JP6515068B2 - Control diagnosis system and control diagnosis method for electric motor - Google Patents

Description

  The present invention relates to a control diagnosis system and control diagnosis method of an electric motor.

  As an electric motor used for a car etc., there are, for example, those for assisting a steering, a brake, an engine, etc., and those for traveling. In the control of such an electric motor, there is a possibility that the assist operation and the traveling operation may be disturbed in the event of a failure or the like, so that diagnosis is always performed and appropriate fail control is performed according to the diagnosis result. It has been demanded.

  As a technology relating to such failure diagnosis of an electric motor, for example, Patent Document 1 (Japanese Patent Laid-Open No. 2013-31356) is a motor control device for controlling current and applied voltage to motors of multiple phases, An inverter for supplying the electric power from the motor to the motor, current control means for generating a voltage command according to the current command to control the current to the motor, and driving the inverter according to the voltage command to drive the motor An inverter drive circuit for controlling a voltage applied to the circuit, and failure detection means for detecting a failure generation state based on the voltage command, the power supply voltage of the power supply, the motor rotational speed of the motor, and the currents of the plurality of phases. The failure detection means may have a phase in which the power supply voltage is equal to or higher than a predetermined voltage and the motor rotational speed is equal to or lower than a predetermined speed and which is a target phase. A state where the voltage command is not near zero and the target phase current is less than a predetermined current and the control error with respect to the current command or the voltage command is more than a predetermined error is detected for a predetermined time or more In this case, a motor control device is disclosed that determines that an open state failure has occurred in the target phase (see claim 1).

JP 2013-31356 A

  By the way, although the operation of the electric motor as in the above-mentioned prior art is controlled by a control ECU (Electronic Control Unit) or the like, for example, when the motor rotational speed is not correctly calculated due to the failure of the clock signal supplied to the control ECU. In this case, it is conceivable that the normality / abnormality diagnosis of the electric motor can not be correctly performed and appropriate control can not be performed according to the state of the electric motor.

  The present invention has been made in view of the above, and it is an object of the present invention to provide a control diagnosis system and control diagnosis method of an electric motor which can diagnose abnormality of the electric motor more correctly.

  In order to achieve the above object, the present invention provides a motor control unit for controlling the operation of an electric motor, a first clock signal oscillation source for supplying a clock signal used for the operation of the motor control unit, and the electric motor Supply a clock signal used for the operation of the rotational speed calculation circuit, an rotational speed calculation circuit for calculating the rotational speed of the electric motor on the basis of the detection result of the angular sensor; And a second clock signal oscillation source different from the first clock signal oscillation source, and the motor control unit calculates an estimated rotational speed of the electric motor based on a detection result from the angle sensor. When the difference between the rotation speed calculated by the rotation speed calculation circuit and the estimated rotation speed is larger than a predetermined threshold value, the first and second clock signal generation may be performed. Shall diagnosing at least one failure sources.

  It is possible to diagnose the control abnormality of the electric motor more correctly, and to perform appropriate fail control according to the control abnormality state of the electric motor.

FIG. 2 is a view showing a motor control ECU to which the control diagnosis system for an electric motor according to the first embodiment is applied, along with its peripheral configuration. It is a flow chart which shows failure diagnosis processing concerning a 1st embodiment. It is a figure which shows the motor control ECU with which the control-diagnosis system of the electric motor which concerns on 2nd Embodiment is applied with a peripheral structure. It is a flow chart which shows failure diagnosis processing concerning a 2nd embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First Embodiment
A first embodiment of the present invention will be described with reference to FIGS. 1 and 2.

  FIG. 1 is a diagram showing a motor control ECU to which a control diagnosis system for an electric motor according to the present embodiment is applied, along with its peripheral configuration.

  In FIG. 1, an electric motor 200 controlled by a motor control ECU (Electronic Control Unit) 100 is, for example, a steering or a brake of an automobile or the like, an electric motor for assisting the engine or the like, or a traveling electric motor. The electric motor 200 is provided with an angle sensor 201 that detects the rotation angle of the rotation shaft. As the angle sensor 201, for example, there are a resolver, a GMR (Giant Magneto Resistive effect) sensor, a TMR (Tunnel Magneto Resistive effect) sensor, and the like.

  The motor control ECU 100 calculates a rotational speed ω2 of the electric motor 200 based on the detection result signal 201b of the angle sensor 201, and transmits it to the arithmetic circuit 101 as the arithmetic result information 105a. The operation of the electric motor 200 is controlled based on the second clock oscillation unit 106 supplying the clock signal 106a used for the operation of the above and the estimated rotation speed .omega.1 calculated using the detection result signal 201a of the angle sensor 201 (motor The arithmetic circuit 101 as a motor control unit (which performs control processing), a first clock oscillation unit 104 that supplies a clock signal 104 a used for the operation of the arithmetic circuit 101 and the timer 102 incorporated in the arithmetic circuit 101, Based on the control signal 101a (eg, PWM output) from the circuit 101 A drive circuit 103 for supplying a drive signal 103a (drive power) to the electric motor 200 is schematically configured. The clock oscillating unit 104 for supplying the clock signal 104a to the arithmetic circuit 101 may be built in the arithmetic circuit 101. Similarly, the clock oscillating unit 106 for supplying the clock signal 106a to the rotational speed calculating circuit 105 has a rotational speed The structure incorporated in the calculation circuit 105 may be used.

  The rotational speed calculation circuit 105 uses the clock signal 106 a from the second clock oscillation unit 106 to calculate the rotational speed ω 2 using the difference between the angles detected at two different times and the difference between the detection times. Further, the calculation of the estimated rotational speed ω1 in the arithmetic circuit 101 is the same, and using the clock signal 104a from the first clock oscillation unit 104, the difference between the detected angles at two different times and the difference between the detected times are used. To calculate the estimated rotational speed ω1.

  The arithmetic circuit 101 generates a control signal 101a based on the estimated rotational speed ω1 and performs failure diagnosis processing based on the arithmetic result information 105a from the rotational speed calculation circuit 105.

  FIG. 2 is a flowchart showing failure diagnosis processing according to the present embodiment.

  In FIG. 2, the arithmetic circuit 101 first determines based on the count result of the timer 102 provided in the arithmetic circuit 101 whether or not it has reached a predetermined diagnostic cycle, that is, whether or not it is diagnostic timing (step S100). If the determination result is NO, the process of step S100 is repeated until the diagnosis timing is reached. If the determination result in step S100 is YES, the arithmetic circuit 101 calculates the estimated rotational speed ω1 of the electric motor 200 based on the detection result signal 201a from the angle sensor 201 (step S110), and the rotational speed The rotational speed ω2 calculated by the calculation circuit 105 is acquired (step S120). The arithmetic circuit 101 may be configured to obtain the detection result of the rotation angle via the rotation speed calculation circuit 105 without directly inputting the detection result signal 201a from the angle sensor 201.

  Subsequently, it is determined whether the absolute value of the difference between the estimated rotational speed ω1 and the rotational speed ω2 is smaller than a predetermined threshold value ωth (step S130). If the determination result is YES, that is, the estimated rotational speed ω1 and If the absolute value of the difference from the rotational speed ω2 is smaller than a predetermined threshold value ωth, at least the first and second clock oscillators 104 and 106 are diagnosed as normal, and the estimation calculated by the arithmetic circuit 101 The motor control process is performed using the rotational speed ω1 (step S140), and the process ends. It should be noted that the determination in step S130 is not limited to the absolute value of the difference between estimated rotational speed ω1 and rotational speed ω2, but the difference on the + side and the difference on the − side may each have a threshold. May be varied. If the determination result in step S130 is NO, that is, if the absolute value of the difference between estimated rotational speed ω1 and rotational speed ω2 is larger than a predetermined threshold value ωth, the first and second clock oscillations are performed. It diagnoses that at least one of the units 104 and 106 is broken, shifts to the fail mode (step S150), and ends the process. The fail mode in the present embodiment is a mode in which transition is made when the operation or control of the electric motor is not normal, and for example, is a mode in which the process of stopping the electric motor 200 according to a predetermined procedure is performed.

  The effects of the present embodiment configured as described above will be described.

  Although the operation of the electric motor is controlled by a control ECU (Electronic Control Unit) or the like, if, for example, the motor rotational speed is not correctly calculated due to a failure of the clock signal supplied to the control ECU, normality of the electric motor It is conceivable that the diagnosis of the abnormality can not be properly performed and appropriate control can not be performed according to the state of the electric motor.

  On the other hand, in the present embodiment, arithmetic circuit 101 for controlling the operation of electric motor 200, first clock oscillator 104 for supplying clock signal 104a used for the operation of arithmetic circuit 101, and electric motor 200. Used in the operation of the rotational speed calculation circuit 105 and the rotational speed calculation circuit 105 which calculates the rotational speed ω2 of the electric motor 200 based on the detection result of the angle sensor 201 The arithmetic circuit 101 is provided with a second clock oscillating unit 106 that supplies the signal 106 a and is different from the first clock oscillating unit 104, and the arithmetic circuit 101 estimates an estimated rotational speed ω2 of the electric motor 200 based on the detection result from the angle sensor 201. The difference between the rotational speed ω2 calculated by the rotational speed calculation circuit 105 and the estimated rotational speed ω1 is previously determined. Since the failure of at least one of the first and second clock oscillating units 104 and 106 is diagnosed when the threshold value ωth is larger than the threshold ωth, it is possible to diagnose the abnormality of the electric motor more correctly, and the electric motor Appropriate control can be performed according to the state of the motor.

Second Embodiment
A second embodiment of the present invention will be described with reference to FIGS. 3 and 4.

  The present embodiment further includes a function of diagnosing a clock signal used in the arithmetic circuit.

  FIG. 3 is a diagram showing a motor control ECU to which the control diagnosis system for an electric motor according to the present embodiment is applied, along with its peripheral configuration. In the figure, the same reference numerals are given to the same members as in the first embodiment, and the description will be omitted.

  In FIG. 3, the motor control ECU 100 calculates the rotational speed ω2 of the electric motor 200 based on the detection result signal 201b of the angle sensor 201, and transmits it to the arithmetic circuit 101 as the arithmetic result information 105a. The operation of the electric motor 200 is performed based on the second clock oscillating unit 106 supplying the clock signal 106 a used for the operation of the speed calculation circuit 105 and the estimated rotational speed ω1 calculated using the detection result signal 201 a of the angle sensor 201. A first clock oscillator that supplies a clock signal 104a used for the operation of the arithmetic circuit 101A as a motor control unit that performs control (performs motor control processing) and the arithmetic circuit 101A and the timer 102 incorporated in the arithmetic circuit 101A. 104 and a control signal 101a from the arithmetic circuit 101A (for example, , And a drive circuit 103 for supplying a drive signal 103a (drive power) to the electric motor 200 based on the PWM output).

  The arithmetic circuit 101A includes a clock diagnosis unit 107 that performs a clock abnormality diagnosis that diagnoses whether the clock signal 104a supplied from the clock oscillation unit 104 to the arithmetic circuit 101A is normal. The clock diagnostic unit 107 incorporates therein another clock oscillating unit (not shown) different from the first and second clock oscillating units 104 and 106, and based on the clock signal of the clock oscillating unit, Functional units related to the abnormality of the clock signal 104a from the clock oscillation unit 104 (including the abnormality of the clock oscillation unit 104 and the abnormality of the signal line transmitting the clock signal 104a) and the processing of the clock signal 104a in the arithmetic circuit 101A (see FIG. Perform a clock fault diagnosis to diagnose a fault (not shown). The clock signal used for the clock abnormality diagnosis in the clock diagnosis unit 107 may be configured to use a clock signal input from the outside of the arithmetic circuit 101 or the motor control ECU 100.

  The arithmetic circuit 101A generates a control signal 101a based on the estimated rotational speed ω1 and performs failure diagnosis processing based on the arithmetic result information 105a from the rotational speed calculation circuit 105.

  FIG. 4 is a flowchart showing failure diagnosis processing according to the present embodiment.

  In FIG. 4, the arithmetic circuit 101A first determines based on the count result of the timer 102 provided in the arithmetic circuit 101A whether or not it has reached a predetermined diagnosis period, that is, whether or not it is a diagnosis timing (step S100). If the determination result is NO, the process of step S100 is repeated until the diagnosis timing is reached. If the determination result in step S100 is YES, the arithmetic circuit 101 calculates the estimated rotational speed ω1 of the electric motor 200 based on the detection result signal 201a from the angle sensor 201 (step S110), and the rotational speed The rotational speed ω2 calculated by the calculation circuit 105 is acquired (step S120).

  Subsequently, it is determined whether the absolute value of the difference between the estimated rotational speed ω1 and the rotational speed ω2 is smaller than a predetermined threshold value ωth (step S130). If the determination result is YES, that is, the estimated rotational speed ω1 and If the absolute value of the difference from the rotational speed ω2 is smaller than a predetermined threshold value ωth, at least the first and second clock oscillators 104 and 106 are diagnosed as normal, and the estimation calculated by the arithmetic circuit 101 The motor control process is performed using the rotational speed ω1 (step S140), and the process ends.

  Further, when the determination result in step S130 is NO, that is, when the absolute value of the difference between estimated rotational speed ω1 and rotational speed ω2 is larger than a predetermined threshold value ωth, clock diagnostic unit 107 of arithmetic circuit 101A. Perform a clock error diagnosis at the clock to see if it is a clock error (ie, an error in the clock signal 104a from the clock oscillation unit 104 (including an abnormality in the clock oscillation unit 104 or an abnormality in a signal line transmitting the clock signal 104a) It is determined whether or not there is an abnormality in a functional unit (not shown) related to the processing of the clock signal 104a in the circuit 101A (step S131). If the determination result is NO, at least the first and second The clock oscillators 104 and 106 are diagnosed as normal, and the estimated rotational speed ω1 calculated by the arithmetic circuit 101 is used. Implement motor control processing (step S140), and ends the process. It should be noted that the determination in step S130 is not limited to the absolute value of the difference between estimated rotational speed ω1 and rotational speed ω2, but the difference on the + side and the difference on the − side may each have a threshold. May be varied. When the determination result in step S131 is NO, the motor control process is performed using the rotational speed ω2 calculated by the rotational speed calculation circuit 105 estimated to have no abnormality (step S151). End the process.

  The other configuration is the same as that of the first embodiment.

  Also in the form of the present embodiment configured as described above, the same effect as that of the first embodiment can be obtained.

  In addition, even when it is determined that an abnormality has occurred in one of the clock oscillating units 140 and 160, control of the electric motor can be continued by using the clock signal from the other clock oscillating unit.

  The present invention is not limited to the embodiments described above, but includes various modifications. For example, the embodiments described above are described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described. Further, each of the configurations, functions, etc. described above may be realized by designing part or all of them, for example, with an integrated circuit. Further, each configuration, function, etc. described above may be realized by software by the processor interpreting and executing a program that realizes each function.

100 Motor Control ECU (Electronic Control Unit)
101, 101A arithmetic circuit (motor control unit)
101a control signal 102 timer 103 drive circuit 103a drive signal 104 first clock oscillator (clock signal oscillation source)
104a, 106a Clock signal 105 Rotational speed calculation circuit 105a Operation result information 106 Second clock oscillator (clock signal oscillation source)
107 Clock diagnostic unit 140, 160 Clock oscillation unit 200 Electric motor 201 Angle sensor 201a, 201b Detection result signal

Claims (3)

A motor control unit that controls the operation of the electric motor;
A first clock signal oscillation source for supplying a clock signal used for the operation of the motor control unit;
An angle sensor for detecting an angle of a rotation shaft of the electric motor;
A rotational speed calculation circuit that calculates the rotational speed of the electric motor based on the detection result of the angle sensor;
And a second clock signal oscillation source different from the first clock signal oscillation source which supplies a clock signal used for the operation of the rotational speed calculation circuit,
The motor control unit calculates an estimated rotational speed of the electric motor based on a detection result from the angle sensor, and a difference between the rotational speed calculated by the rotational speed calculation circuit and the estimated rotational speed is predetermined. A control diagnosis system for an electric motor, comprising diagnosing a failure of at least one of the first and second clock signal oscillation sources when the threshold voltage is larger than a threshold. In the control diagnosis system for an electric motor according to claim 1,
The motor control unit
A clock signal for diagnosing whether the first clock signal oscillation source is normal or abnormal based on a clock signal from a third clock signal oscillation source different from the first and second clock signal oscillation sources Equipped with a diagnostic unit,
If the difference between the rotation speed calculated by the rotation speed calculation circuit and the estimated rotation speed is larger than a predetermined threshold and the clock signal diagnosis unit diagnoses that the rotation is normal, the estimated rotation Use the speed to control the operation of the electric motor,
When the difference between the rotation speed calculated by the rotation speed calculation circuit and the estimated rotation speed is larger than a predetermined threshold and the clock signal diagnosis unit is diagnosed as abnormal, the rotation speed A control diagnosis system for an electric motor, which controls the operation of the electric motor using the rotational speed calculated by a calculation circuit. A procedure of calculating the rotation speed of the electric motor by a rotation speed calculation circuit based on the detection result of an angle sensor which detects the angle of the rotation shaft of the electric motor;
A procedure for calculating an estimated rotational speed of the electric motor based on a detection result from the angle sensor by a motor control unit that controls an operation of the electric motor;
The first clock signal oscillation for supplying a clock signal used for the operation of the motor control unit when the difference between the rotation speed calculated by the rotation speed calculation circuit and the estimated rotation speed is larger than a predetermined threshold. And diagnosing a failure of at least one of a second clock signal oscillation source different from the first clock signal oscillation source, which supplies a clock signal used for the operation of the rotation speed calculation circuit. A control diagnosis method of an electric motor characterized in that.

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