JP2006021610A - Vehicle load control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device of vehicle load capable of preventing a motor load 9 from running out of control by stopping supply of power supply voltage to the motor load 9 being the control object when abnormality occurs in a microcontroller 4. <P>SOLUTION: The control device of vehicle load has a 12V power source B1 and a 42V power source B2, the 42V power source B2 is used as the power source driving the motor load 9 being the control object, and the 12V power source B1 is used as the power source of an ECU1 controlling the motor load 9. The control device supplies an operation signal inputted for operating the motor load 9 to the ECU1 by communication through a bus line L1, and controls the motor load 9 based on the operation signal to be supplied. The ECU1 is equipped with the microcontroller 4 controlling the motor load 9 and a bus guardian 7 monitoring the state of the microcontroller 4, and shuts off a 42V bus when it is detected that the abnormality occurs in the microcontroller 4. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle load control device that controls a load mounted on a vehicle using a bus guardian.

  In recent years, systems for controlling brakes and steering mounted on vehicles using electric signals are being built. That is, the operation amount of the brake or the operation amount of the steering is detected as an electric signal, and this is transmitted to the brake or steering control device by the communication means so that the brake or the steering operation corresponding to the operation amount is performed.

  In such a system, since a large capacity load is used, a power source for driving a large capacity load (for example, 42V, 288V, etc.) and an instrument power source for driving instrumentation and a small capacity load ( For example, it is often equipped with two power supplies of 12V).

  Furthermore, a system called a bus guardian has been constructed in order to detect a communication error by the communication means (see Non-Patent Document 1). The bus guardian is provided in each node (corresponding to each ECU in the case of a vehicle) connected to one channel, and monitors the clock state of the node or other control means, When an abnormality is detected, there is a function for preventing a trouble that the entire channel is stopped by stopping communication by the node where the abnormality is detected.

By the way, when controlling a large-capacity load as described above in such a communication system using a bus guardian, if a clock abnormality or a control means abnormality is detected by the bus guardian, the communication of this node is performed. Although the entire communication system can be protected by stopping the operation, the large-capacity load and the power supply for power supply remain connected, so the large-capacity load that has become uncontrollable runs out of control. There is.
FlexRay Requirements Specification Copyright2000 by BMW AG, DaimlerChrysler AG, Robert Bosch GmbH, GeneralMotors / Opel AG (Version 2.0.2, 9th of April, 2002)

  As described above, in the conventional vehicle load control device, when an abnormality occurs in the control means of the ECU as a node, the load may not be controlled. In such a case, There was a problem that the load would runaway if power for power supply continued to be supplied to the load.

  The present invention has been made to solve such a conventional problem, and the object of the present invention is to stop the load to be controlled by stopping the load to be controlled even when an abnormality occurs in the control device. An object of the present invention is to provide a vehicle load control device that can prevent runaway of the vehicle.

  In order to achieve the above object, the invention described in claim 1 of the present application includes a first power source and a second power source having an output voltage higher than that of the first power source, and drives a load to be controlled. The second power source is used as a power source, the first power source is used as a power source for the control means for controlling the load, and an operation signal input for operating the load is transmitted to the control means by communication. In the vehicle load control apparatus, wherein the control means controls the load based on the supplied operation signal, the control means includes a load control unit for controlling the load and the load control unit. A monitoring unit that monitors the state of the power supply, and when the monitoring unit detects that an abnormality has occurred in the load control unit, the wiring that connects the second power source and the load is shut off It is characterized by.

  According to a second aspect of the present invention, when the monitoring unit detects a stop of the load control unit as an abnormal state occurring in the load control unit, the monitoring unit immediately supplies the second power source and the load. When the runaway of the load control unit is detected as an abnormal state occurring in the load control unit, the wiring to be connected is cut off, and a reset signal is output to the load control unit with a certain time interval and reset. When a runaway is detected again after outputting a signal a predetermined number of times, the wiring connecting the second power source and the load is cut off.

  According to a third aspect of the present invention, the wiring connecting the second power source and the load has a fuse on a wiring path, and the monitoring unit provides a wiring path between the fuse and the load. The wiring connecting the first power source and the load is cut off by grounding to the ground and fusing the fuse.

  In the invention of claim 1 of the present application, the state of the load control unit is monitored by the monitoring unit, and when the occurrence of an abnormality is detected, the wiring connecting the second power source and the load is cut off. When the control state becomes uncontrollable, it is possible to prevent the power supply voltage from being continuously supplied to the load and to prevent the runaway of the load. Thereby, fail safe can be achieved.

  In the invention of claim 2, the abnormal state occurring in the load control unit is classified into two states of stop and runaway, and when the load control unit is stopped, the load cannot be clearly controlled. And the wiring for connecting the second power source and the load is immediately cut off. Also, if the load control unit runs away, give a reset signal once or multiple times to try to restore the load control unit, and after giving the reset signal a predetermined number of times, the runaway is still not avoided The wiring connecting the second power source and the load is cut off. Thereby, appropriate control according to the abnormal state of a load control part is attained.

  In the invention of claim 3, a fuse is provided in the wiring connecting the second power source and the load, and when the wiring is cut off, the wiring between the fuse and the load is grounded to the ground. Since the fuse is blown by supplying an overcurrent, the wiring connecting the second power source and the load can be cut off with a very simple configuration.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a vehicle load control device according to an embodiment of the present invention. As shown in the figure, this control device is mounted on a vehicle and controls a load mounted on the vehicle. The control device is a 12V power source (first power source) B1 that outputs a DC voltage of 12 volts, and a DC voltage of 42 volts. 42V power source (second power source) B2 that outputs a voltage of, for example, a motor load 9 for operating the steering angle of the steering of the vehicle, and an ECU (control means) 1 for controlling the motor load 9 are provided. .

  ECU1 is connected with the main control part (illustration omitted) via bus line L1. The main control unit is connected to a plurality of other ECUs, and performs overall control using the plurality of ECUs connected to the main control unit as the same channel.

  The ECU 1 controls the motor load 9 based on the operation signal when the operation signal for the motor load 9 is input via the bus line L1, and includes a bus driver 5 and a microcontroller (load control). Part) 4, a communication control part 6, a bus guardian (monitoring part) 7, a regulator 8, and an electronic switch T1.

  The bus driver 5 transmits the data to the bus line L1 and performs control to receive the data sent through the bus line L1. The communication control unit 6 controls communication between the ECU 1 and another ECU.

  The microcontroller 4 controls the entire ECU 1 as a whole, and when the operation signal for the motor load 9 is input via the bus driver 5, controls the motor load 9 based on the operation signal. . Furthermore, the state of the motor load 9 is monitored, and if there is an abnormality, this information is transmitted to another ECU via the bus line L1.

  The electronic switch T1 is switched on and off by a control signal output from the bus guardian 7. When the electronic switch T1 is on, the 42V bus connecting the motor load 9 and the 42V power source B2 is grounded.

  The regulator 8 converts the power supply voltage supplied from the 12V power supply B1 through the 12V bus into a predetermined voltage level, and supplies it to the bus guardian 7.

  The bus guardian 7 monitors the clock of the microcontroller 4, and it is detected that this clock greatly differs from the global clock of this channel (a typical clock obtained from the clocks of a plurality of ECUs connected to this channel). In this case, a clock error signal is output to the bus driver 5 and transmission from the bus driver 5 is stopped. Further, the operation state of the communication control unit 6 is monitored, and when an abnormality is detected, communication from the bus driver 5 is stopped as described above.

  Further, the operating state of the microcontroller 4 is monitored, and when it is detected that the microcontroller 4 is out of control or stopped, the electronic switch T1 is turned on and the 42V bus is grounded by the procedure described later. Ground.

  Further, a joint box 2 is provided between each of the power supplies B1, B2 and the ECU 1, and a fuse F is provided for cutting off the 42V bus or the 12V bus when an overcurrent occurs.

  FIG. 2 is a flowchart showing a processing procedure performed by the bus guardian 7. The operation of the vehicle load control device according to the present embodiment will be described with reference to FIG.

  When the ECU 1 is driven, the clock of the microcontroller 4 is first checked, and it is determined whether or not this clock is significantly different from the global clock of this channel (step ST1). When a clock abnormality is detected (“abnormal” in step ST1), data transmission by the bus driver 5 is stopped (step ST2).

  If no clock abnormality is detected (“normal” in step ST1), the operating state of the communication control unit 6 is checked (step ST3). If an abnormality is detected (“abnormal” in step ST3), data transmission by the bus driver 5 is stopped in the same manner as described above (step ST4).

  Further, when the operation of the communication control unit 6 is normal (“normal” in step ST3), the operation state of the microcontroller 4 is checked (step ST5). When it is detected that the microcontroller 4 is operating normally (“normal” in step ST5), the process returns to step ST1.

  Further, in the present embodiment, as the case where the microcontroller 4 is abnormal, the subsequent processing is changed in two cases: a stopped state and a runaway state.

  That is, when it is detected that the microcontroller 4 is running out of control (“runaway” in step ST5), the counter provided internally in the bus guardian 7 is set to “0” (step ST6). A reset signal is output to the microcontroller 4 to reset the microcontroller 4 (step ST7).

  Next, the operation state of the microcontroller 4 is checked in the same manner as in step ST5 (step ST8). If it is normal (“normal” in step ST8), the process returns to step ST1.

  On the other hand, if it is abnormal (runaway state) (“abnormal” in step ST8), the counter is incremented (step ST9), the process of resetting the microcontroller 4 again is repeated, and the counter value is set to a preset value (this In the example, when it reaches 2 times (YES in step ST10), a control signal is output to the electronic switch T1.

  As a result, the electronic switch T1 is turned on, the 42V bus is grounded, and the fuse F in the joint box 2 is blown, so that the power supply from the 42V power source B2 to the motor load 9 is cut off (step ST11). The motor load 9 stops.

  If it is detected in step ST5 that the microcontroller 4 is stopped (“stop” in step ST5), a control signal is immediately output to the electronic switch T1 to the motor load 9. Stop the power supply.

  Thus, when an abnormality of the microcontroller 4 is detected, the motor load 9 can be forcibly stopped.

  FIG. 3 is a timing chart showing a waveform when the electronic switch T1 is turned on when the microcontroller 4 stops. When the microcontroller 4 stops at time t1 shown in FIG. A control signal is output from the bus guardian 7 to the electronic switch T1 at time t2 shown in FIG. Then, the electronic switch T1 is turned on and the 42V bus is shut off.

  FIG. 4 is a timing chart showing a waveform when the electronic switch T1 is turned on when the microcontroller 4 runs out of control. The runaway of the microcontroller 4 is detected at time t3 shown in FIG. If it is, a reset signal is output to the microcontroller 4 at time t4 as shown in FIG. Thereafter, when the runaway of the microcontroller 4 is detected again at time t5, as shown in FIG. 5C, a control signal is output from the bus guardian 7 to the electronic switch T1 at time t6, and the 42V bus Is cut off.

  Thus, in the vehicle load control device according to the present embodiment, when the bus guardian 7 detects a clock abnormality or a communication control unit 6 abnormality, transmission from the bus driver 5 is stopped. Therefore, the entire communication line in the vehicle can be protected.

  Further, the operation state of the ECU 1 is monitored by the bus guardian 7, and when it is confirmed that the microcontroller 4 has stopped or runaway and it is not possible to control the motor load 9, the power to the motor load 9 is The supply is forcibly stopped.

  As a result, the motor load 9 can be protected, and when the motor load 9 becomes uncontrollable, the motor load 9 can be prevented from running out of control, and fail safe can be realized. it can.

  As mentioned above, although the vehicle load control apparatus of the present invention has been described based on the illustrated embodiment, the present invention is not limited to this, and the configuration of each part is of an arbitrary configuration having the same function. Can be replaced.

  For example, in the above-described embodiment, the motor load 9 is given as an example of the load to be controlled by the ECU 1, but other loads may be used.

  Moreover, although the example using 42V power supply B2 as a power supply which supplies a drive voltage to the motor load 9 was demonstrated, this invention is not limited to this, It can also be set as other voltages, such as 288V.

  Furthermore, in the above-described embodiment, the number of resets when a runaway has occurred is set to 2, but the present invention is not limited to this and can be 3 or more.

  Furthermore, in the present embodiment, the example in which the 42V bus is cut off by fusing the fuse F has been described. However, the present invention is not limited to this, and a configuration in which the 42V bus is cut off using other methods. It is also good.

  This is extremely useful for controlling a large-capacity load in a vehicle using two power sources, a control power source and a power source.

It is a block diagram which shows the structure of the control apparatus of the vehicle load which concerns on one Embodiment of this invention. It is a flowchart which shows the processing operation of the control apparatus of the vehicle load which concerns on 1st Embodiment. It is a timing chart which shows the output waveform of a microcontroller, and the waveform of the control signal of an electronic switch when this microcontroller stops. It is a timing chart which shows the waveform of the output signal of a microcontroller, the reset signal when the runaway of the microcontroller is detected, and the control signal of the electronic switch.

Explanation of symbols

1 ECU (control means)
2 Joint box 4 Microcontroller (load control unit)
5 Bus driver 6 Communication control unit 7 Bus guardian (monitoring unit)
8 Regulator 9 Motor load L1 Bus line B1 12V power supply B2 42V power supply T1 Electronic switch F Fuse

Claims (3)

Control means having a first power supply and a second power supply having an output voltage higher than that of the first power supply, using the second power supply as a power supply for driving a load to be controlled, and controlling the load The first power supply is used as a power supply for the power supply, and an operation signal input to operate the load is supplied to the control means by communication, and the control means is configured to supply the operation signal based on the supplied operation signal. In the vehicle load control device that controls the load,
The control means includes a load control unit that controls the load and a monitoring unit that monitors a state of the load control unit, and when the monitoring unit detects that an abnormality has occurred in the load control unit. An apparatus for controlling a vehicle load, wherein a wiring connecting the second power source and the load is cut off. When the monitoring unit detects a stop of the load control unit as an abnormal state occurring in the load control unit, the monitoring unit immediately cuts off the wiring connecting the second power source and the load,
As an abnormal condition that occurs in the load control unit, when a runaway of the load control unit is detected, a reset signal is output to the load control unit with a certain time interval, and a reset signal is output a predetermined number of times. The vehicle load control device according to claim 1, wherein when a runaway is detected again, the wiring for connecting the second power source and the load is cut off. The wiring connecting the second power supply and the load has a fuse on the wiring path, and the monitoring unit grounds the wiring path between the fuse and the load to the ground to blow the fuse. The vehicle load control device according to claim 1, wherein a wiring connecting the first power source and the load is cut off.

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