JP2021035072A - Rotary electric machine control device - Google Patents

Abstract

To provide a rotary electric machine control device that can appropriately switch a driving mode.SOLUTION: Control units 150 and 250 can communicate with each other, and mode selection units 152 and 252 select driving modes including a cooperative driving mode and an independent driving mode. A driving control unit controls inverter units 120 and 220 which are provided correspondingly in a selected driving mode. The cooperative driving mode uses a value acquired from the other control unit and a value calculated by an own control unit. The independent driving mode does not use the value acquired from the other control unit. The mode selection units 152 and 252 transfer the driving mode from the cooperative driving mode to the independent driving mode when at least one transition determination item satisfies an independent transition condition, and return the driving mode from the independent driving mode to the cooperative driving mode when the transition determination item satisfies a returnable condition and a return permission determination item being different from the transition determination item satisfies a return permission condition.SELECTED DRAWING: Figure 4

Description

The present invention relates to a rotary electric machine control device.

Conventionally, a rotary electric machine control device that controls the drive of a motor by a plurality of control units has been known. For example, in Patent Document 1, the control mode is switched according to the type of abnormality that has occurred.

JP-A-2018-130007

In Patent Document 1, when the abnormality is resolved and the count value of the return counter becomes equal to or higher than the return determination threshold value, the control mode is returned to the normal control. However, depending on the timing of returning to the control mode, torque fluctuation may occur, which may give a sense of discomfort to the driver or affect automatic driving control. The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a rotary electric machine control device capable of appropriately switching a drive mode.

The rotary electric machine control device of the present invention controls the drive of a rotary electric machine (80) having a motor winding (180, 280), and has a plurality of inverter units (120, 220) and a plurality of control units (120, 220). 150, 250) and. The inverter section switches the energization of the motor winding. The control units can communicate with each other and have a mode selection unit (152, 252) and a drive control unit (151, 251). The mode selection unit selects a drive mode including a cooperative drive mode and an independent drive mode. The drive control unit controls the corresponding inverter unit in the selected drive mode.

The cooperative drive mode uses the values acquired from other control units and the values calculated by its own control unit. The independent drive mode does not use the value acquired from other control units. The mode selection unit shifts the drive mode from the cooperative drive mode to the independent drive mode when at least one transition determination item satisfies the independent transition condition. Further, the mode selection unit returns the drive mode from the independent drive mode to the cooperative drive mode when the transition judgment item satisfies the cooperative return condition and the return permission judgment item different from the transition judgment item satisfies the return permission condition. Let me. Thereby, the drive mode can be appropriately switched.

It is a schematic block diagram of the steering system by 1st Embodiment. It is sectional drawing of the drive device by 1st Embodiment. FIG. 2 is a cross-sectional view taken along the line III-III of FIG. It is a block diagram which shows the ECU by 1st Embodiment. It is a circuit diagram explaining the power supply relay by 1st Embodiment. It is a block diagram explaining the current feedback control by the control of the sum and the difference by 1st Embodiment. It is a block diagram explaining the independent feedback control by 1st Embodiment. It is a flowchart explaining the independent transition process by 1st Embodiment. It is a flowchart explaining the cooperative return processing by 1st Embodiment. It is a time chart explaining the return from independent drive to cooperative drive by 1st Embodiment. It is a flowchart explaining the independent transition process by 2nd Embodiment.

Hereinafter, the rotary electric machine control device according to the present invention will be described with reference to the drawings. Hereinafter, in a plurality of embodiments, substantially the same configuration will be designated by the same reference numerals and description thereof will be omitted.

(First Embodiment)
The first embodiment is shown in FIGS. 1 to 10. As shown in FIG. 1, the ECU 10 as a rotary electric machine control device controls the drive of the motor 80, which is a rotary electric machine, and together with the motor 80, serves as a steering device for assisting a steering operation of a vehicle, for example. It is applied to the electric power steering device 8.

FIG. 1 shows the configuration of a steering system 90 including an electric power steering device 8. The steering system 90 includes a steering wheel 91, a steering shaft 92, a pinion gear 96, a rack shaft 97, wheels 98, an electric power steering device 8, and the like, which are steering members.

The steering wheel 91 is connected to the steering shaft 92. The steering shaft 92 is provided with a torque sensor 94 that detects steering torque. The torque sensor 94 has a first sensor unit 194 and a second sensor unit 294, and the sensors capable of detecting their own failures are duplicated. A pinion gear 96 is provided at the tip of the steering shaft 92. The pinion gear 96 meshes with the rack shaft 97. A pair of wheels 98 are connected to both ends of the rack shaft 97 via a tie rod or the like.

When the driver rotates the steering wheel 91, the steering shaft 92 connected to the steering wheel 91 rotates. The rotational motion of the steering shaft 92 is converted into a linear motion of the rack shaft 97 by the pinion gear 96. The pair of wheels 98 are steered at an angle corresponding to the amount of displacement of the rack shaft 97.

The electric power steering device 8 includes a motor 80, a reduction gear 89 as a power transmission unit that decelerates the rotation of the motor 80 and transmits the rotation to the steering shaft 92, an ECU 10 and the like. That is, the electric power steering device 8 of the present embodiment is a so-called "column assist type", but may be a so-called "rack assist type" or the like that transmits the rotation of the motor 80 to the rack shaft 97. In this embodiment, the steering shaft 92 corresponds to the "drive target".

As shown in FIGS. 1 to 4, the motor 80 outputs a part or all of the torque required for steering, and is driven by supplying electric power from batteries 101 and 201 as a power source to decelerate. The gear 89 is rotated in the forward and reverse directions. The motor 80 is a three-phase brushless motor and has a rotor 860 and a stator 840.

The motor 80 has a first motor winding 180 and a second motor winding 280. The motor windings 180 and 280 have the same electrical characteristics, and are canceled and wound around a common stator 840 with an electric angle of 30 [deg] shifted from each other. In response to this, the motor windings 180 and 280 are controlled so that a phase current whose phase φ is shifted by 30 [deg] is energized. The output torque is improved by optimizing the energization phase difference. Further, the sixth-order torque ripple can be reduced, and noise and vibration can be reduced. In addition, since heat generation is dispersed and leveled by distributing the current, it is possible to reduce temperature-dependent inter-system errors such as the detected value and torque of each sensor, and increase the amount of current that can be energized. it can. The motor windings 180 and 280 may not be canceled and may have different electrical characteristics.

Hereinafter, the combination of the first inverter unit 120 and the first control unit 150 related to the energization control of the first motor winding 180 is combined with the first system L1, the second inverter unit 220 related to the energization control of the second motor winding 280, and the like. The combination of the second control unit 250 and the like is referred to as the second system L2. Further, the configuration related to the first system L1 is mainly numbered in the 100s, and the configuration related to the second system L2 is mainly numbered in the 200s. Further, in the first system L1 and the second system L2, similar or similar configurations are numbered so that the last two digits are the same. Further, the 500 series is used for a part of the configuration of the first control unit 150, and the 600 series is used for a part of the configuration of the second control unit 250. The 500 series and 600 series, which will be described later, are also numbered so that the last two digits are the same in the same or similar configuration. Hereinafter, "first" will be described as a subscript "1" and "second" will be described as a subscript "2" as appropriate.

As shown in FIG. 2, the drive device 40 is a so-called "mechanical and electrical integrated type" in which the ECU 10 is integrally provided on one side in the axial direction of the motor 80, but the motor 80 and the ECU 10 are separately provided. It may have been. The ECU 10 is arranged coaxially with respect to the shaft Ax of the shaft 870 on the side opposite to the output shaft of the motor 80. The ECU 10 may be provided on the output shaft side of the motor 80. By adopting the mechanical / electrical integrated type, the ECU 10 and the motor 80 can be efficiently arranged in a vehicle having a limited mounting space.

The motor 80 includes a stator 840, a rotor 860, a housing 830 for accommodating them, and the like. The stator 840 is fixed to the housing 830, and the motor windings 180 and 280 are wound around the stator 840. The rotor 860 is provided inside the stator 840 in the radial direction, and is provided so as to be rotatable relative to the stator 840.

The shaft 870 is fitted into the rotor 860 and rotates integrally with the rotor 860. The shaft 870 is rotatably supported by the housings 830 by bearings 835, 836. The end of the shaft 870 on the ECU 10 side projects from the housing 830 toward the ECU 10. A magnet 875 is provided at the end of the shaft 870 on the ECU 10 side.

The housing 830 has a bottomed tubular case 834 including a rear frame end 837 and a front frame end 838 provided on the opening side of the case 834. The case 834 and the front frame end 838 are fastened to each other by bolts or the like. A lead wire insertion hole 839 is formed in the rear frame end 837. Lead wires 185 and 285 connected to each phase of the motor windings 180 and 280 are inserted into the lead wire insertion holes 839. The lead wires 185 and 285 are taken out from the lead wire insertion holes 839 to the ECU 10 side and connected to the substrate 470.

The ECU 10 includes a cover 460, a heat sink 465 fixed to the cover 460, a substrate 470 fixed to the heat sink 465, and various electronic components mounted on the substrate 470. The cover 460 protects electronic components from external impacts and prevents dust, water, and the like from entering the inside of the ECU 10. In the cover 460, the cover main body 461 and the connector portions 103 and 203 are integrally formed. The connector portions 103 and 203 may be separate from the cover main body 461. The terminals 463 of the connector portions 103 and 203 are connected to the substrate 470 via wiring or the like (not shown). The number of connectors and the number of terminals can be appropriately changed according to the number of signals and the like. The connector portions 103 and 203 are provided at the axial end of the drive device 40 and open on the side opposite to the motor 80.

The substrate 470 is, for example, a printed circuit board and is provided so as to face the rear frame end 837. Electronic components for two systems are independently mounted on the board 470 for each system, forming a completely redundant configuration. In the present embodiment, the electronic components are mounted on one board 470, but the electronic components may be mounted on a plurality of boards.

Of the two main surfaces of the substrate 470, the surface on the motor 80 side is the motor surface 471, and the surface on the side opposite to the motor 80 is the cover surface 472. As shown in FIG. 3, a switching element 121 constituting the inverter unit 120, a switching element 221 constituting the inverter unit 220, an angle sensor 126, 226, a custom IC 135, 235, and the like are mounted on the motor surface 471. The angle sensors 126 and 226 are mounted at locations facing the magnet 875 so that changes in the magnetic field accompanying the rotation of the magnet 875 can be detected.

Capacitors 128, 228, inductors 129, 229, and microcomputers constituting control units 150 and 250 are mounted on the cover surface 472. In FIG. 3, the microcomputers constituting the control units 150 and 250 are numbered “150” and “250”, respectively. Capacitors 128 and 228 smooth the power input from the batteries 101 and 201. Further, the capacitors 128 and 228 assist the power supply to the motor 80 by storing electric charges. The capacitors 128 and 228 and the inductors 129 and 229 form a filter circuit to reduce noise transmitted from other devices sharing the battery and reduce noise transmitted from the drive device 40 to other devices sharing the battery. To do. Although not shown in FIG. 3, the power supply relay 122, 222, the motor relay 125, 225, the current sensor 127, 227, and the like are also mounted on the motor surface 471 or the cover surface 472.

As shown in FIG. 4, the ECU 10 includes inverter units 120 and 220, control units 150 and 250, and the like. The ECU 10 is provided with connector portions 103 and 203. The first connector portion 103 is provided with a first power supply terminal 105, a first ground terminal 106, a first IG terminal 107, a first communication terminal 108, and a first torque terminal 109.

The first power supply terminal 105 is connected to the first battery 101 via a fuse (not shown). The electric power supplied from the positive electrode of the first battery 101 via the first power supply terminal 105 is supplied to the first motor winding 180 via the power supply relay 122, the inverter unit 120, the motor relay 125, and the like. To. The first ground terminal 106 is connected to the first ground GND1 which is the ground of the first system inside the ECU 10 and the first external ground GB1 which is the ground of the first system outside the ECU 10. In the car system, the metal body is a common GND plane, the first external ground GB1 indicates one of the connection points on the GND plane, and the negative electrode of the second battery 201 is also the connection point on this GND plane. Be connected.

The first IG terminal 107 is connected to the positive electrode of the first battery 101 via a first switch that is on / off controlled in conjunction with a vehicle start switch such as an ignition switch. Hereinafter, the start switch will be referred to as an “IG key” as appropriate. The electric power supplied from the first battery 101 via the first IG terminal 107 is supplied to the first custom IC 135. The first custom IC 135 includes a first driver circuit 136, a first circuit power supply 137, a microcomputer monitoring monitor (not shown), a current monitor amplifier (not shown), and the like.

The first communication terminal 108 is connected to the first vehicle communication circuit 111 and the first vehicle communication network 195. The first vehicle communication network 195 and the first control unit 150 are connected so as to be able to transmit and receive via the first vehicle communication circuit 111. Further, the first vehicle communication network 195 and the second control unit 250 are connected so as to be able to receive information, and even if the second control unit 250 fails, the first vehicle communication network 195 including the first control unit 150 is connected. It is configured so that there is no effect.

The first torque terminal 109 is connected to the first sensor unit 194 of the torque sensor 94. The detected value of the first sensor unit 194 is input to the first control unit 150 via the first torque terminal 109 and the first torque sensor input circuit 112. Here, the first sensor unit 194 and the first control unit 150 are configured to detect a failure of the torque sensor input circuit system.

The second connector portion 203 is provided with a second power supply terminal 205, a second ground terminal 206, a second IG terminal 207, a second communication terminal 208, and a second torque terminal 209. The second power supply terminal 205 is connected to the positive electrode of the second battery 201 via a fuse (not shown). The electric power supplied from the second battery 201 via the second power supply terminal 205 is supplied to the second motor winding 280 via the power supply relay 222, the inverter unit 220, the motor relay 225, and the like. The second ground terminal 206 is connected to the second ground GND2, which is the ground of the second system inside the ECU 10, and the second external ground GB2, which is the ground of the second system outside the ECU 10. In the car system, the metal body is a common GND plane, the second external ground GB2 indicates one of the connection points on the GND plane, and the negative electrode of the second battery 201 is also connected on this GND plane. Connected to the point. Here, at least different grids are configured not to connect to the same connection point on the GND plane.

The second IG terminal 207 is connected to the positive electrode of the second battery 201 via a second switch that is controlled to be turned on and off in conjunction with the start switch of the vehicle. The electric power supplied from the second battery 201 via the second IG terminal 207 is supplied to the second custom IC 235. The second custom IC 235 includes a second driver circuit 236, a second circuit power supply 237, a microcomputer monitoring monitor (not shown), a current monitor amplifier (not shown), and the like.

The second communication terminal 208 is connected to the second vehicle communication circuit 211 and the second vehicle communication network 295. The second vehicle communication network 295 and the second control unit 250 are connected so as to be able to transmit and receive via the second vehicle communication circuit 211. Further, the second vehicle communication network 295 and the first control unit 150 are connected so as to be able to receive information, and even if the first control unit 150 fails, the second vehicle communication network 295 including the second control unit 250 is connected. It is configured so that there is no effect.

The second torque terminal 209 is connected to the second sensor unit 294 of the torque sensor 94. The detected value of the second sensor unit 294 is input to the second control unit 250 via the second torque terminal 209 and the second torque sensor input circuit 212. Here, the second sensor unit 294 and the second control unit 250 are configured to detect a failure of the torque sensor input circuit system.

In FIG. 4, the communication terminals 108 and 208 are connected to separate vehicle communication networks 195 and 295, respectively, but they may be connected to the same vehicle communication network. Further, in FIG. 4, CAN (Controller Area Network) is illustrated as the vehicle communication network 195 and 295, but a standard other than CAN such as CAN-FD (CAN with Flexible Data rate) and FlexRay is used. May be good.

The first inverter unit 120 is a three-phase inverter having a switching element 121, and converts the electric power of the first motor winding 180. The second inverter unit 220 is a three-phase inverter having a switching element 221 and converts the electric power of the second motor winding 280.

The first power supply relay 122 is provided between the first power supply terminal 105 and the first inverter unit 120. The first motor relay 125 is provided in each phase between the first inverter unit 120 and the first motor winding 180. The second power supply relay 222 is provided in each phase between the second power supply terminal 205 and the second inverter unit 220. The second motor relay 225 is provided between the second inverter unit 220 and the second motor winding 280.

In the present embodiment, the switching elements 121, 221 and the power supply relays 122 and 222, and the motor relays 125 and 225 are all MOSFETs, but other elements such as IGBTs may be used. As shown in FIG. 5, when the first power supply relay 122 is composed of elements having a parasitic diode like a MOSFET, the two elements 123 and 124 are connected in series so that the directions of the parasitic diodes are opposite to each other. Is desirable. Since the second power supply relay 222 is the same, the illustration is omitted. This makes it possible to prevent the reverse current from flowing when the batteries 101 and 201 are erroneously connected in the opposite directions. The power relays 122 and 222 may be mechanical relays.

As shown in FIG. 4, the on / off operation of the first switching element 121, the first power supply relay 122, and the first motor relay 125 is controlled by the first control unit 150. The on / off operation of the second switching element 221 and the second power supply relay 222 and the second motor relay 225 is controlled by the second control unit 250.

The first angle sensor 126 detects the rotation angle of the motor 80 and outputs the detected value to the first control unit 150. The second angle sensor 226 detects the rotation angle of the motor 80 and outputs the detected value to the second control unit 250. Here, the first angle sensor 126 and the first control unit 150, and the second angle sensor 226 and the second control unit 250 are configured to detect failures in their respective angle sensor input circuit systems.

The first current sensor 127 detects the current applied to each phase of the first motor winding 180. The detected value of the first current sensor 127 is amplified by the amplifier circuit in the custom IC 135 and output to the first control unit 150. The second current sensor 227 detects the current applied to each phase of the second motor winding 280. The detected value of the second current sensor 227 is amplified by the amplifier circuit in the custom IC 235 and output to the second control unit 250.

The first driver circuit 136 outputs a drive signal for driving the first switching element 121, the first power supply relay 122, and the first motor relay 125 to each element based on the control signal from the first control unit 150. The second driver circuit 236 outputs a drive signal for driving the second switching element 221 and the second power supply relay 222 and the second motor relay 225 to each element based on the control signal from the second control unit 250.

The circuit power supply 137 is connected to the power supply terminal 105 and the IG terminal 107 to supply electric power to the first control unit 150. The circuit power supply 237 is connected to the power supply terminal 205 and the IG terminal 207, and supplies power to the second control unit 250.

The control units 150 and 250 are mainly composed of a microcomputer and the like, and internally include a CPU, ROM, RAM, I / O, and a bus line connecting these configurations, which are not shown. Each process in the control units 150 and 250 may be software processing by executing a program stored in advance in a physical memory device such as a ROM (that is, a readable non-temporary tangible recording medium) on the CPU. However, it may be hardware processing by a dedicated electronic circuit. Here, the first control unit 150 and the second control unit 250 are configured to detect their own failures by using, for example, a locked step dual microcomputer or the like.

The first control unit 150 includes an individual current limit value calculation unit 531, a current limit unit 535 (see FIG. 6), a drive control unit 151, a mode selection unit 152, and an abnormality monitoring unit 155. The drive control unit 151 controls the energization of the first motor winding 180 by controlling the on / off operation of the first switching element 121. Further, the drive control unit 151 controls the on / off operation of the first power supply relay 122 and the first motor relay 125. The mode selection unit 152 selects the drive mode according to various conditions. Details of mode selection will be described later.

The second control unit 250 includes an individual current limit value calculation unit 631, a current limit unit 635 (see FIG. 6), a drive control unit 251, a mode selection unit 252, and an abnormality monitoring unit 255. The drive control unit 251 controls the energization of the second motor winding 280 by controlling the on / off operation of the second switching element 221. Further, the drive control unit 251 controls the on / off operation of the second power supply relay 222 and the second motor relay 225. The mode selection unit 252 selects the drive mode according to various conditions.

The abnormality monitoring unit 155 monitors the abnormality of the first system L1 which is its own system. Further, when an abnormality that should stop the own system occurs in the own system, the first control unit 150 turns off at least one of the first inverter unit 120, the first power supply relay 122, and the first motor relay 125. ..

Further, the abnormality monitoring unit 155 monitors the communication state with the second control unit 250 and the operating state of the second system L2. A circuit that stops its own system when an abnormality in the second system L2 is detected as a method for monitoring the operating state of the second system L2 (for example, the second inverter unit 220, the second power supply relay 222, and the second motor relay 225). Alternatively, the state of at least one of the communication lines related to the communication between the microcomputers is monitored, and it is determined whether or not the emergency stop is performed. In the present embodiment, another system relay monitoring circuit 139 that acquires the second relay gate signal Vrg2 output from the second driver circuit 236 to the second power supply relay 222 is provided, and the second relay gate signal Vrg2 is used as the basis for the second relay monitoring circuit 139. Monitor the status of the power relay 222.

The abnormality monitoring unit 255 monitors the abnormality of the second system L2, which is its own system. Further, when an abnormality that should stop the own system occurs in the own system, the second control unit 250 turns off at least one of the second inverter unit 220, the second power relay 222, and the second motor relay 225. ..

The abnormality monitoring unit 255 monitors the communication status with the first control unit 150 and the operating status of the first system L1. A circuit that stops its own system when an abnormality in the first system L1 is detected as a method for monitoring the operating state of the first system L1 (for example, the first inverter unit 120, the first power supply relay 122, and the first motor relay 125). Alternatively, the state of at least one of the communication lines related to the communication between the microcomputers is monitored, and it is determined whether or not the emergency stop is performed. In the present embodiment, another system relay monitoring circuit 239 that acquires the first relay gate signal Vrg1 output from the first driver circuit 136 to the first power supply relay 122 is provided, and the first is based on the first relay gate signal Vrg1. Monitor the status of the power relay 122.

Hereinafter, the information acquired from the other system relay monitoring circuit is "other system relay information", the monitoring of the operating status of the other system based on the other system relay information is "other system relay monitoring", and the monitored relay is "other system relay monitoring". It is called "other system relay". Further, when the information indicating that the other system relay is off is acquired at the timing when the other system relay should be turned on, it is considered that "the other system relay information is abnormal".

In the monitoring of the first system L1 by the second control unit 250, instead of the relay gate signal, the intermediate voltage of the two elements 123 and 124 constituting the power supply relay 122, the relay drive signal output from the control unit 150, or The post-relay voltage between the power relay 122 and the inverter 120 may be used. The same applies to the monitoring of the second system L2 in the first control unit 150.

As shown in FIGS. 6 and 7, the first control unit 150 has a communication unit 170, and the second control unit 250 has a communication unit 270. The control units 150 and 250 can transmit and receive information to and from each other by communication between microcomputers by the communication units 170 and 270. In the present embodiment, the current command value, the current detection value, and the current limit value are shared between the systems by communication between microcomputers. Hereinafter, in each process in the second control unit 250, the value related to the second system L2 is used instead of the value related to the first system L1, and the value related to the first system L1 is used instead of the value related to the second system L2. If it is used, it is the same as that of the first control unit 150. Therefore, the processing in the first control unit 150 will be mainly described below, and the description of the second control unit 250 will be omitted as appropriate.

The drive mode of the present embodiment includes a cooperative drive mode, an independent drive mode, and a single system drive mode, and normally controls the drive of the motor 80 by the cooperative drive mode. In the cooperative drive mode, when both the control units 150 and 250 are normal and the communication between the microcomputers is normal, at least one value is shared between the systems, and each system is coordinated to drive the motor 80. Control. In the independent drive mode, each system independently controls the drive of the motor 80 by two systems without using the values of other systems. In the one-system drive mode, one system is stopped and one system controls the drive of the motor 80.

As shown in FIG. 6, the individual current limit value calculation unit 531 calculates the first individual current limit value Illim_k1. The individual current limit value calculation unit 531 calculates, for example, the overheat protection current limit value, the power supply voltage reference current limit value, the steering speed reference current limit value, and the current difference reduction current limit value, and among the calculated values, among the calculated values. The smallest value is defined as the first individual current limit value Ilim_k1. The overheat protection current limit value is calculated based on the phase currents Iu1, Iv1, Iw1, the base temperature H1, and the like. The base temperature H1 is, for example, the heat sink temperature of the region where the first inverter unit 120 is provided. The power supply voltage reference current limit value is calculated based on the battery voltage Vb1, which is the voltage of the first battery 101. The steering speed reference current limit value is calculated according to the steering angular velocity ω. The current difference reduction current limit value is calculated based on the winding current I1 of the first system L1 and the winding current I2 of the second system L2.

The individual current limit value calculation unit 631 calculates the second individual current limit value Ilim_k2. The individual current limit value calculation unit 631 calculates, for example, the overheat protection current limit value, the power supply voltage reference current limit value, the steering speed reference current limit value, and the current difference reduction current limit value, and among the calculated values, among the calculated values. The smallest value is the second individual current limit value Ilim_k2. The overheat protection current limit value is calculated based on the phase currents Iu2, Iv2, Iw2, the base temperature H2, and the like. The base temperature H2 is, for example, the heat sink temperature in the region where the second inverter unit 220 is provided. The power supply voltage reference current limit value is calculated based on the battery voltage Vb2, which is the voltage of the second battery 201. The steering speed reference current limit value is calculated according to the steering angular velocity ω. The current difference reduction current limit value is calculated based on the winding current I1 of the first system L1 and the winding current I2 of the second system L2.

When the current limit values are shared in the cooperative drive mode, the control units 150 and 250 send the individual current limit values Illim_k1 and Ilim_k2 to each other, and the current limit units 535 and 635 have the individual current limit values Illim_k1 and Ilim_k2. , The current limit values Illim1 and Ilim2 are calculated by the minimum select that selects the smaller value. When the current limit value is not shared, the current limit unit 535 sets the individual current limit value Ilim_k1 as it is as the current limit value Ilim1, and the current limit unit 635 sets the individual current limit value Ilim_k2 as it is as the current limit value Ilim2. ^{When the basic current command value Ib1 *} calculated based on the torque command value is larger than the current limit value Illim1 ^{, the current limit unit 535 limits the current command value I1 *} to the current limit value Ilim1 and limits ^{the current command value I1 * to the current limit value Ilim1.} When is equal to or less than the current limit value Illim1, the basic current command value Ib1 ^* is used as it is as the current command value I1 ^* .

Further, in the present embodiment, when the first control unit 150 is the master control unit and the second control unit 250 is the slave control unit and the current command value is shared in the cooperative drive mode, the first control unit 150 is the basic current command value. Ib1 ^* is transmitted to the second control unit 250. The second control unit 250 has a switching unit 636, and can switch ^{between using the basic current command value Ib1 *} acquired from the first control unit 150 and using the basic current command value Ib2 ^{* calculated by its own system.} is there. When the current command value is shared, the basic current command value Ib1 ^* is used, and when the current command value is not shared, the basic current command value Ib2 ^* is used. Here, it is assumed that the basic current command value Ib1 ^* is used. The current limiting unit 635 limits the current command value I2 ^{* to the current limit value Ilim2 when the basic current command value Ib1 *} is larger than the current limit value Illim2, and when the basic current command ^{value Ib2 *} is less than or equal to the current limit value Ilim2. The basic current command value Ib1 ^{* is used as it} is as the current command value I2 ^* . The current command values I1 ^* and I2 ^* are values related to the sum of the currents of the motor windings 180 and 280, and FIGS. 6 and 7 show values related to the q-axis.

The control signal calculation unit 540 ^{generates a control signal by current feedback control based on the current command value I1 *} , and outputs the control signal to the inverter unit 120. In the following, feedback will be referred to as "FB" as appropriate. The control signal calculation unit 540 can switch between FB control of sum and difference (see FIG. 6) and independent FB control (see FIG. 7). Hereinafter, the calculation related to the q-axis will be mainly described, and the description related to the calculation related to the d-axis will be omitted. The control related to the d-axis may be the same as that of the q-axis, or may be different from the q-axis such as field weakening control. In FIG. 6, for convenience, the communication units 170 and 270 are described separately. In FIG. 7, the description of the configuration in which the calculation is not performed is omitted. Note that FIGS. 6 and 7 are examples of current control in the cooperative drive mode and the independent drive mode, and the details of the realization method may be different.

As shown in FIG. 6, the drive control unit 151 includes a dq-axis current calculation unit 541, an adder 542, a subtractor 543, a switching unit 545, a current FB calculation unit 550, a system voltage command value calculation unit 557, and a PWM signal. It has a generator 558 and the like. Further, the drive control unit 251 includes a dq-axis current calculation unit 641, an adder 642, a subtractor 643, a switching unit 645, a current FB calculation unit 650, a system voltage command value calculation unit 657, a PWM signal generation unit 658, and the like. Have.

The dq-axis current calculation unit 541 calculates the first d-axis current detection value Id1 and the first q-axis current detection value Iq1 by dq conversion based on the detection value of the current sensor 127 and the electric angle. Hereinafter, the d-axis current and the q-axis current will be appropriately collectively referred to as “dq-axis current”. The same applies to the voltage. The first dq-axis current detection values Id1 and Iq1 are transmitted to the second control unit 250 by inter-microcomputer communication. Further, the second dq-axis current detection values Id2 and Iq2 calculated by the second control unit 250 are transmitted to the first control unit 150 by inter-microcomputer communication. The switching unit 545 is controlled so that the acquired second q-axis current detection value Iq2 is input to the adder 542 and the subtractor 543.

The adder 542 adds the first q-axis current detection value Iq1 and the second q-axis current detection value Iq2. The subtractor 543 subtracts the second q-axis current detection value Iq2 from the first q-axis current detection value Iq1.

The current FB calculation unit 550 includes subtractors 551 and 552, controllers 555 and 554, a switching unit 555, and an adder 556. The current FB calculation unit 650 includes subtractors 651 and 652, controllers 653 and 654, a switching unit 655, and an adder 656.

The subtractor 551 subtracts the q-axis current sum Iq1 + Iq2 from the ^{current command value I1 * to calculate the current sum deviation ΔIq_a1.} The subtractor 552 subtracts the q-axis current difference Iq1-Iq2 from the q-axis current difference command value Iq_d2 ^{*, and calculates the current difference deviation ΔIq_d1.} In the present embodiment, the q-axis current difference command value Iq_d1 ^{* is set} to 0, but a difference may be provided as a value other than 0.

The controller 553 calculates the basic voltage command value by PI calculation or the like so that the current sum deviation ΔIq_a1 becomes 0, and the controller 554 makes a difference by PI calculation or the like so that the current difference deviation ΔIq_d1 becomes 0. Calculate the voltage command value. In the sum and difference FB control, the switching unit 555 is controlled so that the difference voltage command value is input to the adder 556. The adder 556 adds the basic voltage command value and the differential voltage command value, and calculates the two-system voltage command value.

The system voltage command value calculation unit 557 multiplies the system voltage command value by 0.5 to calculate ^{the first system voltage command value Vq1 *.} The PWM signal generation unit 558 calculates the three-phase voltage command value by inverse dq conversion based on the dq-axis voltage command values Vd1 ^* , Vq2 ^{*, and the electric angle.} The PWM signal generation unit 558 generates a PWM signal by PWM calculation based on the three-phase voltage command value. The on / off operation of the switching element 121 of the inverter unit 120 is controlled based on the generated PWM signal.

As shown in FIG. 7, in the independent FB control, the current FB is controlled for each system without controlling the sum and the difference. Specifically, the switching unit 545 is controlled so that the first q-axis current detection value Iq1 is input to the adder 542 instead of the second q-axis current detection value Iq2. Further, a value twice the first q-axis current detection value Iq1 is input to the subtractor 551 on the subtraction side. In addition, the calculation related to the control of the difference is also stopped. In addition to the same control as the first control unit 150, the second control unit 250 controls the switching unit 636 so that the ^{basic current command value Ib2 * is input to the current limiting unit 635.}

In the present embodiment, the drive of the motor 80 is controlled by the cooperative drive in the normal state, and the cooperative drive is switched to the independent drive when an abnormality occurs. When the abnormality is resolved, the independent drive is restored to the cooperative drive. The term "abnormality" as used herein includes temporary recoverable ones such as a deviation of command values between systems and a decrease in current limit value. When an abnormality occurs, it quickly transitions from cooperative drive to independent drive. On the other hand, when switching from independent drive to cooperative drive when the abnormality is resolved, torque fluctuation may occur depending on the switching timing. Therefore, in the present embodiment, the transition condition for transitioning from the cooperative drive to the independent drive and the return condition for returning from the independent drive to the cooperative drive are different.

The independent transition process for transitioning from cooperative drive to independent drive will be described with reference to the flowchart of FIG. This process is executed by the control units 150 and 250 at a predetermined cycle when the drive mode is the cooperative drive mode. Hereinafter, the “step” in step S101 is omitted and simply referred to as the symbol “S”. The same applies to the other steps. The processing order of S101 to S104 may be changed as appropriate. The same applies to FIGS. 9 and 11.

In S101, the control units 150 and ^{250 determine whether or not the command deviation ΔI *,} which is the absolute value of the difference between the ^{current command values I1 *} and I2 ^* , is equal to or less than the command deviation transition determination value I_th_a. When it is determined that the command deviation ΔI ^* is larger than the command deviation transition determination value I_th_a (S101: NO), the process shifts to S106 and the mode shifts to the independent drive mode. When it is determined that the command deviation ΔI ^* is equal to or less than the command deviation transition determination value I_th_a (S101: YES), the process proceeds to S102.

In S102, the control units 150 and 250 determine whether or not the individual current limit values Illim_k1 and Ilim_k2 are both equal to or higher than the current limit transition determination value Ilim_th_a. When it is determined that at least one of the individual current limit values Illim_k1 and Illim_k2 is smaller than the current limit transition determination value Illim_th_a (S102: NO), the process shifts to S106 and the mode shifts to the independent drive mode. When it is determined that both the individual current limit values Illim_k1 and Illim_k2 are equal to or greater than the current limit transition determination value Ilim_th_a (S102: YES), the process proceeds to S103.

In S103, the control units 150 and 250 determine whether or not the communication between the microcomputers is normal. When it is determined that the communication between the microcomputers is not normal (S103: NO), the process shifts to S106 and the mode shifts to the independent drive mode. When it is determined that the communication between the microcomputers is normal (S103: YES), the process proceeds to S104.

In S104, the control units 150 and 250 determine whether or not the IG key-off state has been reached during traveling. Here, the IG key-off state is not limited to the case where the IG key is turned off, and includes a stop or decrease in power supply from the IG due to a disconnection of wiring or the like. Since power is supplied to the circuit power supplies 137 and 237 from the batteries 101 and 201 via the power supply terminals 105 and 205, the control units 150 and 250 can continue the calculation even if the IG is turned off. .. When it is determined that the IG key-off state is reached during traveling (S104: YES), the process proceeds to S106 and the independent drive is performed. In addition, the control when the IG key-off state is entered during running is "running IG key-off control". In addition, the key-off time Xoff, which is the time after the IG key is turned off during running, is timed. If it is determined that the IG key-off state is not in the running state (S104: NO), the process proceeds to S105 and the cooperative drive is continued.

The cooperative return process for returning from the independent drive to the cooperative drive will be described with reference to the flowchart of FIG. This process is executed by the control units 150 and 250 at a predetermined cycle when the drive mode is the independent drive mode.

In S201, the control units 150 and ^{250 determine whether or not the command deviation ΔI *} is equal to or less than the command deviation return determination value I_th_b. The command deviation return determination value I_th_b is set to be equal to or less than the command deviation transition determination value I_th_a. When it is determined that the command deviation ΔI ^* is larger than the command deviation return determination value I_th_b (S201: NO), the process proceeds to S209 and the independent drive is continued. When it is determined that the command deviation ΔI ^* is equal to or less than the command deviation return determination value I_th_b (S201: YES), the process proceeds to S202.

In S202, the control units 150 and 250 determine whether or not the individual current limit values Illim_k1 and Ilim_k2 are both equal to or higher than the current limit return determination value Ilim_th_b. The current limit return determination value Ilim_th_b is set to be equal to or greater than the current limit transition determination value Ilim_th_a. When it is determined that at least one of the individual current limit values Illim_k1 and Illim_k2 is smaller than the current limit return determination value Illim_th_b (S202: NO), the process shifts to S209 and the independent drive is continued. When it is determined that both the individual current limit values Illim_k1 and Illim_k2 are equal to or higher than the current limit return determination value Ilim_th_b (S202: YES), the process proceeds to S203.

In S203, the control units 150 and 250 determine whether or not the communication between the microcomputers is normal. When it is determined that the communication between the microcomputers is not normal (S203: NO), the process proceeds to S209 and the independent drive is continued. When it is determined that the communication between the microcomputers is normal (S203: YES), the process proceeds to S204.

In S204, the control units 150 and 250 determine whether or not the IG key-off control is being performed during traveling. If it is determined that the IG key-off control is not being performed during traveling (S204: NO), the process proceeds to S207. If it is determined that the IG key-off control is being performed during traveling (S204: YES), the process proceeds to S205. In the present embodiment, when the IG off state is reached during traveling, the processes of S205 and S206 are performed as the IG key off control, but when the temporary IG key off state is resolved, the IG key off control is exited and other recovery conditions are met. If the above conditions are satisfied, it is possible to return from independent drive to cooperative drive.

In S205, the control units 150 and 250 determine whether or not the key-off time Xoff is larger than the estimated stop time Xstp. When it is determined that the key-off time Xoff is larger than the estimated stop time Xstp (S205: YES), the process proceeds to S206, and the current command values I1 ^* and I2 ^* are gradually reduced and stopped. After the gradual decrease stop, the drive control of the motor 80 is not performed until the IG is turned on again. When it is determined that the key-off time Xoff is equal to or less than the estimated stop time Xstp (S205: NO), the process proceeds to S209 and the independent drive is continued.

In S207, the control units 150 and 250 determine whether or not the steering torque Ts is equal to or less than the non-steering determination threshold value Ts_th. The non-steering determination threshold value Ts_th is set to a value such that torque fluctuation does not occur even if the drive mode is returned from independent drive to cooperative drive. When it is determined that the steering torque Ts is larger than the non-steering determination threshold value Ts_th (S207: NO), the process shifts to S209 and the independent drive is continued. When it is determined that the steering torque Ts is equal to or less than the non-steering determination threshold value Ts_th (S207: YES), the process proceeds to S208.

In S208, it is determined whether or not the vehicle speed V is equal to or less than the vehicle speed determination threshold value V_th. The vehicle speed determination threshold value V_th is set to a value such that the drive mode can be safely returned from the independent drive to the cooperative drive. When it is determined that the vehicle speed V is larger than the vehicle speed determination threshold value V_th (S208: NO), the process proceeds to S209 and the independent drive is continued. When it is determined that the vehicle speed V is equal to or less than the vehicle speed determination threshold value V_th (S208: YES), the process shifts to S210 and returns to the cooperative drive.

FIG. 10 shows a time chart illustrating the return from independent drive to cooperative drive. In FIG. 10, the common time axis is the horizontal axis, and from the top, the command deviation ΔI ^* , the individual current limit values Ilim_k1, Ilim_k2, the communication between microcomputers, the IG key-off control during running, the steering torque Ts, the vehicle speed V, and the drive mode are displayed. Shown. The individual current limit values Illim_k1 and Ilim_k2 may have different values, but here, for the sake of simplicity, they are described as having the same value. Further, it is assumed that the communication between the microcomputers is normal and the IG key-off control is not performed during traveling.

Before the time x1, the command deviation ΔI ^* is larger than the command deviation transition determination value I_th_a, and the individual current limit values Ilim_k1 and Ilim_k2 are smaller than the current limit transition determination value Ilim_th_a, and the motor 80 is driven by independent drive. In the present embodiment, when the command deviation ΔI ^* is larger than the command deviation transition judgment value I_th_a, or at least one of the individual current limit values Ilim_k1 and Ilim_k2 is smaller than the current limit transition judgment value Ilim_th_a, the steering torque Ts and the vehicle speed V are used. Instead, it shifts from cooperative drive to independent drive.

At time x1, the individual current limit values Illim_k1 and Ilim_k2 become equal to or greater than the current limit return determination value Ilim_th_b, and at time x2, the command deviation ΔI ^* becomes equal to or less than the command deviation return determination value I_th_b, but the steering torque at time x2. Since Ts is larger than the non-steering determination threshold Ts_th and the vehicle speed V is larger than the vehicle speed determination threshold V_th, the cooperative drive is not restored at this stage, and the independent drive is continued.

At time x3, the steering torque Ts becomes equal to or less than the non-steering determination threshold value Ts_th, and at time x4, the vehicle speed V becomes equal to or less than the vehicle speed determination threshold value V_th. ..

As described above, the ECU 10 of the present embodiment controls the drive of the motor 80 having the motor windings 180 and 280, and includes a plurality of inverter units 120 and 220 and a plurality of control units 150 and 250. , Equipped with. The inverter units 120 and 220 switch the energization of the motor winding.

The control units 150 and 250 are capable of communicating with each other and include mode selection units 152 and 252 and drive control units 151 and 251. The mode selection units 152 and 252 select a drive mode including a cooperative drive mode and an independent drive mode. The drive control units 151 and 251 control the corresponding inverter units 120 and 220 in the selected drive mode.

In the cooperative drive mode, the values acquired from other control units and the values calculated by the own control unit are shared and used. The independent drive mode does not use the value acquired from other control units. It should be noted that the case where the value cannot be acquired from another control unit due to an abnormality in communication between microcomputers is also included in the concept of "do not use the value acquired from another control unit".

The mode selection units 152 and 252 shift the drive mode from the cooperative drive mode to the independent drive mode when at least one transition determination item satisfies the independent transition condition. Further, when the transition determination item satisfies the return permission condition and the return permission determination item different from the transition determination item satisfies the return permission condition, the mode selection units 152 and 252 cooperatively drive the drive mode from the independent drive mode. Return to mode.

In the present embodiment, the transition determination items include a command deviation ΔI ^* , individual current limit values Illim_k1, Ilim_k2, inter-microcomputer communication, and an IG key-off state during traveling. The return permission determination items include steering torque Ts and vehicle speed V. The return permission determination item can also be regarded as a determination item related to vehicle behavior.

In the present embodiment, the motor 80 is normally controlled in the cooperative drive mode, and when the transition determination item satisfies the independent transition condition due to the occurrence of an abnormality or the like, the mode shifts to the independent drive mode. Further, when the transition determination item satisfies the cooperative return condition and the return permission determination item satisfies the return permission condition, the mode is returned to the cooperative drive mode. In other words, even if the transition determination item satisfies the cooperative return condition, if the return permission determination item does not satisfy the return permission condition, the cooperative drive mode is not restored and the independent drive mode is continued. In addition, the return permission judgment item is not considered when transitioning from the cooperative drive mode to the independent drive mode, and is independent if the transition judgment item satisfies the independent transition condition regardless of the return permission judgment item. Transition to drive mode. As a result, it is possible to appropriately return from the independent drive mode to the cooperative drive mode.

^{The transition determination items include the command deviation ΔI *,} which is the deviation of ^{the current command values I1 *} and I2 ^* calculated by the control units 150 and 250, respectively. In the cooperative drive mode, the mode selection units 152 and 252 shift from the cooperative drive mode to the independent drive mode when the ^{command deviation ΔI * becomes larger than the command deviation transition determination value I_th_a.} Further, the mode selection units 152 and 252 satisfy the cooperative return conditions related to ^{the current command values I1 *} and I2 ^{* when the command deviation ΔI *} becomes equal to or less than the command deviation return determination value I_th_b in the independent drive mode. Is determined. As a result, when the current command values I1 ^* and I2 ^* deviate from each other, the mode shifts to the independent drive mode, so that control inconsistency due to the command dissociation can be prevented.

The transition determination items include individual current limit values Illim_k1 and Ilim_k2, which are values related to the limits of the ^{current command values I1 *} and I2 ^{* and are calculated by the respective control units 150 and 250, respectively.} In the cooperative drive mode, the mode selection units 152 and 252 shift from the cooperative drive mode to the independent drive mode when at least one individual current limit value Ilim_k1 or Ilim_k2 becomes smaller than the current limit transition determination value Ilim_th_a. Further, the mode selection units 152 and 252 satisfy the cooperative return condition related to the current limit when all the individual current limit values Illim_k1 and Ilim_k2 are equal to or higher than the current limit return determination value Ilim_th_b in the independent drive mode. judge. That is, in the present embodiment, when the current limit value is lowered, the drive is shifted to independent drive. As a result, it is possible to suppress a torque shortage due to the continuous cooperative drive in a state where the current limit value is lowered.

The ECU 10 is applied to the electric power steering device 8. The transition determination item includes an IG key-off state, which is an on / off state of the vehicle start switch. When the start switch is turned off during traveling, the mode selection units 152 and 252 shift from the cooperative drive mode to the independent drive mode. As a result, even if the IG key-off occurs during traveling, the motor 80 can be appropriately continued to be driven.

The return permission determination item includes the steering state of the steering wheel 91. When the steering wheel 91 is in the non-steering state, the mode selection units 152 and 252 determine that the return permission condition related to the steering state is satisfied. In other words, when the steering wheel 91 is in the steering state, the return from the independent drive mode to the cooperative drive mode is not permitted. In the present embodiment, when the steering torque Ts is equal to or less than the non-steering determination threshold value Ts_th, it is considered to be in the non-steering state. This makes it possible to suppress torque fluctuations caused by switching drive modes during steering. It is possible to reduce the driver's discomfort.

The return permission determination item includes the vehicle speed V. When the vehicle speed V is equal to or less than the vehicle speed determination threshold value V_th, the mode selection units 152 and 252 determine that the return permission condition related to the vehicle speed V is satisfied. In other words, when the vehicle speed is larger than the vehicle speed determination threshold value V_th, the return from the independent drive mode to the cooperative drive mode is not permitted. As a result, it is possible to reduce the driver's discomfort due to the switching of the drive mode.

(Second Embodiment)
The second embodiment is shown in FIG. In the present embodiment, the independent transition process is different from the above-described embodiment, and this point will be mainly described. In the present embodiment, it is possible to switch between a steering assist mode in which the motor 80 is controlled according to the steering torque Ts and an automatic operation mode in which the steering angle θs is automatically controlled regardless of the steering torque Ts. Hereinafter, the steering assist mode will be referred to as “EPS mode” and the automatic operation mode will be referred to as “ADS mode”.

The independent transition process of this embodiment will be described with reference to the flowchart of FIG. The processing of S301 and S302 is the same as the processing of S101 and S102 in FIG. 8, and if a negative determination is made in S301 or S302, the process proceeds to S303. In S303, the control units 150 and 250 determine whether or not ADS is in progress. When it is determined that the ADS is not in progress (S303: NO), the process proceeds to S307 and the process proceeds to independent drive. If it is determined that ADS is in progress (S303: YES), the process proceeds to S304. The processing of S304 to S307 is the same as the processing of S103 to S106 in FIG.

That is, in the present embodiment, when the command deviation ΔI ^* is smaller than the command deviation transition determination value I_th_a, in the EPS mode, the independent drive is performed. On the other hand, in the ADS mode, even if the command deviation ΔI ^* is smaller than the command deviation transition determination value I_th_a, if the communication between the microcomputers is normal, the independent drive is not performed. Further, when at least one of the individual current limit values Illim_k1 and Illim_k2 is smaller than the current limit transition determination value Illim_th_a, the EPS mode transitions to independent drive. On the other hand, in the ADS mode, even if at least one of the individual current limit values Illim_k1 and Ilim_k2 is smaller than the current limit transition determination value Ilim_th_a, if the communication between the microcomputers is normal, the independent drive is not performed. In other words, in the ADS mode, the command deviation ΔI ^* and the individual current limit values Illim_k1 and Ilim_k2 are excluded from the transition determination items from the cooperative drive to the independent drive. The cooperative return process is the same as that of the above embodiment, and the command deviation ΔI ^* and the individual current limit values Illim_k1 and Ilim_k2 are used for the cooperative return determination regardless of whether the operation mode is the ADS mode or the EPS mode.

In the present embodiment, the control units 150 and 250 can switch between the ADS mode, which is an automatic operation control that automatically controls the steering angle θs, and the EPS mode, which is a steering assist control that performs assist control according to the steering torque Ts. Is. The mode selection units 152 and 252 shift the drive mode to the independent drive mode when the command determination item satisfies the independent transition condition in the cooperative drive mode in the steering assist control. On the other hand, the mode selection units 152 and 252 exclude the command determination item from the transition determination target to the independent drive mode in the cooperative drive mode in the automatic operation control. Further, in the independent drive mode, the independent drive mode is continued when the command determination item does not satisfy the cooperative return condition regardless of whether it is steering assist control or automatic driving control.

The transition determination item includes a command determination item related to the current command value. The command determination items of the present embodiment are the command deviation ΔI ^* and the individual current limit values Illim_k1 and Ilim_k2. As a supplement, since the individual current limit values Illim_k1 and Ilim_k2 are values related to the limits of the current command values I1 ^* and I2 ^* , they are included in the concept of "command determination items related to the current command value".

In the present embodiment, in the cooperative drive mode during automatic driving control, the command determination item is excluded from the transition determination target to the independent drive mode. In other words, in the cooperative drive mode during automatic operation control, even if the command deviation ΔI ^* and the individual current limit values Ilim_k1 and Ilim_k2 satisfy the independent transition conditions, the cooperative drive is performed without shifting to the independent drive. continue. Further, once the mode is shifted to the independent drive mode, even during automatic operation control, if the command deviation ΔI ^* and the individual current limit values Illim_k1 and Ilim_k2 do not satisfy the cooperative return condition, the cooperative drive is restored. Instead, the independent drive mode is continued. Thereby, the drive mode can be appropriately switched according to the automatic driving control or the steering assist control. Moreover, the same effect as that of the above-described embodiment is obtained.

(Other embodiments)
In the above embodiment, the steering state is determined based on the steering torque. In another embodiment, the steering state may be determined based on the steering wheel speed, the motor speed, or the rack speed, not limited to the steering torque.

Further, in another embodiment, the steering state may be determined based on the current command value and the current detection value. When the value of the current command value is large, it is highly probable that the vehicle is being steered. Therefore, when the current command value is larger than the determination threshold value, or when the current command value is smaller than the determination threshold value, it is determined that the vehicle is in a non-steering state. The same applies to the current detection value. Further, the steering state may be determined using two or more of the steering torque, the steering wheel speed, the motor speed, the rack speed, the current command value and the current detection value.

In the above embodiment, the transition determination items include the command deviation, the individual current limit value, the communication between microcomputers, and the on / off state of the start switch, and the return permission determination items include the steering state and the vehicle speed. .. In other embodiments, some of the above four items exemplified as transition determination items may be omitted, or other items may be added to the transition determination items. Further, a part of the return permission determination items may be omitted, or other items such as the lateral G of the vehicle and the yaw rate may be added to the return permission determination items as items related to the behavior state of the vehicle.

In the above embodiment, the current command value, the current detection value, and the current limit value are shared between the systems in the cooperative drive mode. In other embodiments, the current limit value may not be shared in the coordinated drive mode. In the above embodiment, the first control unit 150 is used as the master control unit, the second control unit 250 is used as the slave control unit, and the current command value I1 ^* is used by the control units 150 and 250 in the cooperative drive mode. In other embodiments, the current command value is not shared, and the current command value of the own system may be used even in the cooperative drive mode. Further, values other than the current command value, the current detection value, and the current limit value may be shared.

In the above embodiment, two motor windings, two inverter units and two control units are provided. In other embodiments, the number of motor windings may be one or more. Further, the number of inverter units and control units may be three or more. Further, for example, one control unit is provided for a plurality of motor windings and an inverter unit, or a plurality of inverter units and a motor winding are provided for one control unit. The number of units and the number of control units may be different. In the above embodiment, a power supply is provided for each system and the ground is separated. In other embodiments, one power source may be shared by a plurality of systems. Moreover, a plurality of systems may be connected to a common ground.

In the above embodiment, the rotary electric machine is a three-phase brushless motor. In other embodiments, the rotary electric machine is not limited to a brushless motor. Further, it may be a so-called motor generator that also has a function of a generator. In the above embodiment, the rotary electric machine control device is applied to the electric power steering device. In another embodiment, the rotary electric machine control device may be applied to a steering device other than the electric power steering device that controls steering, such as a steer-by-wire device. Further, it may be applied to an in-vehicle device other than the steering device or a device other than the in-vehicle device.

The controls and methods thereof described in the present disclosure are realized by a dedicated computer provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. May be done. Alternatively, the controls and methods thereof described in the present disclosure may be implemented by a dedicated computer provided by configuring the processor with one or more dedicated hardware logic circuits. Alternatively, the control unit and method thereof described in the present disclosure may be a combination of a processor and memory programmed to perform one or more functions and a processor composed of one or more hardware logic circuits. It may be realized by one or more dedicated computers configured. Further, the computer program may be stored in a computer-readable non-transitional tangible recording medium as an instruction executed by the computer. As described above, the present invention is not limited to the above-described embodiment, and can be implemented in various embodiments without departing from the spirit of the invention.

8 ... Electric power steering device (steering device)
10 ... ECU (rotary electric machine control device)
80 ... Motor (rotary machine)
91 ... Steering wheel (steering member)
120, 220 ... Inverter unit 150, 250 ... Control unit 151, 251 ... Drive control unit 152, 252 ... Mode selection unit 180, 280 ... Motor winding

Claims (7)

A rotary electric machine control device that controls the drive of a rotary electric machine (80) having a motor winding (180, 280).
A plurality of inverter units (120, 220) for switching the energization of the motor winding, and
A mode selection unit (152, 252) that selects a drive mode including a cooperative drive mode and an independent drive mode, and a drive control unit (151, 151,) that controls the inverter unit provided corresponding to the selected drive mode. With a plurality of control units (150, 250) having 251) and capable of communicating with each other,
With
The cooperative drive mode uses a value acquired from the other control unit and a value calculated by the control unit itself.
The independent drive mode does not use the value acquired from the other control unit, and does not use the value acquired from the other control unit.
The mode selection unit
When at least one transition determination item satisfies the independent transition condition, the drive mode is changed from the cooperative drive mode to the independent drive mode.
When the transition determination item satisfies the cooperative return condition and the return permission determination item different from the transition determination item satisfies the return permission condition, the rotation for returning the drive mode from the independent drive mode to the cooperative drive mode. Electric control device. The transition determination item includes a command deviation, which is a deviation of the current command value calculated by each of the control units.
The mode selection unit
When the command deviation becomes larger than the command deviation transition determination value in the cooperative drive mode, the mode is changed from the cooperative drive mode to the independent drive mode.
The rotary electric machine control device according to claim 1, wherein when the command deviation becomes equal to or less than the command deviation return determination value in the independent drive mode, it is determined that the cooperative return condition related to the current command value is satisfied. The transition determination item is a value related to the limitation of the current command value, and includes an individual current limit value calculated by each of the control units.
The mode selection unit
In the cooperative drive mode, when at least one individual current limit value becomes smaller than the current limit transition determination value, the cooperative drive mode is changed to the independent drive mode.
The rotary electric machine control according to claim 2, wherein when all the individual current limit values are equal to or higher than the current limit return determination value in the independent drive mode, it is determined that the cooperative return condition related to the current limit is satisfied. apparatus. Applied to the steering device (8),
The control unit can switch between automatic operation control that automatically controls the steering angle and steering assist control that performs assist control according to the steering torque.
The transition determination item includes a command determination item related to the current command value.
The mode selection unit
In the cooperative drive mode in the steering assist control, when the command determination item satisfies the independent transition condition, the drive mode is changed to the independent drive mode.
In the cooperative drive mode in the automatic driving control, the command determination item is excluded from the transition determination target to the independent drive mode.
The rotary electric machine control according to claim 1, wherein in the independent drive mode, the independent drive mode is continued when the command determination item does not satisfy the cooperative return condition regardless of whether the steering assist control or the automatic operation control is performed. apparatus. Applied to the steering device (8),
The transition determination item includes an on / off state of the vehicle start switch.
The rotary electric machine control device according to any one of claims 1 to 4, wherein when the start switch is turned off during traveling, the cooperative drive mode is changed to the independent drive mode. Applied to the steering device (8),
The return permission determination item includes the steering state of the steering member (91).
The rotary electric machine control device according to any one of claims 1 to 5, wherein the mode selection unit determines that the return permission condition related to the steering state is satisfied when the steering member is in the non-steering state. .. The return permission determination item includes the vehicle speed.
The rotary electric machine control device according to claim 6, wherein the mode selection unit determines that the return permission condition related to the vehicle speed is satisfied when the vehicle speed is equal to or less than the vehicle speed determination threshold value.

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