JPS62255252A - Creep control system for vehicle - Google Patents

Abstract

PURPOSE:To enable setting of creeping speed of a vehicle as desired by performing control in such a manner that, when a set creeping speed is below the actual vehicle speed, a brake actuator is operated, an when it is above the actual vehicle speed, brakes are taken off an a throttle valve is opened. CONSTITUTION:Output signal from an engine speed sensor 16, an accelerator sensor 14, a brake pedal sensor 13 and a parking brake sensor 15 are inputted into a control unit 6, which discriminates whether or not conditions for creep control is established. If it discriminates yes, output signals V0, V of a creeping speed setting device 5 and a vehicle speed sensor 4 are compared, and in case V0>V, a brake actuator 10 is operated to take off the brakes 11 and a throttle valve 8 is opened to increase output of an engine 1. In case V0<V, the brakes 11 are applied.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a creep control system for an automobile that allows the creep speed of an automobile equipped with an automatic transmission system (hereinafter referred to as AT) to be arbitrarily set. be.

[Conventional technology]

In a car equipped with a torque converter type AT, even if the accelerator is released, if the drive gear is engaged, the driving torque of the engine is converted by the torque converter and becomes a large torque that is output to the output shaft, so you do not have to step on the brake. Otherwise, there is a creep phenomenon in which it moves at an extremely low speed.

In order to eliminate this creep, systems have been proposed in which, for example, once the brake is depressed, a portion of the braking force is retained even after the brake is released, and is released when the accelerator is depressed.

Creep in a car equipped with a torque converter AT can cause an accident such as a rear-end collision due to driver carelessness, so the concept of applying the brakes to prevent creep and the fact that creep is useful when used wisely. The idea is to leave it as is without making any changes.

[Problem that the invention seeks to solve]

If creep is completely stopped, there will be no risk of accidents due to carelessness, but it will become difficult to drive at extremely low speeds.

Furthermore, if creep is left to its own devices, its condition will change depending on the road conditions. For example, when going up a slope there is no creep, but when going down there is a lot of creep.
It is often inconvenient to use, such as stopping when there is a protrusion on the road surface.

This invention was made to solve this problem, and allows the driver to freely set the creep speed from 0 to an appropriate value, and after setting the creep speed to a certain value, press the accelerator pedal and brake pedal. The objective is to obtain a creep control system for an automobile that can creep at a set creep speed regardless of the road condition when the no-king brake is released.

[Means for solving problems]

A creep control system for an automobile according to the present invention includes a creep setting device for setting a creep speed, and a control unit that reads the set creep speed and outputs a signal to drive a throttle actuator and a brake actuator. .

[Effect]

In this invention, the control unit reads the creep speed set by the creep setting device and compares it with the actual vehicle speed signal read from the vehicle speed sensor, and if the set creep speed is smaller than the actual vehicle speed, the brake actuator is actuated. , apply the brakes to reduce the vehicle speed,
Conversely, if it is larger, the brake is loosened and the throttle actuator opens the throttle valve to increase the engine's output torque, increasing the vehicle speed and causing the vehicle to creep at the set creep speed regardless of road conditions.

〔Example〕

Embodiments of the automobile creep control system of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of one embodiment. In FIG. 1, ▪ is an engine, 2 is a torque converter type AT, 3 is an output shaft, 4 is a vehicle speed sensor, and a 5Fi clip speed setting device.

A signal of the actual vehicle speed detected by the vehicle speed sensor 4, a set speed signal set by the creep speed setting device 5, an output signal of the throttle opening sensor 9, an output signal of the engine rotation sensor 16, and a brake pedal sensor 13. and the output signal of
The output signal of the accelerator sensor 14 and the output signal of the king brake sensor 15 are input.

An output signal from the control unit 6 is output to a throttle actuator 7 and a brake actuator 10. The throttle actuator 7 drives a throttle valve 8 to open and close, and the opening degree of the throttle valve 8 is detected by a throttle opening sensor 9.

Further, the brake actuator 10 operates the brake V-key. The brake 11 has a brake pedal sensor 13 that detects whether the brake is being depressed. Note that 12 is a wheel.

The accelerator sensor 14 detects that the accelerator pedal is released, and the saking brake sensor 1
5 detects whether or not the parking key is being pulled.

Next, the operation of the present invention will be explained using the flowchart of FIG. 2. First, the conditions for performing creep control are when the engine is running, the accelerator pedal is released, the brake pedal is also released, and the brake during parking is also released.

This lever, engine rotation sensor 16, accelerator sensor 14
This can be determined from the output signals of the brake pedal sensor 13 and parking brake sensor 15.

When the conditions for performing creep control are established in step S1, the hunt roll unit 6 starts creep control. As a result, the creep control unit 6 controls the creep speed setting device 5 in step S2.
The set speed is read from the vehicle speed sensor 4, and the vehicle speed is read from the vehicle speed sensor 4.

Next, in step S3, the creep setting speed and vehicle speed are compared. If the creep setting speed is higher than the vehicle speed, a command is given to the brake actuator 10 in step S4, and if the brake is being depressed, the brake 11 is released in step S5.

Furthermore, if the creep setting speed is greater than the vehicle speed,
In step S6, the throttle actuator is commanded,
The throttle valve 8 is opened to increase the output of the engine 1. Of course, in order to control the speed to the set speed, the amount of loosening of the brake 11 and the amount of opening of the throttle valve 8 are changed depending on the speed change rate and the set speed.

For example, the throttle valve 8 is opened by the minimum step in the first stage to detect a change in vehicle speed. If the rate of change is large,
Keep the throttle opening as it is, and if the rate of change is small, open the throttle a further 1 step and observe the change in vehicle speed.

Another method is to maintain the opening degree of the throttle valve 8 and the braking force as they are if the vehicle speed is within an appropriate range around the set speed and the direction of the change in engine speed approaches the set speed.

- If the creep setting speed becomes smaller than the vehicle speed in step S7, first, the throttle actuator 7 is commanded to drive the throttle valve 8 in the closing direction in step S8 (step S9). If the vehicle speed is still high even after closing the throttle valve 8 to the idle rotation position, step SI
Command the brake actuator 10 with O, and brake 1
Activate 1. The method of control is similar to the method described above.

If the accelerator pedal, brake pedal, or parking brake is applied during such control, the timer is activated in step 811, the control is canceled, the throttle actuator 7 is returned to its origin, and the brake is applied. The actuator IO also releases the brake and returns to the normal operating state.

In the embodiment described above, a creep-hundred roll system is added to a normal automobile, but the control unit 6 and the throttle actuator 7 may share a constant speed cruise control system.

Of course, the present invention can also be applied to a system in which the accelerator pedal depression sensor and the throttle actuator 7 are controlled by the control unit 6, eliminating the conventional method of opening and closing the throttle valve 8 using a steel wire from the accelerator pedal.

〔Effect of the invention〕

As explained above, this invention operates the brake actuator when the set creep speed is smaller than the actual vehicle speed read by the vehicle speed sensor, and when the creep speed is higher, the brake is released and the throttle valve is opened by the throttle actuator. Therefore, the creep speed of the car can be set freely, making it convenient to control the speed when driving at extremely low speeds on narrow roads, parking in a garage, and especially when stopping after climbing over a raised area. Good.

Also, if the creep speed is set to zero, the vehicle will not creep even if the brakes are loosened when the vehicle is stopped, so a rear-end collision will not occur.

[Brief explanation of drawings]

FIG. 3 is a Glock diagram showing the configuration of an embodiment of the automobile creep control system of the present invention. FIG. 2 is a flow chart for explaining the operation of the creep control system of the same vehicle. l...Engine, 2...Automatic transmission, 3...Output shaft, 4...Vehicle speed sensor, 5...Creep speed setting device, 6...Control unit, 7...Throttle actuator x-ta, 3...throttle valve, 9...
Throttle opening sensor, lO... Brake actuator, 11... Brake.

Claims (1)

[Claims] Throttle actuator to control the automatic intake air amount of the engine, brake actuator to operate the brakes, vehicle speed sensor to detect the actual vehicle speed, torque converter type automatic transmission, creep speed setting device to set the creep setting speed, creep control When the creep set speed is compared with the set speed and the actual vehicle speed, the brake actuator is operated to loosen the brake and the throttle valve is opened to increase the engine output. A creep control system for an automobile, comprising a control unit that operates the brake actuator and the throttle actuator in the opposite direction when the set creep speed is lower than the actual vehicle speed.