JPH04183643A - Fail-safe device of constant speed traveling device - Google Patents

Abstract

PURPOSE:To enable correct failure judgement of a resume switch by making comparison between respective switching conditions of a main switch and a resume switch that force execution of constant speed traveling, and prohibiting the failure judgement of the resume switch when both switching conditions agree with each other. CONSTITUTION:When a main switch 4 is set on, a processing circuit 20 starts a constant speed traveling action, and when a set switch 23 is set on, the vehicle speed which is obtained by means of a vehicle speed sensor 22 at the point of time is set to the target vehicle speed. The processing circuit 20 thereafter outputs a control signal to an actuator 25 so as to maintain this target vehicle speed, and the opening degree of a throttle valve 28 is controlled. In this case, there is provided in the processing circuit 20 a judgement prohibiting means in relation to a fail-safe device which detects the abnormal condition and the like of the actuator 25. Comparison is made between the switching condition of the main switch 4 and that of the resume switch 32, and arrangement is made so that the failure judgement of the resume switch by means of the fail- safe device may be prohibited when both switching conditions agree with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION Overview In a fail-safe device for a constant-speed traveling system that is equipped with a resume switch for returning to constant-speed traveling control once released, electric power is energized at the same time as the ignition circuit of an internal combustion engine starts to be energized. Provide means for prohibiting such judgments. The determination prohibiting means compares the switching state of the main switch and the switching state of the resume switch, and when the two match, prohibits failure determination of the resume switch in the fail-safe device.

As a result, a failure state in which the resume switch is always on and a normal state in which the main switch and the resume switch are operated at the same time are accurately determined, and fail-safe malfunctions are prevented.

INDUSTRIAL APPLICATION FIELD The present invention relates to a fail-safe device for a constant-speed vehicle that automatically controls the opening of a throttle valve so that the traveling vehicle speed becomes a target vehicle speed without operating an accelerator pedal.

A conventional constant speed traveling device is a device that drives and controls an actuator provided in a link mechanism of a throttle valve so that the vehicle travels at a target vehicle speed preset by the driver. This constant speed traveling device starts operating after the main switch is turned on, sets the vehicle speed at the time when the set switch is turned on as a target vehicle speed, and operates the actuator to maintain the target vehicle speed. to drive and control.

Also, when the brake pedal or clutch pedal is depressed, constant speed driving control is canceled, and if the resume switch is operated after being released again, constant speed driving control is restored again, and the previous set switch The actuator is driven and controlled so as to maintain the target vehicle speed set by the operation.

Therefore, when the actual traveling vehicle speed is lower than the target vehicle speed at the time when the resume switch is operated, the actuator is drive-controlled to accelerate the vehicle. Therefore, if the resume switch is always on due to a short circuit or the like, control will be performed to accelerate, which is very dangerous. Therefore, fail-safe devices are provided to prevent such malfunctions.

Typical prior art fail-safe system! Then, after the main switch is turned on, the switching state of the resume switch is monitored. In addition, if the resume switch is already on when the main switch is turned on, the system will determine whether the resume switch is always on, prohibit constant speed driving control, and turn on a warning light. Shift to failsafe operation.

On the other hand, various switches used for the constant speed running control are integrated into a combination switch 1 and attached to a steering column 2, as shown in FIG. 4, for example. This combination switch 1 is
Similar to the headlight combination switch 3, different functions are realized depending on the direction in which these rod-shaped switches 1 and 3 are tilted.

For example, the combination switch 1 is referred to as A1.
When pushed upward as indicated by reference mark A2, the set switch turns on and the target vehicle speed is set; when pushed downward as indicated by reference mark A2, the resume switch is turned on and returns to constant speed driving control. When pushed forward as indicated by reference numeral A3, the cancel switch is turned on and constant speed driving control is canceled.

A push-button main switch 4 is provided at the tip of the combination switch l, and each time the main switch 4 is pressed, the constant speed driving control changes from the off state to the on state, or from the on state to the off state. The state changes.

In addition, in response to such an on/off operation of constant speed driving control, an indicator light 6 in the instrument panel 5 is turned on or off to indicate whether constant speed driving control is possible. Furthermore, when an abnormality occurs in the constant speed driving control, the indicator light 6 flashes for a predetermined time and then turns off.
Displays that constant speed driving control is not possible.

By using the combination switch 1 integrated in this way, the operability for constant speed driving control is improved.

Problems to be Solved by the Invention However, when performing constant speed driving control using the above-mentioned combination switch 1, at the same time as the main switch 4 is pressed, the combination switch 1 is tilted in the direction of the arrow A2, and the resume switch is turned on. state, the fail-safe device of the prior art described above incorrectly determines that the resume switch is always on, and
After the indicator light 6 flashes, it goes out and constant speed driving control is prohibited.

SUMMARY OF THE INVENTION An object of the present invention is to provide a failsafe device for a constant speed vehicle that can accurately determine failure of a resume switch.

Means for Solving the Problems The present invention provides drive control of an actuator provided in connection with an internal combustion engine so that it starts operating in response to the operation of a main switch and maintains a predetermined target vehicle speed. In a fail-safe device for a constant speed driving device, which realizes constant speed driving control by, and returns to the constant speed driving control by operating a resume switch after the constant speed driving control is once canceled, Judgment prohibiting means is energized when the power supply starts, compares the switching state of the main switch and the switching state of the resume switch, and when the two match, prohibits a failure judgment of the resume switch in the fail-safe device. This is a fail-safe device for a constant speed traveling device, characterized in that it is provided with a.

The constant speed traveling device according to the present invention starts operating in response to the operation of the main switch, and controls internal combustion based on the difference between the target vehicle speed and the actual traveling vehicle speed to maintain a predetermined target vehicle speed. In relation to the engine, for example, an actuator provided in a link mechanism of a throttle valve is driven and controlled to realize constant speed running control.

Further, even after the constant speed driving control is once canceled by, for example, depressing the brake pedal or clutch pedal, the target vehicle speed is maintained at the target vehicle speed before the constant speed driving control is canceled by operating a resume switch. Returns to constant speed driving control.

On the other hand, in connection with the fail-safe device that detects an abnormality in the actuator, a judgment prohibition means is provided, and the judgment prohibition means is connected in parallel with the ignition circuit of the internal combustion engine, and is therefore connected to the ignition circuit. While power is being supplied, the determination inhibiting means is energized.

The determination prohibition means compares the switching state of the main switch and the switching state of the resume switch, and when the two match, causes the failsafe device to prohibit failure determination of the resume switch.

That is, when the driver simultaneously operates the main switch and the resume switch to turn them on, determination of failure of the resume switch is prohibited.

Further, for example, if it is detected that the resume switch is in the on state at the time of starting energization to the ignition circuit, and the resume switch is already in the on state at the time when the main switch is switched to the on state, the resume It is determined that the switch is always on due to a short circuit or the like, and a failure determination of the fail-safe device is performed. In this way, erroneous determination of failure of the resume switch is prevented.

Embodiment FIG. 1 is a block diagram showing a constant speed traveling device 11 and related configurations according to an embodiment of the present invention.

Electric power from the battery 15 is supplied to the constant voltage circuit 12 in the constant speed traveling device ll during a period when the ignition key switch 16 for supplying electric power to the battery 15 to the ignition circuit 14 of the internal combustion engine 13 is conducted. is supplied. The ignition circuit 14 outputs an ignition signal to the ignition plug 18 via the igniter 17.

When power supply to the constant voltage circuit 12 is started, the processing circuit 20, which is implemented by a microcomputer or the like and serves as a determination means as well as a determination prohibition means, starts operating;
It performs fail-safe operation as described below. Note that if the main switch 4 is turned on in this state,
The processing circuit 2° starts a constant speed running operation, reads the vehicle speed pulse from the vehicle speed sensor 22, and calculates the actual running vehicle speed.

Further, when the set switch 23 is turned on, the traveling vehicle speed at that time is set to the target vehicle speed, and the processing circuit 23
Thereafter, outputs a duty M return signal corresponding to the difference between the target vehicle speed and the actual traveling vehicle speed to the actuator 25 via the output interface circuit 24 so as to maintain this target vehicle speed.

The actuator 25 changes the opening degree of the throttle valve 28 by, for example, introducing negative intake pressure of the internal combustion engine 13 into the diaphragm via a magnetic valve that opens and closes in response to the duty-controlled control signal. It is a diaphragm type actuator, and is provided in a link mechanism 26 that connects an accelerator pedal 27 and a throttle valve 28.

The output generated by the internal combustion engine 13 is transmitted to wheels 31 via an automatic transmission 30. The automatic transmission 30 automatically switches gears to obtain an optimal reduction ratio based on information such as vehicle speed and throttle valve opening input from the constant speed traveling device 11 via a line 29. conduct.

In the constant speed traveling device 11, the resume switch 32 is turned on again even after the constant speed traveling control is canceled by, for example, depressing the brake pedal or operating the cancel switch 33. Then, the output of the duty control signal is restarted so that the target vehicle speed that was set at the time when the set switch 23 was turned on is resumed, and the constant speed running control state is restored.

Note that the outputs from each of the switches 4.23, 32.33 and the vehicle speed sensor 22 are input to the input interface circuit 121.
After undergoing waveform shaping and the like, the signal is input to the processing circuit 20.

The processing circuit 20 also responds to the operation of the main switch 4 by turning on an indicator light 6 when constant speed driving control is possible.
The indicator light 6 is turned on, and the indicator light 6 is turned off when the constant speed driving control is not possible. Furthermore, in the event of a failure due to a short circuit in the output transistor in the output ink face circuit 24 or a determination that the resume switch 32 is always on (to be described later), the indicator light 6 flashes and then goes out, making constant speed driving control impossible. .

In the constant speed traveling device 11 configured as described above, the processing circuit 20 is energized from the time when the ignition key switch 16 is turned on, which is indicated at time t1 in FIG. 2(1). The processing circuit 20 firstly processes the time t.
At time t2, when a predetermined time W1 has elapsed from 1, the switching state of the resume switch is detected, as shown in FIG. 2 (4).

Thereafter, at every predetermined detection period W2, the main switch 4
The switching state of is detected, and then the switching state of
From time t3 when it is detected that the main switch 4 is in the on state, as shown in , the processing circuit 20 starts the constant speed running control operation.

When the constant speed running control operation is started, at time t5, when a predetermined time W3 has elapsed from the time when the main switch 4 was turned off, which is indicated at time t4, the operation is resumed as shown in FIG. 2 (3).
) is detected as the switching state of the resume switch 32.

In the example shown in FIG. 2, the switching state of the resume switch 32 is equal to the switching state of the main switch 4 at the monitor timing shown at time t3. Always-on judgment is performed.

On the other hand, in the present invention, the main switch 4 at time t4
At time t5, when a predetermined time W3 has elapsed since the main switch 4 and the resume switch 32 were turned off, the switching states of the main switch 4 and the resume switch 32 are compared again. Therefore, the processing circuit 20 can determine that the main switch 4 and the resume switch 32 were operated at the same time.

Further, the resume switch 32 at the time t2
According to the detection result of the switching state, the resume switch 324 is in the OFF state. Therefore, from the detection result shown in FIG.
It can be determined that the switching operation is performed normally without any failures such as short circuits, and that the main switch 4 was operated at the same time.

Therefore, in such a case, the above-mentioned fail-safe operation is not performed, and it is possible to determine whether the resume switch 32 is in a faulty state where it is always on, or whether it is in a normal state when it is only operated together with the main switch 4. can be judged accurately.

FIG. 3 is a flowchart for explaining the operation shown in FIG. 2 above. In step n1, it is determined whether or not the resume switch 32 is in the on state. If so, the process moves to step n2, and it is determined whether or not the main switch 4 is in the on state. step n2
Then, when the main switch 4 is in the on state, that is, at the timing t3, the process moves to step n3,
It is determined whether the resume switch 32 is in the on state.

In step n3, if the resume switch 32 is in the on state, the process moves to step n4, where it is determined whether or not the main switch 4 has turned off. If so, that is, at the timing t4, the process moves to step n5. , it is determined again whether the resume switch 32 is in the on state, and if so, the process moves to step n6, where it is determined that the resume switch 32 is in a failure state where it is always in the on state, and the indicator light 6 is turned on. After blinking,
The light goes out, and fail-safe actions such as prohibiting constant speed driving control are performed.

Further, the steps nl, n3. When the resume switch 32 is not in the on state at step n5, and step n
2. At n4, if the main switch 4 is not in the ON state, the process moves to the main routine, and if the constant speed running control is in progress, the duty control signal is output as described above, and if the constant speed running control is not in progress, the switching state of each switch is changed. Perform reading etc.

As described above, in the constant speed traveling device 11 according to the present invention, power is supplied to the processing circuit 20 via the ignition key switch 16 that supplies power to the ignition circuit 14 of the internal combustion engine 13, and the ignition key switch 16 is turned on. When a predetermined time W1 has elapsed since then, when the main switch 4 has been turned on, and when a predetermined time W3 has elapsed since the main switch 4 has been turned off, the resume switch 32 is turned off. Since the switching state is detected, it is possible to accurately distinguish between a failure state in which the resume switch 32 is always on due to a short circuit, etc., and simultaneous operation of the resume switch 32 and the main switch 4, and a fail-safe function. It can be expanded.

In addition, although the above-mentioned embodiment explained the always-on determination of the resume switch 32, other switches such as the set switch 23 and the accelerator switch may be implemented as other embodiments of the present invention.

Effects of the Invention As described above, according to the present invention, a determination prohibition means is provided in connection with a failsafe device that determines a failure of a constant speed traveling device, and the determination prohibition means is configured to prevent the start of energization to an ignition circuit of an internal combustion engine. The switching state of the main switch and the switching state of the resume switch are monitored, and when the two match, failure determination of the resume switch is prohibited.

This prevents erroneous failure determinations due to simultaneous operation of the main switch and resume switch, and enables highly accurate fail-safe operation.

[Brief explanation of drawings]

Figure 1 shows a constant speed traveling device according to an embodiment of the present invention! 11 and its related configuration; FIG. 2 is a timing chart for explaining the operation of reading the switching states of the main switch 4 and the resume switch 32;
FIG. 3 is a flowchart for explaining the operation shown in FIG. 2, and FIG. 4 is a perspective view of the vicinity of the instrument panel 5, which includes the combination switch 1 operated to perform constant speed driving control. 1...Combination switch, 4...Main switch, 6...Indicator light, 11...Constant speed running device! ,1
2... Constant voltage circuit, 13... Internal combustion engine, 14...
Ignition circuit, 16...Ignition key switch, 20
...Processing circuit, 23...Set switch, 25...
・Actuator, 28... Throttle valve, 32...
・Resume Switch Agent Patent Attorney Kei Saikyo Figure 2 Figure 4 Figure 3

Claims (1)

[Claims] Constant speed driving control is realized by driving and controlling an actuator provided in connection with the internal combustion engine so as to start operation in response to the operation of a main switch and maintain a predetermined target vehicle speed. In a fail-safe device for a constant speed running device that returns to the constant speed running control by operating a resume switch after the constant speed running control is once released, electric power is energized at the same time as the ignition circuit of the internal combustion engine starts to be energized. , a determination inhibiting means is provided which compares the switching state of the main switch and the switching state of the resume switch, and when the two match, prohibits determination of failure of the resume switch in the fail-safe device. Fail-safe device for speed running equipment.