the ambient temperature, and the sump temperature; and reducing the operating limit of the motor in response to the estimated end winding temperature exceeding a second threshold.
However, the Courts have held that mere duplication of parts has no patentable significance unless a new and unexpected result is produced (see MPEP 2144.04.VI.B). Inasmuch as the claim presently recites an apparently structurally identical dynamic model for the end winding temperature and there does not appear to be any evidence of record showing a new or unexpected result produced by this apparent duplication of those features taught or fairly suggested by the prior art; accordingly the duplicated limitations are nevertheless obvious in view of the prior art.
In the interest of compact prosecution examiner notes that a claim which recited originally disclosed features which differ between the first and second dynamic models such that the claim required more than mere duplication of those features taught or fairly suggested in the prior art would overcome this rejection.
Claim(s) 5 and 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lepka in view Well-Known Practice (as exemplified by Wikipedia), further in view of Sun et al., Chinese Patent CN 114,614,732 (citations to Machine Translation courtesy eSpacenet, furnished with non-final rejection mailed 12 June 2025).
Regarding Claim 5, Lepka in view of Well-Known Practice as exemplified by Wikipedia teaches all of the limitations of parent claim 1,
Lepka differs from the claimed invention in that:
Lepka fails to clearly articulate wherein the dynamic model is a second order dynamic model.
However, Sun teaches a thermal estimation model for a motor winding temperature (see e.g. [0050] “real-time estimation of rotor temperature; [0052] “model outputs are key hot spot temperatures such as motor winding temperature”) can be suitably estimated using a model that is third order or less ([0036] “It is necessary to omit branches that have little effect on the temperature distribution based on the finite element analysis results and simplify the thermal network model to minimize the real-time calculation amount. The model is expressed in state space. In order to improve calculation efficiency, the order of the state space equation is generally not greater than the third order.”)
Sun and Lepka are analogous art because they are from the same field of endeavor of electric motor control and contain overlapping structural and functional similarities; each estimates motor winding temperature via indirect measurement of other parameters of the motor; each controls operational limits of the motor based on the estimated winding temperature)
One of ordinary skill in the art could have modified the teachings of Lepka to use a second order model, as suggested by Sun.
One of ordinary skill in the art could have been motivated to make this modification in order to trade off accuracy and calculation efficiency as suggested by Sun ([0036] “the complex thermal network model is a thermal network constructed entirely according to the characteristics of the physical object. It has a complex structure and involves many parameters. It is necessary to omit branches that have little effect on the temperature distribution based on the finite element analysis results and simplify the thermal network model to minimize the real-time calculation amount. The model is expressed in state space. In order to improve calculation efficiency, the order of the state space equation is generally not greater than the third order.”)
Regarding Claim 11, Lepka in view of Well-Known Practice as Exemplified by Wikipedia teaches all of the limitations of parent claim 7,
Lepka differs from the claimed invention in that:
Lepka does not appear to clearly articulate wherein the first dynamic model is a second order dynamic model.
However, Sun teaches a thermal estimation model for a motor winding temperature (see e.g. [0050] “real-time estimation of rotor temperature; [0052] “model outputs are key hot spot temperatures such as motor winding temperature”) can be suitably estimated using a model that is third order or less ([0036] “It is necessary to omit branches that have little effect on the temperature distribution based on the finite element analysis results and simplify the thermal network model to minimize the real-time calculation amount. The model is expressed in state space. In order to improve calculation efficiency, the order of the state space equation is generally not greater than the third order.”)
Sun and Lepka are analogous art because they are from the same field of endeavor of electric motor control and contain overlapping structural and functional similarities; each estimates motor winding temperature via indirect measurement of other parameters of the motor; each controls operational limits of the motor based on the estimated winding temperature)
One of ordinary skill in the art could have modified the teachings of Lepka to use a second order model, as suggested by Sun.
One of ordinary skill in the art could have been motivated to make this modification in order to trade off accuracy and calculation efficiency as suggested by Sun ([0036] “the complex thermal network model is a thermal network constructed entirely according to the characteristics of the physical object. It has a complex structure and involves many parameters. It is necessary to omit branches that have little effect on the temperature distribution based on the finite element analysis results and simplify the thermal network model to minimize the real-time calculation amount. The model is expressed in state space. In order to improve calculation efficiency, the order of the state space equation is generally not greater than the third order.”)
Claim(s) 14-17, and 19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lepka in view of Thyagarajan and in view of Desrus, US 5,525,881
Regarding Claim 14, Lepka teaches:
An electric drive system, (see fig. 1, “electric motor system 100”, col. 2, line 44) comprising: a motor (fig. 1, 102 Motor) having a rotor (fig. 1, 109 Rotor) and a stator, (fig. 1, 110 Stator)
the stator having a plurality of windings; (Col. 2, line 55 “Windings are disposed within motor 102. For example, stator windings may be provided to create a magnetic field in stator 110.”)
and a controller (Fig. 1, 101, Motor Control Circuit) programmed to control a winding current such that the motor produces torque and power, (see e.g. Col. 4 lines 26-50: “by being provided with maximum temperatures and estimated temperatures of components… improving efficiency, managing torque, managing power, managing speed,” etc.)
the controller further programmed to reduce a motor operating limit (see fig. 7, 504; e.g. “reduce application of power”) in response to an estimate of a temperature of the windings (Col. 9, line 31 “By comparing the estimated winding temperature and the estimated motor mass temperature to…) exceeding a threshold, (ibid. “…respective maximum and limitation values” see e.g. fig. 2 “maximum winding temperature register 374, winding temperature limitation register 334” col. 3 line 48)
wherein the estimate is output by a dynamic model (see col. 15 line 20-47; motor winding temperature may be estimated by a 1st order dynamic model)
Lepka differs from the claimed invention in that:
Lepka does not appear to clearly articulate: a pump configured to circulate oil from a sump through the motor;
nor that the model has a rate of flow of the oil as an input.
nor wherein the controller is programmed to respond to a key-on event by calculating the estimate based on the estimate at a preceding key-off event and a time since the key-off event.
However, Thyagarajan teaches a model for estimating electric motor winding temperature (fig. 1, “Winding Temperature Estimation System [0019] FIG. 1 is a functional block diagram of an example system 100 for estimating winding temperature of an electric machine (such as an electric motor)”) of a motor including a pump for circulating oil through the motor ([0134] “an oil temperature sensor 908 and an oil flow sensor 910 may detect operating parameters of the motor 955, such as a temperature of oil in the motor 955 or supplied to the motor 955, a flow rate of oil to the motor 955 or a component of the motor such as the stator, etc.”) which includes as an input to the estimation model an oil flow rate ([0030] “The motor sensor data 116 may include current operating parameters of a motor… Example motor operating parameters include, but are not limited to, an oil inlet temperature, a rotor oil flow, a stator oil flow, a speed of the motor, a torque of the motor, a direct current (DC) bus voltage of the motor, a quadrature(q)-axis voltage of the motor, a direct(d)-axis voltage of the motor, a q-axis current of the motor or a d-axis current of the motor.”)
Lepka and Thyagarajan are analogous art because they are from the same field of endeavor of electric motor control and contain overlapping structural and functional similarities; each estimates motor winding temperature via indirect measurement of other parameters of the motor; each controls operational limits of the motor based on the estimated winding temperature)
Accordingly, Examiner finds 1) the prior art contained a “base” device (method, or product) upon which the claimed invention can be seen as an “improvement” – the dynamic model of Lepka, upon which the inclusion of oil flow rate as an input to the dynamic model can be seen as an “improvement”; 2) the prior art contained a “comparable” device (method, or product that is not the same as the base device) which has been improved in the same way as the claimed invention – the winding temperature estimation model of Thyagarajan which also includes oil flow rate (and oil temperature) as an input to the estimation model; 3) one of ordinary skill in the could have applied the known “improvement” technique in the same way to the “base” device (method, or product) and the results would have been predictable to one having ordinary skill in the art before the effective filing date of the application at least because Thyagarajan teaches that oil flow rate is a relevant parameter to consider for estimating motor winding temperature ([0095] “For example, in one implementation a rolling mean of the voltage of the q-axis of the motor may have a strongest impact on the temperature estimation output, a stator flow may have a second strongest impact on the temperature estimation output, a rolling mean of the oil temperature may have a third strongest impact on the temperature estimation output, etc.”) and accordingly the improvement would have been obvious to one having ordinary skill in the art before the effective filing date of the application (see MPEP 2143.I.C).
And Desrus teaches a thermal controller (fig. 1, controller 2) for an electric motor (see col. 3 line 60 “a thermal system is shown which consists of the electric motor and its environment”) which responds to a key-on event (i.e. restart, see col. 5 line 34 “if the electric motor restarts before the ambient temperature has been reached by the motor”) by calculating the estimate (see equation 1, column 5 and col. 5 lines 1-41) based on the estimate at a preceding key-off event (see col. 5, line 30 “the motor cools over a period of time which depends on the maximum temperature (Tm,max) attained by the motor” [nb. in the operational phase, see col. 5, line 25-28)”) and a time since the key-off event. (see col. 5 line 7 “A is the cooling time constant, t0 is the instant at which cooling commences, t is the current instant.”) and uses that estimate to initialize the thermal monitoring system. (see col. 5 line 35 “the thermal controller of the invention employs, as a first value of the motor temperature Tm, the value reached at the said instant of restarting during the cooling period.”)(see also e.g. fig. 3 depicting a temperature-to-time-elapsed diagram.)
Accordingly, Examiner finds 1) the prior art contained a “base” device (method, or product) upon which the claimed invention can be seen as an “improvement” – the dynamic model of Lepka, upon which calculating the estimated winding temperature base on intermediate cool down during the period between starts can be regarded as an improvement; 2) the prior art contained a “comparable” device (method, or product that is not the same as the base device) which has been improved in the same way as the claimed invention – the temperature estimation model of Desrus which estimates the initial restart temperature of the motor based on the last operational temperature and the time since last operation; 3) one of ordinary skill in the could have applied the known “improvement” technique in the same way to the “base” device (method, or product) and the results would have been predictable to one having ordinary skill in the art before the effective filing date of the application at least because Desrus suggests that estimating the condition of the motor based on the restarting temperature can help protect the motor from overheating (see col. 2, line 26 “estimation of a condition for stopping the electric supply to the motor on the basis of a further computation of the instantaneous temperature of the motor, the measurement of the ambient temperature, the said value of restarting temperature, and the measurement of the effective current flowing through the windings of the motor, whereby to protect the electric motor and/or its environment from too large an increase in temperature.”) and accordingly the improvement would have been obvious to one having ordinary skill in the art before the effective filing date of the application (see MPEP 2143.I.C).
Regarding Claim 15, Lepka in view of Thyagarajan and in view of Desrus teaches all of the limitations of parent claim 14,
Lepka further teaches:
wherein the inputs of the dynamic model further include a rotor speed. (see col. 15 line 20-47 ““the winding resistance can be modeled according the estimated winding temperature… a second input power calculation option can be used to calculate the power losses from the motor input power minus calculated mechanical power from the speed and torque current component I.sub.q (current component orthogonal to rotor flux). A model with a two-equation first-order system characterizing simplified winding and magnetic circuits can be used.”)
Regarding Claim 16, Lepka in view of Thyagarajan and in view of Desrus teaches all of the limitations of parent claim 15,
Lepka further teaches:
wherein the temperature of the windings is a temperature of a center section of the winding. (Lepka models internal component temperatures, see e.g. Col. 11, lines 14-22 “The difference between electrical power applied to the motor and mechanical power provided by the motor can be used to determine power dissipated by the motor, which heats the motor. Heat flow from the motor windings, through other motor components, to the ambient environment can be modeled on an ongoing basis to provide a mathematically derived dynamic internal temperature measurement of the motor in response to actual motor operation.”)
Regarding Claim 17, Lepka in view of Thyagarajan and in view of Desrus teaches all of the limitations of parent claim 14,
Lepka further teaches:
wherein the inputs of the dynamic model further include the winding current, (col. 8 line 55 “FOC block 371 provides a stator current signal I.sub.s, comprising a direct stator current component I.sub.sd and a quadrature stator current component I.sub.sq, to power losses calculation block 372.” Nb. power losses are an input to the estimation model, see fig. 7) an ambient temperature, (see col. 10, line 7 “Thermal potential 415 represents the ambient temperature, represented as T.sub.A.”)
And Thyagarajan further teaches:
[wherein the inputs include] a sump temperature. ([0030] “The motor sensor data 116 may include current operating parameters of a motor… Example motor operating parameters include, but are not limited to, an oil inlet temperature”)
Accordingly, Examiner finds 1) the prior art contained a “base” device (method, or product) upon which the claimed invention can be seen as an “improvement” – the dynamic model of Lepka, upon which the inclusion of oil flow rate as an input to the dynamic model can be seen as an “improvement”; 2) the prior art contained a “comparable” device (method, or product that is not the same as the base device) which has been improved in the same way as the claimed invention – the winding temperature estimation model of Thyagarajan which also includes oil flow rate (and oil temperature) as an input to the estimation model; 3) one of ordinary skill in the could have applied the known “improvement” technique in the same way to the “base” device (method, or product) and the results would have been predictable to one having ordinary skill in the art before the effective filing date of the application at least because Thyagarajan teaches that oil flow rate is a relevant parameter to consider for estimating motor winding temperature ([0095] “For example, in one implementation a rolling mean of the voltage of the q-axis of the motor may have a strongest impact on the temperature estimation output, a stator flow may have a second strongest impact on the temperature estimation output, a rolling mean of the oil temperature may have a third strongest impact on the temperature estimation output, etc.”) and accordingly the improvement would have been obvious to one having ordinary skill in the art before the effective filing date of the application (see MPEP 2143.I.C).
Regarding Claim 19, Lepka in view of Thyagarajan and in view of Desrus teaches all of the limitations of parent claim 14,
Lepka further teaches:
wherein the motor operating limit is a maximum rotor speed. (Fault handler block (See fig. 3) sends a max angular velocity signal to the motor control block responsive to the fault handler temperature monitoring. See Col. 3, line 59: “Motor control block 301 receives a requested angular velocity signal ω.sub.(EST), a maximum angular velocity signal ω.sub.MAX, a maximum current signal I.sub.MAX, and a fault state request signal from outputs 396 of fault handler block 380.”)
Claim(s) 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lepka in view of Thyagarajan and in view of Desrus, further in view of Sun.
Regarding Claim 18, Lepka in view of Thyagarajan and in view of Desrus teaches all of the limitations of parent claim 14,
Lepka in view of Thyagarajan differs from the claimed invention in that:
Neither reference clearly articulates: wherein the dynamic model is a second order dynamic model.
However, Sun teaches a thermal estimation model for a motor winding temperature (see e.g. [0050] “real-time estimation of rotor temperature; [0052] “model outputs are key hot spot temperatures such as motor winding temperature”) can be suitably estimated using a model that is third order or less ([0036] “It is necessary to omit branches that have little effect on the temperature distribution based on the finite element analysis results and simplify the thermal network model to minimize the real-time calculation amount. The model is expressed in state space. In order to improve calculation efficiency, the order of the state space equation is generally not greater than the third order.”)
Sun and Lepka are analogous art because they are from the same field of endeavor of electric motor control and contain overlapping structural and functional similarities; each estimates motor winding temperature via indirect measurement of other parameters of the motor; each controls operational limits of the motor based on the estimated winding temperature)
One of ordinary skill in the art could have modified the teachings of Lepka to use a second order model, as suggested by Sun.
One of ordinary skill in the art could have been motivated to make this modification in order to trade off accuracy and calculation efficiency as suggested by Sun ([0036] “the complex thermal network model is a thermal network constructed entirely according to the characteristics of the physical object. It has a complex structure and involves many parameters. It is necessary to omit branches that have little effect on the temperature distribution based on the finite element analysis results and simplify the thermal network model to minimize the real-time calculation amount. The model is expressed in state space. In order to improve calculation efficiency, the order of the state space equation is generally not greater than the third order.”)
Claim(s) 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lepka in view of Well-Known Practice (as exemplified by Wikipedia) further in view of Desrus.
Regarding Claim 20, Lepka in view of Well-Known Practice as exemplified by Wikipedia teaches all of the limitations of parent claim 1,
Lepka differs from the claimed invention in that:
Lepka does not appear to clearly articulate: wherein the control is programmed to respond to a key-on event by calculating the estimate based on the estimate at a preceding key-off event and a time since the key-off event.
Desrus teaches a thermal controller (fig. 1, controller 2) for an electric motor (see col. 3 line 60 “a thermal system is shown which consists of the electric motor and its environment”) which responds to a key-on event (i.e. restart, see col. 5 line 34 “if the electric motor restarts before the ambient temperature has been reached by the motor”) by calculating the estimate (see equation 1, column 5 and col. 5 lines 1-41) based on the estimate at a preceding key-off event (see col. 5, line 30 “the motor cools over a period of time which depends on the maximum temperature (Tm,max) attained by the motor” [nb in the operational phase, see col. 5, line 25-28)”) and a time since the key-off event. (see col. 5 line 7 “A is the cooling time constant, t0 is the instant at which cooling commences, t is the current instant.”) and uses that estimate to initialize the thermal monitoring system. (see col. 5 line 35 “the thermal controller of the invention employs, as a first value of the motor temperature Tm, the value reached at the said instant of restarting during the cooling period.”)(see also e.g. fig. 3 depicting a temperature-to-time-elapsed diagram.)
Accordingly,