JPH0544376B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a control circuit for a constant speed traveling device for a vehicle.

<Prior Art> In general, various constant speed traveling devices for maintaining the speed of a vehicle at a predetermined set speed are known.
According to such a constant speed traveling device, by operating the accelerator pedal and operating the set switch when the desired vehicle speed has been reached, an actuator that operates in the same way as the accelerator pedal is activated, and from then on, the foot is removed from the accelerator pedal. Even if you release the button, the vehicle speed can be maintained at the set speed.

When automatically traveling at a constant speed using this constant speed traveling device, for example, when going downhill, the vehicle speed may exceed the set vehicle speed, in which case the actuator is controlled to be driven toward the deceleration side. becomes. Furthermore, if the downhill slope is long, the actuator may reach the deceleration side operating limit and the throttle valve may become fully closed. When this long downhill slope ends and the road becomes flat, the throttle valve is fully closed and the vehicle speed will be lower than the set vehicle speed, so an acceleration signal will be output to the actuator. .

However, since the throttle wire connecting the actuator and the throttle valve is assembled with a certain amount of play, when the throttle valve is in the fully closed position, the throttle wire has the play. Therefore, even if an acceleration signal is output to the actuator to accelerate after completing a long downhill slope, the vehicle speed may not increase immediately and the vehicle speed may drop significantly, making it impossible to maintain a smooth constant speed running state. There is a problem.

<Problems to be Solved by the Invention> In view of the problems of the prior art as described above, the main object of the present invention is to provide a control circuit for a constant speed traveling device for a vehicle that can achieve a smooth constant speed traveling state. It's about doing.

<Means for Solving the Problems> According to the present invention, this object includes a control means for performing calculation control to maintain the vehicle speed at a set vehicle speed and generating acceleration and deceleration control signals, and a control means for controlling the vehicle speed control operation. A control circuit for a constant speed traveling device for a vehicle, which has an actuator that performs the operation, and a drive circuit for driving the actuator based on the control signal, the control circuit having a detection means for detecting a deceleration side operation limit of the actuator, When accelerating the vehicle immediately after the generation of the detection signal by the detection means ends, an initial acceleration control signal is generated by adding a predetermined acceleration enhancement signal to the normal acceleration control signal for driving the actuator toward acceleration. This is achieved by providing a control circuit for a constant speed traveling device for a vehicle, which is characterized by the following.

<Function> In this way, when accelerating again after the actuator reaches the deceleration side operating limit during constant speed driving, an initial acceleration control signal is output by adding a predetermined acceleration enhancement signal to the normal acceleration control signal. As a result, suitable acceleration control can be performed even if there is play in the throttle wire due to the throttle being fully closed.

<Example> Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a circuit diagram showing a general configuration of a constant speed traveling device for a vehicle based on the present invention. Control of this constant speed traveling device is performed via a control unit 1, which includes a power supply circuit 2, an input control circuit 3, an input/output control circuit 4, an actuator drive circuit 5, and a motor current detection circuit 6. ,
and connected to these circuits to perform calculation processing
CPU7 etc. are provided.

The control unit 1 is supplied with voltage from a battery 11 as a power source via an ignition switch 8, a fuse 9, a main switch 10, and a terminal T1. A power supply circuit 2 is connected to the terminal T1, and a voltage stabilized within the power supply circuit 2 is supplied to the CPU 7. still,
A power supply terminal Vb is connected between terminal T1 and power supply circuit 2 for power supply of other circuits of control unit 1.
However, each power supply circuit 2 is provided with a stabilized power supply terminal Vc. Also, main switch 1
The main lamp 12 has one end grounded and the other end connected between the main lamp 12 and the terminal T1. A signal from a vehicle speed sensor 13 is input to the input control circuit 3 via a terminal T2, and a common fuse 1
Signals from a set switch 15 and a resume switch 16 connected to the battery 11 via terminals T3 and T4 are inputted so as to be able to instruct the operation of the CPU 7 via terminals T3 and T4, respectively.

As control inputs, signals from contacts S1 and S2 of a brake switch 21 attached to a brake pedal (not shown) are input to the control unit 1 via terminals T5 and T6. The contact S1 is a normally open contact, and is connected between the fuse 17, which is provided branching off from between the battery 11 and the ignition switch 8, and the terminal T5, and the contact S2 is a normally closed contact, The terminal T6 is connected between the main switch 10 and the terminal T1. Further, as a control input, a signal from a clutch switch 22 attached to a clutch pedal (not shown) is inputted via a terminal T7.

Terminals T8 to T10 of the control unit are connected to a motor actuator 23, terminal T8 is connected to a coil 24a of a magnetic clutch 24 built into the actuator 23, and terminals T9 and T10 are connected to a motor 25, respectively. There is. A control lever 26 is provided on the output side of the magnetic clutch 24, and the control lever 26 and a throttle valve 27 are connected via a throttle wire 28. Therefore, motor 2
5 in the forward and reverse directions, the throttle valve 27 is driven to open and close via the magnetic clutch 24.

Terminal T10 is the output terminal for accelerating the vehicle.
A limit switch 29 with a normally closed contact is connected between the actuator 23 and the motor 25 in order to detect the acceleration side operating limit, and a diode D7 is connected in parallel to flow current in the deceleration direction. ing. Also, the terminal T9 is the output terminal for decelerating the vehicle, but the terminal T9 is the output terminal for decelerating the vehicle.
9 and the motor 25 is an actuator 23.
In order to detect the operating limit on the deceleration side, a normally closed limit switch 30 is connected, and
A diode D8 is connected in parallel to allow current to flow in the acceleration direction.

One end of a cruise lamp 31 for indicating that the constant speed traveling device is in operation is connected to the control unit 1 via a terminal T11, and the other end is connected to ground via a known dimming circuit 32. has been done. Note that the control unit 1 is grounded via a terminal T12.

In the control unit 1, the terminal T
5, T7, T11 via the input/output control circuit 4
Connected to CPU7. The emitter of the power transistor Q1 is connected to the terminal T6,
The collector of power transistor Q1 is connected to terminal T8. In addition, the power transistor Q1
A varistor ZN is connected between the emitter and collector of the varistor ZN, and a diode D1 is connected in parallel with the varistor ZN with its cathode facing the emitter and its anode facing the collector. A resistor R1 is connected between the emitter and the base of the power transistor Q1.
The base of the transistor Q2 is connected to the collector of the transistor Q2 via a resistor R2. The emitter of the transistor Q2 is grounded, and its base is connected to the terminal C1 of the CPU 7 via the input/output control circuit 4, and the coil 24a of the magnetic clutch 24 is turned on or off by the output signal from the CPU 7. becomes.

The anode of the diode D2 is connected to the collector of the power transistor Q1, and the cathode of the diode D2 is connected to the collector of the power transistor Q1 through the input/output control circuit 4.
Connected to terminal C2 of CPU7.

The actuator drive circuit 5 rotates the motor 25 in the forward and reverse directions according to the control output signal of the CPU 7.
It is constructed from a known transistor bridge circuit. In the actuator drive circuit 5, the actuator 23 is connected to the side that accelerates the vehicle.
The acceleration drive circuit 33 for driving the vehicle is configured to flow current from the power transistor Q3 to the power transistor Q4, and the deceleration drive circuit 34 for decelerating the vehicle is configured to flow current from the power transistor Q5 to the power transistor Q6. It is configured to flow. That is, as clearly shown in the figure, the current during acceleration flows from the collector of the power transistor Q3 to the terminal T10 and the limit switch 2.
9, the motor 25, the diode D8, and the terminal T9 are connected to each other so that the current flows toward the collector of the power transistor Q4.
Each of the power transistors Q5 is connected so that a current during deceleration flows from the collector of the power transistor Q5 to the collector of the power transistor Q6 via the terminal T9, the limit switch 30, the motor 25, the diode D7, and the terminal T10. The emitters of power transistors Q4 and Q6 are grounded via motor current detection circuit 6. Note that the motor current detection circuit 6 is also connected to a terminal C3 of the CPU 7.

Further, diodes D3 and D5 are connected to the power transistors Q3 and Q5, respectively, with the cathode facing the emitter and the anode facing the collector, and the power transistors Q4 and Q6 have diodes D4 and D6 connected, respectively, with the cathode facing the collector. It is connected with the anode facing the emitter. Resistors R3 to R are connected between the emitter and base of each power transistor Q3 to Q6, respectively.
6 are connected, each power transistor Q3
The base of ~Q6 is connected to the collectors of transistors Q7-Q10 via resistors R7-R10, respectively. and transistors Q7 and Q
9 are grounded, and their bases are also grounded via resistors R11 and R13. Furthermore, the emitters of transistors Q8 and Q10 are connected to the stabilized power supply Vc, and their bases are also connected to the stabilized power supply Vc via resistors R12 and R14. Furthermore,
The bases of the transistors Q7-Q10 are connected to signal output terminals C4-C7 of the CPU 7 via resistors R15-R18, respectively.

By the way, the emitter of the power transistor Q3 is connected to the cathode of the diode D2 mentioned above, and the voltage from the battery 11 is used as the power supply voltage of the acceleration drive circuit 33 to the ignition switch 8, the fuse 9, the main switch 10, and the brake. It is supplied via the contact S2 of the switch 21 and the power transistor Q1 for driving the clutch. The voltage from the power supply terminal Vb is supplied to the emitter of the power transistor Q5 as the power supply voltage of the deceleration drive circuit 34 in order to make the system separate from the power supply of the acceleration drive circuit 33. Therefore, by stepping on the brake, the contact S2 of the brake switch 21 opens, and the power to the power transistor Q1 and the acceleration drive circuit 33 is cut off. Therefore, even if the power transistors Q3 and Q4 of the acceleration drive circuit 33 are shot, the coil 24 of the magnetic clutch 24
energization to a and the motor 25 of the actuator 23
energization is not performed in the direction of driving the motor toward acceleration.

Next, the operation of the constant speed traveling device configured in this manner will be explained.

By closing the main switch 10 while the ignition switch 8 is closed, power supply voltage is supplied to the control unit 1 and the main lamp 12 is turned on. Then, when the set switch 15 is closed and the condition that, for example, the brake switch 21 and clutch switch 22 are not operated is satisfied, the CPU 7 stores the current vehicle speed as the set vehicle speed based on the signal from the vehicle speed sensor 13. cruise lamp 31
lights up.

Next, when driving the actuator 23 according to the difference between the set vehicle speed and the actual vehicle speed, the CPU 7 outputs a signal to turn on the magnetic clutch 24, energizes the coil 24a, and turns the magnetic clutch 24 on. becomes connected. For example, when accelerating, an ON signal for power transistors Q3 and Q4 is output from terminals C4 and C5, and an OFF signal is output from terminals C6 and C7 for power transistors Q5 and Q6, causing the motor 25 to rotate in the acceleration direction. do. When decelerating, contrary to the above, an OFF signal is output to the power transistors Q3 and Q4, an ON signal is output to the power transistors Q5 and Q6, and the motor 25 rotates in the deceleration direction. In this way, the motor 25 rotates to the acceleration/deceleration side as appropriate, opens and closes the throttle valve 27, and is controlled so that the actual vehicle speed and the set vehicle speed approximately match.
The resume switch 16 is used to store a new set vehicle speed in the CPU 7 by pressing and releasing it when you want to increase the vehicle speed to a desired speed.

In addition, the CPU 7 may, for example, control the brake switch 21.
Alternatively, when it is detected that the clutch switch 22 is being operated, the constant speed running state is canceled. At this time, a deceleration signal is output from the CPU 7 to the actuator drive circuit 5 to drive the actuator 23 in the direction of deceleration, and the vehicle is decelerated and the cruise lamp 31 is turned off.

FIG. 2 shows the connection and disconnection of the magnetic clutch 24, the forward and reverse rotation of the motor 25 (acceleration and deceleration of the vehicle), the opening and closing of the deceleration side limit switch 30, and the control circuit of this embodiment.
This is a time chart showing the output timing of turning on or off the cruise lamp 31 (on or off of the constant speed traveling device) and the level of the vehicle speed relative to the set value.

First, as shown in FIG. 2, before the signal from the set switch 15 is input, the set switch 15 is in the open state, the magnetic clutch 24 is in the disconnected state, and the motor 25 is in the stopped state. . Next, the cruise lamp 31 is turned on by the signal input from the set switch 15, and
The magnetic clutch 24 is brought into a connected state, and the motor 25 rotates toward the acceleration side for a predetermined period of time, for example, 0.5 to 0.6 seconds (t1), for initialization. This initialization process is for absorbing play in the throttle wire 28 during assembly and for operating the throttle valve 27 to an opening state corresponding to the set vehicle speed. After the initialization of the motor 25 is completed, the automatic constant speed driving state starts. During automatic constant speed driving, the motor 25 is accelerated or decelerated for a predetermined time ( t2) Rotate and control.

In addition, in the control circuit of this embodiment, signals for turning on each transistor Q1, Q3 to Q6 are output from terminals C1, C4 to C7 of the CPU 7, but whether or not the circuit is conductive at this time is determined. Terminal C2,
A fault diagnosis circuit is configured by detecting the signal input to C3. This fault diagnosis circuit checks the fault state of each transistor Q1, Q3 to Q6 at each timing depending on the running state.

For example, as shown in FIG. 2, in a state other than automatic constant speed driving (mode A) where the cruise lamp 31 is off, turning on the transistor Q6 changes the short state of the transistor Q5 and the transistor By turning on Q5, the short states of transistors Q4 and Q6 can be detected. Also, transistor Q
By turning off transistors Q3 to Q6, the short state of transistor Q1 can be detected.
If any failure condition is detected through these checks, the CPU 7 takes action to determine that the automatic constant speed running state cannot be set.

Next, in the automatic constant speed running state and the state in which the motor 25 is driven to the acceleration side for initialization (mode B), the transistor Q1,
By turning on Q3 and Q4, each open state can be detected. In addition, when the motor 25 is running at an automatic constant speed and the motor 25 is stopped (mode C), the transistor Q
By turning on transistor Q1 and Q6,
By turning on transistors Q1 and Q5, it is possible to detect the open state of transistor Q1 and the short state of transistors Q4 and Q6, respectively.

Furthermore, when the motor 25 is driven to the acceleration side during constant speed driving (mode D), the transistor Q
3. Since Q4 is turned on, transistor Q
3. The open state of Q4 can be detected. Similarly,
When the motor 25 is being driven to the deceleration side (mode E), the transistors Q5 and Q6 are turned on, so that the open state of the transistors Q5 and Q6 can be detected. If any failure condition is detected through these checks, the CPU 7 will take action to cancel the automatic constant speed running state.

By the way, when traveling downhill while traveling at a constant speed, the vehicle speed increases, so a deceleration drive signal is output to the motor 25. However, in the case of a long downhill slope, the deceleration drive signal will continue to be output, so the limit switch 30 at the deceleration side operating limit, which is interlocked with the control lever 26 of the actuator 23, will be in the open state. Therefore, since no current flows to the motor 25, the CPU 7
It becomes difficult to distinguish this from an open failure in the deceleration side drive circuit 34. Therefore, in the control circuit according to the present embodiment, the fail-safe function is used to disengage the magnetic clutch 24 (mode F). still,
Since the control lever 26 is at the deceleration side operating limit and the throttle valve 27 is fully closed, play occurs in the throttle wire 28.

Next, after traveling on a long downhill slope, for example, when the road becomes flat, the throttle valve 27 is in a fully closed state, so the vehicle speed decreases below the set vehicle speed. Therefore,
In order to return the vehicle speed to the set vehicle speed, the magnetic clutch 24 is connected again and an acceleration signal is output to the motor 25 (mode G). At this time, by adding a signal t4 for absorbing the play of the throttle wire 28 as a predetermined acceleration enhancement signal to the normal acceleration control signal t2, a normal acceleration signal t2 corresponding to the decrease in vehicle speed with respect to the set vehicle speed is generated.
The initial acceleration signal t3, which is more enhanced than the initial acceleration signal t3, is output from the CPU 7. Therefore, for example, when the above-mentioned wire play absorption signal t4 is not output, only the normal acceleration signal t2 shown by the imaginary line in FIG. This will not be transmitted and the vehicle speed will drop significantly as shown in the imaginary line. Here, the wire play absorption signal t4 is not limited to a constant value, but may be variable depending on, for example, the difference between the set vehicle speed and the current vehicle speed.

As described above, according to this embodiment, when the vehicle travels on a flat road after detecting the fully closed state of the throttle valve 27 due to long downhill travel as described above, the wire play absorption signal t4 is added to the normal acceleration control signal t2. Since the initial acceleration signal t3 which is the sum of the following is output, the vehicle speed is controlled so as to smoothly converge to the set vehicle speed as shown by the solid line in FIG. 2 without significantly decreasing.

In the fault diagnosis circuit of this embodiment, in the automatic constant speed running state, for example, if the deceleration side transistors Q5 and Q6 have an open failure, the deceleration signal is output after the acceleration signal is output. When
By detecting that no current flows through the motor 25, the open fault is checked in the same manner as in mode E described above.

Further, in this embodiment, a motor type actuator is shown, but any actuator for a constant speed traveling device may be used. For example, in the case of a negative pressure type actuator, the actuator reaches the deceleration side operating limit as described above. A similar effect can be obtained by outputting an initial acceleration control signal to the acceleration solenoid valve with a longer energization time than a normal acceleration control signal when accelerating again after the acceleration.

Further, the deceleration side operation limit of the motor type actuator can be detected not only by detecting the open state of the deceleration side limit switch 30 but also by detecting the disengaged state of the magnetic clutch 24.

<Effects of the Invention> As described above, according to the present invention, when accelerating again after the actuator reaches the deceleration side operating limit during constant speed driving, the initial acceleration control signal is added to the normal acceleration control signal. By outputting an acceleration control signal, it is possible to absorb the play in the throttle wire and drive the throttle valve to the acceleration side, so it is possible to accelerate the vehicle without significantly reducing the vehicle speed, and maintain a smooth constant speed running condition. can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing the configuration of a constant speed traveling device based on the present invention. FIG. 2 is a diagram showing a time chart of the constant speed traveling device based on the present invention. DESCRIPTION OF SYMBOLS 1... Control unit, 2... Power supply circuit, 3... Input control circuit, 4... Input/output control circuit, 5... Actuator drive circuit, 6... Motor current detection circuit, 7... CPU, 8... Ignition switch, 9...Fuse, 10...Main switch, 11...Battery, 12...Main lamp, 13...Vehicle speed sensor, 14...Fuse, 15...Set switch, 16...Regium switch, 17... Fuse, 21... Brake switch, 22... Clutch switch, 23...
...actuator, 24...magnetic clutch, 24a...coil, 25...motor, 26...
...Control lever, 27...Throttle valve, 28...
Throttle wire, 29, 30... limit switch, 31... cruise lamp, 32... dimming circuit, 33... acceleration drive circuit, 34... deceleration drive circuit.

Claims (1)

[Claims] 1. A control means that performs calculation control to maintain the vehicle speed at a set vehicle speed and generates acceleration and deceleration control signals;
A control circuit for a constant speed traveling device for a vehicle, comprising an actuator that performs a vehicle speed control operation, and a drive circuit for driving the actuator based on the control signal, the detection means detecting a deceleration side operating limit of the actuator. and initial acceleration control in which a predetermined acceleration enhancement signal is added to the normal acceleration control signal for driving the actuator to the acceleration side when accelerating the vehicle immediately after the generation of the detection signal of the detection means ends. A control circuit for a vehicle constant speed traveling device, characterized in that it generates a signal.