JP5387028B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device, a failure detection method for a vehicle control device, and a program to be executed by a computer, and more specifically, a vehicle control device and a vehicle control device capable of determining a failure of a network driver. The present invention relates to a failure detection method and a program executed by a computer.

  In order to reduce the steering force of vehicles such as passenger cars and trucks, there is a so-called electric power steering (EPS) device that assists steering by a steering assist motor. In the electric power steering apparatus, the driving force of the steering assist motor is applied to the steering shaft or the rack shaft by a transmission mechanism such as a gear or a belt via a speed reducer. Such a control device for the electric power steering apparatus performs feedback control of the motor current in order to accurately generate the steering assist torque. In feedback control, the motor applied voltage is adjusted so that the difference between the current command value and the detected motor current value is small. The adjustment of the motor applied voltage is generally performed by the duty ratio of PWM (pulse width modulation) control. It is done by adjusting.

  Conventionally, for example, there is CAN (Controller Area Network) as a communication protocol for in-vehicle LAN. The CAN communication is performed for each electronic control unit (ECU) (multi-master method). For this reason, each communication has an ID, and superiority or inferiority is determined for each communication so that simultaneous transmission or the like is not performed. Basically, a bus-type network topology is adopted, and necessary termination resistors are installed inside the ECU. Four types of frames are prepared for transferring messages: data frame, remote frame, error frame, and overload frame. Among them, the data frame and the remote frame have identifiers. This identifier does not represent the transferred node, but represents the type of data that comes immediately after (for example, vehicle speed, engine speed, etc.). Basically, all nodes on the bus receive the frame, but only the identifiers that are relevant to them are captured and sent to the upper layer.

  Some ECUs of the electric power steering apparatus are equipped with a CAN driver (see, for example, Patent Document 1). Here, in the ECU of the electric power steering apparatus, the CAN driver is used to transmit and receive data to acquire information necessary for controlling the electric power steering apparatus. As a result, problems occur in the control of the electric power steering apparatus.

JP 2004-122942 A

  The present invention has been made in view of the above, and it is possible to easily and accurately detect a failure of a network driver in a vehicle control device including a network driver for performing data communication via an in-vehicle network. An object of the present invention is to provide a possible vehicle control device, a failure detection method for a vehicle control device, and a program executed by a computer.

In order to solve the above-described problems and achieve the object of the present invention, in a vehicle control device that controls a vehicle control target, data communication is performed via an in-vehicle network, and various types of data communication are necessary. A network driver having a register for setting information, a communication state, etc., a buffer for storing transmission / reception data, a control means for controlling the network driver, and a transmission command to the network driver of the control means Measuring means for measuring time until the register is set to indicate normal transmission completion, and the network driver for the transmission command of the control means based on the measurement time measured by the measuring means. The number of times that the register has not been set to indicate normal transmission completion within a specified time continues for a predetermined number of times. When, characterized in that and a failure determining means determines that the failure of the network driver.

  In addition, according to a preferred aspect of the present invention, it is desirable to further include fail-safe means for performing fail-safe processing when the failure determination means determines that a network driver has failed.

  Moreover, according to a preferable aspect of the present invention, it is desirable that the in-vehicle network is a CAN (Controller Area Network).

  Further, according to a preferred aspect of the present invention, the vehicle control device includes a current command value calculated based on at least a steering torque generated in a steering system of the vehicle, and a steering assist that applies a steering assist force to the steering system. It is desirable that the control device for the electric power steering control the steering assist motor based on the detected current value of the motor.

In order to solve the above-described problems and achieve the object of the present invention, the present invention performs data communication via an in-vehicle network and sets various information, communication status, etc. necessary for the data communication. In the fault diagnosis method for a vehicle control apparatus for controlling a control target of a vehicle, the control means includes: a network driver having a register for storing data and a buffer for storing transmission / reception data; and a control means for controlling the network driver. In response to a transmission command to the network driver, a measurement step of measuring time until the register is set to indicate normal transmission completion, and based on the measurement time measured in the measurement step, the control means In response to the transmission command, the register of the network driver is set to indicate that the transmission is normally completed within a specified time If the number was not et continues for a predetermined number of times, the failure and the determination step determines that the failure of the network driver, characterized in including it.

In order to solve the above-described problems and achieve the object of the present invention, the present invention performs data communication via an in-vehicle network and sets various information, communication status, etc. necessary for the data communication. And a network driver having a register for storing transmission / reception data, and a control means for controlling the network driver, the program mounted on the vehicle control device for controlling the control target of the vehicle, the control In response to a transmission command to the network driver of the means, a measuring step for measuring the time until the register is set to indicate normal transmission completion, and based on the measurement time measured in the measuring step, the control means In response to the transmission command, the register of the network driver indicates that the transmission has been completed successfully within a specified time. If the number of times that did not set and continues for a predetermined number of times, characterized in that to execute a determining failure determination process that a failure of the network driver, to the computer.

According to the present invention, in a vehicle control device that controls a control target of a vehicle, a register for performing data communication via an in-vehicle network and setting various information necessary for the data communication, a communication state, and the like A network driver having a buffer for storing transmission / reception data, control means for controlling the network driver, and a setting indicating that the register indicates normal transmission completion in response to a transmission command to the network driver of the control means; Measuring means for measuring the time to be, and based on the measurement time measured by the measuring means, the register of the network driver completes the normal transmission within a specified time in response to the transmission command of the control means If the number of times that did not set and showing a continued a predetermined number of times, because of the network driver Determining a failure determining means is provided with the a, an effect that it becomes possible to provide a vehicle control device capable of detecting a failure of the network driver in a simple manner.

It is a figure which shows the general structure of an electric power steering apparatus. It is a figure which shows the hardware structural example of EPS-ECU of FIG. It is a figure which shows the structural example of the CAN driver of FIG. It is a figure which shows schematic structure of a CAN communication system. It is a flowchart for demonstrating the process which detects the failure of the CAN driver which CPU of EPS-ECU performs. It is a flowchart for demonstrating the process of a CAN driver when CPU of EPS-ECU requests | requires a process with respect to a CAN driver. It is a functional block diagram of MCU of FIG.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same. In the following embodiments, a control device for an electric power steering device will be described as an example of a vehicle control device.

  FIG. 1 is a diagram illustrating a general configuration of an electric power steering apparatus. In FIG. 1, a column shaft 2 of a steering handle 1 is connected to a tie rod 6 of a steering wheel via a reduction gear 3, universal joints 4a and 4b, and a pinion rack mechanism 5. The column shaft 2 is provided with a torque sensor 10 that detects the steering torque T of the steering handle 1, and a steering assist motor 20 that assists the steering force of the steering handle 1 is connected to the column shaft via the reduction gear 3. 2 is connected. Here, the steering assist motor 20 is, for example, a brushless motor or a brush motor. Electric power steering (EPS) -ECU 30 that controls the electric power steering device is supplied with electric power from battery 14 via built-in power supply relay 13, and an ignition signal is supplied from ignition key 11. Further, the EPS-ECU 30 calculates a current command value for the steering assist motor 20 based on the steering torque T detected by the torque sensor 10 and the vehicle speed V detected by the vehicle speed sensor 12, and the current of the steering assist motor 20 is calculated. Based on the detected value and the current command value, the steering assist motor 20 is drive-controlled so that the current detected value of the steering assist motor 20 follows the current command value.

  FIG. 2 is a diagram showing a hardware configuration of the EPS-ECU 30 shown in FIG. As shown in FIG. 2, the EPS-ECU 30 includes an MCU (micro control unit) 100, an FET pre-driver circuit 110, a motor drive circuit (inverter) 120, a current detection circuit 130, a position detection circuit 140, and the like. ing.

  The MCU 100 includes a CPU 101 (control means), a ROM 102, a RAM 103, an EEPROM (nonvolatile memory) 104, an A / D converter 105, a CAN driver (communication driver) 106, an internal bus 107, and the like. The CPU 101 executes various programs stored in the ROM 102 and controls each part of the electric power steering apparatus.

  The ROM 102 stores various programs executed by the CPU 101, and controls, for example, a motor control program for executing a motor control process (steering assist process) for controlling the steering assist motor 20 and a CAN driver 106 (of the CAN driver 106). Stores a communication control program, etc. (including abnormality detection).

  The RAM 103 is used as a work area when the CPU 101 executes a program, and stores data, processing results, and the like necessary in the processing process.

  The EEPROM 104 is a non-volatile memory that can retain stored contents even after the power is shut off, and stores parameters used by the CPU 101 for control of the electric power steering apparatus. The nonvolatile memory is not limited to the EEPROM, and other nonvolatile memory may be used.

  The A / D converter 105 inputs the steering torque T from the torque sensor 10, the current detection value Im of the steering assist motor 20 from the current detection circuit 130, the motor rotation angle signal θ from the position detection circuit 140, and the like. Convert to digital signal.

  The CAN driver 106 is connected to the CAN bus 160 and performs CAN communication, and is controlled by the CPU 101. The CAN driver 106 receives the vehicle speed V, for example.

  In the above configuration, when the CPU 101 executes the program stored in the ROM 102, the control means for controlling the CAN driver 106, and the time until the CAN driver 106 enters the request state for the processing request of the control means. It functions as a failure determination unit that determines a failure of the CAN driver 106 based on a measurement unit that measures and a measurement time measured by the measurement unit.

  The FET pre-driver circuit 110 converts the PWM control signal for each phase of UVW input from the MCU 100 into positive and negative energization signals (Up, Un, Vp, Vn, Wp, Wn) for each phase, and sends them to the motor drive circuit 120. Output.

  The motor drive circuit 120 includes a bridge circuit composed of a pair of FET switching elements for three phases for the U phase, the V phase, and the W phase, and a reflux diode is connected in parallel to each FET switching element. A DC voltage is applied to the bridge circuit from the battery 14 via the power relay 13. An energization signal is input from the FET pre-driver circuit 110 to the control terminal (gate terminal) of each FET switching element. The DC voltage applied to the motor drive circuit 120 is converted into a three-phase AC voltage by the switching operation of the FET switching element in the motor drive circuit 120, thereby driving the steering assist motor 20. Shunt resistors R1 and R2 are connected to this bridge circuit. A current detection circuit 130 is connected to the shunt resistors R1 and R2, and the current detection value Im of the steering assist motor 20 is thereby detected.

  The position detection circuit 140 outputs the output signal from the position sensor 21 to the A / D converter 105 as a motor rotation angle signal θ.

  FIG. 3 is a diagram illustrating a configuration example of the CAN driver 106 of FIG. The CAN driver 106 includes a RAM 201 having a plurality of message buffers (slots) for storing serial data, and a register 202a for setting various information necessary for data communication, a status flag indicating a communication state, and the like. A message control unit 202 that exchanges serial data between the protocol control unit 203, a CAN protocol control unit 203 that transmits and receives serial data according to the CAN protocol, an interface 204, and a CAN that transmits and receives serial data to and from the CAN bus 160 A transceiver 205 and the like are provided.

  Next, a schematic operation of the CAN driver 106 having the above configuration will be described. First, when the CPU 101 uses the CAN driver 106 to transmit serial data, serial data as transmission data is stored in an arbitrary message buffer of the RAM 201 (here, stored in the message buffer 1 for convenience of explanation). The serial data transmission command is output to the message control unit 202.

  When the message control unit 202 receives a serial data transmission command from the CPU 101, the message control unit 202 reads the serial data stored in the message buffer 1 of the RAM 201 and then outputs the serial data to the protocol control unit 203.

  Upon receiving serial data from the message control unit 202, the protocol control unit 202 transmits serial data from the CAN transceiver 205 according to the CAN protocol. As a result, the serial data is output to the CAN bus 160 and the communication destination node acquires the serial data from the CAN bus 160.

  When the transmission of serial data is normally completed, the protocol control unit 203 outputs a transmission normal completion signal indicating that to the message control unit 202. The message control unit 202 sets the status flag related to data transmission in the register 202a to indicate that transmission is normally completed. Thus, the CPU 101 can recognize the normal completion of transmission by referring to the status flag (register 202a).

  On the other hand, when the CPU 101 uses the CAN driver 106 to receive serial data, first, the communication destination node outputs the serial data to the CAN bus 160. The protocol control unit 203 of the CAN driver 106 receives serial data from the CAN bus 160 via the CAN transceiver 205 according to the CAN protocol.

  The message control unit 202 sequentially stores serial data received by the protocol control unit 203 in the message buffer 2 of the RAM 201. When the protocol control unit 203 outputs a reception normal completion signal indicating completion of serial data reception, the message control unit 202 sets the status flag related to data reception in the register 202a to indicate reception normal completion. Thereby, the CPU 101 refers to the status flag (register 202a) and acquires the serial data stored in the message buffer 2 of the message buffer 201.

  FIG. 4 is a diagram showing a schematic configuration of the CAN communication system. In the figure, a CAN bus 160 includes an engine ECU 301 that controls an engine, the above-described EPS-ECU 30, an A / TECU 302 that controls an automatic transmission, a brake ECU 303 that controls a brake, a panel ECU 304 that controls an operation panel, and Various ECUs are connected. Each ECU is equipped with a CAN driver, and controls a control target assigned to each ECU by performing data communication with each other according to the CAN protocol.

  A process in which the CPU 101 of the EPS-ECU 30 diagnoses a failure of the CAN driver 106 will be described with reference to FIGS. 5 and 6. FIG. 5 is a flowchart for explaining processing for diagnosing a failure of the CAN driver 106 executed by the CPU 101 of the EPS-ECU 30. FIG. 6 is a flowchart for explaining processing of the CAN driver 106 when the CPU 101 of the EPS-ECU 30 makes a processing request to the CAN driver 106.

  In FIG. 5, after resetting the timer count value = 0, the CPU 101 starts measuring time (step S1) and outputs a processing request to the message control unit 202 of the CAN driver 106 (step S2).

  After the processing request, the CPU 101 confirms whether or not the register 202a is in the requested state within a specified time (steps S3 and S4). Here, the predetermined time> the normal operation delay time is set.

  When the register 202a is in the requested operation state within the specified time (“Yes” in step S3), the CPU 101 ends the flow. On the other hand, if the register 202a is not in the requested operation state within the specified time (“No” in steps S3 and S4), the CPU 101 increments the repeat count value T by “1” (step S5).

  Then, the CPU 101 determines whether or not the repeat count value T ≧ the specified count (step S6). Here, the specified number of times ≧ 2 is set. If the repetition count value T is not equal to the prescribed number (“No” in step S6), the process returns to step S1, and the CPU 101 requests the CAN driver 106 again, and the register 202a makes a request within the prescribed time. Check if it is in an operating state.

  On the other hand, if the repetition count value T ≧ the specified number of times (“Yes” in step S6), the CPU 101 determines that the CAN driver 106 has failed and executes fail-safe processing (step S7). In this fail-safe process, for example, the CAN communication is stopped, the warning lamp is turned on, and the vehicle speed is fixed.

  FIG. 6 is a flowchart for explaining the operation of the message control unit 202 of the CAN driver 106. In the figure, the message control unit 202 accepts a processing request (step S12) and executes a processing request (step S13) when other processing is not executed ("No" in step S11).

  FIG. 7 is a diagram illustrating functions (functional configuration of the motor control program) realized by the CPU 101 executing the motor control program.

  As shown in FIG. 7, the CPU 101 includes a torque control system module 500 that calculates a steering assist torque command value based on the steering torque T and the vehicle speed V, a compensation control system module 510 that performs various types of torque compensation, a motor current A motor current control system module 520 that performs FB (feedback) control and a motor current auxiliary control system module 530 that performs FF (feed forward) control of the motor current of the steering assist motor 20 are provided. Next, an outline of the operation will be described.

  First, the steering torque T detected by the torque sensor 10 and the vehicle speed V detected by the vehicle speed sensor 12 are input to the assist map 501, and a steering assist command value is calculated. Further, a compensation value calculated by the compensation control system module 510, for example, a compensation value such as convergence, inertia, and SAT, is added to the steering assist command value by the adder 502 to determine the torque command value Tref. The torque command value Tref is phase-compensated by the phase compensator 503 and then input to the current command value calculator 540. Based on the torque command value Tref, the current command value calculation unit 540 determines the current command value Iref. In the brushless motor, in addition to the torque command value Tref, the rotor angle of the rotor is also input to the current command value calculation unit 540 to determine the current command value Iref.

  On the other hand, the motor current of the steering assist motor 20 is detected by the current detection circuit 130 as the current detection value Im, and is input to the subtraction unit 521 together with the current command value Iref. The subtraction unit 521 calculates the deviation ΔI = Iref−Im and inputs it to the PI (proportional integration) control unit 522. A PI (proportional integration) control unit 522 outputs a voltage control value Vref as a proportional integration output of the deviation ΔI. The current command value Iref is input to the auxiliary value calculation unit 531. An auxiliary value calculated by the auxiliary value calculation unit 531, for example, an auxiliary value for dead time / EMF (back electromotive force) / weak field control is added to the voltage control value Vref by the adding unit 535. The output of the adding unit 535 is input to the PWM control unit 550, subjected to PWM processing, and the PWM control signal of each UVW phase is output to the FET pre-driver circuit 110, via the FET pre-driver circuit 110 and the motor drive circuit 120. The steering assist motor 20 is driven.

  As described above, according to the present embodiment, the CAN driver 106 performs data communication via the CAN network, and the register 202a for setting various information, communication status, and the like necessary for the data communication. And the RAM 201 for storing transmission / reception data. The CPU 101 measures the time until the register 202a is in a request state in response to a processing request to the CAN driver 106, and based on the measurement time, the CAN driver Since the failure of 106 is determined, it becomes possible to detect the failure (partial) of the CAN driver with high accuracy by a simple method.

  Further, the CPU 101 determines that the CAN driver 106 is faulty when the number of times that the register 202a has not entered the requested operation state within a specified time has continued for a predetermined number of times in response to a processing request to the CAN driver 106. Therefore, it is possible to prevent erroneous detection of a CAN driver failure.

  In addition, when the CPU 101 determines that the CAN driver 106 has failed, the CPU 101 performs fail-safe processing, so that it is possible to ensure the safety of the passenger.

  In the above embodiment, the CAN has been described as the in-vehicle network. However, the present invention is not limited to this, and can be applied to other in-vehicle networks such as Lin and Flex Ray. In the above embodiment, the EPS-ECU has been described as an example of a vehicle control device including a network driver. However, the present invention is not limited to this, and an engine ECU, an A / TECU, a brake ECU, The present invention can also be applied to other vehicle control devices such as a panel ECU.

  The vehicle control device, the vehicle control device failure detection method, and the program to be executed by the computer according to the present invention can be widely used in an in-vehicle ECU equipped with a network driver.

DESCRIPTION OF SYMBOLS 1 Steering handle 2 Column shaft 3 Reduction gear 4a, 4b Universal joint 5 Pinion rack mechanism 6 Tie rod 10 Torque sensor 12 Vehicle speed sensor 14 Battery 20 Steering auxiliary motor 30 EPS-ECU
100 MCU (micro control unit)
101 CPU (control means)
102 ROM
103 RAM
104 EEPROM
105 A / D converter 106 CAN driver 107 Bus 110 FET pre-driver circuit 120 Motor drive circuit (inverter)
130 current detection circuit 140 position detection circuit 160 CAN bus 201 RAM
202 Message Control Unit 202a Register 203 Protocol Control Unit 204 Interface 205 CAN Transceiver 301 Engine ECU
302 A / TECU
303 Brake ECU
304 Panel ECU
500 Torque control system module 510 Compensation control system module 520 Motor current control system module 530 Motor current auxiliary control system module

Claims (6)

In a vehicle control device that controls a control target of a vehicle,
A network driver that performs data communication via an in-vehicle network and has a register for setting various information and communication status necessary for the data communication, and a buffer for storing transmission / reception data;
Control means for controlling the network driver;
In response to a transmission command to the network driver of the control means, measuring means for measuring the time until the register is set to indicate normal transmission completion;
Based on the measurement time measured by the measurement means, the number of times that the register of the network driver has not been set to indicate that the transmission has been completed within a specified time with respect to the transmission command of the control means is a predetermined number of times. if it continued, and determines failure determining means that a failure of the network driver,
Vehicle control apparatus characterized by comprising a.   The vehicle control device according to claim 1, further comprising fail-safe means for performing fail-safe processing when the failure determination means determines that the network driver has failed.   The vehicle control apparatus according to claim 1, wherein the in-vehicle network is a CAN (Controller Area Network).   The vehicle control device is based on at least a current command value calculated based on a steering torque generated in a steering system of the vehicle, and a current detection value of a steering assist motor that applies a steering assist force to the steering system. The vehicle control device according to any one of claims 1 to 3, wherein the control device is an electric power steering control device that controls a steering assist motor. A network driver for performing data communication via an in-vehicle network and having a register for setting various information and communication state necessary for the data communication, and a buffer for storing transmission / reception data; and the network driver In the fault detection method for a vehicle control device for controlling a control target of the vehicle,
In response to a transmission command for the network driver of the control means, a measurement step of measuring a time until the register is set to indicate normal transmission completion;
Based on the measurement time measured in the measurement step, the number of times that the register of the network driver has not been set to indicate normal transmission completion within a specified time with respect to the transmission command of the control means is a predetermined number of times. if it continued, and determines the failure determination step that a failure of the network driver,
Fault detection method for a vehicle control apparatus according to claim including things. A network driver for performing data communication via an in-vehicle network and having a register for setting various information and communication state necessary for the data communication, and a buffer for storing transmission / reception data; and the network driver A program mounted on a vehicle control device that controls a control target of the vehicle,
In response to a transmission command for the network driver of the control means, a measurement step of measuring a time until the register is set to indicate normal transmission completion;
Based on the measurement time measured in the measurement step, the number of times that the register of the network driver has not been set to indicate normal transmission completion within a specified time with respect to the transmission command of the control means is a predetermined number of times. if it continued, and determines the failure determination step that a failure of the network driver,
A program for the computer to execute, characterized by causing the computer to execute.

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