JPH06314101A - Controller for actuator - Google Patents

Abstract

(57) [Summary] (Correction) [Object] To provide an actuator control device having a simple circuit configuration and an inexpensive element, which can perform backup by switching to normal output when the control circuit is abnormal. The actuator control device 1 includes a control circuit 3 that outputs a control signal to the actuator 2, and a backup circuit 4. The control circuit 3 has a control signal output port connected to a first diode D1 and a backup circuit. 2nd diode D at the backup signal output port of 4
2 is connected, the output sides of the first diode D1 and the second diode D2 are connected to the drive circuit 6 of the actuator 2, and the switching signal output port of the backup circuit 4 is connected to the switching transistor Tr2. Is connected to the first diode D1 to output the switching signal at the same time as the backup signal of the backup circuit 4 and also to operate the drive circuit 6 by the backup signal instead of the control signal to output.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator control device for controlling actuators such as an internal combustion engine ignition device and a fuel injection device.

[0002]

2. Description of the Related Art For example, in a control device for an actuator that controls an actuator such as an ignition device for an internal combustion engine or a fuel injection device, if a component associated with the internal combustion engine becomes abnormal, for example, a fuel injection pulse or an ignition pulse, etc. Conventionally, there has been used a technique of generating the output of (1) by another means and switching it to the normal output to perform backup.

For example, as shown in FIG. 5, since the switching signal from the switching signal output port of the backup circuit 100 is normally low, the output of the inverter 102 forming a part of the switching circuit 101 is high and the 3-state IC 103 is ON
Is in a state. On the other hand, since the switching signal of the backup circuit 100 is low, the 3-state IC 104 is in the OFF state. Therefore, the control signal output port of the control circuit 105 outputs the control signal at the normal time from the 3-state IC 10.
3 is input to the transistor 107 forming a part of the driving circuit 106 via the resistors 108 and 109, and the transistor 107 is turned on by the resistors 108 and 109.
The actuator 111 is driven via.

When the backup circuit 100 detects an abnormality in the control circuit 105, the switching signal goes high.
Then, the 3-state IC 10 is passed through the inverter 102.
3 turns off, while the 3-state IC 104 turns on. Therefore, the backup signal from the backup circuit 100 is input to the base of the transistor 107 via the three-state IC 104, whereby the transistor 107 becomes conductive and the actuator 111 is driven via the driving means 110.

[0005]

As described above, when the backup circuit is provided and the abnormality of the control circuit is detected, the switching circuit is activated by the backup signal from the backup circuit by the switching, whereby the actuator is operated via the drive circuit. Although it is driven, an inverter or a 3-state IC is used in the circuit for connecting and switching between the normal output and the backup output.
, Etc. are used, and the circuit configuration is complicated and expensive.

The present invention has been made in view of the above circumstances, and has a simple circuit configuration and is an inexpensive element, and is an actuator control device capable of performing backup by switching to normal output when the control circuit is abnormal. Is intended to provide.

[0007]

In order to solve the above-mentioned problems, an actuator control device according to the present invention comprises an actuator controlled by a control signal, a control circuit for outputting the control signal to the actuator, and a backup signal. A backup circuit for outputting a switching signal, a first diode is connected to a control signal output port of the control circuit, and a second diode is connected to a backup signal output port of the backup circuit. The output side of the second diode is connected to the drive circuit of the actuator, the switching transistor is connected to the switching signal output port of the backup circuit, and the switching transistor is connected to the first diode, and the backup signal of the backup circuit is connected. At the same time as outputting the switching signal, Instead of the serial control signal is characterized in that so as to output by operating the drive circuit in said backup signal.

[0008]

According to the present invention, when the backup circuit detects an abnormality in the control circuit, the switching signal is output at the same time as the backup signal to replace the control signal of the control circuit, and the drive circuit is operated by the backup signal to drive the actuator. .

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of an actuator control device of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a circuit diagram of an actuator controller. An actuator 2 driven by a control signal, a drive circuit 6 for driving the actuator 2, a control circuit 3 for outputting a control signal, and a backup for outputting a backup signal and a switching signal are included in a control device 1 for this actuator. The circuit 4 and the switching circuit 5 for switching and connecting the control circuit 3 and the backup circuit 4 to the drive circuit 6 of the actuator 2 are provided.

The driving circuit 6 is composed of resistors R1 and R2, a driving transistor Tr1 and a driving means 7. The resistor R1 is connected to the base of the driving transistor Tr1, the resistor R2 is connected between the base and the emitter, and further to the collector. The driving means 7 is connected. Drive transistor Tr
When 1 is input to its base, it becomes conductive, and the driving means 7 operates and outputs to drive the actuator 2.

The switching circuit 5 comprises resistors R3 to R5, a first diode D1, a second diode D2 and a switching transistor Tr2.

The control signal output port of the control circuit 3 is connected to the anode of the first diode D1 via the resistor R3, and the backup signal output port of the backup circuit 4 is connected to the anode of the second diode D2. There is. The first diode D1 and the second diode D2
The cathode of the drive transistor Tr1 via the resistor R1
Connected to the base of.

Further, the switching signal output port of the backup circuit 4 is connected to the switching transistor Tr2 via the resistor R4.
Is connected to the base of the
5 is connected, and the collector is connected to the anode of the first diode D1.

The backup circuit 4 outputs a switching signal at the same time as the backup signal to replace the control signal of the control circuit 3 with the drive signal to make the drive transistor Tr1 conductive and drive the actuator 2 via the drive means 7. Is configured.

Next, the operation of this actuator control device will be described. Normally, the switching signal of the backup circuit 4 is low, and the switching transistor Tr2 is off.
Is. Therefore, since the switching transistor Tr2 does not affect the output of the control signal at the normal time, the output of the control signal at the normal time is the resistance R3, the first diode D1, the resistances R1 and R1.
2 is input to the base of the drive transistor Tr1 via 2, and the drive transistor Tr1 is turned on to drive the actuator 2 via the drive means 7. At this time, since the output of the backup signal of the backup circuit 4 is prohibited inside the backup circuit 4, the output of the backup signal is not input to the base of the drive transistor Tr1.

When the backup circuit 4 detects an abnormality in the control circuit 3, the resistors R4 and R4 are set in order to make the switching signal high.
The switching transistor Tr2 is turned on via 5, and the level at the point a becomes low. Therefore, the output of the control signal from the control circuit 3 is not input to the first diode D1.
On the other hand, at the same time when the switching signal is made high, the backup circuit 4 permits the output of the backup signal. When the backup signal is output from the backup circuit 4, the backup signal is input to the base of the drive transistor Tr1 via the second diode D2, the drive transistor Tr1 is made conductive, and the actuator 2 is driven via the drive means 7. .

If the output of the control signal at the normal time is low, since the first diode D1 and the second diode D2 are connected in parallel to the base of the drive transistor Tr1, the backup signal from the backup circuit 4 is generated. Is output to the base of the drive transistor Tr1.

FIG. 2 is a circuit diagram of another embodiment of the actuator control device. Control device 1 for this actuator
Is an actuator 2 driven by a control signal, a control circuit 3 that outputs a control signal to the actuator 2, a backup circuit 4 that outputs a backup signal and a switching signal, and the control circuit 3 and the backup circuit 4 to the actuator 2 The switching circuit 5 is connected to the driving circuit 6 of FIG.

The switching circuit 5 includes resistors R3 to R8 and a first resistor.
Diode D1, second diode D2, switching transistor Tr2, auxiliary transistor Tr3 and inverter IN
It is composed of 1.

The actuator control device 1 shown in FIG.
The members denoted by the same reference numerals as those in FIG.

In this embodiment, the backup signal output port of the backup circuit 4 is connected to the anode of the second diode D2 via the resistor R6, and the anode of the second diode D2 is connected to the collector of the auxiliary transistor Tr3. Has been done. This auxiliary transistor Tr3
The base of is connected to the switching signal output port of the backup circuit 4 via the resistor R7 and the inverter IN1, and the resistor R8 is connected between the base and the emitter.

Therefore, when the switching signal from the backup circuit 4 is low, it is input to the base of the auxiliary transistor Tr3 via the inverter IN1 and the resistors R7 and R8, and the auxiliary transistor Tr3 is in the ON state. Therefore,
Even if the backup signal from the backup circuit 4 is normally output, it is not input to the second diode D2.

As described above, even if the backup circuit 4 does not permit / prohibit the output of the backup signal or the output of the backup signal becomes abnormal, the operation of the drive transistor Tr1 is not affected.

Next, a more specific embodiment of the actuator control device of the present invention will be described. FIG. 3 is a block diagram in which an actuator control device is applied to the fuel injection system. A power supply circuit 11 is connected to the power supply 10, and an abnormality detection circuit 12 is built in this power supply circuit 11.
The power supply circuit 11 includes a CPU 1 which constitutes a control circuit 13.
4 and the gate circuit 15 are connected. This CPU1
An address bus, a data bus, and a control bus are provided between the switch 4 and the gate circuit 15.

The CPU 14, the gate circuit 15 and the backup circuit 16 are connected to an igniter 18 and a drive circuit 19 via a switching circuit 17, and a fuel pump 20, an air injector 21 and a fuel injector 22 are connected to the drive circuit 19. Has been done. This igniter 18, fuel pump 20, air injector 2
1 and the fuel injector 22 are actuators 23
Are configured.

The backup circuit 16 has a power supply circuit 24 and an abnormality detection circuit 25, and the power supply circuit 24 is connected to a power supply. A starter switch signal, a shift switch signal, and a pulser signal are input to the CPU 14 and the backup circuit 16 of the control circuit 13, respectively. further,
The backup circuit 16 has a backup signal output port and a switching signal output port. The switching circuit 17 replaces the control signal with the backup signal and the switching signal to turn on the drive transistor shown in FIGS. 1 and 2 with the backup signal. The actuator 23 is driven by means of the actuator 23, and the operation of the switching circuit 17 is as described with reference to FIG. 1 or 2.

Next, the operation of this fuel injection system will be described.

Normally, the CPU 14 calculates the optimum fuel injection time and timing for the engine using the pulser signal, the starter switch signal, the shift switch signal, and various sensor signals (not shown), and the gate circuit 15 generates pulses based on the calculated fuel injection time and timing. Through the drive circuit 19, the fuel injector 21 and the air injector 22 are turned on / off to inject fuel. However, if an abnormality occurs in the CPU 14 or a component accompanying it, for example, the gate circuit 15, engine operation becomes impossible. Therefore, the backup circuit 16 is provided to enable the minimum operation, and the CPU
In the event of an abnormality in 14, the backup circuit 16 outputs a switching signal, and at the same time outputs a backup signal to output the drive circuit 1
Enter in 9. The configuration and operation of this switching circuit 17 are shown in FIG.
Alternatively, it is performed as described in FIG.

Next, the abnormality detection of the control circuit 13 will be described. The abnormality detection of the control circuit 13 is performed by the abnormality detection circuit 12 built in the power supply circuit 11 and the abnormality detection circuit 25 built in the backup circuit 16.

In the CPU 14 of the control circuit 13, software is created so that the gate circuit 15 periodically outputs a watchdog pulse during operation. If CPU
If an abnormality such as the runaway of 14 occurs, the watchdog pulse is interrupted. Then, the abnormality detection circuit 12 built in the power supply circuit 11 detects it and outputs an abnormality detection signal, and C
The PU 14 and the gate circuit 15 are initialized. Although it is only necessary to return to the normal state by this, when the CPU 14 cannot return to the normal state due to a failure or the like, an abnormality detection signal is continuously generated. The backup circuit 16 detects a failure of the CPU 14 based on the continuous abnormality detection signal, and the failure detection circuit 25 detects the failure.

The abnormality detecting circuit 25 of the backup circuit 16 is shown in FIG. In FIG. 4, the first counter 26 counts the abnormality detection signal, and when a predetermined number of times is counted, a signal is output to the clock of the flip-flop 27 and the switching signal becomes high. That is, the CPU 14 is determined to be in failure. Further, the second counter 28 counts the pulse of the astable Mighty vibrator 29 and measures the time.

When the count value reaches a certain value, that is, when a certain time elapses, the first counter 26 is cleared via the OR circuit 30. Further, when an abnormality detection signal is input to the second counter 28 via the OR circuit 31, the second counter 2
8 is cleared. Therefore, when an abnormal signal more than a predetermined number of times reaches the second counter 28 within a certain time, the failure of the CPU 14 is detected. The first counter 26,
A reset circuit 32 is connected to the second counter 28 and the flip-flop 27, and the operation of the reset circuit 32 resets the first counter 26, the second counter 28, and the flip-flop 27.

Since the backup signal pulse generation circuit can be easily realized by a combination of a flip-flop, a one-shot multivibrator, etc., its explanation is omitted.

In the embodiment shown in FIG. 4, the present invention is applied to the control signals of the igniter as well as the control signals of the air injector and the fuel injector.

[0036]

As described above, according to the present invention, when a backup circuit detects an abnormality in a control circuit using a diode and a transistor, a switching signal is output at the same time as the backup signal to replace the control signal of the control circuit. The backup signal is used to drive the actuator to drive the actuator, and an integrated circuit such as an inverter or a three-state IC is used, which has a simple circuit configuration and is an inexpensive device. You can switch between output and backup.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a control device for an actuator.

FIG. 2 is a circuit diagram of another embodiment of the actuator control device.

FIG. 3 is a block diagram in which an actuator control device is applied to a fuel injection system.

FIG. 4 is a circuit diagram of an abnormality detection circuit of a backup circuit.

FIG. 5 is a circuit diagram of a conventional actuator control device.

[Explanation of symbols]

 1 Actuator control device 2 Actuator 3 Control circuit 4 Backup circuit 5 Switching circuit 6 Driving circuit D1 First diode D2 Second diode Tr1 Driving transistor Tr2 Switching transistor

Claims (1)

[Claims] 1. A control signal output port of the control circuit, comprising an actuator controlled by a control signal, a control circuit for outputting the control signal to the actuator, and a backup circuit for outputting a backup signal and a switching signal. The first diode is connected, the second diode is connected to the backup signal output port of the backup circuit, the output sides of the first diode and the second diode are connected to the drive circuit of the actuator, and the backup circuit is switched. A switching transistor is connected to the signal output port, the switching transistor is further connected to the first diode, a switching signal is output at the same time as the backup signal of the backup circuit, and the drive signal is driven by the backup signal instead of the control signal. To activate the circuit and output An actuator control device characterized by the above.