JP2920294B2 - Constant speed traveling device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant speed traveling device that prevents a decrease in vehicle speed after a vehicle speed setting operation.

2. Description of the Related Art A constant speed traveling device is a device that controls an opening of a throttle valve in order to maintain a preset vehicle speed. In order to keep the vehicle speed constant, the constant speed traveling device compares the actual vehicle speed from the vehicle speed detector with the set vehicle speed, and if the actual vehicle speed is higher than the set vehicle speed, the actual vehicle speed decreases in the direction to decrease the vehicle speed. If it is lower, the throttle valve opening is controlled via the actuator in a direction to increase the actual vehicle speed. As the actuator, a negative pressure type actuator which generally uses a manifold negative pressure of an internal combustion engine as a driving source, a motor type actuator which uses a rotating torque of a motor as a driving source, and the like are used, and the actuator and the throttle valve are used for a wire and a link mechanism. Connected.

In general, the vehicle driver releases his / her foot from the accelerator pedal after operating the vehicle speed setting switch, so that the throttle valve is temporarily closed or almost fully closed. Therefore, if only the normal duty control in which the acceleration / deceleration control is repeated immediately after the vehicle speed is set is performed, an extremely large decrease in the vehicle speed is caused, and safety such as a following vehicle approaching becomes a problem. Therefore, immediately after setting the vehicle speed, in order to obtain the opening of the throttle valve almost corresponding to the set vehicle speed, the maximum, that is, 100% duty or an increase signal with a duty value close to it was given to the actuator to respond to the set vehicle speed in a short time. Obtain the opening of the throttle valve. Then, the process proceeds to normal constant speed traveling control.

Problems to be Solved by the Invention As described above, in order to prevent a decrease in vehicle speed immediately after the vehicle speed setting switch is operated, the conventional constant speed traveling device increases the speed to obtain a throttle valve opening corresponding to the set vehicle speed. Output a signal.

However, if there is play or slack in the wire or link mechanism connecting the actuator and the throttle valve, the drive signal given to the actuator may not directly contribute to the drive of the throttle valve. That is, a dead time is generated in the control system, which has an adverse effect on the initial characteristics of the constant speed traveling control. FIG. 4 is a timing chart for explaining the operation of the conventional constant-speed traveling device immediately after setting the vehicle speed. FIG. 4 (1) shows the vehicle speed fluctuation immediately after the vehicle speed setting switch is operated, FIG. 4 (2) shows the operation timing of the vehicle speed setting switch, and FIG. 4 (3) shows the signal waveform for controlling the throttle valve to open. FIG. 4 (4) shows a signal waveform from the idle switch, and FIG. 5 (5) shows a fluctuation of the throttle valve opening immediately after setting the vehicle speed.

At time t ₁₁ as shown in FIG. 4 (2), the vehicle speed setting switch is changed from the ON state to the OFF state, constant-speed traveling device stores the actual vehicle speed at time t ₁₁ as the set vehicle speed, fourth As shown in FIG. 3 (3), an acceleration signal at time T11 is given to the actuator in order to initialize the throttle valve opening. However, as shown in FIG. 4 (4), if there is a period in which the idle switch remains on due to the play of the wire, the link mechanism, etc. during the period in which the speed increasing signal is given to the actuator, the slot is set in that period. The valve is not actuated, resulting in dead time. That is, time
period from the time t ₁₂ from t _11, as shown in FIG. 4 (5),
It has no effect on the throttle valve opening. Accordingly, the time obtained by subtracting the time T10 from the time T11 is the effective time of the initial setting of the throttle valve opening.

Normally, the control pulse for initial setting of the throttle valve opening immediately after setting the vehicle speed is set to be longer than the optimum pulse width in consideration of slack of the wire itself, play in connection between the wire and the throttle valve, and the like. Therefore, if there is a lot of play, the dead time becomes longer and an optimum throttle valve opening cannot be obtained, and if there is little play, the throttle valve opening becomes larger.

In FIG. 4 (1), the line V11 shows the vehicle speed fluctuation when the dead time is long, and the line V12 shows the vehicle speed fluctuation when the dead time is short. However, since the amount of play of the wires and the like in each vehicle is not constant for each vehicle, the vehicle speed is greatly reduced immediately after the vehicle speed is set, or so-called hunting occurs, so that the control characteristics are not constant and the convergence time to the set vehicle speed is prolonged. have.

The present invention has been made in order to solve the above problems, and to provide a constant-speed traveling device that minimizes vehicle speed fluctuations immediately after setting the vehicle speed regardless of the amount of play or slack of a wire or a link system. It is in.

Means for Solving the Problems The present invention detects a throttle valve being fully closed in a constant-speed traveling device that controls a throttle valve of an internal combustion engine by an actuator so that the vehicle speed becomes a set vehicle speed that is stored. After the start of the constant-speed running control, when it is detected that the throttle valve has begun to open in response to the output of the idle switch, the set time set by the set vehicle speed elapses.
The actuator continues to be driven by the actuator in a direction to open the throttle valve with the passage of time, and after the set time has elapsed, the actuator is opened and closed according to the difference between the set vehicle speed and the actual vehicle speed. And a control means for controlling the driving of the vehicle at a constant speed.

According to the present invention, the idle switch detects that the throttle valve is fully closed, and inputs a signal from the idle switch to the control means of the constant-speed traveling device to determine that the throttle valve has begun to open. From the point in time, the actuator is driven in the direction in which the throttle valve opens for a set time predetermined by the set vehicle speed. After the lapse of the predetermined time, normal constant-speed running control is performed, that is, control is performed by an actuator to open and close the throttle valve according to the difference between the set vehicle speed and the actual vehicle speed.

Embodiment FIG. 1 is a block diagram of a constant-speed traveling device according to an embodiment of the present invention. A processing circuit 1 constituted by individual semiconductor elements or a micro computer inputs a vehicle speed signal from a vehicle speed detector 2 realized by a lead switch or an optical sensor through a signal line l1. The vehicle speed setting switch 3 is, for example, a switch provided on a dashboard or a pad of a steering wheel. When the switch is pressed, a vehicle speed setting signal is given to the processing circuit 1 via a signal line l2.
The cancel switch 4 is a switch provided near the vehicle speed setting switch 3. When the cancel switch 4 is pressed, a cancel signal is given to the processing circuit 1 via the signal line l3. Cancel.

When the vehicle speed setting signal is input from the vehicle speed setting switch 3, the processing circuit 1 stores the actual vehicle speed from the vehicle speed detector 2 as the set vehicle speed. After the set vehicle speed is stored, the cruise control is started, the set vehicle speed is compared with the actual vehicle speed from the vehicle speed detector 2, and an acceleration / deceleration signal is generated in a direction in which the set vehicle speed matches the actual vehicle speed. The signal is supplied to the actuator 5 via a signal line 14. The actuator 5 is realized by a negative pressure type actuator using the manifold pressure during the internal combustion period 6 or a motor type actuator using the rotational torque of the motor as a driving source, and includes a wire w1, a link mechanism 7, and a wire w.
The opening of the throttle valve 8 is controlled via 2.

The link mechanism 7 is a mechanism for transmitting the greater of the pulling force of the actuator 5 or the depressing force of the accelerator pedal 8 to the wire w2, and the wires w1 to w3 are
Are joined within. Idle switch 10 is the intake path 11
When the throttle valve 8 is completely closed, that is, fully closed, it becomes conductive. The idle signal from the idle switch 10 is connected to the signal line l5.
To the processing circuit 1.

When the vehicle speed setting signal is input, the processing circuit 1 performs an initial setting of the throttle valve opening in accordance with the set vehicle speed. In the initial setting, a time from when the idle switch is turned off is set.

FIG. 2 is a timing chart for explaining the operation of the constant-speed traveling device according to the present invention immediately after setting the vehicle speed. FIG. 2 (1) shows the vehicle speed fluctuation immediately after the vehicle speed setting, FIG. 2 (2) shows the operation timing of the vehicle speed setting switch 3, and FIG. 2 (3) shows the signal line l4 for driving the throttle valve 8 in the opening direction. The upper signal waveform is shown, and FIG.
The upper idle signal waveform is shown, and FIG. 5 (5) shows the opening of the throttle valve 8.

As shown in FIG. 2 (2), when the vehicle speed setting switch 3 is changed from the ON state to the OFF state at time t _1, the processing circuit 1 stores the actual vehicle speed at that time as the set vehicle speed V _s, the second As shown in FIG. 3C, a control signal for driving the throttle valve 8 in the opening direction is sent to the actuator 5 in order to perform the initial setting of the throttle valve opening. But,
As shown in FIG. 2 (4), while the idle signal is on, the throttle valve 8 is in the fully closed state.
Natsuta time the idle signal is turned off, i.e. the initial setting time of Surotsutoru valve opening time t ₂ as a starting point is set, the time T1 from the time t ₂ as shown in FIG. 2 (3) to time t ₃ During this time, the drive signal is provided to the actuator 5. The time T0 shown in FIG. 2 (4) occurs due to the looseness of the wires w1 and w2 or the play of the link mechanism 7, and the time T0 varies depending on the state of the looseness and the play.

Was but connexion, by setting the initialization time of Surotsutoru valve opening from time t ₂ to Surotsutoru valve 8 starts to open, it is possible to eliminate the fluctuation factor of the slack or the like of the wire,
The throttle valve 8 can always be driven to the optimal initial setting position.

When the initial setting of the Surotsutoru valve opening is finished at the time t _3,
The constant speed traveling device performs constant speed traveling control.

FIG. 3 is a flowchart for explaining the processing procedure of the processing circuit 1. Generally, when the vehicle driver shifts to constant-speed driving, the vehicle speed setting switch is operated while the accelerator pedal 9 is depressed and then the foot is released, and the vehicle speed setting switch is operated immediately after the accelerator pedal 9 is released. There are cases. Therefore, the flow chart of FIG. 3 will be described below in two cases.

(1) When the vehicle speed is set while the accelerator pedal 9 is depressed, and the foot is immediately released from the accelerator pedal 9 When it is determined in step n1 that the vehicle speed setting switch 3 is turned off from on, the process proceeds to step n2. Step
At n2, the actual vehicle speed from the vehicle speed detector 2 when the vehicle speed setting switch 3 is turned off from on is stored as the set vehicle speed.
When the set vehicle speed is stored in step n2, the processing circuit 1
Goes to step n3 to actuator 5 throttle valve 8
Gives an acceleration signal that drives in the opening direction. And step
At n4, a counter value corresponding to the set vehicle speed is set in a timer counter in the processing circuit 1.

At step n5, it is determined whether or not the timer counter value is 0. Since the initial value has been set at step n4, the process proceeds to step n6. At step n6, it is determined whether or not the idle switch 10 is turned on (conduction state). Since the vehicle speed setting switch 3 is operated while the accelerator pedal 9 is being depressed, the idle switch 10 is in an off (cut off state). Therefore, step n6
From step n7. At step n7, it is determined whether or not the idle switch 10 has changed from the on state to the off state. However, since the accelerator pedal 9 is still depressed, the process proceeds to step n8. At step n8, a countdown is performed to reduce the value of the timer counter by one. When the countdown processing of the timer counter ends in step n8, the process returns to step n1.

At step n1, it is determined whether or not the vehicle speed setting switch 3 has changed from the on state to the off state. However, as described above, since the change of the vehicle speed setting switch 3 from the on state to the off state has been determined. Then, the process proceeds from step n1 to step n5. At step n5, it is determined whether or not the value of the timer counter is 0. If the timer counter value is 0, the process proceeds to step n11 to start the constant speed traveling control. However, if the timer counter value is not 0, the process proceeds to step n6, where it is determined whether or not the idle switch 10 is on. If the idle switch 10 is off, the process proceeds from step n7 to step n8, and the timer counter is further counted down by one. After the vehicle speed is set, step n1 is performed until the accelerator pedal 9 is released and the throttle valve 8 is fully closed until the idle switch 10 is turned on.
The processing of → step n5 → step n6 → step n7 → step n8 is repeatedly executed.

When the foot is released from the accelerator pedal 9 and the throttle valve 8 is fully closed and the idle switch 10 is turned on, the process proceeds from step n6 to step n9, and the timer counter value is held. That is, the timer counter value is not changed. When the idle switch 10 subsequently changes from the on state to the off state, that is, the throttle valve 8
When the vehicle starts to open, the process proceeds from step n7 to step n10, and the timer counter value corresponding to the set vehicle speed is set in the timer counter again. Then, Step n8 is executed until the timer counter value becomes 0, and if it is determined in Step n5 that the timer counter value is 0, the process proceeds to Step n11 to perform the constant speed traveling control.

In the case of (1), since the accelerator pedal is released after the vehicle speed is set, when the accelerator pedal is released by the speed increase signal immediately after the vehicle speed is set, the actuator is already operated for more than the play and the idle SW is not turned on. There is also. In this case, step n8 is performed without passing through step n9.
The countdown is repeated until the value reaches zero, and then the control proceeds to constant-speed running control. However, in such a case, since the accelerator pedal is depressed for a short time even after the vehicle speed is set, a large decrease in the vehicle speed does not occur.

(2) When the vehicle speed setting switch 3 is operated immediately after the foot is released from the accelerator pedal 9 The processing from the operation of the vehicle speed setting switch 3 until the initial value is set in the timer counter is the same as that of the above (1). This is the same as the processing in the case. Since the vehicle speed setting operation has been performed after the foot is released from the accelerator pedal 9, the idle switch 10 has already been turned on in step n6. Accordingly, the process proceeds from step n6 to step n9, and the timer counter set in step n4 is held. afterwards,
When the throttle valve 8 starts to open and the idle switch 10 changes from the on state to the off state, the operation proceeds from step n7 to step n1.
Proceeding to 0, the timer counter value corresponding to the set vehicle speed is reset to the timer counter. Then, after the timer counter value is reset, the process proceeds from step n7 to step n8, and a countdown is performed in which the timer counter value is reduced by one. Step n8 until the timer counter value becomes 0
Is repeatedly executed, and if it is determined in step n5 that the timer counter value is 0, the process proceeds to step n11, and the constant speed traveling control is started.

As described above, in the present embodiment, the timer corresponding to the set vehicle speed is started from the time when the idle switch 10 changes from the on state to the off state, so that the wires w1, w2
It is possible to prevent variations in the initial setting of the throttle valve opening due to looseness of the link and play of the link mechanism 7. Therefore, it is possible to prevent the actual vehicle speed after the vehicle speed setting from being significantly reduced or increased more than the set vehicle speed.

Effect of the Invention Since the throttle valve opening is set immediately after the operation of the vehicle speed setting switch, the actuator is driven until a predetermined time has elapsed since the opening of the throttle valve, so that the vehicle speed decreases immediately after the operation of the vehicle speed setting switch. Alternatively, an increase in the vehicle speed can be prevented, and the vehicle can smoothly shift to constant speed traveling. Further, it is possible to avoid the danger of a collision due to approaching a following vehicle due to a decrease in vehicle speed or approaching a preceding vehicle due to an increase in vehicle speed, thereby improving safety.

In particular, according to the present invention, the timing of the output of the idle switch for detecting the full closing of the throttle valve is adopted as the reference of the time for performing the control at the start of the constant speed traveling control, that is, the timing when the throttle valve actually starts to open , And there is almost no variation due to the device. Therefore, according to the present invention, it is possible to perform control that is not affected by variations between devices and aging.

[Brief description of the drawings]

FIG. 1 is a block diagram of a constant-speed traveling device according to an embodiment of the present invention, FIG. 2 is a timing chart for explaining an operation immediately after setting a vehicle speed of a constant-speed traveling device according to the present invention, and FIG. FIG. 4 is a flow chart for explaining the processing procedure of the processing circuit 1, and FIG. 4 is a timing chart for explaining the operation immediately after setting the vehicle speed in the conventional constant-speed traveling device. 1 Processing circuit 2, Vehicle speed detector 3, Vehicle speed setting switch 5, Actuator 6, Internal combustion engine 7,
... Link mechanism, 8 ... Throttle valve, 9 ... Accelerator pedal, 10 ... Idle switch

Claims (1)

(57) [Claims] An idle switch for detecting that the throttle valve is fully closed, wherein the throttle valve of the internal combustion engine is controlled by an actuator so that the vehicle speed becomes equal to the stored vehicle speed. After the start of the high-speed running control, when it is detected that the throttle valve starts to open in response to the output of the idle switch, the throttle valve is opened with time until a set time determined by the set vehicle speed elapses. Control means for controlling the actuator to continue to be driven by the actuator and to open and close the throttle valve according to a difference between the set vehicle speed and the actual vehicle speed after the set time has elapsed. A constant-speed traveling device comprising: