JPH0211459B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle travel control device that automatically controls a vehicle travel device according to driving conditions.

Conventional devices of this type are configured to detect the distance to an obstacle in front and the vehicle speed and apply the brakes to stop the vehicle.

However, simply operating the brakes places a burden on the brake system when the accelerator is depressed. Furthermore, if an oncoming vehicle approaches, for example, the vehicle will have no place to escape and will be in danger. Furthermore, if the obstacle in front of the vehicle has already moved or there is a need to accelerate, it is unreasonable to be unable to accelerate the vehicle immediately, which impedes smooth traffic flow.

This invention was made by focusing on these conventional problems, and detects dangerous information based on the distance to obstacles in front and the vehicle speed when the vehicle is running, and uses this information to activate the brakes and control the brakes. To provide a travel control device for a vehicle that immediately releases the brake and operates the accelerator when the need for acceleration arises after activation.

The present invention will be explained below based on the drawings.

FIG. 1 shows an embodiment of the first invention.

First, the configuration will be explained. In the figure, reference numeral 1 is a distance signal circuit, and 2 is a vehicle speed signal circuit. This distance signal circuit 1 converts the distance to an obstacle ahead into an electrical signal, and constitutes a distance measuring device using, for example, a laser beam. Further, the vehicle speed signal circuit 2 converts, for example, a tachometer display into an electrical signal. Each output side of the distance signal circuit 1 and the vehicle speed signal circuit 2 is connected to a differential amplifier 3, which is connected to the base of a transistor _T1 via a resistor _R1 .
This transistor T ₁ constitutes a Darlington circuit together with transistor T ₂ , and the transistor
The collector of T ₁ is connected to the brake servo circuit 4 . This brake servo circuit 4 is connected to, for example, a servo motor, a servo valve, etc., and these are connected to a brake (not shown).

Further, the emitter of the transistor _T2 is connected to one end of the excitation coil _RE1 of the first reed relay, the other end of this excitation coil _RE1 is connected to one end of the excitation coil RE2, and the other end of the excitation coil _RE2 is connected to one end of the excitation coil _RE1 . Grounded. This excitation coil RE ₁ operates in conjunction with a grounded reed contact S ₁ , which is connected to the base of a transistor _{T 3 via} a backflow prevention diode D ₁ and via a monitor lamp L ₁ . It is connected to the B line B _L which is connected to the battery B. Transistor T ₃ forms a Darlington circuit together with transistor T ₄ , and this transistor
The emitter of _T4 is grounded, and its collector is connected to the accelerator servo circuit 5.
Although illustration of this accelerator servo circuit 5 is omitted,
For example, it is connected to a servo valve that can control current, and by opening and closing this servo valve, the negative pressure of the intake manifold is controlled, and this negative pressure operates an actuator, which controls the accelerator wire that is connected to this actuator and opens and closes the throttle valve. It is configured to drive.

The accelerator servo circuit 5 is connected to the B line B _L ,
This B line B _L is connected to the ground and also has a potentiometer that is linked to the accelerator pedal (not shown).
VR is connected, and the output of this potentiometer VR is connected through a resistor R ₂ to the base of the transistor T ₃ .

Then, the potentiometer VR outputs a potentiometer signal corresponding to the amount of depression of the accelerator pedal, following the depression of the accelerator pedal.

On the other hand, there is a resistor at the connection point of excitation coils RE ₁ and RE ₂ .
R ₃ is connected, and one end of this resistor R ₃ is an AND circuit
It is connected to the output end of AND ₁ , and one input end of the OR circuit OR is connected to this output end. Also, one input end of the AND circuit AND ₁ is connected to the output end of the OR circuit OR, and the other input end of the AND circuit AND ₁ is connected to the output end of the potentiometer VR via the relay contact _S3 . has been done. Furthermore, one end of a capacitor _C1 is connected to the output end of the potentiometer VR, and the other end of this capacitor _C1 is grounded via a resistor _R0 and connected to the other input end of the OR circuit OR. There is.

The capacitor _C1 and the resistor _R0 constitute a differential circuit that outputs a differential signal according to the degree of change in the potentiometer signal output from the potentiometer VR.

Excitation coil of the relay that activates the contact _S3
One end of RE ₃ is connected to the B line BL, and the other end is grounded via the lead contact S ₂ of the second relay. Furthermore, the collector of a transistor _T5 is connected to the B line BL via a monitor lamp _L2 , and the emitter of this transistor _T5 is grounded, and its base is connected to the output of an AND circuit _AND1 via a resistor _R4 . connected to the end. Note that a diode _D2 for preventing backflow is connected between the collector of the transistor _T5 and the base of the transistor _T1 . A first reset circuit is constituted by the transistor _T5 , the diode D2 _, etc.

Next, the operation of the first invention will be explained.

For example, when a running vehicle approaches a preceding vehicle as an obstacle ahead, a distance signal and a vehicle speed signal are obtained that correspond to the inter-vehicle distance to the preceding vehicle and the vehicle speed of the vehicle. Then, when both signals reach a predetermined relationship, the differential amplifier 3 is activated to generate a danger signal. Therefore, even if the inter-vehicle distance is short, this danger signal will not be generated if the vehicle speed is below a predetermined speed, and will only be generated when information is obtained that will impede safe driving of the vehicle.

When the differential amplifier 3 operates, the transistors T ₁ and T ₂ turn on, operating the brake servo circuit 4 and applying the brakes. At the same time, the excitation coil RE ₁ is energized and closes the reed contact S ₁ . As a result, transistors T ₃ and T ₄ are turned off, the accelerator servo circuit 5 stops operating, and the accelerator is returned to its original state, causing the monitor lamp to turn off.
L ₁ lights up to notify you that the accelerator has been released. In this way, by obtaining the danger signal, the accelerator is released regardless of the position of the accelerator pedal, in other words, regardless of the output of the potentiometer VR.

Note that in the so-called engine braking state, the accelerator is released, but in this case the output of the potentiometer VR becomes zero and the transistors T ₃ and T ₄
is turned off, causing the accelerator servo circuit 5 to stop operating and work to return the accelerator. In this case, since the accelerator is released, the first reset circuit does not operate, and therefore, if the vehicle approaches the preceding vehicle, the brake servo circuit 4
can operate and ensure safety.

A case will be explained in which a vehicle approaches a preceding vehicle at a predetermined speed, but wants to accelerate to avoid danger, for example. In such a case, the transistor T ₁ ,
Since T ₂ is on, the excitation coil RE ₂ of the second reed relay is energized and the reed contact S ₂ is closed. For this reason, the excitation coil RE ₃ of the relay is energized and closes the contact S ₃ , so that the output of the potentiometer VR is supplied to the other input terminal of the AND circuit AND ₁ and to the capacitor C ₁ . When the accelerator pedal is suddenly depressed in such a state, the potentiometer VR follows the depression of the accelerator pedal and outputs a potentiometer signal corresponding to the amount of depression, and when this potention signal exceeds a predetermined value, the AND _circuit When the other input terminal becomes high level, a differential signal corresponding to the degree of change of the potentiometer signal is output from the differential circuit formed by the capacitor _C1 and the resistor _R0 , and this differential signal is applied to the preset accelerator. The setting value corresponding to the depression speed is exceeded, and the other input terminal of the OR circuit becomes high level. For this reason, the OR circuit
The output terminal of OR becomes high level and it becomes an AND circuit.
AND ₁ output becomes high level. The output of this AND circuit AND ₁ is the excitation coil of the second reed relay.
Since the feedback is sent to RE ₂ and one input terminal of the OR circuit OR, unless the output of the potentiometer VR is equivalent to zero, that is, the amount of depression of the accelerator pedal is almost zero, the high level of the output terminal of the AND circuit AND ₁ will be high. is retained.
When the output terminal of the AND circuit _AND1 becomes high level, the transistor _T5 turns on and the base of the transistor _T1 becomes zero potential, so the brake servo circuit 4
is released and prevents brake operation. Therefore, the excitation coil RE ₁ of the first reed relay is de-energized, causing the reed contact S ₁ to open and the transistor T ₃ ,
_T4 is turned on to operate the accelerator servo circuit 5, and accelerator acceleration is performed. When the transistor _T5 is turned on, the monitor lamp _L2 lights up to notify that the brake servo circuit 4 has been released, while the lead contact _S1 is opened and the monitor lamp _L1 goes out, indicating that the accelerator servo circuit 5 has not been released. I'm starting to let you know. Note that the first reset circuit is reset by releasing the accelerator pedal and setting the input terminal of the AND circuit _AND1 to a low level.

In this way, when the accelerator is depressed at a predetermined speed or higher, the operation of the brake servo circuit 4 is stopped, so when overtaking during normal driving, if the accelerator is depressed at a predetermined speed or higher, the brakes will not be activated during overtaking. There is no danger of being in a dangerous situation.

Next, FIG. 2 shows an embodiment of the second invention. This second invention is obtained by adding a second reset circuit to the first invention. Note that the same reference numerals are used for the same configurations as in the first invention, and redundant explanation will be omitted.

To explain the configuration of the second reset circuit, the anode of a diode _D3 is connected to the output terminal of the AND circuit _AND1 , and its cathode is connected to the connection point of the resistor _R3 and the resistor _R4 . The cathode of the diode D4 is connected to the cathode of the diode _D3 , and the anode of the diode _D4 is connected to the output terminal of the AND circuit _AND2 . One input terminal of this AND circuit AND ₂ is connected to the voltage dividing point of voltage dividing resistors R ₅ and R ₆ ,
One end of this resistor _R5 is connected to the B line B _L via a turn signal switch (lane change switch) SW, and one end of the resistor _R6 is grounded.
Furthermore, a grounded turn signal lamp _L3 is connected to one end of the resistor _R5 . Furthermore, an overspeed detection circuit 6 is connected to the other input terminal of the AND circuit AND ₂ .
is connected, and the overspeed detection circuit 6 is supplied with the output of the vehicle speed signal circuit 2 and is configured to operate when the vehicle speed exceeds a predetermined value. And the AND circuit AND ₂ and the diode D ₄ and the transistor T ₅
A second reset circuit is constituted by the diode _D2 and the like.

Next, the operation of the second invention will be explained.

A case in which a vehicle approaches a preceding vehicle at a predetermined speed, but attempts to overtake by changing lanes while maintaining the vehicle speed due to deceleration of the preceding vehicle, for example, will be described. In such a case, as the vehicle approaches the preceding vehicle, the brake servo circuit 4 should be activated as described above to apply the brakes. However, the turn signal switch SW did not change the position of the accelerator pedal.
When the turn signal lamp L ₃ is turned on, one input terminal of the AND circuit AND ₂ becomes high level, and the other input terminal receives the output of the overspeed detection circuit _6. The output terminal becomes high level. Therefore, the transistor _T5 is turned on and the transistors _T1 and _T2 are turned off, thereby releasing the brake servo circuit 4 and preventing the brake from operating. In this case, since the contact _S1 is open, the accelerator servo circuit 5 operates and accelerator acceleration is performed.

In addition, if the vehicle speed does not exceed the predetermined value even if the turn signal switch SW is turned on, the overspeed detection circuit 6
Since the second reset circuit does not operate, the second reset circuit does not operate when the vehicle is decelerating at an intersection or the like.

Note that the turn signal switch SW may be a separately provided switch, as long as it can provide an overtaking signal indicating a lane change.

As explained above, according to the first invention, there is provided a potentiometer that follows the depression of an accelerator and outputs a potentiometer signal corresponding to the amount of depression, and a differential signal that outputs a differential signal that corresponds to the degree of change in the potentiometer signal. The brake servo circuit is equipped with a differential circuit and a first reset circuit that stops the operation of the brake servo circuit when the differential signal exceeds a preset value corresponding to the accelerator depression speed. Even if the accelerator is close to A signal is output, and when this differential signal exceeds a set value corresponding to a set accelerator depression speed, the first reset circuit stops the operation of the brake servo circuit.

Therefore, after the vehicle approaches a front obstacle and the brakes are activated, the accelerator can be immediately released, thereby eliminating the burden on the brakes.

In addition, since the operation of the brake servo circuit is stopped depending on the speed at which the accelerator is depressed, if the accelerator is not depressed at a predetermined speed or higher, the brake servo circuit will stop operating if the vehicle approaches the preceding vehicle, regardless of the accelerator opening degree. It will work, so choose one that is highly safe. For example, even if the vehicle inadvertently approaches a preceding vehicle while the accelerator is fully open, the brakes will operate unless the accelerator is depressed at a predetermined speed or higher, making it extremely safe. Additionally, if you depress the accelerator at a predetermined speed or higher, the brake servo circuit will stop operating, so when overtaking while driving normally, if you depress the accelerator at a predetermined speed or higher, the brakes will activate during overtaking, which could be dangerous. There is no such thing as a state.

Also, even when driving with engine braking, since the accelerator is released in this case, the first
The reset circuit does not operate, so if the vehicle approaches the preceding vehicle, the brake servo circuit operates and safety can be ensured.

Furthermore, according to a third invention, there is provided a brake servo circuit that operates the brakes based on a danger signal obtained from the distance to a front obstacle and the vehicle speed, and a brake servo circuit that attempts to stop accelerator operation when the brake servo circuit is activated. Since it includes an accelerator servo circuit and a second reset circuit that stops the operation of the brake servo circuit when an overtaking signal is input at a predetermined vehicle speed or a predetermined amount of accelerator depression, the vehicle speed does not change in addition to the effect of the first invention. Even if you want to overtake a vehicle in front of you, you can accelerate without applying the brakes.

[Brief explanation of drawings]

FIG. 1 is an electric circuit diagram showing an embodiment of the first invention, and FIG. 2 is an electric circuit diagram showing an embodiment of the second invention. 1...Distance signal circuit, 2...Vehicle speed signal circuit, 3
... Differential amplifier, 4 ... Brake servo circuit, 5
...Accelerator servo circuit, 6...Overspeed detection circuit.

Claims (1)

[Scope of Claims] 1. A brake servo circuit that operates the brakes based on a danger signal obtained from the distance to an obstacle in front and the vehicle speed, and an accelerator servo circuit that attempts to stop accelerator operation when the brake servo circuit is activated. A vehicle travel control device comprising: a potentiometer that follows depression of the accelerator and outputs a potentiometer signal according to the amount of depression; and a potentiometer that outputs a differential signal according to the degree of change in the potentiometer signal. A vehicle comprising: a differential circuit; and a first reset circuit that stops the operation of the brake servo circuit when the differential signal exceeds a preset value corresponding to a preset accelerator depression speed. Travel control device. 2. A lane change switch that outputs a lane change signal to notify other vehicles of your intention to change lanes, and a brake servo that activates the brakes based on danger signals obtained from the distance to obstacles in front and vehicle speed. and an accelerator servo circuit that stops accelerator operation when the brake servo circuit is activated, the overspeed control device outputs an overspeed signal when the vehicle speed exceeds a predetermined speed. a detection circuit; a potentiometer that follows the depression of the accelerator and outputs a potentiometer signal according to the amount of depression; a differentiation circuit that outputs a differential signal according to the degree of change of the potentiometer signal; a first reset circuit that stops the operation of the brake servo circuit when the accelerator depression speed exceeds a preset value corresponding to a preset accelerator depression speed; and while the brake servo circuit is in operation, the overspeed detection means generates an overspeed signal. and a second reset circuit for stopping operation of the brake servo circuit when a lane change signal is output by the lane change switch.