JPH0274423A - Constant speed travel control device - Google Patents

Abstract

PURPOSE:To reduce vehicle speed variation as much as possible immediately after the change of a target vehicle speed by controlling throttle reset upon completion of acceleration and controlling racing upon completion of coating only for a time corresponding to the immediate previous acceleration or deceleration. CONSTITUTION:ECU is a controller using a microcomputer 1 and detects a vehicle speed on the basis of a signal from a vehicle speed sensor 8. The aforesaid CPU is turned to a set mode when a set switch is turned from the ON position to the OFF position, and makes duty adjustment for the control valve of an actuator ACT so that a vehicle speed will be a target speed. Furthermore, when the control valve is turned ON, negative pressure 2 is introduced and the generating force of a diaphragm 4 linked to a throttle SL is increased. On the other hand, when a cancel signal clutch switch, a parking switch or a brake switch is turned ON, both the control valve and a relief valve are turned OFF. In this case, the reset time of the throttle or racing time is made variable, depending upon acceleration or deceleration upon completion of acceleration or coating operation.

Description

[Detailed Description of the Invention] [Summary] In a duty-controlled constant-speed cruise control device that adjusts the throttle opening using an actuator driven by intake pipe negative pressure, the speed can be increased by operating a switch during constant-speed cruise control. When accelerating (accelerator) or decelerating (coasting), the throttle release time to prevent vehicle speed overshoot or the throttle release time to prevent vehicle speed undershoot can be varied depending on the acceleration (deceleration) speed during that time. Suppress vehicle speed fluctuations.

[Industrial Field of Application] The present invention relates to a constant speed cruise control device using an actuator whose driving source is intake pipe negative pressure.

[Conventional technology]

A duty control type constant speed driving control device uses the duty value required to travel at a constant speed at the target vehicle speed as the set duty, and adds or subtracts the duty amount according to the difference between the target vehicle speed and the traveling vehicle speed to or from the set duty. constant speed driving control is performed while outputting

FIG. 6 shows an example of this type of constant speed cruise control device in which the throttle opening degree is adjusted by an actuator whose driving source is the intake pipe negative pressure of the engine.

The ECU is a controller that uses a microcomputer, and uses a magnet that rotates in proportion to the rotation of the vehicle drive shaft to generate 0N1
The traveling vehicle speed is detected by a signal from a vehicle speed sensor equipped with a reed switch that turns OFF. This ECU enters a set mode when the set switch is turned from ON to OFF, and stores the traveling vehicle speed at the time the switch is OFF as a target vehicle speed from now on. In this set mode, the control valve of the actuator ACT is adjusted by duty to control the traveling vehicle speed to the target vehicle speed.

When the control valve is ON, negative pressure is introduced, increasing the force generated by the diaphragm linked to the throttle SL. OF
At F time, the atmosphere is introduced and weakens the diaphragm generating force. During this time, the release valve is always ON to shut off the atmosphere.

When a cancel signal (clutch switch, parking switch, or brake switch) is manually applied, both the control valve and release valve are turned OFF, air is introduced from both, and the control is immediately stopped. When the resume switch is turned on after cancellation, driving control at the previous target vehicle speed is resumed.

When the resume switch is pressed in the set mode described above, the accelerator mode is set, and the output duty to the control valve is increased to increase the speed. Then, the switch OFF
The traveling vehicle speed at time F is stored as a new target vehicle speed. Similarly, if you press the cent switch in cent mode, the mode becomes coast mode, where both the control valve and release valve are turned OFF and the speed is decelerated. Then, the traveling vehicle speed when the switch is OFF is stored as a new target vehicle speed.

Turn off the resume switch in the accelerator mode mentioned above.
Even so, the increase in vehicle speed does not stop immediately at that point (the end of the accelerator pedal), and an overshoot as shown in FIG. 2(a) occurs due to the response delay of the actuator ACT.

On the contrary, turn off the set switch in coast mode.
However, for the same reason, an undershoot in the vehicle speed occurs as shown in FIG. 3(a).

Conventionally, in order to improve such problems, in accelerator mode, when the accelerator is finished, the release valve is temporarily turned off to introduce atmospheric air, and the throttle is returned to reduce overshoot, and in coast mode, At the end of course 1, temporary throttle control (outputs maximum duty and increases throttle opening) is used to reduce undershoot.

[Problem H to be solved by the invention] However, since conventional release valve OFF control (throttle return control) and throttle control are always performed only for a certain period of time, overshoot or underspeed may still occur depending on the previous acceleration speed. A shoot occurs. for example,
As shown in Figure 2(b), the acceleration is moderate (for example, 1.7
The OFF time (e.g. 0.1 s) set so that oat N-shoot does not occur at Km/h/s) is
It is not possible to prevent overshoot from occurring when the acceleration is irregular as shown in (C), and on the contrary, undershoot occurs when the acceleration is small as shown in (d).

Similarly, as shown in Fig. 3(b), the warm-up time is set so that undershoot does not occur at moderate deceleration.
As shown in (C), undershoot occurs when the deceleration is reduced, and on the other hand, when the deceleration is small as shown in (d), overshoot occurs.

The present invention minimizes vehicle speed fluctuations immediately after changing the target vehicle speed by varying the throttle release time (or release time) according to the acceleration (or deceleration) at the end of the accelerator (or at the end of coasting). It is an attempt to suppress it.

[Means for Solving the Problems] The present invention provides a constant speed cruise control device that adjusts the throttle opening using an actuator driven by negative pressure in the intake pipe of the engine, which provides a constant speed cruise control device that adjusts the throttle opening at the end of an accelerator operation to increase a target vehicle speed. It is characterized in that the throttle return control is performed for a time corresponding to the immediately preceding acceleration, and at the end of the coasting operation to reduce the target vehicle speed, the throttle is increased for a period corresponding to the immediately preceding deceleration. It is characterized by:

[Effect]

If the throttle return control at the end of the accelerator and the throttle control at the end of the coast are performed for a time corresponding to the previous acceleration (deceleration), vehicle speed fluctuations immediately after the target vehicle speed is changed can be reduced as much as possible. .

FIG. 1 is a diagram of the operating principle of the present invention, where (a) shows when accelerating;
(b) is when coasting. The acceleration (?li speed) is the ratio of the change in vehicle speed ΔV per constant time ΔL (Δ■/ΔL), and this changes depending on the slope of the road, the magnitude of the engine load such as the loaded weight, or the gear position.

The off time of the release valve (throttle return time) in (a) is set, for example, as shown in the table below.

Table 1 In the table above, if the off time is 0.33 as the standard, then 0.5s and 0°73 will prevent overshoot, and 0.5s and 0°73 will prevent overshoot. IS prevents undershoot.

The inflating time in (b) is set, for example, as shown in the table below.

Table 2 In this case, for example, if 0.6s is the standard, then 0.8S and 1
, O3 prevents undershoot, and 0.43 prevents overshoot.

(Example) Fig. 4 is a flowchart when operating the accelerator.In step Sll, the accelerator SW (resume SW substitute) is
If N is determined, and Y (yes), it is determined in step S12 whether or not the accelerator mode is set. If N (No), it is the set mode, so the off time is set to 0 in step S13, and the accelerator mode is set in step S14.

After this, if the result in step 312 is Y, step S15
Measure acceleration with . This is calculated from the program - the actual vehicle speed change ΔV (Vn is the current vehicle speed, V n
-1 is the previous vehicle speed). Next, in steps 316 to 31B, the value of Δ■ is determined, and an off time corresponding to the determination result is provided in steps 319 to S22. The contents are shown in Table 1.

On the other hand, if the result is N in step Sll, it is determined in step S23 whether or not the accelerator mode is set. If Y, the accelerator is finished, so go back to the set mode in step S25 (here the target vehicle speed is changed), pass through step 326, and then release the release valve OF F II in steps S27 and 328.
j control. Step S27 is the subtraction of the OFF time, and Step 32B is the OFF output of the release valve.

Thereafter, steps S11 to S24 until the off time becomes 0.
, 326. S27. Through the loop of S28, the OFF control of the release valve is continued. When the off time reaches 0, the release valve is turned on in step S29, and constant speed driving control after changing the target vehicle speed is started (this part is not shown).

FIG. 5 is a flowchart during coast operation, and each step is given the same reference numeral as in FIG. 4.

The difference is that step Sll is now a coast SW (substitute for set SW), and step 312. , S14°324 becomes coast mode, and further steps 313 and S19
~S22. S26 and 327 have become the warm-up time, the numerical values in steps 316 to 318 have been changed to negative values, step 328 has become the maximum duty output to fully open the throttle, and step S2
9 is the point where the calculated duty output corresponds to the vehicle speed.

Step 528. S29 all relate to control valves.

(Effects of the Invention) As described above, according to the present invention, in a constant speed cruise control device using an intake pipe negative pressure drive type actuator with a response delay, the vehicle speed immediately after the target vehicle speed is changed by accelerator operation or coast operation. This has the advantage of suppressing fluctuations as much as possible.

[Brief explanation of the drawing]

Fig. 1 is a diagram of the operating principle of the present invention; Fig. 2 is an explanatory diagram of the conventional accelerator mode; Fig. 3 is an explanatory diagram of the conventional coast mode; Fig. 4 is a flowchart of the accelerator operation of the present invention; The figure is a flowchart during coast operation according to the present invention, and FIG. 6 is a configuration diagram of a constant speed cruise control device. (Hata) When accelerating l0 Opening degree without FF control' (7 - - -1 Without throttle control Figure 1 (bl Acceleration - Sea - (BL During deceleration Figure 3 At stroke (e) Addition 11! Degrees tel Large deceleration (dll acceleration - sea + d + small deceleration

Claims (1)

[Scope of Claims] 1. In a constant speed cruise control device that adjusts the throttle opening using an actuator driven by negative pressure in the intake pipe of the engine, at the end of an accelerator operation to increase a target vehicle speed, the control device adjusts the throttle opening according to the previous acceleration. A constant speed cruise control device, characterized in that the throttle is controlled to be returned only for a certain period of time. 2. In a constant speed cruise control system that adjusts the throttle opening using an actuator driven by the negative pressure in the engine's intake pipe, at the end of a coasting operation to reduce the target vehicle speed, the vehicle is ramped up for a period of time corresponding to the previous deceleration. A constant speed traveling control device characterized in that it performs the following.