Control device for electric vehicle

Abstract

To establish sufficient fail-safe when a microcomputer for controlling two motors fails, and to achieve simplification and cost reduction of a configuration of a control device for an electric vehicle as a whole.SOLUTION: A control device for an electric vehicle includes a motor 2, an upper ECU7 that obtains a target value for controlling the motor 2, and an MG ECU11 that controls the motor 2 so as to achieve the target value, the MG ECU1 including a motor microcomputer 3 that controls the motor 2 and a ASIC5 that controls the motor 2 in place of the motor microcomputer 3 when the motor microcomputer 3 fails. The higher-level ECU7 includes a monitoring ECU1 that monitors at least the system of the ASIC5 included in the MG IC9, and the ASIC5 is data-communicably connected to the higher-level ECU7.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a control device for an electric vehicle equipped with a motor or motor-generator as a driving force source, and more particularly to a control device equipped with a fail-safe function. [Background technology]

[0002] Patent Document 1 describes a motor control device that controls two motors mounted on an electric vehicle. The motor control device includes a microcomputer and an application-specific integrated circuit (ASIC). The microcomputer outputs a control target value for each motor based on a command value calculated using vehicle speed, drive demand, and the like. The ASIC is configured to control the two motors and has a control circuit for control in the event of a failure, providing feedback control of motor torque when torque control by the microcomputer fails. Therefore, according to the control device described in Patent Document 1, even if an abnormality occurs in the microcomputer and it is no longer able to control the two motors, the ASIC can still control each motor, thereby establishing a sufficient fail-safe. Furthermore, since there is no need to provide a microcomputer for each of the two motors, costs can be reduced. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-035146 Summary of the Invention [Problem to be solved by the invention]

[0004] When a motor serving as a driving force source in an electric vehicle is controlled by an electronic control device such as a microcomputer, even if the ASIC described above is not used, it is common to monitor the system, torque, and the monitoring status. When an ASIC is provided for each motor, as in the control device described in Patent Document 1, it is desirable to monitor the system, torque, and the monitoring status even when the ASIC controls motor torque in the event of a microcomputer malfunction. Therefore, if a monitoring device were provided for each ASIC provided for each of the two motors, the overall configuration of the control device would become complicated and potentially expensive.

[0005] The present invention has been made in light of the above technical problems, and aims to provide a control device that can establish a sufficient fail-safe in the event of a failure of the microcomputer that controls the two motors, and that can simplify the overall configuration of the device and reduce costs. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the present invention provides a control device for an electric vehicle comprising a motor as a driving force source, a host electronic control device that determines a target value for controlling the motor based on data input from outside, and a motor electronic control device that controls the motor to achieve the target value, wherein the motor electronic control device comprises a motor microcomputer that controls the motor, and an application-specific integrated circuit that controls the motor in place of the motor microcomputer in the event of a failure of the motor microcomputer, wherein the host electronic control device has a monitoring integrated circuit that monitors the system of at least the application-specific integrated circuit included in the motor electronic control device, and the application-specific integrated circuit is connected to the host electronic control device so as to be able to communicate data. [Effects of the Invention]

[0007] In the present invention, in the event of a failure of the motor microcomputer, an application-specific integrated circuit controls the motor in place of the motor microcomputer. The application-specific integrated circuit is connected to a host electronic control device so as to be able to communicate data. The host electronic control device also has a monitoring integrated circuit that monitors at least the system of the application-specific integrated circuit. Therefore, when the application-specific integrated circuit controls the motor due to a microcomputer failure, at least the system of the application-specific integrated circuit is monitored by the monitoring integrated circuit. Furthermore, the control status of the torque command value, etc., by the application-specific integrated circuit is monitored as necessary. As a result, according to the present invention, a sufficient fail-safe can be established in the event of a failure of the motor electronic control device. Furthermore, since at least the system of the application-specific integrated circuit can be monitored by using a monitoring integrated circuit or monitor normally provided in the host electronic control device, the overall configuration of the control device can be simplified and reduced in cost. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram showing a control system of a control device according to an embodiment of the present invention; [Figure 2] FIG. 2 is a block diagram illustrating a monitoring system selected from the control systems shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Next, an embodiment of the present invention will be described with reference to the accompanying drawings. Note that the embodiment described below is merely an example of how the present invention can be implemented, and is not intended to limit the present invention.

[0010] Vehicles targeted by embodiments of the present invention are electric vehicles such as battery electric vehicles (BEVs) that use a motor or motor-generator (hereinafter collectively referred to as "motor") driven by battery power as a driving force source, and hybrid vehicles (HEVs, PHEVs) that use an internal combustion engine and a motor as a driving force source. The motors may be, for example, two motors, one for front-wheel drive and one for rear-wheel drive, or two motors, one for the left wheel and one for the right wheel, and examples of such motors are permanent magnet three-phase synchronous motors. Therefore, each motor is supplied with power from a battery via an inverter, and the rotation speed and torque of the motor are controlled by controlling the frequency and current.

[0011] Like a normal vehicle, an electric vehicle in an embodiment of the present invention is equipped with an acceleration / deceleration operation means such as an accelerator pedal, and a required driving force is calculated based on data indicating the vehicle's running state, such as the amount of operation of the accelerator pedal and the vehicle speed. The required driving force is essentially a target value for the driving force of the entire vehicle, and a control target value for the motor required to achieve the target value of the driving force is calculated, and the motor is controlled based on the control target value.

[0012] The target driving force is calculated by a host electronic control device that controls the overall driving of the electric vehicle. This host electronic control device is primarily composed of a microcomputer consisting of a processing element (CPU), memory elements (RAM, ROM), and various interfaces (I / F). This host electronic control device has, as its functions (i.e., programs), a function for calculating the target driving force for the entire electric vehicle, as well as a function for monitoring the entire system that controls the driving force and the torque of each drive wheel of the electric vehicle. The host electronic control device may be equipped with a monitoring integrated circuit (monitoring IC) for this monitoring. Therefore, various sensors that detect the accelerator position, vehicle speed, etc. are connected to the host electronic control device to obtain data from outside. A monitor or the like may also be connected to output the monitoring status or monitoring results to an external device.

[0013] The motor's control target value is calculated and output by the motor electronic control device. The motor electronic control device is primarily composed of a microcomputer consisting of a processing element (CPU), memory elements (RAM, ROM), and various interfaces (I / F). The main function (i.e., program) of the motor electronic control device is to calculate a control target value corresponding to the output torque for each motor required to achieve the target driving force transmitted from the above-mentioned upper-level electronic control device. The control target value is directly the control value of the inverter, and by applying a current of a frequency corresponding to that control value to the motor, a torque corresponding to the control target value is output from the motor.

[0014] A motor microcomputer that controls the motor for such driving is provided in the motor electronic control device. The motor microcomputer also has the function of monitoring and supervising the system and torque of the motor electronic control device, and therefore may include a monitoring integrated circuit (monitoring IC).

[0015] In preparation for the failure of the motor microcomputer, the motor electronic control device can be equipped with an application-specific integrated circuit (ASIC). This ASIC can be provided for each motor. The ASIC is a device that controls the motor in place of the motor microcomputer in the event of a failure of the motor microcomputer. Therefore, in terms of so-called motor control functions such as output torque, it is similar to the motor microcomputer. The ASIC is also connected to the above-mentioned host electronic control device so as to be able to communicate data. Examples of the data to be communicated include the above-mentioned target driving force or torque command value and monitoring data.

[0016] Figure 1 shows a block diagram of a control system of a control device according to an embodiment of the present invention. Figure 1 shows a control system for one of two motors. In Figure 1, reference numeral "1" denotes a motor electronic control unit (MG-ECU), which includes a motor microcomputer (motor microcomputer) 3 that calculates a control target value for a motor 2. The MG-ECU 1 is provided with a monitoring integrated circuit (monitoring IC) 4 for monitoring the system and control torque of the motor microcomputer 3. A run pulse signal and a reset signal are exchanged between the motor microcomputer 3 and the monitoring IC 4.

[0017] Furthermore, the MG-ECU 1 is provided with an ASIC 5 that controls the motor 2 in place of the motor microcomputer 3 in the event of a failure of the motor microcomputer 3. A motor microcomputer 3 may be provided for each of the two motors 2, or may be provided to control both motors 2 collectively. In contrast, an ASIC 5 is provided for each motor 2. In other words, in the event of a failure of the motor microcomputer 3, each motor 2 is controlled by the ASIC 5 provided for that motor 2. Note that the motor 2 is directly controlled by an inverter 6. In other words, the inverter 6 is controlled to a frequency and current value according to a control target value input from the MG-ECU 1, and the motor 2 outputs a torque that satisfies the required driving force.

[0018] The system is provided with a host electronic control unit (host ECU) 7 that calculates a target driving force. The host ECU 7 is equipped with a host microcomputer (host microcomputer) 8 that calculates the target driving force based on externally input data (e.g., accelerator opening and vehicle speed) and outputs the calculated target driving force to the MG-ECU 1. In addition to the function of calculating and outputting the target driving force, the host microcomputer 8 also has the function of monitoring the torque of the ASIC 5 and the system in the event of a failure of the motor microcomputer 3. Furthermore, the host ECU 7 is equipped with a monitoring integrated circuit (monitoring IC) 9 for monitoring purposes. A run pulse signal and a reset signal are exchanged between the monitoring IC 9 and the host microcomputer 8. To enable such monitoring and monitoring, each ASIC 5 and the host microcomputer 8 are connected to each other so that data can be communicated. The data communicated includes a torque command value (control target value) from the ASIC 5 and monitoring data.

[0019] FIG. 2 is a block diagram illustrating the monitoring system of the control system shown in FIG. 1. A torque command based on the required driving force for the electric vehicle is input to the motor microcomputer 3 and ASIC 5 in the MG-ECU 1. A control target value is output to the inverter 6 as a control command signal from the motor microcomputer 3 when there is no malfunction in the motor microcomputer 3, or from the ASIC 5 when there is a malfunction in the motor microcomputer 3. In other words, motor control is executed. The motor 2 is controlled and rotated at a frequency and current value based on this. The phase current value in the inverter 6 and the rotation angle of the motor 2 in this case are input as feedback signals to the motor microcomputer 3 and ASIC 5.

[0020] On the other hand, the host microcomputer 8 in the host ECU 7 monitors (torque monitors) the torque control by the motor microcomputer 3 and the ASIC 5. To this end, the host microcomputer 8 receives a torque command as input, as well as a phase current value from the inverter 6 and a rotation angle from the motor 2 as feedback signals.

[0021] The monitoring IC 9 in the host ECU 7 monitors the system of the host microcomputer 8. The monitoring IC 9 also monitors the maximum output (CMLM) from a charger (not shown).

[0022] In the above-described embodiment, the torque and rotation speed of the motor 2 are controlled by the motor microcomputer 3 in the MG-ECU 1. In this case, the system that controls the motor 2 and the torque are monitored by the monitoring IC 4 in the MG-ECU 1. In contrast, if the motor microcomputer 3 fails, the ASIC 5 controls the motor in place of the motor microcomputer 3. As described above, this ASIC 5 is connected to the host ECU 7 so as to send and receive data to and from the host ECU 7, and the monitoring IC 9 monitors the host microcomputer 8. Therefore, the system and torque of the ASIC 5 are effectively monitored by the monitoring IC 9 in the host microcomputer 8.

[0023] The state in which torque control by ASIC 5 and monitoring or supervision by supervisory IC 9 in host microcomputer 8 are performed is the same as the state in which motor control by motor microcomputer 3 without a malfunction is performed and the system and torque are monitored by supervisory IC 4. In other words, even when motor microcomputer 3 has a malfunction, motor control and monitoring are performed in the same way as when no malfunction occurs in motor microcomputer 3, so a fail-safe can be sufficiently established when motor microcomputer 3 has a malfunction.

[0024] The present invention is not limited to the above-described embodiment, and can be modified and implemented as appropriate within the scope of the object of the present invention. [Explanation of symbols]

[0025] 1. Motor electronic control unit (MG-ECU) 2 motors 3. Microcomputers for motors (motor microcomputers) 4. Monitoring Integrated Circuits (Monitoring ICs) 5 Application Specific Integrated Circuits (ASICs) 6 inverters 7 Upper electronic control unit (upper ECU) 8. Upper microcomputer (upper microcomputer) 9. Monitoring Integrated Circuits (Monitoring ICs)

Claims

[Claim 1] A control device for an electric vehicle comprising: a motor as a driving force source; a host electronic control device that determines a target value for controlling the motor based on data input from outside; and a motor electronic control device that controls the motor so as to achieve the target value, wherein the motor electronic control device comprises a motor microcomputer that controls the motor; and an application specific integrated circuit that controls the motor in place of the motor microcomputer when the motor microcomputer fails, the host electronic control device has a monitoring integrated circuit that monitors a system of at least the application specific integrated circuit included in the motor electronic control device, The application specific integrated circuit is connected to the host electronic control device so as to be able to communicate data with the host electronic control device. A control device for an electric vehicle.

Images