JP7239030B2 - motor controller - Google Patents

Description

The present invention relates to a motor control device that controls driving of a motor using a plurality of microcomputers.

2. Description of the Related Art Conventionally, in a motor control device that controls motor driving by a plurality of redundantly provided microcomputers, there is known a device in which each microcomputer operates with a clock generated by an independent clock generation circuit. When operating all microcomputers with a single clock generation circuit, the motor stops when the clock generation circuit fails. improves.

However, in reality, there is a problem that the calculation control timing of each microcomputer is deviated due to the manufacturing variation of the clock generation circuit.

Therefore, for example, in the electric motor control device disclosed in Patent Document 1, a synchronization signal is transmitted and received between a plurality of microcomputers, and the microcomputer that receives the synchronization signal corrects the arithmetic control timing based on the synchronization signal. By synchronizing the calculation control timings of a plurality of microcomputers in this manner, torque pulsation of the motor is suppressed.

Japanese Patent No. 5412095

However, the conventional technology does not assume the initial synchronization when a plurality of microcomputers are activated. For example, due to the difference in power supply voltage supplied to each microcomputer, the wiring resistance, the difference in voltage detection characteristics, etc., there is a case where the activation timing of turning on the power of each microcomputer deviates. As a result, only the microcomputer that starts earlier operates asynchronously during the period from when the microcomputer that started earlier starts the timer until the microcomputer that starts later starts the timer. Therefore, there is a problem that a plurality of microcomputers cannot be synchronized from the first time.

In this specification, the term "asynchronous control" includes control in which only some microcomputers among a plurality of microcomputers drive the motor.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and its object is to provide a motor control device that enables synchronization from the first time after activation of a plurality of microcomputers.

A motor control device of the present invention comprises a plurality of motor drive circuits (701, 702), a plurality of microcomputers (401, 402), and a plurality of clock generation circuits (651, 652).

A plurality of motor drive circuits drive one or more motors (80) having, for example, a plurality of winding sets.

The plurality of microcomputers have drive signal generators (451, 452) and drive timing generators (441, 442). The drive signal generator generates motor drive signals (Dr1, Dr2) that command the plurality of motor drive circuits. The drive timing generator generates drive timing, which is the pulse timing of the motor drive signal.

A plurality of clock generation circuits independently generate a clock that is used as a reference for operation of a plurality of microcomputers.

A clock generation circuit, a microcomputer, and a motor drive circuit are provided in correspondence with each other, and a group of these components is defined as a "system". The motor control device drives the motor by controlling the energization of the winding sets corresponding to the constituent elements of each system.

Among the plurality of microcomputers, ``at least one microcomputer that synchronizes with the drive timing of its own microcomputer and that transmits a synchronization signal for synchronizing the drive timings of a plurality of microcomputers'' is defined as a synchronization signal transmission side microcomputer (401). At least one microcomputer that receives the synchronizing signal transmitted from the signal transmitting microcomputer is defined as a synchronizing signal receiving microcomputer (402). Further, for each microcomputer, the microcomputer itself is called "own microcomputer".

The motor control device of the present invention has the following three drive modes on the premise of the basic configuration described above.
(1) Synchronous drive mode in which the microcomputer on the synchronous signal sending side and the synchronous signal receiving side microcomputer that has received the synchronous signal drive the motor in synchronization (2) The synchronous signal sending side microcomputer and the synchronous signal receiving side do not use the synchronous signal. Asynchronous drive mode in which the microcomputer drives the motor asynchronously (3) Partial system drive mode in which the motor is driven by either the synchronous signal sending microcomputer or the synchronous signal receiving microcomputer.

This motor control device may shift to the partial system drive mode, the asynchronous drive mode, and the synchronous drive mode in this order when the synchronization signal transmission side microcomputer and the synchronization signal reception side microcomputer are started.

1 is a configuration diagram of an electric power steering apparatus to which an ECU of each embodiment is applied as an electromechanical integrated motor drive system; FIG. 1 is a configuration diagram of an electric power steering apparatus in which an ECU of each embodiment is applied as a separate electromechanical motor drive system; FIG. Axial cross-sectional view of a two-system electromechanical integrated motor. FIG. 4 is a sectional view taken along line IV-IV of FIG. 3; Schematic diagram showing the configuration of a multiphase coaxial motor. FIG. 1 is an overall block diagram of an ECU (motor control device) according to each embodiment; FIG. 2 is a detailed configuration diagram of an ECU (motor control device) according to the basic form of the first embodiment; FIG. 4 is a diagram showing the relationship between a motor drive signal and analog signal sampling timing; FIG. 2 is a configuration diagram of an ECU (motor control device) according to the first embodiment; 4 is a time chart of handshake operation example 1; 4 is a time chart of a modification of handshake operation example 1; 4 is a time chart of handshake operation example 2; 10 is a time chart of modification A of handshake operation example 2; 10 is a time chart of modification B of handshake operation example 2; 11 is a time chart of handshake operation example 3; 10 is a flowchart of post-startup processing of the first microcomputer in operation examples 1 to 3; 10 is a flowchart of post-startup processing of the second microcomputer in operation examples 1 to 3; 10 is a flowchart of post-startup processing of the second microcomputer in Modification B of Operation Example 2; 4 is a flowchart of handshake success/failure storage processing. 4 is a flowchart of second microcomputer synchronous processing during asynchronous control; 10 is a time chart of handshake operation example 4; FIG. 11 is a flowchart of post-startup processing of the second microcomputer in operation example 4; FIG. The time chart of handshake operation example 5A at the time of restart. The time chart of handshake operation example 5B at the time of restart. 10 is a time chart of handshake operation example 6 at the time of restart; The block diagram of ECU (motor control unit) by 2nd Embodiment. Time chart of handshake operation example in 3 microcomputers. The block diagram of the part corresponding to the basic form of ECU (motor control unit) by 3rd Embodiment. FIG. 11 is a diagram showing bidirectional synchronization signal transmission/reception timings according to the third embodiment; 11 is a time chart of handshake operation example 7; FIG. 12 is a flowchart of a process after starting the first microcomputer in operation example 7; FIG. FIG. 12 is a flowchart of a process after activation of the second microcomputer in operation example 7; FIG.

A plurality of embodiments of the motor control device will be described below with reference to the drawings. In each embodiment, an ECU as a "motor control device" is applied to an electric power steering device of a vehicle and controls energization of a motor that outputs steering assist torque. A "motor drive system" is configured by the ECU and the motor.
The same reference numerals are assigned to substantially the same configurations in a plurality of embodiments, and descriptions thereof are omitted. Also, the following first to third embodiments will be collectively referred to as "this embodiment".

First, as matters common to each embodiment, the configuration of an electric power steering device, the configuration of a motor drive system, and the like, which are applied, will be described with reference to FIGS. 1 to 6. FIG.
1 and 2 show the overall configuration of a steering system 99 including an electric power steering device 90. FIG. FIG. 1 shows a "mechanical and electrical integrated type" configuration in which the ECU 10 is integrally configured on one side of the motor 80 in the axial direction, and FIG. The configuration of the "mechanical and electrical separate type" is illustrated. Although the electric power steering device 90 shown in FIGS. 1 and 2 is of a column assist type, it can also be applied to a rack assist type electric power steering device.

The steering system 99 includes a steering wheel 91, a steering shaft 92, a pinion gear 96, a rack shaft 97, wheels 98, an electric power steering device 90, and the like.
A steering shaft 92 is connected to the handle 91 . A pinion gear 96 provided at the tip of the steering shaft 92 meshes with a rack shaft 97 . A pair of wheels 98 are provided at both ends of the rack shaft 97 via tie rods or the like. When the driver rotates the steering wheel 91, the steering shaft 92 connected to the steering wheel 91 rotates. Rotational motion of the steering shaft 92 is converted into linear motion of the rack shaft 97 by the pinion gear 96 , and 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 90 includes a steering torque sensor 93, an ECU 10, a motor 80, a reduction gear 94, and the like.
A steering torque sensor 93 is provided in the middle of the steering shaft 92 and detects the steering torque of the driver. In the form shown in FIGS. 1 and 2, the redundant steering torque sensor 93 includes a first torque sensor 931 and a second torque sensor 932, and double detects the first steering torque trq1 and the second steering torque trq2. .
If the steering torque sensor is not redundantly provided, one detection value of the steering torque trq may be used in common for the two systems. Hereinafter, where there is no particular meaning in using the redundantly detected steering torques trq1 and trq2, they will be described as one steering torque trq.

The ECU 10 controls driving of the motor 80 based on the steering torques trq1 and trq2 so that the motor 80 generates desired assist torque. The assist torque output by the motor 80 is transmitted to the steering shaft 92 via the reduction gear 94 .
The ECU 10 acquires the electrical angles θ1 and θ2 of the motor 80 detected by the rotation angle sensor and the steering torques trq1 and trq2 detected by the steering torque sensor 93 . The ECU 10 controls driving of the motor 80 based on these information and information such as the motor current detected inside the ECU 10 .

The configuration of an electromechanical integrated motor 800 in which the ECU 10 is integrally configured on one side of the motor 80 in the axial direction will be described with reference to FIGS. 3 and 4. FIG. In the form shown in FIG. 3 , the ECU 10 is arranged coaxially with the axis Ax of the shaft 87 on the side opposite to the output side of the motor 80 . Note that, in another embodiment, the ECU 10 may be configured integrally with the motor 80 on the output side of the motor 80 .
The motor 80 is a three-phase brushless motor and includes a stator 840, a rotor 860, and a housing 830 that accommodates them.

Stator 840 has a stator core 845 fixed to housing 830 and two sets of three-phase winding sets 801 and 802 assembled to stator core 845 .
Lead wires 851 , 853 , and 855 extend from each phase winding that constitutes the first winding set 801 . Lead wires 852 , 854 , 856 extend from each phase winding that constitutes the second winding set 802 .
The rotor 860 has a shaft 87 supported by a rear bearing 835 and a front bearing 836, and a rotor core 865 in which the shaft 87 is fitted. Rotor 860 is provided inside stator 840 and is rotatable relative to stator 840 . A permanent magnet 88 is provided at one end of the shaft 87 .

The housing 830 has a bottomed tubular case 834 including a rear frame end 837 and a front frame end 838 provided at one end of the case 834 . The case 834 and the front frame end 838 are fastened together with bolts or the like. The lead wires 851 and 852 of the respective winding sets 801 and 802 are inserted through the lead wire insertion holes 839 of the rear frame end 837 to extend toward the ECU 10 side and connected to the board 230 .

The ECU 10 includes a cover 21, a heat sink 22 fixed to the cover 21, a substrate 230 fixed to the heat sink 22, and various electronic components mounted on the substrate 230. The cover 21 protects the electronic components from external shocks and prevents dust, water, and the like from entering the ECU 10 .
The cover 21 has a connector portion 214 for external connection of a power supply cable or a signal cable from the outside, and a cover portion 213 . The power supply terminals 215 and 216 of the external connection connector section 214 are connected to the board 230 via paths (not shown).

The board 230 is, for example, a printed board, is provided at a position facing the rear frame end 837 and is fixed to the heat sink 22 . On the substrate 230, electronic components for two systems are provided independently for each system to form a complete redundant configuration. Although one substrate 230 is provided in this embodiment, two or more substrates may be provided in other embodiments.
Of the two main surfaces of the substrate 230 , the surface facing the rear frame end 837 is the motor surface 237 , and the opposite surface, that is, the surface facing the heat sink 22 is the cover surface 238 .

A plurality of switching elements 241 , 242 , rotation angle sensors 251 , 252 , custom ICs 261 , 262 , etc. are mounted on the motor surface 237 .
In this embodiment, six switching elements 241 and 242 are provided for each system, and constitute three-phase upper and lower arms of the motor drive circuit. The rotation angle sensors 251 and 252 are arranged so as to face a permanent magnet 88 provided at the tip of the shaft 87 . Custom ICs 261 and 262 and microcomputers 401 and 402 have control circuits for the ECU 10 . The custom ICs 261 and 262 are provided with clock monitoring units 661 and 662 shown in FIG. 7, for example.

Microcomputers 401 and 402 , capacitors 281 and 282 , inductors 271 and 272 and the like are mounted on the cover surface 238 . In particular, the first microcomputer 401 and the second microcomputer 402 are arranged on the cover surface 238 on the same side of the substrate 230 with a predetermined gap therebetween.
The capacitors 281 and 282 smooth the power input from the power supply and prevent outflow of noise caused by switching operations of the switching elements 241 and 242 and the like. Inductors 271 and 272 form a filter circuit together with capacitors 281 and 282 .

As shown in FIGS. 5 and 6, a motor 80 to be controlled by the ECU 10 is a three-phase brushless motor in which two sets of three-phase winding sets 801 and 802 are coaxially provided.
The winding sets 801 and 802 have the same electrical characteristics, and are arranged on a common stator with an electrical angle of 30 degrees shifted from each other, as shown in FIG. 3 of Japanese Patent No. 5672278, for example. In response to this, the winding sets 801 and 802 are controlled so that, for example, phase currents having the same amplitude and 30 degrees out of phase are applied.

In FIG. 6, the combination of the first winding set 801, the first microcomputer 401, the motor drive circuit 701, and the like, which are involved in controlling the energization of the first winding set 801, is defined as a first system GR1. A combination of the second winding set 802 and the second microcomputer 402, the second motor drive circuit 702, and the like, which control the energization of the second winding set 802, is referred to as a second system GR2. The first system GR1 and the second system GR2 are composed of two sets of independent element groups, forming a so-called "complete two-system" redundant configuration.

In the specification, if necessary, "first" is added to the beginning of the component or signal of the first system GR1, and "second" is added to the beginning of the component or signal of the second system GR2. distinguish between Matters common to each system are described collectively without being attached with "first" and "second". In addition, "1" is added to the end of the code of the component or signal of the first system, and "2" is added to the end of the code of the component or signal of the second system.
Hereinafter, for a given component, the system containing that component will be referred to as the "own system", and the other system will be referred to as the "other system". Similarly, with respect to the two-system microcomputers 401 and 402, the self-system microcomputer is called the "own microcomputer", and the other system microcomputer is called the "other microcomputer".

The first connector portion 351 of the ECU 10 includes a first power connector 131 , a first vehicle communication connector 311 and a first torque connector 331 . Second connector portion 352 includes second power connector 132 , second vehicle communication connector 312 , and second torque connector 332 . The connector portions 351 and 352 may each be formed as a single connector, or may be divided into a plurality of connectors.

The first power connector 131 is connected to the first power supply 111 . Power from the first power supply 111 is supplied to the first winding set 801 via the power connector 131 , the power relay 141 , the first motor drive circuit 701 and the motor relay 731 . The power of the first power supply 111 is also supplied to the first microcomputer 401 and the sensors of the first system GR1.
A second power connector 132 is connected to the second power supply 112 . Power from the second power supply 112 is supplied to the second winding set 802 via the power connector 132 , the power relay 142 , the second motor drive circuit 702 , and the motor relay 732 . The power of the second power supply 112 is also supplied to the second microcomputer 402 and the sensors of the second system GR2.
If power supplies are not redundantly provided, the dual power connectors 131 and 132 may be connected to a common power supply.

When CAN is provided redundantly as the vehicle communication network, the first vehicle communication connector 311 is connected between the first CAN 301 and the first vehicle communication circuit 321, and the second vehicle communication connector 312 is connected between the second CAN 302 and the second vehicle communication circuit 321. It is connected between vehicle communication circuit 322 .
If the CAN is not redundantly provided, the two-system vehicle communication connectors 311 and 312 may be connected to the common CAN 30 . As a vehicle communication network other than CAN, any standard network such as CAN-FD (CAN with Flexible Data rate) or FlexRay may be used.
Vehicle communication circuits 321 and 322 bi-directionally communicate information with respective microcomputers 401 and 402 of their own system and other systems.

First torque connector 331 is connected between first torque sensor 931 and first torque sensor input circuit 341 . The first torque sensor input circuit 341 notifies the first microcomputer 401 of the steering torque trq1 detected by the first torque connector 331 .
A second torque connector 332 is connected between the second torque sensor 932 and the second torque sensor input circuit 342 . The second torque sensor input circuit 342 notifies the second microcomputer 402 of the steering torque trq2 detected by the second torque connector 332 .

Each processing in the microcomputers 401 and 402 may be software processing by executing a program stored in advance in a physical memory device such as a ROM by the CPU, or hardware processing by a dedicated electronic circuit. good too.
Microcomputers 401 and 402 operate according to the reference clocks generated by clock generation circuits 651 and 652 . Clock monitoring units 661 and 662 monitor the reference clocks generated by clock generating circuits 651 and 652, respectively. The generation and monitoring of the reference clock will be detailed later.

The first microcomputer 401 generates a motor drive signal Dr1 for operating the switching element 241 of the first motor drive circuit 701 and commands the first motor drive circuit 701 . The first microcomputer 401 also generates a first power relay drive signal Vpr1 and a first motor relay drive signal Vmr1.
The second microcomputer 402 generates a motor drive signal Dr2 for operating the switching element 242 of the second motor drive circuit 702 and instructs the second motor drive circuit 702 to generate the motor drive signal Dr2. The second microcomputer 402 also generates a second power relay drive signal Vpr2 and a second motor relay drive signal Vmr2.
The power relay drive signals Vpr1 and Vpr2 generated by the microcomputers 401 and 402 are instructed to the power relays 141 and 142 of their own systems, and also notified to other microcomputers.

The microcomputers 401 and 402 can mutually transmit and receive information through inter-microcomputer communication. The microcomputers 401 and 402 can mutually transmit and receive a current detection value, a current command value, and the like through inter-microcomputer communication, and can drive the motor 80 by cooperating the first system GR1 and the second system GR2. . A communication frame for inter-microcomputer communication includes a current detection value and the like. In addition, a current command value, a current limit value, an update counter, a status signal, a CRC signal that is an error detection value signal, or a checksum signal may be included. Note that this embodiment can be applied regardless of the communication content of communication between microcomputers, and other information may be transmitted and received as necessary, or part or all of the above data may not be included. .

If each microcomputer receives the power relay drive signals Vpr1 and Vpr2 from other microcomputers but does not receive signals from other microcomputers in inter-microcomputer communication, the other microcomputers are normal and inter-microcomputer communication is judged to be abnormal.
On the other hand, when each microcomputer does not receive the power relay drive signals Vpr1 and Vpr2 from the other microcomputer and does not receive the signal from the other microcomputer in inter-microcomputer communication, it is determined that the other microcomputer is abnormal.

The first motor drive circuit 701 is a three-phase inverter having a plurality of switching elements 241 and converts power supplied to the first winding set 801 . The switching element 241 of the first motor drive circuit 701 is controlled to turn on and off based on the motor drive signal Dr1 output from the first microcomputer 401 .
The second motor drive circuit 702 is a three-phase inverter having a plurality of switching elements 242 and converts power supplied to the second winding set 802 . The switching element 242 of the second motor drive circuit 702 is controlled to turn on and off based on the motor drive signal Dr2 output from the second microcomputer 402 .

The first power relay 141 is provided between the first power connector 131 and the first motor drive circuit 701 and controlled by the first power relay drive signal Vpr1 from the first microcomputer 401 . When the first power relay 141 is on, energization between the first power supply 111 and the first motor drive circuit 701 is permitted, and when the first power relay 141 is off, the first power supply 111 and the first motor drive circuit 701 is cut off.
The second power relay 142 is provided between the second power connector 132 and the second motor drive circuit 702 and is controlled by the second power relay drive signal Vpr2 from the second microcomputer 402 . When the second power relay 142 is on, energization between the second power supply 112 and the second motor drive circuit 702 is allowed, and when the second power relay 142 is off, the second power supply 112 and the second motor drive circuit 702 is cut off.

The power relays 141 and 142 of this embodiment are semiconductor relays such as MOSFETs. If the power relays 141 and 142 have parasitic diodes such as MOSFETs, it is desirable to provide reverse connection protection relays (not shown) connected in series with the power relays 141 and 142 so that the directions of the parasitic diodes are reversed. Also, the power relays 141 and 142 may be mechanical relays.

The first motor relay 731 is provided in each phase power path between the first motor drive circuit 701 and the first winding set 801 and is controlled by the first motor relay drive signal Vmr1 from the first microcomputer 401 . When the first motor relay 731 is on, energization between the first motor drive circuit 701 and the first winding set 801 is allowed, and when the first motor relay 731 is off, the first motor drive circuit 701 and the first The energization between the first winding set 801 is interrupted.
A second motor relay 732 is provided in each phase power path between the second motor drive circuit 702 and the second winding set 802 and is controlled by a second motor relay drive signal Vmr2 from the second microcomputer 402 . When the second motor relay 732 is on, conduction between the second motor drive circuit 702 and the second winding set 802 is allowed, and when the second motor relay 732 is off, the second motor drive circuit 702 and the second The energization between the two-winding set 802 is interrupted.

The first current sensor 741 detects the current Im1 flowing through each phase of the first winding set 801 and outputs it to the first microcomputer 401 . A second current sensor 742 detects a current Im<b>2 that flows through each phase of the second winding set 802 and outputs it to the second microcomputer 402 .
When the rotation angle sensors 251 and 252 are provided redundantly, the first rotation angle sensor 251 detects the electrical angle θ1 of the motor 80 and outputs it to the first microcomputer 401 . The second rotation angle sensor 252 detects the electrical angle θ2 of the motor 80 and outputs it to the second microcomputer 402 .
If the rotation angle sensor is not provided redundantly, for example, based on the electrical angle θ1 of the first system detected by the first rotation angle sensor 251, the electrical angle θ2 of the second system is calculated by the formula “θ2=θ1+30deg”. may

[Configuration of ECU]
Hereinafter, the configuration and effects of the ECU of each embodiment will be described for each embodiment. The description of each configuration related to the two-system redundancy shown in FIG. 6 is omitted as appropriate. The code|symbol of ECU of each embodiment attaches the number of embodiment to the 3rd digit following "10."
(Basic form of the first embodiment)
Prior to the description of the first embodiment, first, the configuration and effects of the basic form forming the core part of the first embodiment will be described with reference to FIGS. 7 and 8. FIG.
FIG. 7 shows, of the configuration of the ECU 101 according to the first embodiment shown in FIG. 9, a configuration particularly related to synchronization during operation. The basic form of the ECU shown in FIG. 1 is denoted by "100".
As shown in FIG. 7 , the ECU 100 includes a first system control section 601 that controls energization of the first winding set 801 and a second system control section 602 that controls energization of the second winding set 802 . The control units 601 and 602 of each system include clock generation circuits 651 and 652, clock monitoring units 661 and 662, microcomputers 401 and 402, and motor drive circuits 701 and 702, respectively. In other words, a unit of a group of components including a clock generation circuit, a microcomputer, and a motor drive circuit that correspond to each other is called a "system".

The first clock generation circuit 651 and the second clock generation circuit 652 independently generate reference clocks that the first microcomputer 401 and the second microcomputer 402 use as a reference for operation.
The first clock monitoring unit 661 monitors the reference clock generated by the first clock generation circuit 651 and output to the first microcomputer 401 . The second clock monitoring unit 662 monitors the reference clock generated by the second clock generation circuit 652 and output to the second microcomputer 402 . In addition, the clock monitoring units 661 and 662 output reset (“RESET” in the figure) signals to the microcomputers 401 and 402 when detecting an abnormality in the reference clock.

The microcomputers 401 and 402 receive information such as vehicle information input via the CANs 301 and 302, steering torques trq1 and trq2, phase currents Im1 and Im2, and electrical angles θ1 and θ2 input from sensors. . The microcomputers 401 and 402 generate motor drive signals Dr1 and Dr2 by performing control calculations based on these various types of input information, and output them to motor drive circuits 701 and 702, respectively. Here, the timing of control calculation is determined based on the clocks generated by the clock generation circuits 651 and 652 .

Motor drive circuits 701 and 702 energize winding sets 801 and 802 based on motor drive signals Dr1 and Dr2 commanded from microcomputers 401 and 402, respectively. Typically, the motor drive circuits 701 and 702 are power conversion circuits in which a plurality of switching elements such as MOSFETs are bridge-connected. Motor drive signals Dr1 and Dr2 are switching signals for turning on/off each switching element. For example, in this embodiment for driving a three-phase brushless motor, the motor drive circuits 701 and 702 are three-phase inverters.

Each of the microcomputers 401 and 402 is independently equipped with a ROM that stores fixed values such as control programs and parameters, and a RAM that temporarily stores and retains arithmetic processing results. Can not.
Based on this assumption, the two microcomputers 401 and 402 are connected by a synchronous signal line 471 . In the example shown in FIG. 7, there is one synchronizing signal line 471, but in a third embodiment described later or another embodiment having three or more microcomputers, a plurality of synchronizing signal lines may be provided. . That is, an ECU based on the basic form of the first embodiment generally has at least one synchronization signal line.

This synchronous signal line is not limited to a dedicated line for synchronous signal transmission, which will be described later. may be shared with other signal lines.
Further, for example, as disclosed in paragraph [0044] of Japanese Unexamined Patent Application Publication No. 2011-148498, instead of communication by the synchronous signal line, the first microcomputer 401 changes the level of the port signal to the second microcomputer 402. By doing so, the synchronization signal can be notified.

The first microcomputer 401 and the second microcomputer 402 have drive timing generation units 441 and 442, drive signal generation units 451 and 452, and analog signal sampling units 461 and 462 as common configurations.
The drive timing generators 441 and 442 generate drive timings, which are the pulse timings of the motor drive signals Dr1 and Dr2, using, for example, a PWM carrier common to each phase, and instruct the drive signal generators 451 and 452 to generate drive timings. The drive signal generators 451 and 452 generate motor drive signals Dr1 and Dr2, which are PWM signals, by comparing the DUTY of the voltage command signal and the PWM carrier, for example, and instruct the motor drive circuits 701 and 702 to generate motor drive signals Dr1 and Dr2.

Analog signal sampling units 461 and 462 sample analog signals.
Detected values of motor currents Im1 and Im2 of each system are mainly assumed as analog signals. In a three-phase motor, motor currents Im1 and Im2 are currents of U-phase, V-phase and W-phase of winding sets 801 and 802, respectively. In FIG. 7, arrows are shown assuming that the motor currents Im1 and Im2 detected by shunt resistors provided in the motor drive circuits 701 and 702 are acquired. In addition, assuming that the motor currents Im1 and Im2 are obtained from a current sensor provided on the motor 80 side, arrows from outside the ECU 100 to the analog signal sampling units 461 and 462 may be drawn. Further, as indicated by dashed lines, the analog signal sampling units 461 and 462 may acquire analog signals of the electrical angles θ1 and θ2 and the steering torques trq1 and trq2.

The analog signal sampling units 461 and 462 are synchronized with the drive timing generators 441 and 442 and sample analog signals at timings different from the switching timings of the motor drive signals Dr1 and Dr2.
FIG. 8 shows a configuration for generating the motor drive signal Dr by commonly using the PWM carrier of period Tp for each phase. Here, assumed DUTY is, for example, a value in the range of 10% to 90%, 0% and 100%. In this specification, 0% DUTY is expressed as the peak side of the PWM carrier, and 100% DUTY is expressed as the valley side of the PWM carrier. The period Tp of the PWM carrier corresponds to the pulse period of the motor drive signal Dr.

When the DUTY is 90%, the pulse of the motor drive signal Dr rises at time u9 and falls at time d9, and the ON time is expressed as 0.9Tp.
When the DUTY is 10%, the pulse of the motor drive signal Dr rises at time u1 and falls at time d1, and the ON time is expressed as 0.1Tp.

In the 10% to 90% DUTY range, the pulse of the motor drive signal Dr rises during the period SWu from time u9 to time u1 and falls during the period SWd from time d1 to time d9. In addition, the rise and fall of the pulse do not occur during the periods of DUTY 0% and 100%. Therefore, during the "non-switching period NSW" hatched with a dashed line, switching of the motor drive signal Dr does not occur for the switching elements of all phases. It should be noted that the non-switching period NSW in PWM control corresponds to a minute period that spans the timings of the trough and peak of the carrier.

When a duty other than 0% is switched to 0%, or when a duty other than 100% is switched to 100%, the pulse rises or falls. However, by setting the switching timing of DUTY to the valley timing of the carrier, it is possible to avoid switching at the peak timing in the non-switching period NSW. Conversely, if the switching timing of DUTY is fixed at the peak timing, it is possible to avoid switching at the valley timing in the non-switching period NSW. Further, if the DUTY is set to be switched once every N times, for example, at the trough and peak timings of the PWM carrier, switching does not occur at the trough and peak timings of (N-1) times when the DUTY is not switched.

Therefore, the analog signal sampling units 461 and 462 are synchronized with the driving timing generating units 441 and 442 and perform sampling at timings during which switching to 0% or 100% DUTY does not occur during the non-switching period NSW. This makes the sampling signal less susceptible to switching noise and improves the sampling accuracy.
More specifically, sampling is preferably performed after a period of time for the surge voltage generated by switching to attenuate.

Furthermore, in the basic form of the first embodiment, the first microcomputer 401 has a synchronization signal generator 411 and the second microcomputer 402 has a timing corrector 422 . The first microcomputer 401 functions as a "synchronization signal transmitting microcomputer" that transmits a synchronization signal, and the second microcomputer 402 functions as a "synchronization signal receiving microcomputer" that receives the synchronization signal. For each of the microcomputers 401 and 402, the microcomputer itself is called "own microcomputer".

The synchronization signal generator 411 of the first microcomputer 401 generates a synchronization signal that synchronizes with the drive timing generated by the drive timing generator 441 of its own microcomputer and synchronizes the drive timings of the two microcomputers 401 and 402 . The synchronization signal generator 411 then transmits the synchronization signal to the second microcomputer 402 via the synchronization signal line 471 .
The timing correction unit 422 of the second microcomputer 402 can receive the synchronization signal transmitted from the first microcomputer 401 and correct the drive timing generated by the drive timing generation unit 442 of the own microcomputer so as to synchronize with the received synchronization signal. is. This correction is called "timing correction". As indicated by the dashed line in the second microcomputer 402 in FIG. 7, in the timing correction, the timing correction unit 422 outputs a timing correction instruction to the drive timing generation unit 442, and the drive timing generation unit 442 adjusts the drive timing accordingly. to correct.

(First embodiment)
Based on the configuration of the basic form as described above, the first embodiment will be described with reference to FIGS. 9 to 25. FIG.
FIG. 9 shows the configuration of the ECU 101 of the first embodiment. As in FIG. 7 of the basic form, in FIG. 9, the symbols of the components of the first system are appended with "1", and the symbols of the components of the second system are appended with "2". . In the following description, when distinguishing components of each system, the components or signals are prefixed with "first" or "second", and common items are collectively described.

In this specification, regarding the control of the microcomputers, control in which the plurality of microcomputers 401 and 402 operate in synchronization is referred to as "synchronous control", and control in which the plurality of microcomputers 401 and 402 operate independently without synchronization is referred to as " asynchronous control". Further, there are three drive modes for the motor 80 driven by the microcomputers 401 and 402 as follows.
(1) "Synchronous drive mode" in which the first microcomputer 401 and the second microcomputer 402 synchronously drive the motor
(2) "Asynchronous drive mode" in which the first microcomputer 401 and the second microcomputer 402 asynchronously drive the motor without using a synchronous signal.
(3) "Single system drive mode" in which the motor is driven by only one of the microcomputers 401 and 402

A synchronous drive mode is applied when the microcomputers 401 and 402 perform synchronous control. Also, when the microcomputers 401 and 402 perform asynchronous control, an asynchronous drive mode or a single system drive mode is applied. At the start of asynchronous control, each microcomputer 401, 402 independently starts the timer, except when continuing the previous operation.
In the asynchronous drive mode, the microcomputers 401 and 402 generate motor drive signals Dr1 and Dr2 at their respective timings. In the single-system drive mode, for example, the second microcomputer 402, which is its own microcomputer, does not cause the first microcomputer 401, which is another microcomputer, to generate the motor drive signal Dr1, and drives the motor 80 only with the motor drive signal Dr2 generated by its own microcomputer. do.

In the basic mode, the synchronous control state can be continued while the microcomputers 401 and 402 are operating. However, the initial synchronization after the microcomputers 401 and 402 are activated is not considered.
For example, due to the difference in power supply voltage supplied to each microcomputer, the wiring resistance, the difference in voltage detection characteristics, etc., there is a case where the activation timing of turning on the power of each microcomputer deviates. As a result, only the microcomputer that starts earlier operates asynchronously during the period from when the microcomputer that started earlier starts the timer until the microcomputer that starts later starts the timer. Therefore, the two microcomputers 401 and 402 cannot be synchronized from the first time.

Further, each microcomputer may perform control in units of a plurality of cycles of the synchronization signal. Then, when one microcomputer synchronizes with a synchronization signal several cycles later than the control unit after the timer starts, there is an offset in the control timing between the microcomputers, so control in units of multiple cycles cannot be synchronized. I have a problem that I can't make it work.

Therefore, the ECU 101 of the first embodiment enables synchronous control from the first time after the microcomputers 401 and 402 are activated. Therefore, the microcomputers 401 and 402 perform "initial handshake" by transmitting and receiving signals to each other after starting. It also has an "initial handshake determination unit" that determines whether or not the initial handshake was successful. Note that the handshake referred to in the present embodiment is the first time after startup, so hereinafter the "first time" will be omitted and the terms "handshake" and "handshake determination unit" will be used.

Differences in the configurations of the first microcomputer 401 and the second microcomputer 402 included in the ECU 101 of the first embodiment will be mainly described with respect to the basic configuration of the ECU 100 shown in FIG. As in the basic configuration, the first microcomputer 401 is a "synchronization signal transmitting side microcomputer" and the second microcomputer 402 is a "synchronizing signal receiving side microcomputer".
The first microcomputer 401 further has a handshake determination section 611 and a ready signal reception section 621 in addition to the configuration of the basic configuration. The second microcomputer 402 further has a handshake determination section 612 and a ready signal transmission section 622 in addition to the configuration of the basic configuration.
A thick solid line arrow in FIG. 9 indicates a synchronizing signal, and a thick one-dot chain line arrow indicates a ready signal.

The ready signal transmitting section 622 transmits a ready signal indicating that the synchronization preparation of the second microcomputer 402 is completed to the ready signal receiving section 621 of the first microcomputer 401 via the ready signal line 475 . Here, the ready signal line 475 may be shared with the synchronization signal line 471 or may be provided separately from the synchronization signal line 471 . As with the synchronization signal, the ready signal may also be notified by changing the level of the port signal instead of communicating via the ready signal line.
Ready signal receiving section 621 receives a ready signal. Specifically, the ready signal receiver 621 detects that the ready signal has been received. Hereinafter, "receiving" means "detecting reception" including reception of the synchronization signal by the timing correction unit 422. FIG.

The handshake determination unit 611 of the first microcomputer 401 determines whether the handshake has succeeded or failed based on the synchronization signal transmitted by the synchronization signal generation unit 411 and the ready signal received by the ready signal reception unit 621. .
The handshake determination unit 612 of the second microcomputer 402 determines whether the handshake has succeeded or failed based on the synchronization signal received by the timing correction unit 422 and the ready signal transmitted by the ready signal transmission unit 622 .
Details of signal transmission/reception and success/failure determination in handshake will be described later.

The microcomputers 401 and 402 also have current calculators 631 and 632 that output commands to the drive signal generators 451 and 452, respectively. Note that the current calculators 631 and 632 are actually included in the basic form. However, it is not shown in FIG. 7 because it has little relevance to the peculiar operation of the basic form.

In the example shown in FIG. 9, it is assumed that the ready signal is generated as one of the communication clock signals, and that the communication clock signal includes data signals for inter-microcomputer communication other than the ready signal. In this case, the ready signal transmitter 622 transmits the communication clock signal including the data signal input from the current calculator 632 . The ready signal receiver 621 outputs the data signal included in the received communication clock signal to the current calculator 632 .
Therefore, from the viewpoint of transmission and reception of data signals, the ready signal transmitter 622 and the ready signal receiver 621 may simply be referred to as "communication section", and the ready signal line 475 may simply be referred to as "signal line". However, in the present embodiment, names are used that focus particularly on the function of transmitting and receiving a ready signal in handshake.

FIG. 9 also shows the timing determination unit 432 in the timing correction unit 422 of the second microcomputer 402 and the analog signal sampling units 461 and 462 of the microcomputers 401 and 402 shown in FIG. omitted. These may be omitted in the handshake operation of the first embodiment.
In other words, for the synchronization between the microcomputers after the first time, it is sufficient if the timing correction section 422 can correct the timing based on at least the synchronization signal transmitted from the first microcomputer 401 to the second microcomputer 402 . In addition to this, in the configuration provided with the timing determination unit 432, as described in the basic mode, when the synchronization signal is abnormal, the timing correction can be prohibited to prevent the control of the second microcomputer 402 from breaking down. can.

Next, examples of handshake operations according to the first embodiment will be described with reference to the time charts and flowcharts of FIGS. 10 to 25. FIG.
First, the terms described on the left side of each time chart are noted.
The "PWM timer" of each microcomputer 401, 402 is a PWM carrier reference timer generated by the clock generation circuits 651, 652. Based on this timer, the drive signals Dr1, Dr2 are generated, and the motor winding set 81 of each system is generated. , 82 is controlled. The start of generation of the PWM timer is hereinafter referred to as "timer start".
For the sake of convenience, the startup timings at which the microcomputers 401 and 402 are powered on are shown on the chart of the PWM timer.

“Synchronization signal 1→2” means a synchronization signal transmitted from the synchronization signal generation unit 411 of the first microcomputer 401 to the timing correction unit 422 of the second microcomputer 402 . In this example, the sync signal is low at startup.
10, before the timer of the first microcomputer 401 starts, the synchronization signal once rises from low level to high level and then returns to low level again. In this case, the first rising edge of the synchronization signal is not recognized as synchronization timing with the second microcomputer 402, but has the meaning of foretelling synchronization at the time of timer start. Therefore, the operation of setting the synchronization signal to a high level before starting the timer is called "outputting or transmitting a synchronization notice signal". Also, the operation of returning a high-level synchronization signal to a low level before the timer starts is called "termination of the synchronization notice signal".

In this embodiment, the first microcomputer 401 switches the synchronization signal between low level and high level and transmits it to the second microcomputer 402 via the synchronization signal line 471, thereby also functioning as a synchronization notice signal. This eliminates the need to provide a signal generator and a signal line dedicated to the notification of synchronization in handshake.

After the timer of the first microcomputer 401 is started, the synchronization signal is toggled so as to periodically repeat high level and low level with four cycles of the PWM timer as the synchronization cycle Ts. In this embodiment, the rise timing and fall timing of the synchronization signal coincide with the valley timing of the PWM timer.
As in the basic mode, the rise timing of the synchronization signal is the synchronization timing with the second microcomputer 402 . In addition, in the configuration in which the second microcomputer 402 performs timing determination, whether the synchronization signal is normal or abnormal is determined according to the rise timing of the synchronization signal.

“Ready signal 2→1” means the ready signal transmitted from the ready signal transmitter 622 of the second microcomputer 402 to the ready signal receiver 621 of the first microcomputer 401 . In this example, the ready signal is set to a high level as a default at start-up. After that, a pulse signal that repeats high level and low level four times in succession is output as a ready signal notifying that the second microcomputer 402 is ready for synchronization. Note that the pulse width and number of times may be set as appropriate. In this embodiment, the communication clock signal used as the ready signal is continuously output periodically even after the timer of the second microcomputer 402 is started.
Thus, in this embodiment, the synchronization notice signal and the ready signal correspond to "signals to be transmitted and received" in handshake.

"Period" indicates a portion quoted in the following description. Note that the symbols <0> to <6> are assigned independently for each figure, and are not related to the periods of the same symbols in other figures. Also, in the description of the specification, the period corresponding to <1> is described as "period 1" without attaching <>.
The description of the operation at one point in time in each period ignores the time lag of the control, and is, in principle, the description of the operation performed at the start of that period.

[Operation example 1]
As a specific operation example, first, with reference to FIG. 10, an operation example 1 in which the handshake is successful after the microcomputers 401 and 402 are activated at the same time will be described.
In period 1, the microcomputers 401 and 402 are in a state after activation. The second microcomputer 402 counts the elapsed time from the start of period 1 as a second handshake time Ths2.
In period 2, the first microcomputer 401 transmits a synchronization notice signal to the second microcomputer 402 . The second microcomputer 402 receives this synchronization notice signal before the second handshake time Ths2 elapses.

Also, the first microcomputer 401 counts the elapsed time from the start of period 2 .
The second microcomputer 402 transmits a ready signal to the first microcomputer 401 in period 3 as a response to the synchronization notice signal received in period 2 . The first microcomputer 401 receives this ready signal before the first handshake time Ths1 elapses.
After receiving the ready signal in period 3, the first microcomputer 401 terminates the synchronization notice signal in period 4 when the first handshake time Ths1 elapses.

Through the operations in Periods 2, 3, and 4, the transmission of the synchronization notice signal and the reception of the ready signal were performed normally. The drive timing generator 441 is instructed to perform initial synchronization.
Similarly, since the reception of the synchronization notice signal and the transmission of the ready signal were performed normally, the handshake determination unit 612 of the second microcomputer 402 determines that the handshake was successful, and sends the drive timing generation unit 442 Command the initial synchronization.
In period 5, the first microcomputer 401 outputs the synchronization signal and simultaneously starts the timer. The second microcomputer 402 starts a timer at the rising timing of the synchronization signal received from the first microcomputer 401 . As a result, the microcomputers 401 and 402 drive the motor 80 synchronously from the first time after activation, that is, in the synchronous drive mode.

[Modification of Operation Example 1]
In operation example 1, it is assumed that the first microcomputer 401 and the second microcomputer 402 start simultaneously and instantaneously. However, in reality, when the power supplies 111 and 112 corresponding to the respective microcomputers 401 and 402 were turned on from an off state, the supply voltage to the microcomputers 401 and 402 gradually increased from 0 and then reached a certain value. At this time, the microcomputers 401 and 402 are activated. Even if the power supplies 111 and 112 are turned on at the same time, the rising gradient varies due to the wiring resistance of the power supply path or the like. The activation timing of the microcomputers 401 and 402 varies.
Referring to FIG. 11, as a modification of the operation example 1, the timing difference between the start-up timings UT1 of the first power supply 111 and the rise time UT2 of the second power supply 112 is relatively small. An operation example will be described.

At the start of period 1, the first power supply 111 and the second power supply 112 are simultaneously turned on from the off state, and the voltages supplied to the microcomputers 401 and 402 are increased. The second power supply 112 completes startup after time UT2, and the second microcomputer 402 starts up. Shortly after the second handshake time Ths2 starts, the first power supply 111 finishes rising after the time UT1, and the first microcomputer 401 starts up.
After that, at the start of period 2, the first microcomputer 401 transmits a synchronization notice signal to the second microcomputer 402 . Thereafter, it is determined that the handshake has succeeded through periods 2, 3, and 4 in the same manner as in operation example 1 of FIG.

In period 5, the first microcomputer 401 outputs the synchronization signal and simultaneously starts the timer, and the second microcomputer 402 starts the timer at the rising edge of the synchronization signal received from the first microcomputer 401 . As a result, the microcomputers 401 and 402 drive the motor 80 synchronously from the first time after activation, that is, in the synchronous drive mode.
As described above, even if the activation timing of the first microcomputer 401 is slightly delayed, if the first microcomputer 401 transmits the synchronization notice signal within the second handshake time Ths2, the handshake is successful as in the operation example 1. do. Conversely, even if the activation timing of the second microcomputer 402 is slightly delayed, if the second microcomputer 402 transmits the ready signal within the first handshake time Ths1, the operation is the same as in the first operation example.

[Operation example 2]
Next, an operation example will be described in which the handshake fails due to a "timeout" in which the other microcomputer does not start within a predetermined time after one microcomputer starts. It should be noted that the case where the signal to be transmitted is not transmitted within a predetermined time after the other microcomputer is activated can be considered in the same manner as the case where the other microcomputer is not activated.
First, with reference to FIG. 12, operation example 2 in which the handshake fails due to timeout after the second microcomputer 402 is started will be described. In operation example 2, the first microcomputer 401 does not start up even after a predetermined time has passed since the second microcomputer 402 started up, or the ready signal is not transmitted even if the first microcomputer 401 starts up.

In period 1 of FIG. 12, only the second microcomputer 402 is in a state after startup. The second microcomputer 402 counts the elapsed time from the start of period 1 . After that, time passes without the second microcomputer 402 receiving the synchronization notice signal to be transmitted from the first microcomputer 401 .
When the elapsed time from the start of period 1 reaches the second handshake time Ths2, the handshake determination unit 612 of the second microcomputer 402 determines that the handshake has failed due to timeout. The handshake determination unit 612 then notifies the drive timing generation unit 442 so that the second microcomputer 402 independently generates the drive signal Dr2.
In period 2, the second microcomputer 402, which is the sync signal receiving microcomputer, independently starts the timer. Accordingly, the ECU 101 drives the motor 80 in the single-system drive mode of the second system without causing the first microcomputer 401 to generate the motor drive signal Dr1.

[Modification A of Operation Example 2]
Next, with reference to FIG. 13, the modification A of the operation example 2 considering the rise time of the power supply will be described. In this example, the time difference between the rise time UT1 of the first power supply 111 and the rise time UT2 of the second power supply 112 is large compared to the modification of the operation example 1 shown in FIG. .
At the start of period 1, the first power supply 111 and the second power supply 112 are simultaneously turned on from the off state, and the voltages supplied to the microcomputers 401 and 402 are increased. The second power supply 112 completes startup after time UT2, and the second microcomputer 402 starts up. Here, the rise time UT1 of the first power supply 111 is longer than the sum of the rise time UT2 of the second power supply 112 and the second handshake time Ths2. Therefore, the second handshake time Ths2 elapses before the first microcomputer 401 is activated, and in period 2, the second microcomputer 402 independently starts the timer. Therefore, the motor 80 is driven in the single-system drive mode of the second system.

After that, in the middle of the period 2, the first power supply 111 finishes rising, and the first microcomputer 401 starts up. Subsequently, in period 3, the second microcomputer 402 after timer start transmits an invalid ready signal to the first microcomputer 401 during the elapse of the first handshake time Ths1.
Here, "ineffective" means that the receiving microcomputer (here, the first microcomputer 401) does not recognize the signal as a ready signal. For example, the microcomputer that receives the ready signal determines whether the ready signal is valid or invalid based on the ID. The invalid ready signal transmitted while the second microcomputer 402 is executing the one-system drive mode is not recognized as a signal indicating completion of synchronization preparation with respect to the synchronization notice signal of the first microcomputer 401 . Therefore, even if an invalid ready signal is sent, it is not determined that the handshake was successful.
After period 3 ends, period 4 passes, and at the start of period 5, the first microcomputer 401 starts a timer without synchronizing with the second microcomputer 402 . Thus, in period 5, the motor 80 is driven in the asynchronous drive mode by the two systems of microcomputers 401 and 402 .

After the synchronization period Ts from the start of the period 5, the first microcomputer 401 transmits a synchronization signal to the second microcomputer 402 at the start of the period 6, and the second microcomputer 402 receives it. At this time, if the timing determination is normal, or if the timing determination is not performed, the timing correction of the second microcomputer 402 is performed at the rising timing of the synchronization signal, and thereafter the microcomputers 401 and 402 are synchronously driven. drive the motor 80 in mode.
As described above, when the difference between the activation timings of the microcomputers 401 and 402 is large, the drive mode of the motor 80 by the ECU 101 shifts to the single-system drive mode, the asynchronous drive mode, and the synchronous drive mode in this order. In other words, a motor control device that may shift to the single-system drive mode, the asynchronous drive mode, and the synchronous drive mode in order when the microcomputers 401 and 402 are activated can be regarded as equivalent to the ECU of the present embodiment.

[Modification B of Operation Example 2]
Modification B of Operation Example 2 illustrated in FIG. 14 is the same as Modification A in FIG. 13 in the operations up to period 1 and period 2 . However, in the modification B, when the first microcomputer 401 is activated while the second microcomputer 402 is operating in the single-system drive mode, the first microcomputer 401 performs processing such as transmission of the synchronization notice signal, timer start processing, and synchronization processing. Not performed. That is, the first microcomputer 401 does not generate the motor drive signal Dr1 even though the microcomputer itself is activated, so the motor is not driven by the first system. As a result, as in FIG. 12, the first microcomputer 401 continues the single-system drive mode during the period 2 . Thus, the transition to the synchronous drive mode is not essential, and the single-system drive mode may be used continuously.

[Operation Example 3]
Next, with reference to FIG. 15, an operation example 3 will be described in which the handshake fails due to a timeout after the first microcomputer 401 is activated, contrary to the operation example 2. FIG. In the operation example 3, the second microcomputer 402 does not start even after a predetermined time has passed since the first microcomputer 401 started, or the ready signal is not transmitted even if the second microcomputer 402 starts.
In period 1, only the first microcomputer 401 is in a state after activation.
In period 2, the first microcomputer 401 transmits a synchronization notice signal and counts the elapsed time from the start of period 2. FIG. After that, time passes without the first microcomputer 401 receiving the ready signal to be transmitted from the second microcomputer 402 .

When the elapsed time from the start of period 2 reaches the first handshake time Ths1, the handshake determination unit 611 of the twelfth microcomputer 401 determines that the handshake has failed due to timeout. The handshake determination unit 611 then notifies the drive timing generation unit 441 so that the first microcomputer 401 independently generates the drive signal Dr1.
The first microcomputer 401 terminates the synchronization notice signal in period 3 when the first handshake time Ths1 has elapsed.
In period 4 of operation example 3, the first microcomputer 401, which is the sync signal transmitting side microcomputer, outputs the sync signal and independently starts the timer. Accordingly, the ECU 101 drives the motor 80 in the single-system drive mode of the first system without causing the second microcomputer 402 to generate the motor drive signal Dr2.

[Flow chart of operation examples 1 to 3]
Operation examples 1 to 3 assuming a handshake failure due to timeout and post-startup processing of the first microcomputer 401 and the second microcomputer 402, handshake success/failure storage processing, and synchronization processing of the second microcomputer 402 related to their modifications Refer to each flow chart for
In the post-startup process of the first microcomputer shown in FIG. 16, the first microcomputer 401 sets the synchronization signal to high level in S51 after being activated in S50, transmits a synchronization notice signal, and starts counting the elapsed time.
In S52, it is determined whether the elapsed time is less than the first handshake time Ths1.
If it is determined YES in S52, it is determined whether a ready signal has been received from the second microcomputer 402 in a ready signal reception step S53. If the first microcomputer 401 has not received the ready signal and it is determined NO in S53, the process returns to before S52.

If the first microcomputer 401 receives the ready signal, the determination in S53 is YES, and the process proceeds to S54. Thereby, it is determined that the handshake was successful.
Further, when the elapsed time reaches the first handshake time Ths1 and the handshake fails due to timeout, it is determined as NO in S52, and the process proceeds to S54.
In S54, the first microcomputer 401 returns the synchronization signal to low level and ends the synchronization notice signal.
In S56, the first microcomputer 401 transmits a synchronization signal to the second microcomputer 402. FIG.

If it is determined YES in the previous S52, that is, if it is determined that the handshake was successful, it is determined YES in the handshake determination step S57, and the process proceeds to the synchronous drive step S58. In S58, the first microcomputer 401 and the second microcomputer 402 start timers at the same time, and drive the motor 80 synchronously from the first time.
On the other hand, if it is determined NO in the previous S52, that is, if the handshake fails due to timeout, it is determined NO in S57 and the process proceeds to S59. In S59, the first microcomputer 401 independently starts the timer and drives the motor 80 asynchronously.

17 and 18, the second microcomputer 402 is activated in S60 and starts counting the elapsed time in S61.
In S62, it is determined whether the elapsed time is less than the second handshake time Ths2.
If it is determined YES in S62, it is determined in S63 whether a synchronization notice signal has been received from the first microcomputer 401. FIG. If the second microcomputer 402 has not received the synchronization notice signal and it is determined NO in S63, the process returns to before S62.

If the second microcomputer 402 has received the synchronization notice signal, YES is determined in S63, and the process proceeds to ready signal transmission step S64. In S64, the second microcomputer 402 transmits a ready signal. The step in which the first microcomputer 401 responds to this S64 is the ready signal reception step S53 in FIG. Thereby, it is determined that the handshake was successful.
After that, in S66, the second microcomputer 402 receives the synchronization signal from the first microcomputer 401 and starts the timer at the same time as the first microcomputer 401 by interruption. As a result, the first microcomputer 401 and the second microcomputer 402 drive the motor 80 synchronously from the first time.

On the other hand, when the elapsed time reaches the second handshake time Ths2 and the handshake fails due to timeout, it is determined as NO in S62, and the process proceeds to S67. In S67, the second microcomputer 402 independently starts the timer and drives the motor 80 in the single-system drive mode.
In the following S50, it is determined whether the first microcomputer 401 has started after the timer of the second microcomputer 402 has started. In the operation example 2 shown in FIG. 12, the first microcomputer 401 is not activated, and it is determined as NO in S50. In the modification of the operation example 2 shown in FIGS. 13 and 14, the first microcomputer 401 is activated after the timer of the second microcomputer 402 is started, and YES is determined in S50.

In the modification A of the operation example 2, as shown in FIG. 17, when YES is determined in S50, in S68, the second microcomputer 402 transmits an invalid ready signal in response to the synchronization notice signal from the first microcomputer 401. do. In S69, the first microcomputer 401 independently and asynchronously with the second microcomputer 402 starts a timer due to a timeout due to the passage of the first handshake time Ths1. As a result, the one-system drive mode is changed to the two-system asynchronous drive mode.
After that, in S80, the "second microcomputer synchronization process" shown in FIG. 20 is executed, and when the synchronization condition is satisfied, the mode shifts to the synchronization drive mode.
In Modified Example B of Operation Example 2, as shown in FIG. 18, if YES is determined in S50, the process is terminated. Therefore, the "single-system drive mode by the second microcomputer" of S67 is continued.

Next, in the handshake success/failure storage process shown in FIG. 19, a handshake is performed in S71.
When the handshake is successful and YES is determined in S72, the handshake determination units 611 and 612 turn on the success flag in S73. At this time, synchronous control is performed.
When the handshake fails and it is determined NO in S72, the handshake determination units 611 and 612 turn off the success flag in S74. At this time, asynchronous control is performed.
Handshake determination units 611 and 612 store ON/OFF information of the success flag.

The second microcomputer synchronization process in FIG. 20 corresponds to S80 in FIGS. 17 and 22. FIG. In FIG. 20, when the success flag is OFF and asynchronous control is in progress, YES is determined in S81, and the process proceeds to S82 to attempt synchronization. If the success flag is ON and synchronous control is in progress, a determination of NO is made in S81, and the process ends.
After that, the second microcomputer 402 waits for the synchronization signal to be transmitted from the first microcomputer 401 every synchronization cycle Ts, and receives the synchronization signal in S82. Note that if the first microcomputer 401 is not activated and only the second microcomputer 402 is operating in the single-system drive mode, the synchronization signal is not transmitted. You may do so.

In the configuration in which the timing correction unit 422 of the second microcomputer 402 includes the timing determination unit 432 as in the basic configuration, it is determined in S83 whether the reception timing of the synchronization signal is within the synchronization permission section. If YES is determined in S83, timing correction is performed in S84. If NO in S83, the process returns to S82, and the second microcomputer 402 waits for the next synchronization signal to be transmitted.
In a configuration in which the timing correction unit 422 does not include the timing determination unit 432, S83 may be skipped and timing correction may be performed whenever the second microcomputer 402 receives the synchronization signal.

[Operation example 4]
Next, with reference to FIG. 21, operation example 4 in which the handshake fails due to transmission/reception of an abnormal signal will be described. Here, the description of the timeout as in Operation Examples 2 and 3 will be omitted.
As in operation example 1, the microcomputers 401 and 402 are activated simultaneously, and in period 1, the microcomputers 401 and 402 are in a state after activation.
In the period 2, the high-frequency noise abnormal signal is transmitted from the first microcomputer 401 to the second microcomputer 402 instead of the synchronization notice signal that should be transmitted.

The handshake determination unit 612 of the second microcomputer 402 determines that the handshake has failed as soon as it detects that an abnormal signal has been received in period 2 . The handshake determination unit 612 then notifies the drive timing generation unit 442 so that the second microcomputer 402 independently generates the drive signal Dr2.
In period 3, the second microcomputer 402 independently starts the timer. Therefore, the motor 80 is driven in the single-system drive mode of the second system.

After the second microcomputer 402 starts the timer in period 3, the second microcomputer 402 transmits an invalid ready signal to the first microcomputer 401 .
The handshake determination unit 611 of the first microcomputer 401 determines that the handshake has failed, and notifies the drive timing generation unit 441 so that the first microcomputer 401 independently generates the drive signal Dr1. In period 4, the first microcomputer 401 terminates the synchronization notice signal.
In period 5, the first microcomputer 401 outputs the synchronization signal and simultaneously starts the timer. Thus, in period 5, the motor 80 is driven in the asynchronous drive mode by the two systems of microcomputers 401 and 402 .

After the synchronization period Ts from the start of the period 5, the first microcomputer 401 transmits a synchronization signal to the second microcomputer 402 at the start of the period 6, and the second microcomputer 402 receives it. At this time, if the timing determination is normal, or if the timing determination is not performed, the timing correction of the second microcomputer 402 is performed at the rising timing of the synchronization signal, and thereafter the microcomputers 401 and 402 are synchronously driven. drive the motor 80 in mode.
As described above, even when the second microcomputer 402 receives the abnormality signal instead of the synchronization notice signal, the drive mode of the motor 80 by the ECU 101 shifts to the single-system drive mode, the asynchronous drive mode, and the synchronous drive mode in this order.

[Flowchart of Operation Example 4]
The flowchart of FIG. 22 will be referred to for the processing after starting the second microcomputer in the operation example 4 assuming that the handshake has failed due to transmission/reception of an abnormal signal. In FIG. 22, steps common to those in FIG. 17 are assigned the same step numbers, and descriptions thereof are omitted as appropriate. Further, a step unique to Operation Example 4 is indicated with the letter "X" at the end of the step number.
In FIG. 22, it is not assumed that the signal transmitted from the first microcomputer 401 times out after the second microcomputer 402 is activated. That is, it is assumed that the second microcomputer 402 receives some signal during the second handshake time Ths2.

After the second microcomputer 402 is activated in S60, the second microcomputer 402 receives some signal from the first microcomputer 401. If YES is determined in S62X, in S63X the signal received by the second microcomputer 402 is an abnormal signal. It is determined whether there is
If the signal received by the second microcomputer 402 is a normal synchronization notice signal and it is determined NO in S63X, S64 and S66 are executed in the same manner as in FIG.
If the signal received by the second microcomputer 402 is an abnormal signal and YES is determined in S63X, the second microcomputer 402 independently starts the timer in S67 and drives the motor 80 in the single-system drive mode. Thereafter, S68, S69, and S80 are performed in the same manner as in FIG.

(effect)
As described above, after starting the microcomputers 401 and 402, the ECU 101 of the present embodiment carries out a handshake for mutually transmitting and receiving the synchronization notice signal and the ready signal. take corrective action. If it is determined that the handshake has succeeded, the motor 80 can be driven synchronously from the first time. On the other hand, if it is determined that the handshake has failed, the motor 80 is started to be driven asynchronously, and then the timing is corrected at the transmission timing of the synchronization signal from the next time onwards, and the control shifts to synchronization control.

In this manner, the ECU 101 of the present embodiment can enable synchronization from the first time when the handshake is successful after the microcomputers 401 and 402 are activated. Also, when the handshake is successful, the two microcomputers 401 and 402 start timers at the same time, so even when each microcomputer performs control in units of a plurality of cycles of the synchronization signal, the control can be synchronized.

[Operation examples 5 and 6]
The above operation examples 1 to 4 relate to the initial handshake when both the first microcomputer 401 and the second microcomputer 402 are powered on from the stopped state and started. However, the idea of the initial handshake according to this embodiment can also be applied when the microcomputer in operation is restarted due to reset or the like.
Next, referring to FIGS. 23 to 25, handshake operation examples 5 and 6 when one microcomputer is restarted after being temporarily stopped due to a reset or the like while the other microcomputer continues to operate in the single-system drive mode. will be explained. As for operation example 5, two patterns 5A and 5B will be described.

In an operation example 5A shown in FIG. 23, the first microcomputer 401 is restarted by reset or the like while the second microcomputer 402 continues to operate. Also, the transmission start timing of the ready signal of the second microcomputer 402 is offset by a predetermined time τR with respect to the timing of the trough of the PWM timer.
Period 0 is the state before the first microcomputer 401 is restarted, and the second microcomputer 402 is operating alone. In period 1, the first microcomputer 401 is restarted.

In period 2, the first microcomputer 401 receives the ready signal from the second microcomputer 402 and grasps the timing of the trough of the PWM timer of the second microcomputer 402 based on the reception start timing. Then, the first microcomputer 401 calculates the timing at which the synchronization signal should be transmitted in accordance with the timing of the trough of the second microcomputer 402, and waits until that timing.
In period 3, the first microcomputer 401 transmits the synchronization signal at the calculated timing. The second microcomputer 402 restarts the timer at the rise timing of the synchronization signal received from the first microcomputer 401 and shifts to the synchronous drive mode. As a result, the continuity of the operation of the second microcomputer 402 can be ensured, and synchronous control can be performed after the first microcomputer 401 is restarted.

In operation example 5B shown in FIG. 24, as in operation example 5A, the first microcomputer 401 is restarted by reset or the like while the second microcomputer 402 continues to operate. Also, the transmission start timing of the ready signal of the second microcomputer 402 coincides with the timing of the trough of the PWM timer. In other words, the operation example 5B corresponds to the case of "τR=0" in the operation example 5A.
Period 0 and period 1 are the same as in Operation Example 5A.
In period 2, the first microcomputer 401 receives the ready signal from the second microcomputer 402 and simultaneously transmits the synchronization signal. The second microcomputer 402 restarts the timer at the rise timing of the synchronization signal received from the first microcomputer 401 and shifts to the synchronous drive mode. As a result, the continuity of the operation of the second microcomputer 402 can be ensured, and synchronous control can be performed after the first microcomputer 401 is restarted.

In operation example 6 shown in FIG. 25, the second microcomputer 402 is restarted by a reset or the like while the first microcomputer 401 continues to operate.
Period 0 is the state before the second microcomputer 402 is restarted, and the first microcomputer 401 is operating alone. In period 1, the second microcomputer 402 is restarted.
In period 2, the second microcomputer 402 restarts the timer at the rising timing of the synchronization signal received from the first microcomputer 401 and shifts to the synchronous drive mode. As a result, synchronous control can be performed after the second microcomputer 402 is restarted.

As described above, even if one microcomputer restarts while the other microcomputer continues to operate, the restarted microcomputer synchronizes with the synchronous signal or ready signal of the microcomputer that continues to operate to ensure continuity of operation. Synchronous control can be performed from the timer start time.
Furthermore, when each microcomputer performs control in units of multiple cycles of the synchronization signal, it is possible to synchronize the control of multiple cycles by recognizing the reference timing of the control cycle and restarting the microcomputer to start the timer. can.

(Second embodiment)
A second embodiment will be described with reference to FIGS. 26 and 27. FIG.
As shown in FIG. 26, the ECU 102 of the second embodiment includes a first microcomputer 401 as a synchronization signal transmitting side microcomputer, and two second and third microcomputers 402 and 403 as a synchronization signal receiving side microcomputer. I have. For each microcomputer, only the configuration related to transmission/reception of synchronization signals and ready signals is illustrated. The timing correction unit 423, the ready signal transmission unit 623, and the handshake determination unit 613 of the third microcomputer 403 are all the same as the timing correction unit 422, the ready signal transmission unit 622, and the handshake determination unit 612 of the second microcomputer 402. It has the same configuration.
It should be noted that the description of the reference numerals of the third microcomputer 403 is omitted from the reference numerals in parentheses in the claims.

FIG. 27 shows an operation example in which handshake after startup is successful between three microcomputers according to operation example 1 of the first embodiment shown in FIG. Notes on the illustration are the same as in FIG. 10 and the like. Also, the description of the handshake time is omitted.
In period 1, the microcomputers 401, 402, and 403 are in a state after activation.
In period 2 , the first microcomputer 401 transmits a synchronization notice signal to the second microcomputer 402 and the third microcomputer 403 .

The second microcomputer 402 and the third microcomputer 403 receive the synchronization notice signal in period 2 .
In period 3, the second microcomputer 402 and the third microcomputer 403 transmit ready signals to the first microcomputer 401 in response.
When the first microcomputer 401 receives the ready signal in period 3, it terminates the synchronization notice signal in period 4. FIG.

Through operations in periods 2, 3, and 4, the handshake determination units 611, 612, and 613 of the microcomputers 401, 402, and 403 determine that the handshake has succeeded, and issue an initial synchronization command to each drive timing generation unit. .
In period 5, the first microcomputer 401 outputs the synchronization signal and simultaneously starts the timer. Also, the second microcomputer 402 and the third microcomputer 403 start timers at the rising timing of the synchronization signal received from the first microcomputer 401 . As a result, the microcomputers 401, 402, and 403 drive the motor 80 synchronously from the first time after activation, that is, in the synchronous drive mode.

In the above-described second embodiment, handshake is performed with a master/slave type ECU configuration in which one sync signal transmitting microcomputer is regarded as a master and a plurality of sync signal receiving microcomputers are regarded as slaves.
Further, as another configuration of the ECU including three microcomputers, for example, a configuration in which the synchronization signal is transmitted from the first microcomputer to the second microcomputer and the synchronization signal is transmitted from the second microcomputer to the third microcomputer may be employed. In this configuration, the second microcomputer functions as a synchronizing signal receiving microcomputer in relation to the first microcomputer, and functions as a synchronizing signal transmitting microcomputer in relation to the third microcomputer. That is, the handshake is implemented by the chained ECU configuration.

Furthermore, even in an ECU having four or more microcomputers, it is possible to implement handshake between a plurality of microcomputers by using a master/slave type configuration, a chain type configuration, or a combination thereof. In addition, when it is determined that the handshake has failed in a device with three or more systems, the drive mode in which the motor drive signal is not generated by the other microcomputer and the motor is driven only by the own microcomputer is the " In contrast to "single system drive mode", it can be rephrased as "partial system drive mode".

(Third embodiment)
A third embodiment will be described with reference to FIGS. 28 to 32. FIG. The third embodiment differs from the first embodiment in the configuration regarding the communication of the synchronization signal and the ready signal.
As shown in FIG. 28, in the ECU 103 of the third embodiment, the first microcomputer 401 and the second microcomputer 402 have synchronization signal generators 411 and 412 and timing correctors 421 and 422, respectively. The first microcomputer 401 and the second microcomputer 402 function as a "synchronization signal transmitting side microcomputer" and a "synchronization signal receiving side microcomputer", and mutually transmit and receive synchronization signals.
The configuration of the synchronous signal lines in this embodiment consists of a first synchronous signal line 471 for transmission from the first microcomputer 401 to the second microcomputer 402 and a transmission line from the second microcomputer 402 to the first microcomputer 401, as indicated by solid lines. A reliable second synchronization signal line 472 may be separately provided. Alternatively, a synchronization signal line 48 capable of bi-directional communication may be used, as indicated by the dashed line. At least one of the bidirectional sync signal line 48 and the unidirectional sync signal lines 471 and 472 may be shared with other communication signal lines used for inter-microcomputer communication.

When the common synchronous signal line 48 is used as a bidirectional signal line, as shown in FIG. are set at different timings. Especially in the example of FIG. 29, microcomputers 401 and 402 alternately transmit synchronization signals.
As in the description of the first embodiment, instead of two-way communication using the synchronization signal line, the level of the port signal is changed from the microcomputer on the synchronization signal transmission side to the microcomputer on the synchronization signal reception side. may be notified in both directions.

In addition, for example, when the activation timings of the microcomputers 401 and 402 are different, the microcomputer activated first may transmit the synchronization signal to the microcomputer activated later.
Alternatively, the synchronization signal may be mainly transmitted from the first microcomputer 401 to the second microcomputer 402, and may be transmitted in the opposite direction only in some cases. For example, the first microcomputer 401 may be activated in synchronization with the synchronization signal from the second microcomputer 402 at startup, and thereafter the second microcomputer 402 may operate in synchronization with the synchronization signal from the first microcomputer 401. . Further, for example, when the first microcomputer 401 has an abnormality and is reset, the operation start timing of the own microcomputer may be determined based on the synchronization signal from the second microcomputer 402 and the operation may be started. In this case, when the microcomputer recovers from the abnormality, it is possible to restart the motor drive in a synchronized state from the beginning.

In addition, regarding transmission and reception of ready signals, both the first microcomputer 401 and the second microcomputer 402 have ready signal transmission/reception units 621 and 622, and can mutually transmit and receive ready signals. Here, the ready signal transmission line 475 may be composed of two unidirectional communication lines like the synchronization signal line, or may be composed of two-way communication lines.
In the third embodiment, the first microcomputer 401 and the second microcomputer 402 have exactly the same functions and have complete redundancy. Therefore, since it is possible to cope with all failure patterns for one system, the reliability can be further improved.
Further, by using a common two-way synchronization signal line 48 with different transmission timings of the synchronization signals in each direction, the number of parts of the ECU can be reduced and the configuration can be simplified.

[Operation example 7]
FIG. 30 shows an operation example 7 in which the microcomputers 401 and 402 transmit and receive ready signals to each other and perform handshake according to the third embodiment. For the synchronization signal transmission/reception in Operation Example 7, the first microcomputer 401 is assumed to be the synchronization signal transmission side microcomputer, and the second microcomputer 402 is assumed to be the synchronization signal reception side microcomputer for convenience. However, the microcomputers 401 and 402 may alternate the transmitting side and the receiving side of the synchronization signal. Alternatively, without being limited to the configuration of FIG. 28, the operation example 7 may be executed in an ECU configured so that only the ready signal can be transmitted/received bidirectionally and the synchronization signal is transmitted/received unidirectionally.

Arrows “R1-n (n=1, 2, 3)” in FIG. 30 represent the ready signal transmitted from the first microcomputer 401 to the second microcomputer 402 at the n-th time after the first microcomputer 401 is activated. The arrow “R2-n (n=1, 2)” represents the ready signal transmitted from the second microcomputer 402 to the first microcomputer 401 at the n-th time after the second microcomputer 401 is activated. These ready signals include two types, a ready signal that notifies completion of activation of the own microcomputer and a ready signal that indicates success of handshake ("HS-OK" in the figure).
In FIG. 30, the fine segmentation of the fine periods is omitted and distinguished only in the broad framework. At time r10 in period 1, the first microcomputer 401 is activated before the second microcomputer 402 is activated. After starting, the first microcomputer 401 transmits ready signals R1-1 and R1-2 indicating "completion of starting" at times r11 and r12 in a predetermined period. "NG" in the figure means that the ready signal is not received.

Next, after the second microcomputer 402 is activated at time r20 of period 2, the second microcomputer 402 transmits a ready signal R2-1 indicating "activation completed" at time r21, and the first microcomputer 401 receives this. At time r13 after receiving the ready signal R2-1, the first microcomputer 401 transmits the ready signal R1-3 of "handshake successful", and the second microcomputer 402 receives this. Subsequently, at time r22 after receiving the ready signal R1-3, the second microcomputer 402 transmits a ready signal R2-2 indicating "handshake successful". Although the first microcomputer 401 receives the ready signal R2-2, it ignores the ready signal R2-2 because it has already determined that the handshake was successful.

In this way, when both the microcomputers 401 and 402 determine that the handshake has succeeded, in the next period 3, the first microcomputer 401 outputs the synchronization signal and simultaneously starts the timer. The second microcomputer 402 starts a timer at the rising timing of the synchronization signal received from the first microcomputer 401 . As a result, the microcomputers 401 and 402 drive the motor 80 synchronously from the first time after activation.

The post-startup processing of the first microcomputer 401 and the second microcomputer 402 of Operation Example 7 are shown in the flowcharts of FIGS. 31 and 32, respectively. In FIGS. 31 and 32, steps common to those in FIGS. 16 and 17 are denoted by the same step numbers, and description thereof will be omitted as appropriate. Further, the step specific to the operation example 7 is marked with the letter "R" at the end of the step number.
In the first microcomputer activation post-processing shown in FIG. 31, in S51R, the first microcomputer 401 transmits a ready signal indicating "completion of activation" to the second microcomputer 402 and starts counting the elapsed time.
When the elapsed time is less than the first handshake time Ths1 and it is determined YES in S52, it is determined in S53R whether the first microcomputer 401 has received a ready signal indicating "completion of activation" from the second microcomputer 402. If the first microcomputer 401 has received the "completion of startup" ready signal and it is determined YES in S53R, the first microcomputer 401 transmits the "handshake successful" ready signal to the second microcomputer 402 in S54R. Then, the process proceeds to S56.

If the first microcomputer 401 has not received the "startup complete" ready signal and it is determined NO in S53R, the first microcomputer 401 receives the "handshake successful" ready signal from the second microcomputer 402 in S55R. It is determined whether it has been received. If YES is determined in S55R, the process proceeds to S56. If the ready signal of "handshake success" has not been received and it is determined NO in S55R, the process returns to before S52.
If the elapsed time reaches the first handshake time Ths1 and it is determined as NO (that is, timeout) in S52, the process also proceeds to S56.
The first microcomputer 401 transmits a synchronization signal to the second microcomputer 402 in S56. The following S57 to S59 are the same as in FIG. That is, when the ready signal of "handshake success" is transmitted/received, synchronous control is performed in S58, and when timeout occurs, asynchronous control is performed in S59.

In the second microcomputer activation post-processing shown in FIG. 32, in S61R, the second microcomputer 402 transmits a ready signal indicating "completion of activation" to the first microcomputer 402 and starts counting the elapsed time.
When the elapsed time is less than the second handshake time Ths2 and it is determined YES in S62, it is determined in S63R whether the second microcomputer 402 has received a ready signal indicating "completion of activation" from the first microcomputer 401. FIG. If the second microcomputer 402 has received the ready signal of "completion of startup" and YES is determined in S63R, the second microcomputer 402 sends the ready signal of "handshake success" to the first microcomputer 401 in S64R. It transmits, and it transfers to S66.

If the second microcomputer 402 has not received the "completion of startup" ready signal and it is determined NO in S63R, the second microcomputer 402 receives the "successful handshake" ready signal from the first microcomputer 401 in S65R. It is determined whether it has been received. If YES is determined in S65R, the process proceeds to S66. If the "handshake successful" ready signal has not been received and it is determined NO in S65R, the process returns to before S62.
When the elapsed time reaches the second handshake time Ths2 and it is determined NO (that is, timeout) in S62, the second microcomputer 402 independently starts the timer in S67 to perform asynchronous control. After S67, synchronization processing steps S50, S68, S69, and S80 after starting the first microcomputer may be performed in the same manner as in FIG.
As described above, in the operation example 7, the microcomputers 401 and 402 transmit and receive ready signals to each other, so that the handshake can be preferably executed.

(Other embodiments)
(a) The motor 80 to be controlled in the above embodiment is a multi-winding motor in which two sets of windings 801 and 802 are arranged on a common stator with an electrical angle of 30 degrees shifted from each other. A motor to be controlled in other embodiments may have two or more winding sets arranged in the same phase. In addition, the configuration is not limited to a configuration in which two or more sets of windings are arranged on a common stator of one motor. may be applied to the motor of
Also, the number of phases of the polyphase brushless motor is not limited to three, and may be four or more. Furthermore, the motor to be driven is not limited to an AC brushless motor, and may be a brushed DC motor. In that case, an H-bridge circuit may be used as the "motor drive circuit".

(b) In the handshake operation examples shown in FIGS. 10 and 15, after the first microcomputer 401 is activated, it transmits a high-level synchronization signal to the second microcomputer 402 as a synchronization notice signal. The second microcomputer 402 may be notified by some means that the first microcomputer 401 has started, and the second microcomputer 402 may transmit the ready signal based on this, without being limited to the configuration using such a synchronization notice signal. .

Further, for example, in a system in which the first microcomputer 401 always starts up before the second microcomputer 402 starts up, the second microcomputer 402 does not use the synchronization notice signal from the first microcomputer 401, and the second microcomputer 402 transmits a ready signal at its own timing. You may In this case, the initial handshake units 611 and 612 can determine that the handshake was successful only by the fact that the ready signal was normally transmitted and received from the second microcomputer 402 to the first microcomputer 401 .

(c) The motor control device does not have to include an analog signal sampling section that synchronizes with the motor drive timing generation section. In that case, the motor control device may perform control calculations based on externally acquired digital data. Alternatively, feedforward control may be implemented without using feedback information.
Further, in a configuration including an analog signal sampling section, the sampling timing may overlap with the switching timing of the motor drive signal.

(d) The method of generating the motor drive signal is not limited to the PWM control method shown in FIG. method or the like may be adopted. Further, the carrier of the PWM control method is not limited to a triangular wave, and a sawtooth wave may be used.

(e) The motor control device of the present invention is not limited to motors for electric power steering devices, and may be applied to motors for any other purpose.
As described above, the present invention is not limited to such embodiments, and can be embodied in various forms without departing from the scope of the invention.

101, 102, 103...ECU (motor control device),
401... First (synchronization signal transmitting side) microcomputer,
402 ... second (synchronization signal receiving side) microcomputer,
441, 442 ... drive timing generators,
451, 452 ... drive signal generator,
651, 652... clock generation circuit,
701, 702... Motor drive circuit, 80... Motor.

Claims (1)

a plurality of motor drive circuits (701, 702) for driving one or more motors (80);
Drive signal generators (451, 452) for generating motor drive signals (Dr1, Dr2) for commanding the plurality of motor drive circuits, and drive timing generators for generating drive timings, which are pulse timings of the motor drive signals. a plurality of microcomputers (401, 402) having units (441, 442);
a plurality of clock generation circuits (651, 652) that independently generate clocks that are used as references for the operation of the plurality of microcomputers;
with
At least one microcomputer among the plurality of microcomputers that synchronizes with the drive timing of its own microcomputer and that transmits a synchronization signal for synchronizing the drive timings of the plurality of microcomputers is defined as a synchronization signal transmission side microcomputer (401), Assuming that at least one microcomputer that receives the synchronization signal transmitted from the synchronization signal transmission side microcomputer is a synchronization signal reception side microcomputer (402),
a synchronous drive mode in which the synchronization signal transmitting side microcomputer and the synchronization signal receiving side microcomputer that has received the synchronization signal drive the motor in synchronization;
an asynchronous drive mode in which the synchronization signal transmitting side microcomputer and the synchronization signal receiving side microcomputer drive the motor asynchronously without using the synchronization signal;
a partial system drive mode in which the motor is driven by only one of the synchronization signal transmitting side microcomputer and the synchronization signal receiving side microcomputer;
For the three driving modes of
A motor control device that may shift in order of the partial system drive mode, the asynchronous drive mode, and the synchronous drive mode when the synchronous signal transmission side microcomputer and the synchronous signal reception side microcomputer are started.

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