JPH02216329A - Device for controlling constant speed traveling - Google Patents

Abstract

PURPOSE:To prevent the temporary reduction in vehicle speed by executing a racing control at the time of the setting, coasting or resuming of a vehicle having a constant speed travel control device. CONSTITUTION:At the time of turning on a set switch, a constant speed travel control device makes a vehicle speed from a vehicle speed sensor at this time a memory vehicle speed and adjusts a throttle opening by means of an actuator based on the difference between the memory vehicle speed and a traveling vehicle speed. At the time of turning on the set switch during a constant speed travel control, a throttle is totally closed to carry out deceleration and, then, control is resumed with the traveling vehicle speed at the point of time of turning off the set switch as a new memory vehicle speed (coasting function). Further, when the resume switch is turned on at the time of canceling the constant speed travel control, the control by the memory vehicle speed is resumed. In this case, racing control is carried out until acceleration becomes a defined value close to zero, at the time of setting, coasting, or resuming.

Description

[Detailed Description of the Invention] [Summary] By performing acceleration control until the acceleration reaches a predetermined value when the vehicle's constant speed cruise control device is set, when coasting, or when resuming, it is possible to prevent a temporary decrease in vehicle speed. Shoot).

[Industrial application field]

The present invention relates to a constant speed cruise control device that performs inflating control at the start of constant speed cruise control to reduce a decrease in vehicle speed.

[Conventional technology]

There are various types of constant speed cruise control devices for automobiles.
For example, as shown in Fig. 5, in a system in which a negative pressure-driven actuator ACT is duty-controlled by an electronic control unit ECU using a CPU, control valve C■ is turned on/off.
The off ratio (duty ratio) adjusts the ratio of atmospheric pressure and negative pressure introduced into the actuator ACT, controls the diaphragm generated force, and adjusts the throttle opening. This actuator ACT is used only during constant speed travel control, and when the control is not performed (when cancelled), atmospheric air is introduced from the release valve RV to eliminate the diaphragm generated force. This release valve R
One of the switches (SW) that operates V is a brake SW that is turned on when the brake is stepped on.

Constant speed running control is started by turning on and off a set switch with a main switch (not shown) turned on. In other words,
If the time to turn on the set SW is when canceling, the corresponding S
The running vehicle speed when the W is off is read from the vehicle speed sensor and stored in the memory, and from now on, constant speed running control is performed with the stored vehicle speed as the target. This is the set function, and Fig. 2 shows a time chart for setting.

When the set SW is turned on as shown in FIG. 3 during constant speed running control, the throttle is fully closed (duty 0%) during that period to decelerate the vehicle. Then, control is resumed with the traveling vehicle speed at the time the SW is turned off as a new stored vehicle speed. This is the coast function.

On the other hand, if you turn on the resume switch when canceling,
As shown in FIG. 4, control is resumed at the stored vehicle speed V, which was previously held in the memory. This is the resume function.

[Problem to be solved by the invention]

As mentioned above, a transient decrease in vehicle speed (undershoot) occurs during setting, coasting, and resuming, so sometimes it is necessary to set the duty to the maximum value (for example, 90%) to maximize the diaphragm generation force of actuator ACT. Performs inflation control.

However, since conventional inflating control is only performed for a certain period of time (for example, 0.4 s) regardless of the driving condition, response delays due to the actuator time constant and play in the link system can cause problems such as those shown by the broken lines in Figures 2 to 4. A large undershoot may remain.

The present invention attempts to reduce undershoot by continuing the acceleration control until the acceleration reaches a predetermined value.

[Means to solve the problem]

The present invention provides a set for transitioning from a non-control state to a control state based on a newly set memorized vehicle speed in a constant speed travel control device that uses an actuator to adjust the throttle opening so that the difference between the traveling vehicle speed and the memorized vehicle speed is zero. During coasting, which lowers the memorized vehicle speed in a controlled state, or during resume, which returns from a non-controlled state to a controlled state based on the previously set memorized vehicle speed, the acceleration is close to zero from the start or completion of these switch operations. This feature is characterized in that the inflating control is performed until the value is reached.

[Effect]

Acceleration during constant speed driving control indicates the driving state, and is close to 0 in a stable constant speed driving state on a flat ground.When the engine load becomes heavier than this state, the acceleration temporarily becomes negative, and then the throttle opening changes. As the speed increases, the acceleration increases, and eventually the vehicle returns to a constant speed running state. Therefore, if the ramp-up control during set, coast, and resume is continued until the acceleration returns to a constant value close to zero, a practical undershoot reduction effect can be expected that takes into account the delay of the actual actuator and link system. .

〔Example〕

FIG. 1 is a flowchart showing one embodiment of the present invention, showing a part of the processing performed by the CPU shown in FIG. Check the cancel signal of brake SW etc. in step SL,
If there is, a cancel mode is set in step S2, and an inflate F (inflate control determination flag) is set in the subsequent step S3.

On the other hand, if there is no cancel signal, the resume SW is checked in step S4, and if it is on, the resume switch is checked in step S4.
5 to check whether it is in cancel mode. If it is the cancel mode, it is determined in step S6 whether or not there is a memorized vehicle speed, and if so, the resume mode is set in step S7.

On the other hand, if it is determined in step S5 that the mode is not the cancel mode, this means that the resume SW has been turned on during control (set mode), so the accelerator mode is set in step S8. In this mode, the memorized vehicle speed can be increased by accelerating only while the jammer switch is on.

If it is determined in step S4 that the resume SW is not on, the set SW is checked in step S9. If this is on, coast mode is set in step SIO, and inflate F is set in subsequent step 311.

On the other hand, if it is determined in step S9 that the set SW is not on, then in step S12 it is checked whether the mode is the accelerator mode or the coast mode, and if either is selected, the set mode is set in step 513. As described above, in this example, when the set SW is turned on, the coast mode is first set in step SIO, and then when the set SW is turned off, the set mode is set in step 313.

Now that each mode setting has been completed, the next step is step S1.
4, calculate vehicle speed ■7 and acceleration DVO.

The vehicle speed ■7 can be determined by calculating the period of the vehicle speed pulse obtained from the vehicle speed sensor in Fig. 5, and the acceleration DVO can be simply calculated by calculating the current vehicle speed ■ and the previous vehicle speed V, -, (50 ms ago). It can be obtained as the difference.

DVO=V, -V,.

When the calculation in step S14 is completed, it is determined in step S15 whether the mode is set mode or resume mode, and if it is either, inflate F is checked in step 516. If the increase F is set, the acceleration DVO is determined in step S17.

Then, if DVO does not reach a predetermined value A close to O,
In step 318, the maximum duty (90% in this example) is output and "inflated" is performed.

This inflation control continues until DVO≧A. The duration of this inflate @go is the same as before (for example, 0.
4 s), the undershoot can be reduced by the amount that the incubation time (time for outputting 90% duty) is extended, as shown by the solid lines in FIGS. 2 and 3.

These figures show examples set to A-0, but
can be small positive or negative values.

If it is determined in step S15 that the mode is neither set mode nor resume mode, it is determined in step S19 whether or not the mode is accelerator mode. If it is determined that the mode is not the accelerator mode, the mode is cancel mode or coast mode, so the duty is set to 0% in step S20.

As a result, in the coast mode, the vehicle speed decreases while the set SW is on, as shown in FIG.

On the other hand, when it is determined that the accelerator mode is set in step S19, when it is determined that the blowout F is not set in step 316, and when it is determined that DVO≧A in step S17, the blowout F is reset in step S21. Then, in step S22, the output duty for constant speed driving control is calculated.

This calculation is performed using the following formula, for example.

D=K -('/, -Vn)+SD Fig. 1 is a flowchart showing an embodiment of the present invention, Fig. 2 is a time chart during setting, Fig. 3 is a time chart during coasting, and Fig. 4 is a time chart during coasting. The time chart at the time of resume, FIG. 5, is a system configuration diagram showing an example of a constant speed traveling control device.

Applicant: Minoru Aoyagi, Patent Attorney, Fujitsu Ten Ltd. [Effects of the Invention] As described above, according to the present invention, when a vehicle equipped with a constant speed cruise control device is set, when coasting, and when resuming, temporary This has the advantage of reducing vehicle speed reduction (undershoot).

[Brief explanation of the drawing]

￥41 figure

Claims (1)

[Claims] 1. In a constant speed cruise control system that uses an actuator (ACT) to adjust the throttle opening so that the difference between the traveling vehicle speed and the memorized vehicle speed is zero, the set time is used to transition from a non-control state to a control state based on the newly set memorized vehicle speed. , or when coasting to reduce the memorized vehicle speed in a controlled state, or when resuming from a non-controlled state to a controlled state based on the previously set memorized vehicle speed, the acceleration (
1. A constant speed cruise control device, characterized in that the engine speed is controlled until DVO) reaches a predetermined value (A) close to zero.