JPS6345974B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a constant speed traveling device for a vehicle, and more specifically, it includes an actual vehicle speed detection section that detects a voltage signal corresponding to the actual vehicle speed of the vehicle, and a device for driving the vehicle at a constant speed. The vehicle is equipped with a set vehicle speed storage unit that stores the actual vehicle speed as a set vehicle speed when the actual vehicle speed reaches the vehicle speed, and an error amplification control unit that controls the deviation between the actual vehicle speed and the set vehicle speed to zero. This invention relates to a constant speed traveling device that controls the vehicle to travel at a constant speed.

A constant speed running device for a vehicle is a device that automatically drives a vehicle at a constant speed. For example, it detects the engine rotation speed or vehicle speed and automatically adjusts the throttle valve opening to maintain them at a certain value. It is something to control. The prior art will be explained with reference to FIGS. 1, 2, and 3. Figure 1 is a layout diagram of the control system, Figure 2
The figure is a partially enlarged view, and FIG. 3 is a block diagram of the control system. This constant speed traveling device includes a controller 20 that detects a deviation between the actual vehicle speed and a set vehicle speed and outputs a control signal in the direction of zeroing this deviation, and a controller 20 that controls the opening degree of the carburetor 3 according to the control signal from the controller 20. It is composed of a negative pressure servo system that adjusts the actual vehicle speed by increasing or decreasing it. The controller 20 includes an actual vehicle speed detection section 30 that detects a DC voltage signal corresponding to the actual vehicle speed, and a set vehicle speed storage section 40 that stores the actual vehicle speed as a set vehicle speed when the actual vehicle speed reaches the vehicle speed at which the vehicle is to be driven at a constant speed. and error amplification control, which is formed by an error amplifier 51, a power amplifier 52, and a feedback circuit 53, and outputs a control signal in the direction of zeroing the deviation between the actual vehicle speed and the set vehicle speed to the servo valve 7 in the negative pressure servo system. It consists of a department. More specifically, the actual vehicle speed detection section 30 receives as input a pulse signal corresponding to the vehicle speed sent from the vehicle speed sensor 11, shapes it into a rectangular wave in the waveform shaping circuit 31, and then uses the next FV converter 32 to shape the pulse signal into a rectangular wave. By converting it into a DC voltage signal, a DC voltage signal V _R corresponding to the vehicle speed is obtained and sent to the comparator 50 and the error amplifier 51. The set vehicle speed storage unit 40 includes an oscillator 42, a gate circuit 43, a counter 44, and a D/A converter 45. The oscillator 42 generates a constant frequency pulse signal of, for example, 1kHz, and the gate circuit 43 is a setting signal circuit. 41 outputs an ON signal and the comparator 50 outputs a "1" signal, the gate is opened and the output of the oscillator 42 is sent to the counter 44, and the counter 44 counts the constant frequency pulse signal from the oscillator 42. For example, when the count value reaches 128, it returns to zero and repeats the counting operation, and the D/A converter 45 momentarily converts the count result of the counter 44 into analog and sends the result to the comparator 50 and the error amplifier. 51, and the comparator 50 receives the actual vehicle speed signal V _R from the FV converter 32 and the analog signal from the D/A converter 45 at two inputs, compares their magnitude, and calculates the two input values. A "0" signal is output when the speed becomes equal or the actual vehicle speed signal is high, and a "1" signal is output at other times. When the actual vehicle speed reaches the vehicle speed you want to drive at a constant speed, press the vehicle speed setting switch SW.
When (SET) is pressed for a short time, the setting signal circuit 41
An on signal is output for a short time from gate circuit 4.
3 opens, the counter 44 starts counting, and when the output of the comparator 50 becomes "0", that is, when the output of the D/A converter 45 becomes equal to the actual vehicle speed signal V _R , Gate 43 is closed, counter 4
4 stops the counting operation while maintaining the counting contents at that point in time, and as a result, the set vehicle speed signal V _M , which is approximately equal to the actual vehicle speed signal V _R , is stored in the storage section 40.

This set vehicle speed signal V _M is sent to an error amplifier 51, where the deviation from the actual vehicle speed signal V _R is determined.
It is output to the servo valve 7 via the power amplifier 52 as a control signal in the direction of making the deviation signal zero. The servo valve 7 converts the negative pressure from the intake manifold 2 into a controlled negative pressure that is compared to the control current signal from the power amplifier 52. The valve solenoid 6 is operated by on/off signals from the output relay 22 in the controller 20,
When energized, servo valve 7 is connected as shown by the solid line arrow in Figure 2.
and actuator 5 are connected, and the second
The actuator 5 is communicated with the atmosphere as indicated by the broken line arrow in the figure. Actuator 5 is servo valve 7
Converts the controlled negative pressure from wire 4 into mechanical force.
The accelerator link 12 is actuated via the engine to increase or decrease the opening degree of the carburetor 3, thereby adjusting the vehicle speed.

The operation of the conventional device will be explained according to the flow of control signals. When neither the brake nor the clutch is operated, brake switch SW3 and clutch switch
SW4 is closed, and when the ignition switch SW1 and main switch SW2 are turned on in this state, the voltage of the battery power supply E is applied to the controller 20, and the constant voltage passing through the constant voltage circuit 23 is applied to each internal circuit of the controller 20. The controller 20 is now ready for operation. At this time, a pulse signal corresponding to the vehicle speed from the vehicle speed sensor 11 is converted into a DC voltage V _R by the actual vehicle speed detection section 30 and sent to the error amplifier 51. Vehicle speed setting switch SW (SET)
When you press and release , the set vehicle speed memory section 40 is switched.
A voltage V _M that is approximately equal to the actual vehicle speed signal V _R at the time when SW (SET) is released is stored as a set vehicle speed, and is sent to the error amplifier 51 .

The error amplifier 51 compares the set vehicle speed V _M stored in the storage section 40 with the actual vehicle speed V _R , which changes from time to time, and amplifies and outputs the difference between the two voltages. In addition, in the above explanation, the error amplifier control section was explained as outputting a control signal in the direction of zeroing the deviation, but the error amplifier 51 also generates a certain output voltage when V _R =V _M. . This becomes a control signal to flow the servo current necessary for the car to drive on a flat road. Actual vehicle speed V _R is set vehicle speed V _M
If it becomes larger, the error amplifier 51 operates in the direction of decreasing the servo current ( _servp ) to the servo valve 7. When the actual vehicle speed V _R becomes lower than the set vehicle speed V _M , the operation is performed in the opposite direction. The output signal of the error amplifier 51 is power amplified by the power amplifier 52 and then sent to the coil of the servo valve 7 as a negative pressure control signal. A servo current of approximately 140 to 180 mA normally flows through the coil of the servo valve 7, and when the actual vehicle speed becomes higher than the set vehicle speed and the output voltage of the error amplifier 51 decreases, the power amplifier 5
The output from 2 also decreases and the servo current decreases.
The servo valve 7 outputs a controlled negative pressure corresponding to a negative pressure control signal from the power amplifier 52 using the negative pressure of the intake manifold 2 as a negative pressure source. This control negative pressure operates the actuator 5 when the valve solenoid 6 is energized, and adjusts the opening of the carburetor 3. In this way, in the conventional constant speed traveling device, the vehicle speed of the vehicle is automatically controlled by the combination of the controller 20 and the negative pressure servo system.

In the above conventional devices, the constant speed driving function is canceled by the brake switch SW3 or clutch switch SW4, or even the ignition switch.
This is done by opening either SW1 or main switch SW2 to cut off the power supply to constant voltage circuit 23, output relay 22, and vehicle speed setting switch SW (SET). Further, as the output relay 22, either a contact type electromagnetic relay or a non-contact type relay having a semiconductor structure can be used, but in either case, one with self-holding characteristics is used. In other words, vehicle speed setting switch SW
Once the output relay 22 is turned on by the on signal from (SET), the vehicle speed setting switch SW
Even if the (SET) output turns off, the output relay 2
2 continues to generate an on output. Therefore, if this output relay 22 experiences a welding accident (in the case of a non-contact type relay, a short-circuit accident of the semiconductor element), etc., and the output side contact remains in the welded state, a vehicle speed running function release signal is input. During this period, the constant speed driving function is canceled by cutting off the power supply, but if the cancellation signal disappears, the constant speed driving function is restored and there is a danger that the vehicle will continue to maintain constant speed driving.

The present invention cancels the constant speed driving function using a constant speed driving function release signal even when the output relay in the constant speed driving device has a welding failure (in the case of a semiconductor relay, it causes a short circuit failure of the output transistor, etc.). It is an object of the present invention to provide a highly safe constant speed traveling device for a vehicle that is capable of displaying a warning.

In order to achieve the above object, the features of the present invention are as follows:
an actual vehicle speed detection unit that detects the actual vehicle speed and outputs an actual vehicle speed signal; a constant speed driving command unit that commands constant speed driving;
a cancellation command unit that commands cancellation of constant speed driving; a vehicle speed storage unit that stores a constant speed driving vehicle speed value as a set vehicle speed; storing the set vehicle speed in a vehicle speed storage unit, and outputting a signal to cause the vehicle to travel at a constant speed at the set vehicle speed according to the difference between the set vehicle speed and the actual vehicle speed;
and a calculation unit that determines that there is an abnormality and outputs an abnormal signal when the signal for driving at a constant speed is output even though the release command has been issued by the release command unit. be.

An embodiment of the present invention will be described below with reference to FIGS. 4 and 5. FIG. 4 is a circuit configuration diagram of an embodiment, and FIG. 5 is a diagram showing the level relationship of signals of each part in FIG. 4. The difference between the embodiment shown in FIG. 4 and the conventional example shown in FIG. 3 is that a portion surrounded by a broken line in FIG. 4 is added. Although a contact type electromagnetic relay is shown in FIG. 4 as the output relay 22, it may be a contactless type relay having a transistor configuration. The output voltage of this output relay 22
V _cc is supplied to each circuit within the constant speed traveling device 20 and serves as a driving power source for each circuit. AND1, AND
2 is an AND circuit, NOT is a negative circuit, and 61 is an output that once becomes a low level "L", it cannot output a high level "H" signal unless a reset signal is input from the reset terminal RESET. The holding circuit 62 is a warning light driven by the output of the AND circuit AND2. and circuit
AND1 is the relay drive circuit 21 for the battery power signal ' that has passed through the clutch switch SW4.
The signal after passing and the output signal from the output relay 22 are received at two inputs, and the output signal becomes an input to the holding circuit 61. The AND circuit AND2 receives at two inputs a signal obtained by inverting the sign of the output signal of the holding circuit 61 by the NOT circuit NOT, and an output signal from the output relay 22.

In the above configuration, the battery power supply signal' becomes high level "H", and then the vehicle speed setting switch
When SW (SET) is turned on, the actual vehicle speed at that time is stored in the vehicle speed storage section 40, and at the same time, the output relay 22 is activated via the relay drive circuit 21, its output contact is closed, and the vehicle speed setting switch SW ( SET)
Even if the output relay 22 turns off, the output relay 22 continues to generate an output by self-holding, and the output signal of the AND circuit AND1 maintains a high level "H".
and the valve solenoid 6, and the output _Vcc of the output relay 22 is also supplied to each circuit in the controller 20 to perform constant speed running control. Here, if the output relay 22 is normal, the battery power signal' falls to the low level "L" and the output signal of the output relay 22 also falls to the low level "L", thereby canceling the constant speed running function. be done. During the above normal operation, the output signal of the AND circuit AND2 is always at a low level "L", and the warning light 62 does not light up. However, when a welding failure occurs in the output relay 22, the output signal of the output relay 22 continues to be at a high level "H" even if the battery power signal' becomes a low level "L". In this case, the output signal of the AND circuit AND1 is low level “L”
Therefore, the power amplifier 52 and the valve solenoid 6
At the same time, the output of the AND circuit AND2 changes to a high level "H" and the warning light 62 lights up to notify the driver of the abnormality. Furthermore, since the holding circuit 61 is inserted and installed, once the signal becomes low level and the constant speed driving function is canceled, in order to reactivate this constant speed driving function, the ignition switch SW1 or It is necessary to turn on the main switch SW2 again to reset the holding circuit 61, which makes it easy for the driver to know that the constant speed traveling device is out of order. The relationship shown in the special abnormality column in the level relationship diagram in Figure 5 is for the relay drive circuit 2.
1 or the coil side of the output relay 22, and the output relay 22 does not generate an output even if the power signal ' is set to a high level when setting the vehicle speed. In this case, the constant speed driving function will not operate. Also, the warning light 62 does not light up. Of course, it is possible to easily create a configuration in which another warning light is turned on even in the event of this special abnormality by adding a small number of logic circuits.

As explained above, according to the present invention, there is provided a gate circuit that blocks the supply of driving power to the error amplification control section in response to generation of a command signal for canceling the constant speed driving function, and a gate circuit that blocks the supply of driving power to the error amplification control section in response to generation of a command signal for canceling the constant speed driving function; However, by providing an abnormality warning circuit that determines that the output relay is abnormal and displays a warning to the driver when it detects that driving power is generated from the output relay, the output relay is activated. Even if a welding failure occurs, the constant speed driving function is completely canceled, making it a highly safe device, and the warning light illuminates so that the driver can easily notice an abnormality.

[Brief explanation of the drawing]

Fig. 1 is a control system layout diagram of a conventional device, Fig. 2 is a partially enlarged view thereof, Fig. 3 is a block diagram of a conventional device, Fig. 4 is a circuit diagram of an embodiment of the present invention, and Fig. 5 is a level relationship diagram of various signals in FIG. 4. Explanation of symbols 1... Engine, 2... Intake manifold, 3... Carburetor, 5... Actuator, 6... Valve solenoid, 7... Servo valve, 8... Transmission, 10... Speed meter, 11... Vehicle speed sensor, 12... Accelerator link , 12'... accelerator pedal, 13... return spring, 20... controller, 21... relay drive circuit, 22... output relay, 23... constant voltage circuit, 30... actual vehicle speed detection section, 31... waveform shaping circuit,
32... FV converter, 40... Set vehicle speed storage section, 41
...setting signal circuit, 42...oscillator, 43...gate circuit, 44...counter, 45...D/A converter, 50
...Comparator, 51...Error amplifier, 52...Power amplifier, 53...Feedback circuit, 61...Holding circuit, 62...Warning light, SW (SET)...Vehicle speed setting switch.

Claims (1)

[Claims] 1 In a constant speed traveling device that causes a vehicle to travel at a constant speed, an actual vehicle speed detection section that detects the actual vehicle speed and outputs an actual vehicle speed signal, a constant speed traveling command section that commands constant speed traveling, and a constant speed traveling canceling section. a release command unit that commands the
A vehicle speed storage unit that stores a constant speed traveling vehicle speed value as a set vehicle speed; and a vehicle speed storage unit that stores an actual vehicle speed value when the constant vehicle speed command is issued by inputting the actual vehicle speed signal as the set vehicle speed; A signal to cause the vehicle to travel at a constant speed at a set vehicle speed corresponding to the difference between the vehicle speed and the actual vehicle speed is output, and the signal to cause the vehicle to travel at a constant speed is output even though a release command has been issued from the release command section. 1. A constant speed traveling device for a vehicle, comprising: a calculation section that determines that there is an abnormality and outputs an abnormal signal when there is an abnormality.