Motor control device

Abstract

The present invention provides a motor control device capable of determining the cause of abnormal communication between a plurality of control circuits. A first microcomputer (21) determines the success or failure of communication through a first communication line (41), the success or failure of communication through a second communication line (42), and a second clock (S CL2 ) is correct or not, to determine the cause of the communication abnormality (the actual abnormal content). Specifically, the first microcomputer (21) separately determines whether the communication abnormality between the first microcomputer (21) and the second microcomputer (31) is caused by the abnormality of the first communication line (41) and the second communication line (42), or is caused by the functional stop of the second microcomputer (31). The second microcomputer (31) determines whether the communication abnormality between the first microcomputer (21) and the second microcomputer (31) is caused by the abnormality of the first communication line (41) and the second communication line (42), and the first clock (S CL1 ) to determine the cause of the communication abnormality.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Japanese Patent Application No. 2018-208146 filed on November 5, 2018, the entire contents of which are hereby incorporated by reference. Technical Field

[0003] The invention relates to a motor control device. Background Art

[0004] In the past, there is a known control device that controls a motor as a source of auxiliary torque applied to a steering mechanism of a vehicle. For example, a control device in Japanese Patent Publication No. 2018-103899 controls the power supply to a motor having two systems of windings. The control device has two sets of drive circuits and a control system corresponding to the two systems of windings, respectively. Each control system independently controls the power supply to the windings of each system by controlling each drive circuit.

[0005] The control system of each system has a microcomputer. One of the microcomputers of each system functions as a master computer, and the other functions as a slave computer. The microcomputers of each system mutually exchange information indicating abnormalities of their own systems. When an abnormality occurs in the microcomputer that functions as the master computer, the microcomputer that previously functions as the slave computer functions as the master computer.

[0006] In the control device of Japanese Patent Gazette No. 2018-103899, when detecting these abnormalities, the first microcomputer and the second microcomputer are worried that the same abnormality will be detected despite the different causes. For example, in the case where the second microcomputer stops functioning and the communication with the second microcomputer is not established, in either case, the first microcomputer detects that the communication with the second microcomputer is abnormal. In addition, in the case where the first microcomputer stops functioning and the communication with the first microcomputer is not established, in either case, the second microcomputer detects that the communication with the first microcomputer is abnormal. This is because in the case where the first microcomputer or the second microcomputer stops functioning, the communication between the first microcomputer and the second microcomputer is not established. In this way, there is a possibility that the first microcomputer and the second microcomputer cannot determine the cause of the communication abnormality. Summary of the invention

[0007] One of the objects of the present invention is to provide a motor control device capable of identifying the cause of abnormality in communication between a plurality of control circuits.

[0008] A motor control device according to one embodiment of the present invention comprises: a control circuit for independently controlling the power supply to the winding groups of the plurality of systems of the motor by system, the number of the control circuits being the same as the number of the plurality of systems; a plurality of communication lines for transmitting and receiving status signals representing the status of each system respectively generated by the plurality of control circuits between the control circuits; and a signal line for transmitting and receiving periodic pulse signals representing normal operation respectively generated by the plurality of control circuits between the plurality of control circuits. The control circuit determines whether the communication through the communication line is abnormal or the function of the control circuit of the other system has stopped based on a combination of the success or failure of the communication through the communication line and the correctness or failure of the periodic pulse signals of the other system obtained through the signal line.

[0009] Regardless of whether the communication through the communication line is not established or the control circuit of the other system as the communication object stops functioning, the communication between the control circuit and the control circuit of the other system becomes an abnormal state. However, according to the above structure, the abnormal cause of the communication between multiple control circuits can be determined. For example, when the communication through the communication line is not established, when the periodic pulse signal of the other system is normal, it can be said that the control circuit of the other system is in operation. Therefore, it can be known that it is not the state in which the control circuit of the other system stops functioning, but the communication through the communication line is abnormal. In this way, the control circuit can determine whether the communication through the communication line is abnormal or the function of the control circuit of the other system stops functioning based on the combination of the success or failure of the communication through the communication line and the correctness or failure of the periodic pulse signal of the other system obtained through the signal line.

[0010] Another aspect of the present invention is preferably that in the motor control device of the above aspect, when communication through the communication line is not established and the periodic pulse signal of the other system obtained through the signal line is normal, the control circuit determines that communication through the communication line is abnormal.

[0011] According to this structure, when the communication through the communication line is not established and the periodic pulse signal of the other system obtained through the signal line is normal, it can be said that the control circuit of the other system is operating. Therefore, it can be known that the control circuit of the other system is not in a state of stopping function, but the communication through the communication line is abnormal.

[0012] Another embodiment of the present invention is preferably that in the motor control device of the above embodiment, when communication through the communication line is not established and the periodic pulse signal of the other system obtained through the signal line is abnormal, the control circuit determines that the function of the control circuit of the other system is stopped.

[0013] When the function of the control circuit of the other system as the communication object stops, the communication through the communication line is not established. In addition, the periodic pulse signal generated by the control circuit of the other system whose function is stopped also shows abnormality. Therefore, according to the above structure, if the communication through the communication line is not established and the periodic pulse signal of the other system obtained through the signal line is abnormal, it can be said that the function of the control circuit of the other system is stopped.

[0014] Another embodiment of the present invention is preferably that in the motor control device of the above embodiment, a plurality of the communication lines and a plurality of the signal lines are respectively provided, and when communication through any one of the plurality of communication lines is not established and the periodic pulse signal of the other system obtained through the signal line is normal, the control circuit determines that the communication through any one of the plurality of communication lines is abnormal.

[0015] According to this structure, when the communication through any one of the multiple communication lines is not established, and the periodic pulse signal of the other system obtained through the signal line is normal, it can be said that the control circuit of the other system is operating. Therefore, it can be known that it is not the state in which the control circuit of the other system stops functioning, but the abnormality of the communication through any one of the multiple communication lines.

[0016] Another embodiment of the present invention is preferably that in the motor control device of the above embodiment, a plurality of the communication lines and a plurality of the signal lines are respectively provided, and when communication is established through any one of the plurality of communication lines and the periodic pulse signal of other systems obtained through the signal line is abnormal, the control circuit determines that the signal line transmitting the periodic pulse signal indicating the abnormality is abnormal.

[0017] In the case where the function of the control circuit of the other system as the communication object stops, all communications through the communication line are not established. Therefore, according to the above structure, if the periodic pulse signal of the other system obtained through the signal line is abnormal, and the communication through any one of the multiple communication lines is established, it can be said that it is not the state where the control circuit of the other system stops functioning, but the signal line that transmits the periodic pulse signal indicating the abnormality is abnormal. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and other features and advantages of the present invention are further clarified by the following detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings.

[0019] Figure 1 This is a block diagram showing one embodiment of a motor control device.

[0020] Figure 2This is a diagram showing an overview of abnormality determination conditions of a first microcomputer, abnormality contents as determination results, an operating state of a first control unit, and an operating state of a second control unit in one embodiment.

[0021] Figure 3 This is an overview diagram showing abnormality determination conditions of the second microcomputer in one embodiment, the content of abnormality as a determination result, the operating state of the first control unit, and the operating state of the second control unit. DETAILED DESCRIPTION

[0022] Hereinafter, an embodiment of the motor control device of the present invention will be described. Figure 1 As shown, an ECU (electronic control unit) 11 as a motor control device controls the drive of a motor 12. The motor 12 is a three-phase brushless motor. The motor 12 has a rotor 13, a first winding group 14, a second winding group 15, a first rotation angle sensor 16, and a second rotation angle sensor 17. The first winding group 14 and the second winding group 15 have a U-phase coil, a V-phase coil, and a W-phase coil, respectively. The first rotation angle sensor 16 and the second rotation angle sensor 17 detect the rotation angles θm1 and θm2 of the motor 12 (rotor 13).

[0023] The ECU 11 and the motor 12 (the first winding group 14 and the second winding group 15) are connected to each other via a bus bar or a cable. The ECU 11 controls the power supply to the first winding group 14 and the second winding group 15 according to the system. The ECU 11 has a first control unit 20 that controls the power supply to the first winding group 14, and a second control unit 30 that controls the power supply to the second winding group 15.

[0024] The first control unit 20 includes a first microcomputer 21 as a control circuit and a first inverter 22 .

[0025] The first microcomputer 21 includes a first clock generating unit 21a. The first clock generating unit 21a generates a first clock S based on a clock of a fundamental frequency obtained from a crystal oscillator (not shown) provided in the ECU 11. CL1 . The first clock S CL1 It is a clock signal for defining the operation timing of each part (CPU and its peripheral circuit) of the first microcomputer 21. CL1 It is also a periodic pulse signal indicating that the first microcomputer 21 is operating normally. CL1 The high-level voltage and the low-level voltage are repeated alternately at a constant cycle.

[0026] The first microcomputer 21 calculates a first current command value, which is a target value of the current to be supplied to the first winding group 14. The first current command value is set to a value that is half (50%) of the amount of current required for the first winding group 14 to generate half of the total torque required of the motor 12. The first microcomputer 21 generates a command signal S1 (PWM signal) for the first inverter 22 by performing current feedback control so that the actual current value supplied to the first winding group 14 follows the first current command value. The first microcomputer 21 controls the energization of the first winding group 14 using the rotation angle θm1 of the motor 12 (rotor 13) detected by the first rotation angle sensor 16.

[0027] The first inverter 22 is a three-phase inverter of PWM method, and converts the DC power supplied from the DC power supply into three-phase AC power by switching the switching elements of each phase based on the command signal S1 generated by the first microcomputer 21. The first inverter 22 supplies the current corresponding to the command signal S1 to the first winding group 14.

[0028] The second control unit 30 basically has the same configuration as the first control unit 20. That is, the second control unit 30 includes a second microcomputer 31 as a control circuit and a second inverter 32.

[0029] The second microcomputer 31 includes a second clock generating unit 31a. The second clock generating unit 31a generates a second clock S based on a clock of a fundamental frequency obtained from a crystal oscillator (not shown) provided in the ECU 11. CL2 . Second clock S CL2 The second clock S is a clock signal for determining the operation timing of each part (CPU and its peripheral circuits) of the second microcomputer 31. CL2 This is also a periodic pulse signal indicating that the second microcomputer 31 is operating normally.

[0030] The second microcomputer 31 calculates the second current command value, which is the target value of the current to be supplied to the second winding group 15. The second current command value is set to a value that is half (50%) of the amount of current required for the second winding group 15 to generate half of the total torque required of the motor 12. The second microcomputer 31 generates a command signal S2 (PWM signal) for the second inverter 32 by performing current feedback control so that the actual current value supplied to the second winding group 15 follows the second current command value. The second microcomputer 31 controls the energization of the second winding group 15 using the rotation angle θm2 of the motor 12 (rotor 13) detected by the second rotation angle sensor 17. The current corresponding to the command signal S2 is supplied to the second winding group 15 through the second inverter 32.

[0031] The first microcomputer 21 and the second microcomputer 31 exchange digital signals with each other via the first communication line 41 and the second communication line 42. As a standard for the communication between the first microcomputer 21 and the second microcomputer 31 via the first communication line 41 and the second communication line 42, for example, SPI (Serial Peripheral Interface), which is a standard for synchronous serial communication, is adopted. In addition, the first microcomputer 21 and the second microcomputer 31 each have a function of detecting abnormalities in themselves and the systems to which they belong.

[0032] The first microcomputer 21 generates a first state signal S which is a digital signal indicating the state of the first system to which the first microcomputer 21 belongs. d1 , and the generated first state signal S d1 The first state signal S is supplied to the second microcomputer 31 via the first communication line 41 and the second communication line 42. d1 The abnormality occurrence state of the first system, the operating state of the first system, and the generated torque generated by the first winding group 14 are included. The abnormality occurrence state of the first system includes, for example, the presence or absence of abnormalities in the first microcomputer 21, the first inverter 22, and the first rotation angle sensor 16. The operating state of the first system has two states: a state in which the first microcomputer 21 can perform power supply control for the first winding group 14, and a state in which the power supply control for the first winding group 14 cannot be performed due to a decrease in the power supply voltage. The generated torque is the degree of torque generated by the first winding group 14, and corresponds to the target value of the current supplied to the first winding group 14, that is, the current command value.

[0033] The second microcomputer 31 is similar to the first microcomputer 21 and generates a second state signal S which is a digital signal indicating the state of the second system to which the second microcomputer 31 belongs. d2 , and the generated second state signal S d2 The signal is supplied to the first microcomputer 21 via the first communication line 41 and the second communication line 42 .

[0034] The first microcomputer 21 is connected to the second state signal S d2When it is recognized that the power supply control for the second winding group 15 by the second system cannot be executed, the first power supply control or the second power supply control is executed for the first winding group 14. The so-called first power supply control refers to the power supply control in the normal time when the two-system drive is executed, and is a power supply control for supplying half of the total torque required by the motor 12 through the torque generated by the first winding group 14. The so-called second power supply control refers to the power supply control for supplying all of the total torque required by the motor 12 through the torque generated by the first winding group 14. When the second power supply control is executed, the current command value for the first winding group 14 is set to a value twice that of the normal time when the two-system drive is executed.

[0035] The second microcomputer 31 receives the first state signal S d1 When it is recognized that the power supply control for the first winding group 14 by the first system cannot be executed, the first power supply control or the second power supply control is executed for the second winding group 15 in the same manner as the first microcomputer 21 .

[0036] In this way, by independently controlling the power supply to the two winding groups in the motor 12 , when an abnormality occurs in the first winding group, the motor 12 can continue to rotate by power supply to the second winding group.

[0037] The first microcomputer 21 and the second microcomputer 31 mutually perform a first clock S via the first signal line 43 and the second signal line 44. CL1 and the second clock S CL2 The first microcomputer 21 and the second microcomputer 31 are connected based on the first state signal S d1 , the second state signal S d2 , the first clock S CL1 , the second clock S CL2 Here, when the function of either the first microcomputer 21 or the second microcomputer 31 stops, the first clock S generated by the stopped microcomputer CL1 Or the second clock S CL2 This indicates an abnormality, and all communications are interrupted via the first communication line 41 and the second communication line 42. Using this fact, the first microcomputer 21 and the second microcomputer 31 determine whether it is a simple communication abnormality with the microcomputer of the communication partner or whether the function of the microcomputer of the communication partner has stopped.

[0038] like Figure 2 As shown, the first microcomputer 21 detects the following abnormalities (A) to (E).

[0039] (A) Function stop of the second microcomputer 31

[0040] (B) Abnormality of the second signal line 44 (including open circuit failure)

[0041] (C) First communication abnormality (both the first communication line 41 and the second communication line 42 are abnormal)

[0042] (D) Second communication abnormality (abnormality of the second communication line 42)

[0043] (E) Third communication abnormality (abnormality of the first communication line 41)

[0044] The specific detection method of abnormalities (A) to (E) is as follows.

[0045] <Abnormal (A)>

[0046] The first microcomputer 21 determines that the function of the second microcomputer 31 is stopped when all of the following determination conditions (A1) to (A3) are satisfied simultaneously.

[0047] (A1) Communication via the first communication line 41 is not established.

[0048] (A2) Communication via the second communication line 42 is not established.

[0049] (A3) Second clock S CL2 Exception (including failure to obtain).

[0050] When both the communication through the first communication line 41 and the communication through the second communication line 42 are not established, and the second clock S CL2 In the case of an abnormality, the second microcomputer 31 is likely to be in a state of stopping its function. Therefore, the power supply control for the motor 12 (first winding group 14) is performed only by the first microcomputer 21 that operates normally. That is, in the ECU 11, although the second control unit 30 including the second microcomputer 31 is in a state of stopping its operation, the first control unit 20 including the first microcomputer 21 continues to operate normally.

[0051] <Abnormal (B)>

[0052] The first microcomputer 21 determines that an abnormality has occurred in the second signal line 44 when the following determination conditions (B1) and (B2) are all satisfied simultaneously.

[0053] (B1) At least one of the communication through the first communication line 41 and the communication through the second communication line 42 is established.

[0054] (B2) Second clock S CL2 Exception (including failure to obtain).

[0055] When the function of the second microcomputer 31 stops, both the communication through the first communication line 41 and the communication through the second communication line 42 are not established. Therefore, when at least one of the communication through the first communication line 41 and the communication through the second communication line 42 is established, the second microcomputer 31 is not in a state of stopping its function but in an operating state. Therefore, although at least one of the communication through the first communication line 41 and the communication through the second communication line 42 is established, the second clock S CL2 In the case of an abnormality, the second signal line 44 is more likely to be abnormal. CL2 The abnormal state is that the second clock S cannot be obtained. CL2 In the case of the state, there is a possibility that an open circuit failure (disconnection) of the second signal line 44 will occur.

[0056] When the first microcomputer 21 determines that an abnormality has occurred in the second signal line 44, it stops its own operation. CL2 After the first microcomputer 21 becomes abnormal (including being unable to obtain), it is impossible to determine whether it is a simple communication abnormality between the first microcomputer 21 and the second microcomputer 31 or whether the function of the second microcomputer 31 stops. Therefore, when an abnormality occurs in the second signal line 44, the power supply control for the motor 12 (the second winding group 15) is performed only by the second microcomputer 31. That is, in the ECU 11, the first control unit 20 including the first microcomputer 21 stops its operation, while the second control unit 30 including the second microcomputer 31 continues to operate normally.

[0057] <Abnormal (C)>

[0058] The first microcomputer 21 determines that a first communication abnormality has occurred when all of the following determination conditions (C1) to (C3) are satisfied simultaneously. The first communication abnormality refers to a state in which both the first communication line 41 and the second communication line 42 are abnormal.

[0059] (C1) Communication via the first communication line 41 is not established.

[0060] (C2) Communication via the second communication line 42 is not established.

[0061] (C3) Second clock S CL2 normal.

[0062] In the case where both the communication through the first communication line 41 and the communication through the second communication line 42 are not established, and the second clock S CL2Under normal circumstances, only the first communication line 41 and the second communication line 42 are abnormal, and the second microcomputer 31 operates normally. However, here, although it depends on the product specifications, in the case of the first communication abnormality, the first microcomputer 21 is operated in priority to the second microcomputer 31. Therefore, in the case of the first communication abnormality, the power supply control for the motor 12 (first winding group 14) is performed only by the first microcomputer 21 that operates normally. That is, in the ECU 11, the first control unit 20 including the first microcomputer 21 continues to operate normally, while the second control unit 30 including the second microcomputer 31 stops its operation.

[0063] Incidentally, depending on product specifications, when the first communication abnormality occurs, the second microcomputer 31 may be configured to operate with priority over the first microcomputer 21. In this case, when the first communication abnormality occurs, the power supply control for the motor 12 (second winding group 15) is performed only by the second microcomputer 31.

[0064] <Abnormal (D)>

[0065] The first microcomputer 21 determines that the second communication abnormality has occurred when all of the following determination conditions (D1) to (D3) are satisfied simultaneously. The second communication abnormality refers to a state in which the second communication line 42 is abnormal.

[0066] (D1) Communication via the first communication line 41 is established.

[0067] (D2) Communication via the second communication line 42 is not established.

[0068] (D3) Second clock S CL2 normal.

[0069] Even if the communication via the second communication line 42 is not established, since the communication via the first communication line 41 is established and the second clock S CL2 The second microcomputer 31 also operates normally. However, when the first microcomputer 21 determines that the second communication abnormality has occurred, it stops its own operation. This is because after the second communication line 42 becomes abnormal, the first microcomputer 21 cannot obtain the second status signal S d2 Therefore, in the case of the second communication abnormality, the power supply control for the motor 12 (the second winding group 15) is performed only by the second microcomputer 31 operating normally. That is, in the ECU 11, the first control unit 20 including the first microcomputer 21 stops its operation, while the second control unit 30 including the second microcomputer 31 continues to operate normally.

[0070] <Abnormal (E)>

[0071] The first microcomputer 21 determines that the third communication abnormality has occurred when all of the following determination conditions (E1) to (E3) are satisfied simultaneously. The third communication abnormality refers to a state in which the first communication line 41 is abnormal.

[0072] (E1) Communication via the first communication line 41 is not established.

[0073] (E2) Communication via the second communication line 42 is established.

[0074] (E3) Second clock S CL2 normal.

[0075] Even if the communication via the first communication line 41 is not established, since the communication via the second communication line 42 is established and the second clock S CL2 Normal, so the second microcomputer 31 also operates normally. However, as described later, the second microcomputer 31 also has the same abnormality detection function as the first microcomputer 21. Moreover, when the second microcomputer 31 determines that the third communication abnormality has occurred, it stops its own operation. This is because after the first communication line 41 is abnormal, the second microcomputer 31 cannot obtain the first status signal S d1 Therefore, when the third communication abnormality occurs, the power supply control for the motor 12 (first winding group 14) is performed only by the first microcomputer 21 that operates normally. That is, in the ECU 11, the first control unit 20 including the first microcomputer 21 continues to operate normally, while the second control unit 30 including the second microcomputer 31 stops its operation.

[0076] like Figure 3 As shown, the second microcomputer 31 detects the following abnormalities (F) to (J).

[0077] (F) Function stop of the first microcomputer 21

[0078] (G) Abnormality of the first signal line 43 (including open circuit failure)

[0079] (H) First communication abnormality (both the first communication line 41 and the second communication line 42 are abnormal)

[0080] (I) Second communication abnormality (abnormality of the second communication line 42)

[0081] (J) Third communication abnormality (abnormality of the first communication line 41)

[0082] The specific detection method of abnormalities (F) to (J) is as follows.

[0083] <Abnormal (F)>

[0084] The second microcomputer 31 determines that the function of the first microcomputer 21 is stopped when all of the following determination conditions (F1) to (F3) are satisfied simultaneously.

[0085] (F1) Communication via the first communication line 41 is not established.

[0086] (F2) Communication via the second communication line 42 is not established.

[0087] (F3) First clock S CL1 Exception (including failure to obtain).

[0088] When both the communication through the first communication line 41 and the communication through the second communication line 42 are not established, and the first clock S CL1 In the case of an abnormality, the first microcomputer 21 is likely to be in a state of stopping its function. Therefore, the power supply control for the motor 12 (the second winding group 15) is performed only by the second microcomputer 31 that is operating normally. That is, in the ECU 11, although the first control unit 20 including the first microcomputer 21 is in a state of stopping its operation, the second control unit 30 including the second microcomputer 31 continues to operate normally.

[0089] <Abnormal (G)>

[0090] The second microcomputer 31 determines that an abnormality has occurred in the first signal line 43 when the following determination conditions (G1) and (G2) are all satisfied simultaneously.

[0091] (G1) At least one of communication through the first communication line 41 and communication through the second communication line 42 is established.

[0092] (G2) First clock S CL1 Exception (including failure to obtain).

[0093] When the first microcomputer 21 stops functioning, both the communication through the first communication line 41 and the communication through the second communication line 42 are not established. Therefore, when at least one of the communication through the first communication line 41 and the communication through the second communication line 42 is established, the first microcomputer 21 is not in a state of stopping its function but in an operating state. Therefore, although at least one of the communication through the first communication line 41 and the communication through the second communication line 42 is established, at the first clock S CL1 In the case of an abnormality, the first signal line 43 is more likely to be abnormal. CL1 The abnormal state is that the first clock S cannot be obtained. CL1 In the case of the state, there is a possibility that an open circuit failure (disconnection) of the first signal line 43 may occur.

[0094] The second microcomputer 31 stops its own operation when it determines that an abnormality has occurred in the first signal line 43. This is because CL1 After the second microcomputer 31 becomes abnormal (including being unable to obtain), it is impossible to determine whether it is a simple communication abnormality with the first microcomputer 21 or a functional stop of the first microcomputer 21. Therefore, when an abnormality occurs in the first signal line 43, the power supply control for the motor 12 (first winding group 14) is performed only by the first microcomputer 21. That is, in the ECU 11, the first control unit 20 including the first microcomputer 21 continues to operate normally, while the second control unit 30 including the second microcomputer 31 stops its operation.

[0095] <Abnormal(H)>

[0096] The second microcomputer 31 determines that a first communication abnormality has occurred when all of the following determination conditions (H1) to (H3) are satisfied simultaneously. The first communication abnormality refers to a state in which both the first communication line 41 and the second communication line 42 are abnormal.

[0097] (H1) Communication via the first communication line 41 is not established.

[0098] (H2) Communication via the second communication line 42 is not established.

[0099] (H3) First clock S CL1 normal.

[0100] In the case where both the communication through the first communication line 41 and the communication through the second communication line 42 are not established, and the first clock S CL1 Under normal circumstances, only the first communication line 41 and the second communication line 42 are abnormal, and the first microcomputer 21 operates normally. However, here, although it depends on the product specifications, in the event of a first communication abnormality, the first microcomputer 21 is made to operate in priority over the second microcomputer 31. Therefore, the second microcomputer 31 stops its own operation when it is determined that the first communication abnormality has occurred. Therefore, in the event of a first communication abnormality, the power supply control for the motor 12 (first winding group 14) is performed only by the first microcomputer 21 that operates normally. That is, in the ECU 11, the first control unit 20 including the first microcomputer 21 continues to operate normally, and on the other hand, the second control unit 30 including the second microcomputer 31 stops its operation.

[0101] Incidentally, depending on product specifications, when the first communication abnormality occurs, the second microcomputer 31 may be configured to operate with priority over the first microcomputer 21. In this case, when the first communication abnormality occurs, the power supply control for the motor 12 (second winding group 15) is performed only by the second microcomputer 31.

[0102] <Abnormal (I)>

[0103] The second microcomputer 31 determines that a second communication abnormality has occurred when all of the following determination conditions (I1) to (I3) are satisfied simultaneously. The second communication abnormality refers to a state in which the second communication line 42 is abnormal.

[0104] (I1) Communication via the first communication line 41 is established.

[0105] (I2) Communication via the second communication line 42 is not established.

[0106] (I3) First Clock S CL1 normal.

[0107] Even if the communication through the second communication line 42 is not established, since the communication through the first communication line 41 is established and the first clock S CL1 Normal, so the first microcomputer 21 operates normally. However, as mentioned above, the first microcomputer 21 stops its own operation when it determines that the second abnormality has occurred. This is because after the second communication line 42 is abnormal, the first microcomputer 21 cannot obtain the second status signal S d2 Therefore, in the case of the second communication abnormality, the power supply control for the motor 12 (the second winding group 15) is performed only by the second microcomputer 31 operating normally. That is, in the ECU 11, the first control unit 20 including the first microcomputer 21 stops its operation, while the second control unit 30 including the second microcomputer 31 continues to operate normally.

[0108] <Abnormal(J)>

[0109] The second microcomputer 31 determines that the third communication abnormality has occurred when all of the following determination conditions (J1) to (J3) are satisfied simultaneously. The third communication abnormality refers to a state in which the first communication line 41 is abnormal.

[0110] (J1) Communication via the first communication line 41 is not established.

[0111] (J2) Communication via the second communication line 42 is established.

[0112] (J3) First clock S CL1 normal.

[0113] Even if the communication through the first communication line 41 is not established, since the communication through the second communication line 42 is established and the first clock S CL1 The first microcomputer 21 also operates normally. However, when the second microcomputer 31 determines that the third communication abnormality has occurred, it stops its own operation. This is because after the first communication line 41 is abnormal, the second microcomputer 31 cannot obtain the first status signal S d1 Therefore, when the third communication abnormality occurs, the power supply control for the motor 12 (first winding group 14) is performed only by the first microcomputer 21 that operates normally. That is, in the ECU 11, the first control unit 20 including the first microcomputer 21 continues to operate normally, while the second control unit 30 including the second microcomputer 31 stops its operation.

[0114] Therefore, according to this embodiment, the following effects can be obtained.

[0115] (1) The first microcomputer 21 can generate a signal based on the success or failure of communication through the first communication line 41, the success or failure of communication through the second communication line 42, and the second clock S CL2 Specifically, the first microcomputer 21 can separately determine whether the communication abnormality with the second microcomputer 31 is caused only by the abnormality of the first communication line 41 and the second communication line 42, or by the cessation of the function of the second microcomputer 31. In addition, the second microcomputer 31 is also the same as the first microcomputer 21, and can determine the cause of the communication abnormality (the true abnormality content) based on the success or failure of the communication through the first communication line 41, the success or failure of the communication through the second communication line 42, and the first clock S CL1 Specifically, the second microcomputer 31 can separately determine whether the communication abnormality between the second microcomputer 31 and the first microcomputer 21 is caused only by the abnormality of the first communication line 41 and the second communication line 42, or by the functional stop of the first microcomputer 21. Therefore, the first microcomputer 21 and the second microcomputer 31 can determine the cause of the mutual communication abnormality.

[0116] The success or failure of communication through the communication line (41, 42) refers to the result of determining whether communication through the communication line is established (whether signals are correctly transmitted and received). The reasons why communication between the microcomputers (21, 31) is not established include, for example, an abnormality of the microcomputer, an abnormality of the communication line (disconnection, short circuit), or electromagnetic noise. CL1 , S CL2) refers to the result of the determination of whether the clock is correct. For example, if the pulse pattern of the clock is a prescribed pattern, the clock is determined to be normal. When the pulse pattern of the clock shows an abnormal pattern different from the prescribed pattern, the clock is determined to be abnormal. The abnormality of the clock includes the interruption of the clock. In addition, the so-called communication abnormality refers to a state (a state in which communication is not established) in which, although the microcomputer (21, 31) operates correctly, the communication (transmission and reception of signals) through the communication line between the microcomputers is not performed correctly due to an abnormality such as a disconnection or a short circuit in the communication line. In addition, the so-called function of the microcomputer refers to various functions of the microcomputer, such as a communication function (input and output function) for transmitting and receiving signals with external devices, and a calculation function (control function) performed by a CPU (central processing unit). The so-called functional stop of the microcomputer refers to the stop of at least one of the various functions of the microcomputer. Due to the functional part that stops operating in the microcomputer, it is difficult to communicate (transmit and receive signals) with external devices. As the cause of the functional stop of the microcomputer, for example, a reduction in power supply voltage or noise is considered.

[0117] (2) In ECU11, the first microcomputer 21 and the second microcomputer 31 can determine the cause of the communication abnormality, that is, the real abnormal content. Therefore, ECU11 is suitable for use as a control device for an electric power steering device or a wire-controlled steering device that requires higher operation reliability. In this case, ECU11 controls the auxiliary motor as the driving source of the electric power steering device, or the steering motor as the driving source of the steering mechanism in the wire-controlled steering device. As the auxiliary motor or the steering motor, a structure with a winding group of multiple systems is adopted, as in the present embodiment. Therefore, the first microcomputer 21 and the second microcomputer 31 in ECU11 can continue to supply power to the auxiliary motor or the steering motor according to the cause of the communication abnormality (the real abnormal content), and then continue the steering operation assistance or steering action.

[0118] By the way, when the first microcomputer 21 and the second microcomputer 31 are configured not to have the above-mentioned function of identifying the cause of the communication abnormality (the actual abnormality content), the following situation is concerned. That is, the first microcomputer 21 and the second microcomputer 31 may have to adopt a configuration that immediately stops the power supply to the motor (the first winding group 14 and the second winding group 15) when a communication abnormality is detected from the perspective of fail-safe.

[0119] (3) By independently controlling the power supply to the winding groups (14, 15) of the two systems in the motor 12, the motor 12 can be rotated by supplying the power to the winding group of the second system when an abnormality occurs in the first system. In addition, in this case, when the microcomputer of the normal system adopts a structure that executes the second power supply control before (power supply control for supplying the total torque required by the motor 12 with the torque generated by the winding group of the normal system), the following effect is also obtained. That is, since the target value (first current command value or second current command value) of the current supplied to the winding group of the normal system is set to a value twice that of the normal time when the two systems are driven, when an abnormality occurs in one system, the motor 12 generates a torque of the same degree as the total torque when the two systems are driven. In particular, when the ECU 11 is applied to an electric power steering device or a steer-by-wire control device, appropriate steering assistance or steering action can be continued.

[0120] (4) Even in the case of a communication anomaly, the first microcomputer 21 and the second microcomputer 31 may operate. In this case, when the first microcomputer 21 and the second microcomputer 31 mutually determine that the functions of the communication objects have stopped due to the communication anomaly, and in order to compensate for the torque generated by the winding group of the faulty system, the first microcomputer 21 and the second microcomputer 31 perform the previous second power supply control to increase the power supply to the winding group of the own system, and the following situation is concerned. That is, since the total current supplied to the motor 12 is greater than the current originally supplied, there is a possibility that the motor 12 generates excessive torque. In particular, when the ECU 11 is applied to an electric power steering device, there is a concern that self-steering may occur.

[0121] In this regard, in the present embodiment, when the cause of the communication abnormality (the real abnormality content) can be determined, if the communication of at least one of the first communication line 41 and the second communication line 42 is not established, the status signal (S) from the communication object cannot be obtained. d1 , S d2 ) stops the microcomputer of the other party. Therefore, even if the status signal (S d1 , S d2 ) performs the second power supply control, and the total current supplied to the motor 12 is the same as the current when the two systems are normally driven. Therefore, the motor 12 does not generate excessive torque. In addition, when the ECU 11 is applied to the electric power steering device, self-steering does not occur.

[0122] In addition, this embodiment can also be implemented by being modified as follows.

[0123] The ECU 11 of the present embodiment may be embodied as a control device for a motor used in other vehicle-mounted equipment other than an electric power steering device or a steer-by-wire device.

[0124] In the present embodiment, a first communication line 41 and a second communication line 42 are provided, but more than three communication lines may be provided. In the present embodiment, the power supply to the winding groups (14, 15) of the two systems is independently controlled, but in the case where the motor 12 has more than three winding groups, the power supply to the winding groups of the three systems may be independently controlled. In this case, as the ECU 11, a structure having the same number of discrete control units as the number of systems is adopted. The control units of each system are connected to each other via a plurality of communication lines and a plurality of signal lines.

[0125] The signal indicating the normal operation of the first microcomputer 21 and the second microcomputer 31 is not limited to the clock (S CL1 , S CL2 ). That is, the first microcomputer 21 and the second microcomputer 31 may also generate a dedicated periodic pulse signal for monitoring the action. The pulse period of the dedicated periodic pulse signal may not be constant. In addition, the pulse pattern of the dedicated periodic pulse signal may also be different from the clock.

[0126] The first microcomputer 21 can also determine the previous Figure 2 At least one of the abnormalities (A) to (E) shown in the figure is abnormal. In addition, the second microcomputer 31 may also determine the previous Figure 3 At least one of the abnormalities (F) to (J) shown.

[0127] In this embodiment, the first signal line 43 and the second signal line 44 are provided, but a single signal line for bidirectional communication (clock transmission and reception) between the first microcomputer 21 and the second microcomputer 31 may be provided instead.

[0128] The second microcomputer 31 can also communicate with each other via the first clock S CL1 and the second clock S CL2 The granting and receiving of.

[0129] In this embodiment, the first communication line 41 and the second communication line 42 are provided, but only one of them may be provided. That is, the first microcomputer 21 and the second microcomputer 31 may also perform two-way communication (signal transmission and reception) with each other via the first communication line 41 or the second communication line 42. Even so, the first microcomputer 21 can determine the previous Figure 2 In addition, the second microcomputer 31 can also determine the previous Figure 3The anomaly shown (F).

Claims

1. A motor control device, comprising: A plurality of control circuits for independently controlling the power supply to the winding groups of the plurality of systems of the motor, the number of the control circuits being the same as the number of the plurality of systems; a plurality of communication lines for transmitting and receiving status signals representing the status of each system respectively generated by the plurality of control circuits; and A plurality of signal lines are used to transmit and receive periodic pulse signals generated by the plurality of control circuits respectively and indicating normal operation of the control circuits. The control circuits are respectively configured to determine whether the communication through the communication line is abnormal or the function of the control circuit of the other system stops, based on the combination of the success or failure of the communication through the communication line and the correctness or failure of the periodic pulse signal of the other system obtained through the signal line. The above-mentioned control circuits are respectively constructed to, when communication is established through any one of the multiple communication lines and the above-mentioned periodic pulse signal of the other system obtained through the above-mentioned signal line is abnormal, determine that the above-mentioned signal line that transmits the above-mentioned periodic pulse signal indicating the abnormality is abnormal, stop the operation of the control circuit itself, and only perform power supply to the motor through the control circuit of the above-mentioned other system.

2. The motor control device according to claim 1, wherein: When the communication through the communication line is not established and the periodic pulse signal of the other system acquired through the signal line is normal, the control circuit determines that the communication through the communication line is abnormal.

3. The motor control device according to claim 1 or 2, wherein: When the communication through the communication line is not established and the periodic pulse signal of the other system acquired through the signal line is abnormal, the control circuit determines that the function of the control circuit of the other system is stopped.

4. The motor control device according to claim 1 or 2, wherein: When communication through any one of the plurality of communication lines is not established and the periodic pulse signal of the other system acquired through the signal line is normal, the control circuit determines that communication through any one of the plurality of communication lines is abnormal.

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