JP2017184388A - Motor controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor controller capable of preventing harmful effect of noise of a drive circuit included in every motor control section, when a synchronization signal between a plurality of motor control sections cannot be received normally due to hardware fault.SOLUTION: A motor control device 10 has a motor controller 24A and a clock generator 32A, and a motor controller 24B and a clock generator 32B. The motor control device 10 has inverters 23A, 23B, and motor current controllers 22A, 22B outputting a control signal to the inverters 23A, 23B. A synchronization clock monitor 41 permits supply of a synchronization signal from the clock generator 32A to a motor control timer 33B, when input of the synchronization signal is normal, otherwise uses the synchronization signal from the clock generator 32B in the second motor control section. In this case, the first motor control section stops control of a motor M.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a motor control device.

  As the motor control device, for example, the one described in Patent Document 1 is known. In Patent Document 1, two independent control means are provided for a common motor, and an abnormality is determined when the current deviation between the calculated current command value and the actual current command value is an abnormal value. ing. When the current deviation between the current command value and the actual current command value is normal, the motor control is executed by synchronizing the control means of both systems.

  The motor control described in Patent Document 2 includes a pair of CPUs (central processing units) that drive motors and a pair of clock generation circuits that generate clock signals for operating both CPUs. The clock signal generated by is distributed and supplied to the pair of CPUs. When there is an abnormality in the one clock generation circuit, the clock signal generated by the other clock generation circuit is distributed and supplied to the pair of CPUs instead of the one clock signal generation circuit. .

JP 2011-20482 A JP 2014-106874 A

  Patent Document 1 does not describe the clock signal when synchronizing two independent control means, and does not disclose a coping method when there is an abnormality in the clock generation circuit or the like.

  On the other hand, in Patent Document 2, when the clock signals cannot be transmitted and received between both CPUs, the clock signals generated by the individual clock generation circuits of the CPUs are used as synchronization signals. In this case, the following problems occur.

  That is, a shift occurs in the clock signals generated by the clock signal generation circuits of both systems, and the shift is not eliminated. The calculation shift time increases as time elapses, and a control timing shift occurs. Then, noise due to switching of the inverter that supplies power to the motor in one system is superimposed on the AD conversion value (data) of the AD conversion unit that AD converts the detection signals of various sensors in the other system. As a result, the CPU of the other system may not be able to perform accurate motor control by controlling the inverter based on the data on which the noise is superimposed.

  An object of the present invention is to prevent adverse effects of noise in a drive circuit unit provided for each motor control unit when a synchronization signal between a plurality of motor control units cannot be normally received due to a hardware failure or the like. The object is to provide a motor control device.

  In order to solve the above problems, a motor control device of the present invention has a plurality of motor control units including a first motor control unit and a second motor control unit that control a motor, and each motor control unit is configured as described above. The drive circuit unit that supplies power to the motor, the calculation unit that calculates a motor command value and outputs a control signal based on the motor command value, and the control operations of the motor control units are synchronized with each other. A motor control device including a synchronization signal generation unit that generates a synchronization signal, wherein the synchronization signal generation unit belonging to the first motor control unit supplies a synchronization signal to the remaining motor control units. A determination unit configured to determine whether or not the synchronization signal supplied from the motor control unit is normally input to the other remaining motor control units; if the determination by the determination unit is negative, the first motor control And When one of the two motor control units is one and the other is the other, the synchronization signal from the synchronization signal generating unit in the one motor control unit is sent to the other of the plurality of motor control units. The other motor control unit is used for stopping the control of the motor.

  With the above configuration, when the synchronization signal input between the plurality of motor control units is not normal due to a hardware failure or the like, a plurality of synchronization signals from the synchronization signal generation unit of one motor control unit are set according to the determination result of the determination unit. Of all the motor control units, the remaining motor control unit except the other motor control unit is used, and the other motor control unit stops the control of the motor. As a result, the adverse effect of noise in the drive circuit unit provided for each motor control unit is prevented.

  In addition, when the determination is negative, the determination unit outputs an abnormality notification signal to all the remaining motor control units including the other motor control unit while excluding the one motor control unit. It is preferable.

  With the above configuration, when the determination is negative, the determination unit removes the one motor control unit and outputs an abnormality notification signal to all the remaining motor control units including the one motor control unit. Thus, the motor control unit that has input the abnormality notification signal can perform processing corresponding to the abnormality notification signal.

  Further, the other motor control unit stops the control of the motor based on the input abnormality notification signal, and the other motor control unit other than the other motor control unit and the one motor control, It is preferable to input a synchronization signal from the one motor control unit based on the input abnormality notification signal.

  With the above configuration, the one motor control unit stops the control of the motor based on the input abnormality notification signal. The other motor control units other than the one motor control unit and the other motor control input the synchronization signal from the one motor control unit based on the input abnormality notification signal. As a result, the motor control unit that has input the abnormality notification signal can perform processing corresponding to the abnormality based on the abnormality notification signal.

  According to the present invention, when a synchronization signal between a plurality of motor control units cannot be normally received due to a hardware failure or the like, it is possible to prevent an adverse effect of noise of a drive circuit unit provided for each motor control unit. .

The circuit block diagram of the motor control device of one embodiment. The circuit block diagram of the conventional motor control apparatus.

Hereinafter, an embodiment of a motor control device according to the present invention will be described with reference to FIG.
In the present embodiment, the motor M that is symmetrical to the control of the motor control device 10 is, for example, a motor that is a generation source of the steering assist force in the electric power steering device, but the motor that is the control target is the motor of the electric power steering device. It is not limited to.

  The motor M is a so-called IPM motor (Interior Permanent Magnet Motor). The motor is not limited to the IPM motor, and may be an SPM motor (Surface Permanent Magnet Motor).

  The motor M includes a stator and a rotor (not shown). In the rotor, a plurality of permanent magnets (not shown) are embedded in the circumferential direction inside, and each permanent magnet is magnetized along the radial direction of the rotor and is adjacent to each other in the circumferential direction of the rotor. The two permanent magnets are provided so that the magnetization directions are opposite to each other. The stator has a pair of coils wound around a stator core (not shown). The pair of coil groups includes a coil group driven by a motor controller 24A of the A system 20A described later and a coil group driven by a motor controller 24B of the B system 20B described later. Each coil group is composed of U-phase, V-phase, and W-phase coils connected in a star connection.

  The motor control device 10 includes a steering device ECU 12 and a pair of inverters 23A and 23B, and the steering device ECU 12 controls the pair of coils of the motor M via the inverters 23A and 23B, respectively. The inverters 23A and 23B correspond to a drive circuit unit.

  The steering device ECU 12 includes a pair of microcomputers (microcomputers) 21A and 21B and a pair of oscillators 30A and 30B that output clocks having the same fundamental frequency to the microcomputers 21A and 21B.

The A system 20A and the B system 20B will be described. Both systems are for driving a pair of coils of the motor M, respectively.
The A system 20A includes a microcomputer 21A, an oscillator 30A, an inverter 23A, and a current sensor 25A that detects a motor current output from the inverter 23A to the motor M. As shown in FIG. 1, the microcomputer 21A includes a clock generator 32A, a motor control timer 33A, a motor current controller 22A, an AD converter 35A, a clock output device 40, and a port 42. The motor current controller 22A corresponds to a calculation unit. The clock generator 32A corresponds to a synchronization signal generator.

  The clock generator 32A is a multiplier, which multiplies the clock of the fundamental frequency input from the oscillator 30A made of a crystal element or the like by a predetermined multiple and outputs it to the motor control timer 33A, the clock output unit 40, and the motor current controller 22A. To do. Hereinafter, the clock multiplied by a predetermined multiple of the clock of the basic frequency is referred to as a microcomputer built-in synchronization signal A.

  The motor control timer 33A includes a known frequency divider and an up / down counter. When the clock divided by the frequency divider counts up and down with the up / down counter and reaches a predetermined count value, respectively. The operation trigger is output to the AD converter 35A and the motor current controller 22A.

The AD converter 35A performs AD conversion on the detection signal (analog signal) input from the current sensor 25A based on the operation trigger, and then inputs the detection signal (analog signal) to the motor current controller 22A.
The operation trigger defines the operation cycle timing of the motor current controller 22A in the motor current controller 22A, and defines the AD conversion timing in the AD converter 35A, and both timings are synchronized.

  The motor current controller 22A calculates a motor command value based on various information such as a detection signal from the current sensor 25A at the calculation cycle timing, generates a control signal (PWM signal) based on the motor command value, and sends it to the inverter 23A. Output.

  In the above description, the motor current detected by the current sensor 25A is described as an example of various types of information. However, in the electric power steering apparatus, in addition to the motor current, the motor current controller 22A includes various sensors provided in the vehicle. Is obtained as information indicating the driver's request or the running state. And the motor M is controlled according to these various information acquired, ie, the said parameter.

  Here, various sensors that indicate the driver's request or the running state include, for example, a rotation angle sensor that detects the rotation angle of the rotor of the motor M, a torque sensor, and a vehicle speed sensor in addition to the current sensor 25A. The torque sensor is provided on a steering shaft (not shown), for example, and detects a steering torque applied to a steering wheel (not shown). The vehicle speed sensor detects a vehicle speed that is the traveling speed of the vehicle. These rotation angle, steering torque, and vehicle speed correspond to the parameters, and these signals are analog values, and are converted into digital values by an AD converter (not shown). That is, these AD converters also receive the operation trigger output by the motor control timer 33A, and are converted in synchronization with the detection cycle based on this operation trigger. The operation trigger may be either the rising edge or falling edge of the clock.

  The inverter 23A has a three-phase (U phase, V phase, W phase) inverter circuit. The inverter circuit generates DC power supplied from a DC power source such as a battery by turning on and off switching elements such as MOSFETs constituting the inverter circuit based on a control signal (PWM signal) output at the operation cycle timing. Convert to three-phase AC power. Inverter 23A has three arms (single-phase half bridges) each composed of two FETs (field-effect transistors) connected in series, each being connected in parallel between the + terminal and the-terminal of the DC power supply. Become connected.

  The motor controller 24A includes a motor control timer 33A, a motor current controller 22A, an AD converter 35A, a port 42, an inverter 23A, and a current sensor 25A. The combination of the motor controller 24A and the clock generator 32A corresponds to the motor control unit and to the first motor control unit.

  The B system 20B includes a microcomputer 21B, an oscillator 30B, an inverter 23B, and a current sensor 25B that detects a current output from the inverter 23B to the motor M. As shown in FIG. 1, the microcomputer 21B includes a clock generator 32B, a motor control timer 33B, a motor current controller 22B, an AD converter 35B, a synchronous clock monitor 41, a changeover switch 43, and a port 44. The motor current controller 22B corresponds to a calculation unit. The clock generator 32B corresponds to a synchronization signal generator. The synchronous clock monitor 41 corresponds to a determination unit.

  The functions of the oscillator 30B, the clock generator 32B, the motor control timer 33B, the motor current controller 22B, and the AD converter 35B in the B system 20B are the same as the oscillator 30A, the clock generator 32A, the motor control timer 33A in the A system 20A, Since it is the same as motor current controller 22A and AD converter 35A, description is abbreviate | omitted. Note that a clock generator 32B obtained by multiplying the clock of the fundamental frequency input from the oscillator 30B by a predetermined multiple is called a microcomputer built-in synchronization signal B. The microcomputer built-in synchronization signal B has the same frequency as the microcomputer built-in synchronization signal A.

  The synchronous clock monitor 41 is electrically connected to the clock output unit 40 of the A system 20A, and the microcomputer built-in synchronization signal B is input through the output terminal of the clock generator 32B. The synchronous clock monitor 41 monitors whether or not the microcomputer built-in synchronization signal A is normally input from the clock output unit 40 as an inter-microcomputer synchronization signal. As an example of this monitoring method, the microcomputer built-in synchronization signal A (inter-microcomputer synchronization signal) and the microcomputer built-in synchronization signal B are compared to determine whether or not the microcomputer built-in synchronization signal A is normally input. The monitoring method is not limited to this method, and a preset threshold value and the microcomputer built-in synchronization signal A may be compared.

  The changeover switch 43 has an a contact, a b contact, and a common terminal. The a contact is connected to the output terminal of the clock generator 32B, the b contact is connected to the clock output device 40, and the common terminal is a motor control. It is connected to the timer 33B. The changeover switch 43 is switched from the b-contact to the a-contact by the synchronous clock monitor 41 when the microcomputer built-in synchronization signal A of the synchronous clock monitor 41 is not normally input. The fact that the microcomputer built-in synchronization signal A is not input normally includes the interruption of the synchronization signal due to a clock abnormality, that is, when a noise is superimposed, due to a power fault, a ground fault, or a disconnection between systems.

The motor controller 24B includes a motor control timer 33B, a motor current controller 22B, an AD converter 35B, a port 44, an inverter 23B, and a current sensor 25B.
The combination of the motor controller 24B and the clock generator 32B corresponds to a motor controller and a second motor controller.

<Operation of Embodiment>
The operation of the motor control device 10 configured as described above will be described.
When the input (communication) of the inter-microcomputer synchronization signal (microcomputer built-in synchronization signal A) from the A system 20A to the B system 20B is normal, in the B system 20B, the microcomputer built-in synchronization signal A (between microcomputers) output from the clock generator 32A. Synchronization signal) is input to the motor control timer 33B via the clock output device 40 and the changeover switch 43.

  In the A system 20A, the microcomputer built-in synchronization signal A output from the clock generator 32A is input to the motor control timer 33A. For this reason, in both systems, the operation triggers of the motor control timers 33A and 33B are output in synchronism, so that the calculation cycle timing of the motor current controllers 22A and 22B, the switch timing of the inverters 23A and 23B (on / off timing) The AD conversion timings of AD converters such as AD converters 35A and 35B are synchronized.

  When the input (communication) of the inter-microcomputer synchronization signal (microcomputer built-in synchronization signal A) from the A system 20A to the B system 20B is not normal, the synchronous clock monitor 41 of the B system 20B detects this. Based on this detection, the synchronous clock monitor 41 switches and connects the common terminal of the changeover switch 43 to the a contact.

  As a result, the microcomputer built-in synchronization signal B from the clock generator 32B is input to the motor control timer 33B. For this reason, in the B system 20B, since the operation trigger of the motor control timer 33B is output based on the microcomputer built-in synchronization signal B, the calculation cycle timing of the motor current controller 22B, the switch timing of the inverters 23A and 23B (ON / OFF) Timing) and AD conversion timings of AD converters such as the AD converter 35B are synchronized.

  When the synchronous clock monitor 41 detects that the input of the synchronization signal between the microcomputers is not normal, the microcomputer 21B outputs an abnormality flag from the port 44 to the port 42 of the microcomputer 21A of the A system 20A. The abnormality flag output from the port 44 to the port 42 of the microcomputer 21A corresponds to an abnormality notification signal. When the abnormality flag is input, the microcomputer 21A recognizes that the microcomputer built-in synchronization signal A is not normally output as the synchronization signal between microcomputers, and stops the motor control of the microcomputer 21A based on the identification result. When the motor control of the microcomputer 21A is stopped, AD conversion of detection signals of various sensors in the A system 20A is stopped. As a result, it is possible to prevent an adverse effect on the motor control of the B system 20B due to noise in AD conversion between microcomputers.

  Further, when outputting the abnormality flag, the microcomputer 21B operates a notifying unit such as a warning lamp and a buzzer (not shown) at the same time or before and after the output to notify the user that there is an abnormality.

  In the case where the present embodiment is embodied in an electric power steering apparatus, if the input of the synchronization signal between microcomputers is not normal, the motor control is stopped in one motor control unit, but the remaining motor control Depending on the part, the assist can be continued.

<Conventional example>
Here, a conventional motor control apparatus will be described with reference to FIG. In addition, about the same structure as the said embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted. In the motor control apparatus 10 of the conventional example of FIG. 2, in the configuration of the A system 20A, the clock output device 40 and the port 42 are omitted in the above embodiment, and in the configuration of the B system 20B, the synchronous clock monitor 41 and the changeover switch 43 , And the port 44 are omitted.

  Also in the conventional example, it is assumed that the switch timing (on / off timing) of the inverters 23A and 23B and the AD conversion timing of the AD converters 35A and 35B are performed in synchronization with the calculation cycle timing in the motor current controllers 22A and 22B. It is said.

  In the conventional example, the oscillator 30A of the A system 20A and the oscillator 30B of the B system 20B independently generate clocks having the same basic frequency, and use motor control timers 33A and 33B that are independent of each other. When the oscillators (for example, crystal elements) of the oscillators 30A and 30B of both systems have variations, the clocks generated by the clock generators 32A and 32B of both systems generate a shift. As the time elapses, the calculation deviation time increases, and a control timing deviation occurs.

  When noise due to switching of the inverter in one system is superimposed on the AD conversion value (data) of the other system, the motor current controller of the other system controls the inverter based on the data with this noise superimposed. As a result, accurate motor control (for example, assist control) cannot be performed.

  The motor M has redundancy that the rotor can be rotated by each of a plurality of one coil groups. The motor having such redundancy is expected to be used, for example, when realizing an automatic steering device. In the case of an automatic steering device, for example, even when one of the two systems cannot be used, it is required that automatic steering can be continuously performed by the other remaining system.

For this reason, when the conventional example as described above is applied to the automatic steering device, there is a possibility that the target rudder angle cannot be accurately controlled when both systems are normal.
In this embodiment, there is no problem of the conventional example as described above.

This embodiment has the following features.
(1) The motor control device 10 of the present embodiment includes a motor controller 24A and a clock generator 32A (first motor control unit) that control the motor M, and a motor controller 24B and a clock generator 32B (second motor control). Part). Each motor control unit calculates motor command values with inverters 23A and 23B (drive circuit units), and outputs motor control signals 22A and 22B to the inverters 23A and 23B based on the motor command values. (Calculation unit). Each motor control unit includes clock generators 32A and 32B (synchronization signal generation units) that generate synchronization signals that synchronize the control operations of the motor control units. Then, the synchronization signal of the clock generator 32A (synchronization signal generation unit) is supplied to the second motor control unit.

  Further, a synchronous clock monitor 41 (determination) that determines whether or not the synchronization signal supplied from the motor controller 24A and the clock generator 32A (first motor controller) is normally input to the second motor controller. Part). When the determination of the synchronous clock monitor 41 (determination unit) is negative, the synchronization signal from the clock generator 32B (the synchronization signal generation unit of the second motor control unit) is used for the second motor control unit, The 1 motor control unit stops the control of the motor M.

  As a result, when the synchronization signal is normally input to the second motor control unit, the motor control is performed regardless of individual differences between the first motor control unit and the oscillator and clock generator in the second motor control unit. The offset amount of the control signal (PWM signal) is fixed. For this reason, noise due to switching of one inverter (drive circuit unit) is not superimposed on the AD conversion value (data) of the other system. For this reason, the accuracy of motor control can be maintained.

  When the synchronization signal is not normally input to the second motor control unit, the first motor control unit stops the motor control, and the second motor control unit generates the clock of the second motor control unit. Use the sync signal from the instrument. This prevents both motor control units from individually operating with a synchronization signal, thereby preventing the adverse effects of the noise.

  On the contrary, when the synchronization signal is not normally input to the first motor control unit, the motor control is stopped in the second motor control unit, and the clock generator of the first motor control unit is stopped in the first motor control unit. May be used.

  (2) In the motor control device 10 of the present embodiment, when the determination by the synchronous clock monitor 41 (determination unit) is negative, an abnormality flag (abnormality notification signal) is output to the first motor control unit. To do. As a result, when there is an abnormality in the synchronization signal between microcomputers between systems, the abnormality can be notified to the motor control part of the system outputting the synchronization signal between microcomputers, and the motor control part of the system that receives this Then, it is possible to cope with the abnormality flag.

In addition, embodiment of this invention is not limited to the said embodiment, You may change as follows.
In the above-described embodiment, the case of the two-system motor control unit has been described, but it is obvious that the present invention can be similarly applied to a motor control device including a plurality of three or more system motor control units.

  That is, in the motor control device 10 including a plurality of systems of motor control units of three or more systems, when the synchronous clock monitor 41 of the second motor control unit determines that the synchronization signal between microcomputers is not normally input, Similar to the above embodiment, an abnormality flag (abnormality notification signal) is transmitted to the remaining motor control units excluding the second motor control unit.

  Then, the first motor control unit stops the control of the motor based on the input of the abnormality flag (abnormality notification signal). Further, in the remaining motor control units other than the first and second motor control units, when the abnormality flag (abnormality notification signal) is input, the clock generator belonging to the second motor control unit is based on the abnormality flag. The microcomputer built-in synchronization signal B from 32B is input as a synchronization signal between microcomputers. Even if comprised in this way, there can exist an effect similar to the said embodiment.

  The relationship between the first motor control unit and the second motor control unit may be interchanged.

10 ... motor control device, 12 ... steering device ECU,
20A ... A system, 20B ... B system, 21A, 21B ... microcomputer,
22A, 22B ... motor current controller (calculation unit),
23A, 23B ... inverter (drive circuit unit),
24A, 24B ... motor controller, 25A, 25B ... current sensor,
30A, 30B ... Oscillator,
32A... Clock generator (constitutes the first motor controller together with the synchronization signal generator and motor controller 24A),
32B ... Clock generator (constitutes the second motor control unit together with the synchronization signal generation unit and motor controller 24B),
33A, 33B ... motor control timer, 35A, 35B ... AD converter,
40 ... Clock output device, 41 ... Synchronous clock monitor (determination unit),
42 ... port, 43 ... switch, 44 ... port, M ... motor.

Claims (3)

A plurality of motor control units including a first motor control unit and a second motor control unit for controlling the motor; each motor control unit calculates a motor command value; a drive circuit unit for supplying power to the motor; The motor control device includes a calculation unit that outputs a control signal based thereon to the drive circuit unit, and a synchronization signal generation unit that generates a synchronization signal that synchronizes each control operation of each motor control unit. In the motor control device that supplies the synchronization signal of the synchronization signal generation unit belonging to the first motor control unit to the remaining motor control units,
A determination unit that determines whether the synchronization signal supplied from the first motor control unit is normally input to the other motor control units;
When the determination by the determination unit is negative, when one of the first motor control unit and the second motor control unit is one and the other is the other, the synchronization signal generation unit in the one motor control unit Is used for the remaining motor control units excluding the other motor control unit among all the plurality of motor control units, and the other motor control unit stops the control of the motor. Motor control device.   The determination unit, when the determination is negative, outputs an abnormality notification signal to all the remaining motor control units including the other motor control unit while excluding the one motor control unit. The motor control device according to 1. The other motor control unit stops the control of the motor based on the input abnormality notification signal,
3. The other motor control unit other than the other motor control unit and the one motor control inputs a synchronization signal from the one motor control unit based on the input abnormality notification signal. The motor control apparatus described.

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