JP4889762B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device that controls driving of an external load such as a linear solenoid, a relay coil, or a lamp provided in a vehicle via an IPD (Intelligent Power Device).

  For example, in a conventional vehicle control device as shown in Patent Document 1, a current detection circuit detects, for example, a current that actually flows through a linear solenoid as a voltage across a resistor connected in series to the linear solenoid. The detected both-end voltage is amplified by an amplifying circuit including an operational amplifier and a resistor. The amplified both-end voltage is integrated by an integrating circuit composed of a resistor and a capacitor.

  A current flowing through the linear solenoid is detected as a voltage signal by a microcomputer connected to the integration circuit. The microcomputer performs AD conversion on the detected voltage, and then compares the AD conversion value with a determination reference value set in advance in the ROM to determine whether the linear solenoid or the like has failed.

  Thereby, in the conventional vehicle control apparatus as shown in Patent Document 1, the microcomputer has a failure in a series of paths from the output port to the linear solenoid through the drive circuit, and from the linear solenoid to the current detection circuit, It becomes possible to detect a failure in a series of paths to the input port of the microcomputer through the integration circuit and the comparison circuit.

Next, FIG. 4 is a block diagram showing a conventional electronic control unit as shown in Patent Document 1. In FIG. In FIG. 4 , the vehicle control device 100 includes a MOS transistor 101, an abnormality detection circuit 102, and a microcomputer 103. The MOS transistor 101 is a switching element. The MOS transistor 101 constitutes an external load drive circuit for switching energization / cutoff of a current flowing from the external power source 110 (battery) to the external load 111 (for example, a solenoid).

  Energization / interruption (ON / OFF) of the MOS transistor 101 is switched according to a command signal Sa from the output port 103a of the microcomputer 103. The abnormality detection circuit 102 includes a transistor 104 and a resistor 105. The base of the transistor 104 is connected to the load drive port 100 a of the vehicle control device 100. The collector of the transistor 104 is connected to the input port 103 b of the microcomputer 103. The emitter of the transistor 104 is connected to the GND port 100 b of the vehicle control device 100. One end of the resistor 105 is connected between the microcomputer 103 and the transistor 104. The other end of the resistor 105 is connected to the reference voltage Vr.

In the vehicle control apparatus 100 as shown in FIG. 4 , when the external load 111 and the MOS transistor 101 are normal, the voltage Vo at the load drive port 100a becomes approximately 0V when the MOS transistor 101 is turned on. At the same time, the voltage Sc at the input port 103b of the microcomputer 103 becomes H level. On the other hand, when the MOS transistor 101 is turned off, the voltage Vo of the load drive port 100a becomes substantially equal to the voltage VB of the external power supply 110. At the same time, the voltage Sc of the input port 103b of the microcomputer 103 becomes L level.

  On the other hand, in the case of an abnormal state in which the external load 111 is disconnected, the voltage Vo of the load drive port 100a becomes 0V regardless of the ON / OFF state of the transistor 101, and the voltage of the input port 103b of the microcomputer 103 Sc is always at the H level. In an abnormal state where both terminals of the external load 111 are short-circuited (abnormal state where the load drive port 100a is short-circuited to the + terminal of the external power supply 110), the load is applied regardless of the ON / OFF state of the MOS transistor 101. The voltage Vo of the drive port 100a is equal to the voltage VB of the external power supply 110.

  In this case, the voltage Sc of the input port 103b of the microcomputer 103 is always L level. As a result, the microcomputer 103 can detect an abnormality of the external load 111 based on the voltage Sa of the output port 103a and the voltage Sc of the input port 103b of the microcomputer 103.

Here, FIG. 4 shows only an external load drive circuit for one channel. However, in an actual vehicle-mounted electronic control unit, for example, an external load 111 to be driven (not limited to a solenoid, a relay coil or a lamp Multiple loads). For this reason, it is necessary to provide a load driving circuit for each external load, and there is a problem that the cost of components and the area of the board increase.

On the other hand, for example, in a conventional electronic control unit as shown in Patent Document 2, an IPD in which a plurality of external load driving circuits are integrated in one element is used. The IPD incorporates an abnormality detection circuit, an abnormality state from IPD output port to an external load, and can detect similar to that of FIG. 4 and Patent Document 1.

JP 2000-114039 A JP 2000-16174 A

Here, in the conventional electronic control unit as shown in Patent Document 2, unlike the electronic control unit as shown in FIG. 4 , the external load drive port of the IPD (that is, the external load drive port of the load drive unit) is externally connected. Only the abnormal state up to the load is the detection target. For this reason, the circuit abnormality between the microcomputer (drive control unit) and the IPD (load control unit) is not a detection target, and the circuit abnormality cannot be detected.

  The present invention has been made to solve the above-described problems. Even when the load drive unit is used to switch between energization / cutoff of a plurality of external loads, the drive control unit and the load drive unit are provided. An object of the present invention is to obtain a vehicle control device capable of detecting a circuit abnormality between the two.

The vehicle control device according to the present invention switches between energization / cutoff of a plurality of external loads, generates a plurality of load drive commands for switching energization / cutoff of the plurality of external loads, and A drive control unit that controls energization / cutoff of each load; a plurality of load drive command input ports that respectively receive the plurality of load drive commands from the drive control unit; and a control information input that receives control information from the drive control unit Ports, a plurality of external load drive ports connected to the plurality of external loads, and contents of the load drive commands received by the plurality of load drive command input ports are output to the drive control unit as feedback information A feedback information output port for switching the energization / interruption of each of the plurality of external loads based on the plurality of load drive commands. A drive unit, and the drive mode of the load drive unit is based on a normal drive mode for switching energization / cutoff of the plurality of external loads based on the plurality of load drive commands, and on preset drive information The drive control unit is switched from one to the other in accordance with a mode switching command received from the outside from one of the diagnostic drive modes in which the energization / cutoff states of the plurality of external loads are constant, and the drive control unit itself When the initialization process is executed after the start-up, it is possible to execute a diagnosis process for a circuit abnormality with the load driving unit, and when executing the diagnosis process, the mode switching command is used as the control information. To the load drive unit, the drive mode of the load drive unit is set to the diagnostic drive mode, and then the plurality of load drive commands are sent to the plurality of load drive command input ports, respectively. When the contents of the feedback information at that time are compared with the contents of the plurality of load drive commands sent to the plurality of load drive command input ports, it is confirmed that both are different from each other. It is determined that an abnormality has occurred in a circuit between the drive unit, and a signal of an L level voltage level is applied to one of the load drive command input ports adjacent to each other among the plurality of load drive command input ports. A load drive command is sent to the other of the load drive command input ports adjacent to each other, and an H level voltage level signal is sent as the load drive command. Based on the content of the feedback information at that time, the one of When comparing the voltage level of the other load drive command input port with the voltage level of the other load drive command input port and confirming that both voltage levels match , It is determined that an abnormality has occurred in the circuit between the load driving unit .

According to the vehicle control apparatus according to the present invention, the drive control unit, when executing the diagnosis processing for the circuit fault between the load drive unit, sends a mode switch command to the load driver, the load driver The drive mode is set to the diagnostic drive mode, then a load drive command is sent to the load drive unit, the content of the feedback information at that time is compared with the content of the load drive command sent to the load drive unit, and both are different. When it is confirmed that there is a circuit abnormality, even when switching between energization / cutoff of a plurality of external loads using the load drive unit, the drive control unit and the load drive unit A circuit abnormality during the period can be detected.

It is a block diagram which shows the vehicle control apparatus by Embodiment 1 of this invention. It is a flowchart which shows the diagnostic process of the microcomputer of FIG. It is a flowchart which shows the diagnostic process of the microcomputer of FIG. It is a block diagram which shows the conventional vehicle control apparatus.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
1 is a block diagram showing a vehicle control apparatus according to Embodiment 1 of the present invention.
In FIG. 1, a vehicle control device (engine control device) 1 includes a microcomputer 2 as a drive control unit and an IPD 3 as a load drive unit.

  Moreover, the vehicle control apparatus 1 is connected to one end of the some external load 21-28 provided in the vehicle (not shown). The external loads 21 to 28 are, for example, a solenoid, a relay coil, or a lamp. The other ends of the plurality of external loads 21 to 28 are connected to the battery 31. The vehicle control device 1 switches energization / interruption of the current of the battery 31 to the external loads 21 to 28. In FIG. 1, only three of the external loads 21, 27, and 28 among the external loads 21 to 28 are shown.

The microcomputer 2 includes an arithmetic processing unit (not shown), a data storage unit (not shown), and a plurality of input / output ports. The data storage unit stores in advance a program for performing vehicle control and a program for performing IPD failure diagnosis. The input / output port of the microcomputer 2 includes a plurality of load drive command output ports M _out 1 to M _out 8, a control information output port MCN _out, and a feedback information input port MFB _in . In FIG. 1, of the load drive command output ports _{M out 1~M} out _8, shows only _{M out 1, M out 7,} M out 8.

The IPD 3 includes a plurality of input / output ports, a plurality of buffer registers, a load drive circuit (not shown), an abnormality detection circuit 16, and a plurality of switches (hereinafter referred to as SW1 to SW8). . IPD3 output port includes a plurality of load driving command input port _{I in 1~I} in 8, a plurality of external loads driven port _I out _{1 to I out} 8, a control information input port _{ICN in,} the feedback information output ports IFB _out .

Load drive command input port _{I in 1~I} in 8 _is disposed adjacent each in the order of _{I in 1, I in 2 ···} I in 8. For example, the load drive command input port I _in 3 is next to the load drive command input port I _in 2 and the load drive command input port I _in 4. In FIG 1, among the plurality of load driving command input port _{I in 1~I} in _8, shows only _{I in 1, I in 7,} I in 8, the external load driving port _{I out 1~I} out 8 Of these, only I _out 1, I _out 7 and I _out 8 are shown. External load driving port _{I out 1~I} out 8 is electrically connected to one end of the external load 21 to 28, respectively. The load driving circuit of the IPD 3 switches between energization and interruption of the external loads 21 to 28.

The plurality of buffer registers of the IPD 3 include a transmission buffer register 11, a state monitoring buffer register 12, a constant drive buffer register 13, a mode switching buffer register 14, and a reception buffer register 15. The transmission buffer register 11 is for sending feedback information to the microcomputer 2. The state monitoring buffer register 12 is for monitoring the state of the load drive command input ports I _in 1 to I _in 8.

  The constant drive buffer register 13 is for making the state of energization / cutoff of the external loads 21 to 28 constant. The mode switching buffer register 14 is for switching the connection destination of the movable contacts SW1 to SW8. The reception buffer register 15 is for receiving control information from the microcomputer 2.

Here, the microcomputer 2 and the IPD 3 are electrically connected via a plurality of communication lines 4-8. Specifically, the feedback information input port MFB _in and the feedback information output port IFB _out are connected via the communication line 4. The feedback information generated by the IPD 3 is transmitted to the microcomputer 2 through the communication line 4. This feedback information is information for notifying the microcomputer 2 of the internal state of the IPD 3.

Load drive command and the output port _{M out 1~M} out 8 and the load drive command input port _{I in 1~I} in 8 are connected via a communication line 5-7, respectively. In FIG. _1, the communication line between the _{M out} 2~M out 6 and _{I in 2~I} in 6 illustrates omitted. The load driving command generated by the microcomputer 2 is transmitted to the IPD 3 through the communication lines 5 to 7. This load drive command is a command for switching energization / cutoff of the external loads 21 to 28.

The control information output port MCN _out and the control information input port ICN _in are connected via the communication line 8. Control information generated by the microcomputer 2 is transmitted to the IPD 3 through the communication line 8. This control information is information for the microcomputer 2 to control the IPD 3.

Next, the driving mode of the IPD 3 will be described. The drive mode of the IPD 3 can be switched from one of the normal drive mode and the diagnostic drive mode to the other. The normal driving mode, based on the state of the load driving instruction input port _{I in 1~I} in 8, which is a drive mode for switching the energization and interruption of the external load 21 to 28. The diagnostic drive mode is a drive mode for making the energization / cutoff states of the external loads 21 to 28 constant based on information (set drive information) stored in the constant drive buffer register 13.

The driving mode of the IPD 3 is switched from one of the normal driving mode and the diagnostic driving mode to the other by SW1 to SW8. When the movable contact of SW1~SW8 are connected to the fixed contact of the load driving instruction input port _{I in 1~I} in 8 side, IPD3 is normal drive mode. On the other hand, when the movable contacts of SW1 to SW8 are connected to the fixed contacts on the constant drive buffer register 13, the IPD 3 is in the diagnostic drive mode.

The operation of the movable contacts SW1 to SW8 is performed based on the information stored in the mode switching buffer register 14. An example of this operation will be described using SW1. When bit0 of the mode switching buffer register 14 is “0”, the movable contact of SW1 is connected to the fixed contact on the load drive command input port I _in 1 side. When bit 0 of the mode switching buffer register 14 is “1”, the movable contact of SW 1 is connected to the fixed contact on the constant drive buffer register 13 side.

The mode switching buffer register 14 is composed of 8 bits (bits 0 to 7). Similarly to SW1, each of the movable contacts of SW2 to SW8 is also a fixed contact on the side of the load drive command input ports I _in 2 to I _in 8, and a constant drive buffer, with the value of each bit of the mode switching buffer register 14 The connection destination can be switched from one of the fixed contacts on the register 13 side to the other. Of the bits 1 to 8 of the mode switching buffer register 14, bit1 is SW2, bit2 is SW3, bit3 is SW4, bit4 is SW5, bit5 is SW6, bit6 is SW7, bit7 is SW8, respectively. It corresponds.

  Here, the control information of the microcomputer 2 includes a mode switching command for switching the driving mode of the IPD 3. This mode switching command is transmitted to the mode switching buffer register 14 via the reception buffer register 15 and stored in the mode switching buffer register 14. That is, switching of the driving mode of the IPD 3 is controlled by the microcomputer 2.

Next, the operation of energizing / cutting off the external loads 21 to 28 by the microcomputer 2 when the IPD 3 is in the normal drive mode will be described. The microcomputer 2 sends a plurality of load drive commands to the IPD 3 through the load drive command output ports M _out 1 to M _out 8 and the communication lines 5 to 7.

When the IPD 3 receives a load drive command from the microcomputer 2 through the load drive command input ports I _in 1 to I _in 8 _in the normal drive mode, the IPD 3 determines the external loads 21 to 28 based on the load drive command. Switch between energization and shutdown. Load drive command to the load driving instruction input port _{I in 1~I} in 8 is at the H level, the external load 21 to 28 is energized. In contrast, when the load drive command to the load driving instruction input port _{I in 1~I} in 8 is at the L level, the current to the external load 21 through 28 is cut off.

  Next, the operation of energizing / cutting off the external loads 21 to 28 by the microcomputer 2 when the IPD 3 is in the diagnostic drive mode will be described. The control information of the microcomputer 2 includes constant load driving information for making the energization / cutoff states of the external loads 21 to 28 constant.

This constant load drive information is sent from the microcomputer 2 to the constant drive buffer register 13 through the control information output port MCN _out , the communication line 8, the control information input port ICN _in and the reception buffer register 15 for constant drive. Stored in the buffer register 13. The IPD 3 switches between energization and interruption of the external loads 21 to 28 based on the information stored in the constant drive buffer register 13 in the diagnostic drive mode.

The constant drive buffer register 13 is composed of 8 bits (bits 0 to 7). When each bit of the constant drive buffer register 13 is “1”, the external loads 21 to 28 are energized through the external load drive ports I _out 1 to I _out 8. When each bit of the constant drive buffer register 13 is “0”, the current to the external loads 21 to 28 is cut off through the external load drive ports I _out 1 to I _out 8.

Specifically, among the bits 0 to 7 of the constant drive buffer register 13, bit0 is the external load drive port Iout1, bit1 is Iout2, bit2 is Iout3, bit3 is Iout4, bit4 is Iout5, bit5 is Iout6 , Bit6 corresponds to Iout7, and bit7 corresponds to Iout8.

Next, the monitoring function of the load drive command input ports I _in 1 to I _in 8 by the IPD 3 will be described. IPD3 each of the input voltage level is High level of the load driving instruction input port _{I in 1~I} in 8 (hereinafter referred to as "H") is either a, or Low level (hereinafter referred to as "L") The input voltage level information is stored in the state monitoring buffer register 12.

The state monitoring buffer register 12 is composed of 8 bits (bit0 to bit7). Of bit 0 to bit 7 of the state monitoring buffer register 12, bit 0 is the load drive command input port I _in 1, bit 1 is I _in 2, bit 2 is I _in 3, bit 3 is I _in 4, bit 4 is I _in 5, bit 5 corresponds to I _in 6, bit 6 corresponds to I _in 7, and bit 7 corresponds to I _in 8.

Further, when the input voltage level of the load driving instruction input port _{I in} 1~I _{in 8} is "L", "0" is stored in each bit of the state monitoring buffer register 12. In contrast, when the input voltage level of the load driving instruction input port _{I in} 1~I _{in 8} is "H", "1" is stored in each bit of the state monitoring buffer register 12. The information stored in the state monitoring buffer register 12 is stored in the transmission buffer register 11 and transmitted to the microcomputer 2 as feedback information via the transmission buffer register 11.

Next, the function of the abnormality detection circuit 16 of the IPD 3 will be described. Abnormality detection circuit 16, respectively of the external load driving port _{I out 1~I} out 8 of IPD3, it is possible to detect an abnormality occurring in the circuit between each of the external load 21 to 28. The abnormality detection circuit 16 includes a load-side monitoring buffer register (not shown) similar to the state monitoring buffer register 12.

The abnormality detection circuit 16 transmits detected abnormality information as feedback information to the microcomputer 2 via the load-side monitoring buffer register and the transmission buffer register 11. Accordingly, the microcomputer 2 detects an abnormality that has occurred in the circuit between each of the external load drive ports I _out 1 to I _out 8 and each of the external loads 21 to 28 via the abnormality detection circuit 16.

  Next, circuit abnormality diagnosis processing between the microcomputer 2 and the IPD 3 by the microcomputer 2 (hereinafter, circuit abnormality diagnosis processing between the microcomputer 2 and the IPD 3) will be described. 2 and 3 are flowcharts showing the diagnostic processing of the microcomputer 2 of FIG. First, the microcomputer 2 executes a series of processes shown in FIGS. 2 and 3 during the initialization process after the power supply voltage is applied to the vehicle control device 1.

  2 and 3, in step S101, the microcomputer 2 resets the abnormality determination number counter to zero. In step S102, the microcomputer 2 transmits constant load drive information to the IPD 3, and stores "0" in each bit of the constant drive buffer register 13.

  Thereafter, in step S103, the microcomputer 2 causes the mode switching buffer register 14 to connect to the mode switching buffer register 14 through the communication line 8 and a mode switching command “for connecting the movable contacts SW1 to SW8 to the fixed contact on the constant driving buffer register 13 side. 11111111 "is transmitted. That is, the microcomputer 2 sets the drive mode of the IPD 3 to the diagnostic drive mode.

By the operations in steps S102 and S103, the current to the external load 21 to the external load 28 is cut off (off state), and the voltage level of the load drive command output ports M _out 1 to M _out 8 of the microcomputer 2 changes. However, the state of the external load drive ports I _out 1 to I _out 8 of the IPD 3 does not change. Therefore, in this state, the external load 21 to the external load 28 are always in a current interruption state, and are disconnected from the control using the load drive command of the microcomputer 2. Thereby, the malfunction of the external loads 21 to 28 accompanying the diagnosis process by the microcomputer 2 is avoided.

In step S104, the microcomputer 2 executes a load drive command / feedback information transmission / reception process shown in FIG. In step S201 in FIG. 3, the microcomputer 2 resets the repetition counter to zero. In step S202, the microcomputer 2 sets the voltage levels of the load drive command output ports M _out 1 to M _out 8 to “L · H · L · H · L · H · L · H”. L, H, L, H, L, H, L, and H ”load drive commands are sent to the IPD 3.

That is, when the microcomputer 2 executes the circuit abnormality diagnosis process between the microcomputer 2 and the IPD 3, it is connected to one of the load drive command input ports adjacent to each other among the load drive command input ports I _in 1 to I _in 8. , L level voltage level signals are sent as load drive commands. At the same time, the microcomputer 2, the second end of the load driving instruction input ports adjacent to each other among the load drive command input port _{I in} 1~I _{in 8,} and sends the voltage level of the signal of the H level signal as the load drive command.

Here, if the circuit between the load drive command output ports _{M out 1~M} out 8 and the load drive command input port _{I in 1~I} in 8 is normal, the load drive command input port _I in. 1 to the IPD3 the voltage level of I _in 8 coincides with the voltage level of the load drive command output ports _{M out 1~M} out 8, it becomes "L · H · L · H · L · H · L · H ".

Thereafter, when the microcomputer 2 receives the feedback information from the IPD 3, the microcomputer 2 compares the content of the feedback information (that is, the information stored in the state monitoring buffer register 12) with the content of the load drive command transmitted to the IPD 3. . In step S203, the microcomputer 2 checks whether the information stored in the state monitoring buffer register 12 is “01010101”. That is, the microcomputer 2 checks whether the information stored in the status buffer register 12 is different from the load drive command .

  At this time, if it is confirmed that the microcomputer 2 is different even by 1 bit, 1 is added to the abnormality determination number counter in step S204, and the process proceeds to step S205. On the other hand, when the microcomputer 2 confirms that the information stored in the state monitoring buffer register 12 is “01010101”, the microcomputer 2 proceeds to step S205 as it is.

In step S205, the microcomputer 2 sets the voltage levels of the load drive command output ports M _out 1 to M _out 8 of the microcomputer 2 to “H, L, H, L, H, L, H, and L”. A load drive command of “H, L, H, L, H, L, H, L” is transmitted to the IPD 3. That is, the load drive command here is the one obtained by inverting the load drive command in step S202. Therefore, in steps S202 and S205, both the “H” and “L” commands are output from all the load drive command output ports M _out 1 to M _out 8 of the microcomputer 2.

  Thereafter, when the microcomputer 2 receives the feedback information from the IPD 3, the microcomputer 2 compares the content of the feedback information with the content of the load drive command transmitted to the IPD 3. In step S206, the microcomputer 2 checks whether the information stored in the state monitoring buffer register 12 is “10101010”.

  At this time, if it is confirmed that the microcomputer 2 is different even by 1 bit, 1 is added to the abnormality determination number counter in step S207, and the process proceeds to step S208. On the other hand, when the microcomputer 2 confirms that the information stored in the state monitoring buffer register 12 is “10101010”, the microcomputer 2 proceeds to step S208 as it is.

  In step S208, the microcomputer 2 checks whether or not the repeat count counter is 3 or more. At this time, if the microcomputer 2 confirms that the repeat count counter is less than 3, the microcomputer 2 adds 1 to the repeat count counter in step S209, and then proceeds to step S202 to repeat the same operation. The reason why the processes of steps S202 to S207 are repeatedly executed is to enable detection even when an abnormal state is not always established and becomes abnormal.

  On the other hand, when the microcomputer 2 confirms that the repeat count counter is 3 or more, the microcomputer 2 ends the load drive command / feedback information transmission / reception process and proceeds to step S105 in FIG. In step S105, the microcomputer 2 checks whether or not the abnormality determination number counter is 2 or more.

  At this time, if the microcomputer 2 confirms that the abnormality determination number counter is 2 or more, in step S106, the microcomputer 2 determines that a circuit abnormality between the microcomputer 2 and the IPD 3 has occurred. An indicator (not shown) is lit to notify the person of the abnormality. Thereafter, the microcomputer 2 proceeds to step S108.

  On the other hand, when the microcomputer 2 confirms that the abnormality determination number counter is less than 2, the microcomputer 2 determines that the circuit between the microcomputer 2 and the IPD 3 is normal, and proceeds to step S108 as it is.

In step S108, the microcomputer 2 transmits all “L” load drive commands to the IPD 3, and proceeds to step S109. Then, in step S109, the microcomputer 2, the mode switching buffer register 14 through the communication line 8, for connecting the movable contact of the SW1~SW8 the fixed contact of the load driving instruction input port _I in _{1 to I in} 8 side Mode switching command “00000000” is transmitted. That is, the microcomputer 2 sets the drive mode of the IPD 3 to the normal drive mode. Thus, the circuit abnormality diagnosis process between the microcomputer 2 and the IPD 3 is completed, and thereafter, the energization / interruption of the external loads 21 to 28 is switched based on the load drive command of the microcomputer 2.

  According to the vehicle control apparatus of the first embodiment as described above, when the microcomputer 2 executes the diagnostic process for the circuit abnormality with the IPD 3, the mode switching command is transmitted to the IPD 3, and the IPD 3 The drive mode is a diagnostic drive mode. After that, the microcomputer 2 sends a load drive command to the IPD 3, compares the content of the feedback information at that time with the content of the load drive command sent to the IPD 3, and confirms that they are different. It is determined that a circuit abnormality has occurred. With this configuration, it is possible to detect a circuit abnormality between the microcomputer 2 and the IPD 3 even when the energization / interruption of the external loads 21 to 28 is switched using the IPD 3.

Further, when the microcomputer 2 executes the circuit abnormality diagnosis process between the microcomputer 2 and the IPD 3, the microcomputer 2 is connected to one of the load drive command input ports adjacent to each other among the load drive command input ports I _in 1 to I _in 8. , L level voltage level signals are sent as load drive commands. At the same time, the microcomputer 2, the second end of the load driving instruction input ports adjacent to each other among the load drive command input port _{I in} 1~I _{in 8,} and sends the voltage level of the signal of the H level signal as the load drive command. Then, the microcomputer 2 compares the voltage level of one load drive command input port with the voltage level of the other load drive command input port based on the content of the feedback information, and both voltage levels match. If this is confirmed, it is determined that an abnormality has occurred in the circuit with the IPD 3. With this configuration, it is possible to detect a contact abnormality (short circuit abnormality) between adjacent load drive command input ports.

Here, this short circuit abnormality will be described more specifically. For example, when adjacent load drive command input ports I _in 1 and I _in 2 are in contact with each other, the potentials of the load drive command input ports I _in 1 and I _in 2 are at the same level. For this reason, even if the microcomputer 2 transmits “L·L” of the same level as the load drive command to the load drive command input ports I _in 1 and I _in 2, the IPD 3 recognizes “L·L”. . As a result, the microcomputer 2 erroneously determines that it is normal. Therefore, the microcomputer 2 recognizes the IPD 3 as “H · H” or “L·L” by transmitting it as the “L · H” load drive command to the load drive command input ports I _in 1 and I _in 2. The microcomputer 2 can detect a contact abnormality (short circuit) of the load drive command input ports I _in 1 and I _in 2.

Further, the microcomputer 2 detects an abnormality that has occurred in a circuit between each of the external load drive ports I _out 1 to I _out 8 and each of the external loads 21 to 28 via the abnormality detection circuit 16. With this configuration, circuit abnormalities from the load drive command output ports M _out 1 to M _out 8 of the microcomputer 2 to the external loads 21 to 28 can be detected without omission.

  In the first embodiment, the case where the number of external loads 21 to 28 is eight has been described. However, the number of external loads can be changed as appropriate. At the same time, the number of bits of each of the buffer registers 11 to 15 and the number of ports can be appropriately changed.

  In the first embodiment, the determination threshold value for the abnormality determination number counter in step S105 in FIG. The determination threshold is set to avoid erroneous determination, and the value can be changed as appropriate.

  Furthermore, in the first embodiment, the determination threshold value for the repetition counter in step S208 in FIG. This determination threshold is for determining the number of repetitions of step S202 to step S207, and the number of repetitions and the determination threshold can be appropriately changed.

DESCRIPTION OF SYMBOLS 1 Vehicle control apparatus, 2 Microcomputer (drive control part), 3 IPD (load drive part), 11 Transmission buffer register, 12 State monitoring buffer register, 13 Constant drive buffer register, 14 Mode switching buffer register, 15 Buffer register for reception, 16 abnormality detection circuit, 21 to 28 external load, ICN _in control information input port, IFB _out feedback information output port, I _in 1 to I _in 8 load drive command input port, I _out 1 to I _out 8 External load drive port, MCN _out control information output port, MFB _in feedback information input port, M _out 1 to M _out 8 load drive command output port.

Claims (1)

A vehicle control device that switches between energization and interruption of a plurality of external loads,
A plurality of load drive commands for switching energization / interruption of the plurality of external loads, and a drive control unit for controlling energization / interruption of each of the plurality of external loads;
A plurality of load drive command input ports that respectively receive the plurality of load drive commands from the drive control unit, a control information input port that receives control information from the drive control unit, and a plurality of respective external loads connected to the plurality of external loads An external load drive port; and a feedback information output port for outputting the content of the load drive command received by each of the plurality of load drive command input ports to the drive control unit as feedback information. A load drive unit that switches between energization and interruption of each of the plurality of external loads based on a load drive command,
The drive mode of the load drive unit includes a normal drive mode that switches between energization / cut-off of the plurality of external loads based on the plurality of load drive commands, and a plurality of external loads based on preset setting drive information. Switching from one to the other in the diagnostic drive mode that keeps the power supply / cutoff state constant, according to the mode switching command received from the outside,
The drive control unit can execute a diagnosis process for a circuit abnormality with the load drive unit when executing an initialization process after the drive control unit itself is started, and when executing the diagnosis process In addition,
Sending the mode switching command to the load drive unit as the control information, the drive mode of the load drive unit as the diagnostic drive mode,
Thereafter, the plurality of load drive commands are sent to the plurality of load drive command input ports, respectively, the contents of the feedback information at that time, and the contents of the plurality of load drive commands sent to the plurality of load drive command input ports When it is confirmed that both are different, it is determined that an abnormality has occurred in the circuit between the load drive unit ,
An L level voltage level signal is sent as the load drive command to one of the load drive command input ports adjacent to each other among the plurality of load drive command input ports, and the load drive command input ports adjacent to each other To the other side, a signal of an H level voltage level is sent as the load drive command,
Based on the content of the feedback information at that time, the voltage level of the one load drive command input port is compared with the voltage level of the other load drive command input port, and both voltage levels match. When the vehicle control device is confirmed, it is determined that an abnormality has occurred in the circuit between the load drive unit and the vehicle control device.

Images