JP5345192B2 - Control device and method for electric vehicle - Google Patents

Description

  In the present invention, a communication abnormality has occurred between a control device for an electric vehicle equipped with a motor (electric motor, rotating electric machine) as a drive source, in particular, a motor control device connected by an in-vehicle communication path (CAN) in the vehicle control device. It relates to the detection of the driving state of the motor.

  In general, in an electric vehicle equipped with a motor as a driving source of a vehicle or a hybrid vehicle, a command value such as a target torque and a rotation speed is transmitted from the vehicle control device to the motor control device through an in-vehicle communication path such as a CAN (Controller Area Network). The motor control device performs the motor control according to the command value. If a communication abnormality occurs between the vehicle control device and the motor control device, the motor cannot be controlled, and it is necessary to detect the communication abnormality promptly.

  In general, communication channels are multiplexed as a countermeasure against communication abnormality. For example, Patent Document 1 below shows a configuration in which a READY signal is connected between controllers separately from CAN to detect an abnormality. Between the vehicle controller (HCU) and the motor controller (MCU), the HCU READY signal can be connected to the MCU, the MCU READY signal can be connected to the HCU, and the HCU can detect the MCU abnormality and the MCU can detect the HCU abnormality. It is configured.

  Further, in Patent Document 1, when a communication abnormality occurs between the HCU and the MCU, the use of the motor is prohibited. When the READY signal from the MCU is failed, the hybrid operation mode function is prohibited for the MCU. A proposal for drive control by an engine controller is shown.

JP 2007-131293 A

The configuration presented in Patent Document 1 has a problem that only the communication state between the controllers can be detected, and the operation state of the motor controller cannot be detected.
In addition, in order to detect the operation state of the motor controller, it is necessary to provide a CAN or a communication path for transmitting the same information as CAN, and there are problems of increased wiring and complicated controller. There is.
Further, in Patent Document 1, there is a problem that even if the motor drive is stopped, there is no means for confirming whether the motor drive can be stopped normally in a situation where CAN communication is abnormal.

  In view of the above problems, an object of the present invention is to provide an electric vehicle control apparatus and method that can detect a driving state of a motor with simple and low-cost means in a state where communication abnormality has occurred.

According to the present invention, a vehicle control device that is a second control device that outputs a motor drive command via a communication path to a motor control device that is a first control device that drives and controls a traveling motor according to a motor drive command. When a communication abnormality with the motor control device on the communication path is detected, the traveling motor is detected from an output from a third control device connected on the communication path that detects a change according to a driving state of the traveling motor. A battery control device including a sensor for detecting a battery current by estimating a drive state of the motor, comparing the estimation result with the motor drive command to determine whether or not the motor is operating according to the motor drive command , and the said vehicle control device estimates the driving state of the traction motor from the battery current, in the electric vehicle control device or the like, characterized in that.

  According to the present invention, it is possible to provide an electric vehicle control apparatus and method capable of detecting the driving state of a motor with simple and low-cost means in a state where communication abnormality has occurred.

1 is an overall schematic configuration diagram of an electric vehicle control device according to an embodiment of the present invention. It is an operation | movement flowchart at the time of the communication abnormality detection in the vehicle control apparatus by this invention.

  Hereinafter, an electric vehicle control apparatus and method according to the present invention will be described with reference to the drawings in accordance with embodiments. In addition, in each figure, the same or an equivalent part is shown with the same code | symbol, and the overlapping description is abbreviate | omitted.

Embodiment 1 FIG.
FIG. 1 is an overall schematic configuration diagram of an electric vehicle control apparatus for an electric vehicle as an electric vehicle according to an embodiment of the present invention. In FIG. 1, various sensors 7 are connected to the vehicle control device 1 (second control device) to detect each state quantity. Here, for example, an accelerator position sensor that detects the amount of depression of the driver's accelerator pedal, a brake position sensor that detects the amount of depression of the brake pedal, and a vehicle speed sensor (both not shown) that detects the speed of the vehicle are connected to control the vehicle. The device 1 determines a torque command value (motor drive command) to the traveling motor 3 according to the accelerator and brake input amounts from these drivers and the vehicle speed.

  A motor control device 2 is connected to the vehicle control device 1 via a CAN (vehicle communication channel), and is configured to perform bidirectional communication at a constant cycle, for example, a 10 millisecond cycle, and the torque command value is controlled by the vehicle via the CAN. The data is transmitted from the device 1 to the motor control device 2 (first control device). In order to notify that the motor control device 2 has normally received the torque command value, the motor control device 2 feeds back the torque command value received to the vehicle control device 1 via CAN.

  The motor control device 2 outputs a control signal from the controller 11 to the inverter 12 so as to drive the traveling motor 3 according to the received torque command value, and the inverter 12 converts the direct current from the drive battery 9 into an alternating current. Output (drive current). The traveling motor 3 is connected to driving wheels 6 via a transmission (T / M) 5, and the driving wheels 6 are rotated by the torque of the traveling motor 3, and the vehicle obtains a propulsive force by a reaction force from the ground. The controller 11 receives a signal from the motor angle sensor 4 for inverter control of the traveling motor 3.

  Further, the vehicle control device 1 includes a motor stop signal 13 separately from the torque command by CAN, and the inverter 12 gives priority to the motor stop signal 13 over the control signal of the controller 11 and stops the alternating current.

  The battery control device 8 (third control device) controls the charging and discharging of the driving battery 9 and attaches information (battery information) such as voltage, current, and temperature necessary for the control around the driving battery 9. Obtain from each sensor. In FIG. 1, a current sensor 10 is shown as an example. The battery control device 8 is connected to the same CAN as the vehicle control device 1 and the motor control device 2, and notifies the vehicle control device 1 of battery information acquired at a constant cycle.

  In the electric vehicle according to this embodiment, the output torque of the traveling motor 3 is changed by signals from various sensors 7 according to the driver's accelerator or brake operation, and the current supplied from the driving battery 9 has the above configuration. Also changes according to the output torque. The current sensor 10 detects this. The vehicle control device 1 estimates whether the traveling motor 3 is operating normally based on the battery current value acquired from the battery control device 8 and the torque command value transmitted to the motor control device 2. For example, when the torque command value is increased so as to increase the output of the traveling motor 3, it is possible to obtain an estimation result of normal operation if the current value increases and abnormal operation if the current value does not increase.

  FIG. 2 is a flowchart showing an operation when the vehicle control device 1 of FIG. 1 detects a communication abnormality. The vehicle control device 1 individually measures the interval of CAN communication from the motor control device 2 and the battery control device 8 (configured as such) (STEP 1). Measurement starts when CAN reception is completed at the end, and when a time until the CAN reception is normally completed exceeds a specified time (first predetermined time), for example, 200 milliseconds, a communication error occurs. It is determined that it has occurred (STEP 2). If a CAN communication abnormality with the motor control device 2 is detected (communication abnormality only in the motor control device 2), the operation is switched to the first operation (restriction) mode (low torque mode) for restricting the motor output. When other communication abnormality is detected, the mode is switched to the second operation (restriction) mode (torque prohibition mode) (STEP3, STEP9).

  The low torque mode reduces the torque command to the motor control device 2. In this embodiment, the torque command is limited to 50% of the normal torque command (STEP 4). The vehicle control device 1 transmits the reduced torque command value (motor drive command) to the motor control device 2 (STEP 5). The estimation result is confirmed whether the motor operation is in accordance with the transmitted torque command value, and in the case of an abnormal operation where the estimation result does not match the reduced torque command value, the state does not match, that is, the first operation mode is the specified time ( The second predetermined time) shifts to confirmation of whether or not the time has passed (STEP 7). If the estimated result is a normal operation that matches the reduced torque command value, the communication recovery is confirmed (STEP 8). Transition (STEP 6).

  In STEP7, when the specified time (second predetermined time) has not elapsed, the process proceeds to STEP8, and when the specified time (second predetermined time) has elapsed, the process proceeds to the second operation (limitation) mode. . In STEP 8, the recovery of the communication state is confirmed. If the communication state is recovered, the normal operation is performed (STEP 11). If the communication state is not recovered, the low torque mode is continued.

  In STEP 9, the operation is switched to the second operation mode. In this embodiment, the output of the traveling motor 3 is stopped (torque inhibition mode). The vehicle control device 1 controls the motor stop signal 13, stops the output of the inverter 12, and stops the driving of the traveling motor 3 (STEP 10).

  In the above example, when the vehicle control device 1 detects an abnormality in communication with the motor control device 2 in the CAN (communication path), the operation is switched to the first operation mode (low torque mode) for limiting the motor output. Thereafter, the driving state of the traveling motor 3 is estimated from the output from the battery control device 8, and the estimation result and the torque command value are compared to determine whether or not the operation is in accordance with the torque command value. After the abnormality is detected, the driving state of the traveling motor 3 may be estimated from the output from the battery control device 8 without switching to the first operation mode.

  With the above operation, the electric vehicle according to the present embodiment is for driving (driving) according to the battery information acquired by the battery control device 8 even when the CAN communication abnormality between the vehicle control device 1 and the motor control device 2 occurs. For example, it is possible to estimate the operation state of the motor 3, and thus it is possible to appropriately perform motor control when communication is abnormal.

  That is, it is possible to estimate the output torque of the traveling motor from the current value of the driving battery and determine whether the motor control device is driving the traveling motor according to the torque command value transmitted from the vehicle control device. Further, when a communication abnormality occurs in the motor control device, it is possible to detect a state that does not require an immediate stop of the motor drive, and to wait for the recovery of the communication abnormality.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various design changes can be made. For example, a signal indicating the battery current from the battery control device (third control device) as a feedback signal obtained via the CAN for estimating the driving state of the traveling motor at the time of communication abnormality with the motor control device However, as long as it is a signal that changes quickly depending on the driving state of the driving motor, it can also be used with a feedback signal from another control device connected to CAN, and the same effect Play.

  DESCRIPTION OF SYMBOLS 1 Vehicle control apparatus, 2 Motor control apparatus, 3 Driving motor, 4 Motor angle sensor, 5 Transmission (T / M), 6 Drive wheel, 7 Various sensors, 8 Battery control apparatus, 9 Drive battery, 10 Current sensor, 11 Controller, 12 Inverter, 13 Motor stop signal, CAN communication path, T / M transmission.

Claims (5)

A vehicle control device that is a second control device that outputs the motor drive command via a communication path to a motor control device that is a first control device that drives and controls the traveling motor according to the motor drive command. When a communication abnormality with the motor control device is detected, a driving state of the traveling motor is determined from an output from a third control device connected through the communication path that detects a change according to a driving state of the traveling motor. Estimating, comparing the estimation result and the motor drive command to determine whether or not it is operating according to the motor drive command , the third control device is a battery control device including a sensor for detecting a battery current, An electric vehicle control device, wherein the vehicle control device estimates a driving state of the traveling motor from a battery current . When the vehicle control device detects a communication abnormality with the motor control device on the communication path, the vehicle control device shifts to a first restriction mode in which the motor drive command is set so as to restrict the output of the traveling motor. The control apparatus for an electric vehicle according to claim 1 , wherein The vehicle control device cancels the first limit mode when the determination changes in the first limit mode that the determination result is an operation according to a motor drive command within a predetermined time. The electric vehicle control device according to claim 2 , wherein when the operation continues for the predetermined time or longer, the operation mode shifts to a second restriction mode. The electric vehicle control device according to claim 3 , wherein the second restriction mode is to stop driving of the traveling motor. In a vehicle control device that is a second control device that outputs the motor drive command via a communication path to a motor control device that is a first control device that drives and controls the travel motor in accordance with the motor drive command, When a communication abnormality with the motor control device is detected, the driving state of the traveling motor is detected from an output from the third control device connected through the communication path that detects a change according to the driving state of the traveling motor. Is a battery control device including a sensor for comparing the estimation result and the motor drive command to determine whether the motor is operating according to the motor drive command, and the third control device detects a battery current. The vehicle control apparatus estimates the driving state of the traveling motor from the battery current .

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