JPS5995616A - Constant-speed running device of vehicle - Google Patents

Abstract

PURPOSE:To prevent deterioration in responsibility due to the difference of an actual vehicle speed and the generation of an overshoot of the vehicle speed by varying the arithmetic contents of a control signal according to an actual vehicle speed level at the point of time when a control signal receives an operation instruction signal. CONSTITUTION:The control circuit 16 constituted as a microcomputer which includes a one-chip CPU, an oscillator, etc., inputs a vehicle speed signal Sa, cancel signal Sb, power-on signal Sc, set signal Sd, and resume signal Se, and outputs a duty ratio control signal Sf and a time control signal Sg for controlling a control valve 6 by arithmetics based upon the input data, a previously stored program, etc., and also outputs a opening instruction signal Sh and a closing instruction signal Si for controlling a release valve 7 respectively. Consequently, deterioration in responsibility due to the difference of the actual vehicle speed and the generation of an overshoot of the vehicle speed are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a control circuit that compares an actual vehicle speed with a set vehicle speed and outputs a control signal by calculation based on the comparison result, and a control circuit that adjusts a throttle opening according to the control signal. The present invention relates to a heavy vehicle constant speed traveling device equipped with an actuator.

As an example of a control circuit in this type of constant speed vehicle traveling system, when receiving an operation command signal, the difference between the actual vehicle speed value detected by the vehicle speed sensor and the set vehicle speed value, and the actual vehicle speed value The duty ratio control signal is determined by calculation using the estimated vehicle speed value obtained by multiplying the differential value (that is, the rate of change of the actual vehicle speed) by a certain conversion coefficient as data, and the negative pressure actuator is controlled by this duty ratio control signal. There is a system in which the throttle opening is adjusted by so-called duty ratio control.

In addition, in this case, when the negative pressure actuator is driven for the first time (C when the vehicle constant speed traveling system is operated for the first time after the power is turned on), the negative pressure indoor pressure of the negative pressure actuator is at the same level as atmospheric pressure. Therefore, the time control signal is determined based on calculation using the set vehicle speed as data.
The atmosphere inlet passage of the negative pressure actuator is continuously closed for a certain period of time according to this time control signal, and the structure is configured to shorten the time until the negative pressure indoor pressure reaches a certain level suitable for the control. , has been.

However, in the above-mentioned conventional vehicle constant speed running device, the coefficients such as the conversion coefficients used when the control circuit operates are constant regardless of the actual vehicle speed at the time when the operation command signal is received. As a result, there were unresolved problems as described below. That is, for example, assuming that the actual vehicle speed at the time of receiving the operation command signal is slower than the set vehicle speed, in this case, in the conventional configuration, regardless of the actual vehicle speed, the throttle opening and degree are determined by a constant conversion factor. A constant state is maintained based on the calculated duty ratio control signal. However, the acceleration performance of a vehicle such as a car differs depending on its actual running speed. Therefore, in conventional configurations, if the actual vehicle speed at the time of receiving the operation command signal is relatively high, the acceleration performance of a vehicle such as an automobile is not adjusted to the set vehicle speed. If the actual vehicle speed at the time of receiving the operation command signal is relatively low, too much acceleration may be applied to reach the set vehicle speed. This causes so-called vehicle speed overshoot and hunting. On the other hand, the intake manifold pressure of the engine, which is the negative pressure source for the negative pressure actuator, also changes depending on the driving speed. However, if the atmospheric air inlet passage of the negative pressure actuator is continuously closed for a certain period of time based on a time control signal calculated by a certain coefficient, the negative pressure indoor pressure will be at a certain level suitable for the control. The time it takes to reach this point becomes unstable, and in some cases, this may lead to deterioration in responsiveness or overshoot in vehicle speed.

The present invention has been made to address the above-mentioned problems, and its purpose is to cause deterioration in responsiveness and overshoot of vehicle speed due to differences in actual vehicle speed at the time of receiving the operation command signal. An object of the present invention is to provide a constant speed vehicle running device that can reliably prevent such problems.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic configuration of a negative pressure actuator 1 having a well-known configuration. In this negative pressure actuator 1, 2 is a negative pressure chamber, 5 is a communication passage for communicating the negative pressure chamber 2 with the intake manifold of the engine, and 4 and 5 are communication passages for communicating the negative pressure chamber 2 with the atmosphere. Passage, 6 is communication passage 6
, 4 is a control knob (lube) for opening and closing, 7 is a release knob for opening and closing the communication path 5. Also,
8 is a diaphragm arranged in the negative pressure chamber 2; 9 is a throttle opening/closing wire connected to the diaphragm 8; 1;
0 is a spring that biases the diaphragm 8 and the wire 9 in the throttle closing direction (in the direction of the arrow). In such a negative pressure actuator 1, the pressure in the negative pressure chamber 2 is regulated by alternately opening and closing the communicating passages 3 and 4 by the coy) roll pulp 6 in relatively short cycles. The throttle opening degree is changed by the displacement of the diaphragm 8 according to the pressure in the negative pressure chamber 2. The release pulp 7 is opened in the non-energized state to introduce the atmosphere into the negative pressure chamber 2 via the communication path 5. In this atmosphere introduction state, the diaphragm 8 and the wire 9 move in the direction of arrow A. and the throttle is closed.

Next, in FIG. 2 showing the electrical configuration, 11 is a vehicle speed sensor, which outputs a vehicle speed signal Sa with a number of pulses proportional to the actual running speed of the vehicle. 012 is a cancel signal generator, which is a foot pedal. .

When at least one of the rake, clutch, and brake brake is operated, cancel No. 48 Sb is output. Reference numeral 15 denotes a main power switch, which outputs a power-on signal So when turned on. 14 is a set switch, and when this is turned on, a set signal Sa, which is an operation command signal, is output. 15 is a resume switch which, when turned on, outputs a resume signal Se which is an operation command signal.
power (output)

Now, 16 is a flflJ control circuit configured as a microcomputer including a one-chip CPU, a J generator, etc., and this is a flflJ control circuit that is configured as a microcomputer including a one-chip CPU and a J generator, etc.
, @Power input signal So, set signal Sa, and resume signal Se are input, and the control knob (duty ratio control signal Sf and time control signal for lubricant 6 control) is calculated based on the input data and a pre-stored program. Sg respectively, and an open command signal sh and a close command signal S for controlling the +71J-s valve 7.
Output 1 respectively.

The control pulp 6 receives the duty ratio control signal Sr and the time control signal Sg via the drive circuit 17, and periodically opens the communication path 3 at the duty ratio instructed by the duty ratio control signal Sr. When the communication path 3 is opened, the communication path 4 is closed), and the communication path 3 is continuously opened for a predetermined time specified by the time control signal Sg. The release pulp 7 receives the open command signal Sh and the close command signal S1 via the drive circuit 18, and when it receives the open command signal Sh, the power is cut off and the communication path 5 is opened, and the close command signal S1 is released. When received, it is energized and closes the communication path 5.

FIG. 3 shows a control flowchart for the control circuit 160, which will be described below. Now, when the main power switch 16 is turned on and the power-on signal SC is input,
The function of the control circuit 16 is enabled and the start process (a)
K is set, and the process moves to the "signal reading" process (b), and in this "signal reading" line, in the arrogance (b), cancel 1 word Sb, set signal Sd, resume No. 18 S
Read e.

In the next determination step (c), it is determined whether or not the cancellation signal Sb has been read, and if "YES", the process moves to the "cancellation processing" line s), and in this "cancellation processing" step), Duty ratio control signal Sf.

If the time control signal Sg has been output, the output is stopped, and an open command signal Sh is output to open the communication passage 5 to the release pulp 7, thereby introducing the entire atmosphere into the negative pressure chamber 2. . If the determination is “NO” in the determination step (c), that is, the cancel signal S is output from the cancel signal generator 12.
If b has not been output, the process moves to the "logical processing" step (e). In this "logic processing" step (e), the input states of the set signal sa and resume signal Se are subjected to logic processing and stored. In the "output processing" step (e) after the "logical processing" step (e), when either the set signal Sa or the resume signal Se is input, the closing command signal S
1 is output and the release pulp 7 is energized and closed, after which the process moves to the determination step (g). In the discrimination process (g),
It is determined whether or not the "output processing" step (a) is performed for the first time after the power-on signal Sc is input, and if "YES", the process moves to the "set vehicle speed calculation" step (a). In the "projection speed calculation" step (a), the currently running program is temporarily interrupted and the input step of the vehicle speed signal Sa is interrupted, and after the interruption of this input step is completed, the actual vehicle speed signal Sa is calculated based on the vehicle speed signal Sa. The vehicle speed VR and the set vehicle speed ■0 are calculated, and the process moves to the next "output processing" step (wa). In the "output processing" step (su), the actual vehicle speed VR and the set vehicle speed ■0
The time control signal Sg is determined and output based on the reference time count obtained by calculation using the data and timer interrupt. In this case, the control knob 8 used for controlling the time control signal Sg operates when the actual vehicle speed VR at the time when the input of the set signal Sd or the resume signal Se is stopped is relatively high. A value is adopted such that the continuous opening time of the communication passage 3 by the control valve 6 becomes longer when the actual vehicle speed ■R at the above point in time is relatively low. Incidentally, the intake manifold pressure of the engine, which is the negative pressure source of the negative pressure actuator 1, has a property that the higher the actual vehicle speed VR, the smaller the pressure is.

Therefore, as described above, when the actual vehicle speed 'VR at the time when the input of the set signal Sa or the resume signal Se is stopped is relatively high, the continuous open time of the communication path 3 is controlled to be longer. If the actual vehicle speed VR at the above point in time is relatively low, if the continuous open time of the communication passage 3 is controlled to be short, it will take the time until the pressure in the negative pressure chamber 2 reaches a certain level suitable for the control. is no longer unstable as in the conventional configuration, and it is possible to eliminate the possibility of deterioration of responsiveness or so-called vehicle speed overshoot. After the "output processing" step (S) is completed, the process returns to the "signal reading" step (B).

On the other hand, when the process proceeds to the determination line @()1 after going through the "output section 1 ri" step (S) as described above, the determination step (G) returns "No" and the next "Tun" Move on to the "speed acting fraud" process (b). In the "vehicle speed calculation" step (b), the currently running program is temporarily interrupted and the input line 4 of the vehicle speed signal Sa is interrupted, and the MIJ of this input step is
After the C-inclusion is completed, the following calculations are performed. That is, the actual vehicle speed VFI is calculated based on the input vehicle communication signal Sa, the difference between the actual vehicle speed VR and the set vehicle speed Va is calculated, and the differential value VRK of the actual vehicle speed VR is calculated.
An estimated vehicle speed value Vp is calculated by multiplying by a calculation coefficient K. At this time, the conversion coefficient includes the actual vehicle speed V at the time when the input of the set signal Sd or the resume signal Se is stopped.
The configuration is such that a larger value is adopted as the level of E becomes higher. In the "output calculation a" step Q→ after the radical "vehicle speed calculation" step (b), a calculation is performed using the difference between the actual vehicle speed VR and the set vehicle speed vO and the estimated vehicle speed value ■F as data. Based on the calculation result and the base time count obtained by the timer interrupt, the duty f
The ratio 1dlJ control signal Sf is determined and output. in this case,
Estimated vehicle speed 1 used to determine duty ratio control signal Sr
For the conversion coefficient of direct Vp, set signal Sli 戊 is the actual ■, 1i at the time when input of resume signal Se is stopped.
When VR is relatively high, a larger value is adopted than in the conventional case, so the duty ratio control signal S
The negative a[2 pressure controlled by r via the control valve 6 and thus the throttle opening are larger than in the conventional case, and therefore the acceleration force required to reach the set vehicle speed is insufficient as in the conventional case, resulting in poor responsiveness. There is no risk of it getting worse. Furthermore, when the actual vehicle speed VR at the time when the human power of the set signal Sd or the resume signal Be is stopped is relatively low, a smaller value is adopted as the conversion factor compared to the conventional case. Therefore, the throttle opening controlled by the duty ratio control signal Sf is larger than in the conventional case, and therefore, as in the conventional case, the acceleration is too rapid up to the set vehicle speed, resulting in so-called vehicle speed overshoot and henching. The fear disappears. After this "output calculation" step), the process returns to the "signal reading" step (b), and by repeating the above-mentioned control, the running state at the set east speed is maintained. .

The control circuit 16 narrows down the throttle to maintain a so-called coast state when the set signal Sd continues to be input, and opens the throttle to maintain an accelerator-like state when the resume signal Se continues to be input. hold it.

As explained above, the present invention includes a control circuit that compares an actual vehicle speed and a set vehicle speed in response to a ζ operation command signal, and outputs a 1llll control signal by calculation based on the comparison result, To reliably prevent deterioration of responsiveness and occurrence of vehicle speed overshoot, etc. due to differences in actual vehicle speed at the time when an operation command signal is received in a heavy vehicle constant speed traveling system equipped with an actuator that adjusts the opening degree. It has the impressive effect of being able to

[Brief explanation of drawings]

I'Aun shows one embodiment of the present invention, Fig. 1 is a schematic vertical cross-sectional view of a negative pressure actuator, Fig. 2 is a block diagram of electrical purchasing, and Fig. Pg6 shows the control contents of the control circuit. It is a flowchart which shows. In the figure, 1 is a negative pressure actuator, 11 is a vehicle speed sensor,
16 is a control circuit. 1st loco ¥12 Figure 3 Figure 75

Claims (1)

[Claims] 1. Compare the actual vehicle speed and the set vehicle speed according to the operation command signal and calculate the ratio! ! 2. In the vehicle constant speed running system, the control circuit includes a control circuit that outputs a control signal based on calculations based on the result, and an actuator that adjusts the throttle and lever openings in accordance with the restriction number. The command is issued according to the actual vehicle speed level at the time the command is received.
1. A constant speed vehicle running device, characterized in that it is configured to change the calculation content of the l jill signal.