JP3201218B2 - Auto cruise control method - Google Patents

Abstract

PURPOSE: To prevent release of automatic cruise control under a stable releasing condition by continuing automatic cruise control if an auxiliary brake is operated and a present vehicle speed exceeds a preset vehicle speed complying with a target vehicle speed, when a foot brake is operated. CONSTITUTION: It is assumed that a driver actuates a foot brake during traveling downhill, and a present vehicle speed Vh is compared with a target vehicle speed Vo (S6). If it is determined that the present vehicle speed Vh is not more than the target vehicle speed Vo, it is assumed that the foot brake is operated because of a stop or intensive speed reduction on a descending slope, and automatic cruise control is released (S5). If it is determined that the present vehicle speed Vh exceeds the target vehicle speed Vo (S6), it is assumed that the foot brake is operated for slight speed reduction in entering a curve, for example, during traveling on a descending slope, and the automatic cruise control is continued.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic cruise control method for a vehicle accompanied by an auxiliary brake operation control.

[0002]

2. Description of the Related Art Conventionally, as disclosed in Japanese Utility Model Laid-Open No. 4-65624, there is known an automatic cruise system which includes operation control of an auxiliary brake. This is to use control of the fuel supply amount and braking control of an exhaust brake, a retarder, and the like when the vehicle travels at a constant speed. By using an auto cruise system with operation control of the auxiliary brake, it is difficult to control the fuel supply amount at a constant speed.For example, by controlling the operation of the auxiliary brake even on a downhill, the vehicle speed can be increased. It is possible to drive at a constant speed while suppressing it.

[0003]

Generally, in an auto cruise system, as shown in FIG. 3, when a driver operates a foot brake during auto cruise control, the auto cruise control is released. I have. If the driver operates the foot brake during the control by the auto cruise device with the above-described auxiliary brake operation control, the auto cruise control is released regardless of the running state of the vehicle. For this reason, during the auto cruise control, for example, even if the driver operates the foot brake lightly so that the driver does not want a large deceleration just before a downhill curve, the auto cruise control is released, and the continuous constant speed You will not be able to run.

On the other hand, as disclosed in Japanese Utility Model Laid-Open Publication No. 3-69536, a constant-speed traveling device has been developed which cancels the auto-cruise control when the amount of depression of a foot brake (brake pedal) exceeds a certain reference value. ing. According to this constant speed traveling device, the auto cruise control is not released until the amount of depression of the brake pedal reaches a certain reference value, such as when the brake pedal is lightly actuated. However, the operation state of the brake pedal differs for each driver, and the amount of depression of the brake pedal for obtaining the same braking state also varies depending on the vehicle loading state, vehicle speed, and other vehicle conditions. For this reason, in this constant-speed traveling device, the release condition of the auto-cruise control according to the operation of the brake pedal cannot be said to be constant, and the operation may be different from the driver's expectation. Sometimes did not reflect the driver's intention.

The present invention has been made in view of the above circumstances, and even if the foot brake is lightly actuated to perform a slight deceleration during the auto cruise control, the auto cruise control is not released under stable release conditions. An object of the present invention is to provide an automatic cruise control method as described above.

[0006]

According to the present invention, there is provided an automatic cruise control method for increasing the amount of fuel supplied.
Engine power control by reduction and foot brake
Vehicle in cooperation with an auxiliary brake
Auto crew to match the speed to the set target vehicle speed
Control is performed and the foot brake is activated.
Auto cruise system that cancels the auto cruise control when
In the control method, the vehicle is traveling by the auto cruise control.
When the foot brake is actuated, the auxiliary
When the operation of the brake is being controlled and the current vehicle speed exceeds the target vehicle speed , the automatic cruise control is performed.
Is configured not to be canceled .
The auxiliary brake is an exhaust brake, compression release type
Engine brakes, hydraulic or electromagnetic retarders
Is characterized by including at least one of the following.

[0007]

[Function] When the foot brake is operated, the automatic cruise control is released when the auxiliary brake is operated and the current vehicle speed exceeds the set vehicle speed corresponding to the target vehicle speed.
And when the auxiliary brake is not operating,
Alternatively, the automatic cruise control is canceled when the auxiliary brake is operating and the current vehicle speed is equal to or lower than the set vehicle speed corresponding to the target vehicle speed.

[0008]

FIG. 1 is a schematic block diagram of an automatic cruise control device for implementing an automatic cruise control method according to one embodiment of the present invention, and FIG. 2 is a flowchart of the automatic cruise control method.

Referring to FIG. 1, a schematic configuration of an auto cruise device will be described. An auto cruise main switch 2 is connected to a control unit 1 of a vehicle such as a truck, and a signal for executing auto cruise control is input to the control unit 1 by operating the main switch 2. In addition, a set switch 3 and a resume switch 4 are connected to the control unit 1. The set switch 3 is used to set the auto cruise vehicle speed and decrease the auto cruise vehicle speed, and the resume switch 4 is used to return from the temporary cancellation of the auto cruise and increase the auto cruise vehicle speed.

An automatic cruise release switch 5 is connected to the control unit 1. The auto cruise release switch 5 is closed by a clutch operation signal or a transmission neutral signal. Furthermore, the auto cruise release switch 5
Is closed based on the operation status of the auxiliary brake, the operation status of the foot brake, and the vehicle speed, which will be described later.

The control unit 1 is connected with an accelerator switch 6 for detecting the operation of the accelerator pedal and a stop lamp switch 7 linked to the operation of the foot brake, and controls the operation signal of the accelerator pedal and the operation signal of the foot brake. Input to unit 1. The control unit 1 includes a vehicle speed sensor 8.
The vehicle speed signal is input from the vehicle and the set vehicle speed is compared with the current vehicle speed.

The control unit 1 turns on the cruise lamp 9 during auto cruise control driving, and sends a signal to an electronic governor 10 of a diesel engine (not shown) to increase or decrease the amount of fuel supplied to the diesel engine.
Control is performed to maintain the vehicle speed at the set vehicle speed. When the vehicle speed exceeds the set vehicle speed while the engine brake is operating, the control unit 1 controls the operation of the auxiliary brake 11 so that the actual vehicle speed approaches the set vehicle speed.

The auxiliary brake 11 includes an exhaust brake 12, a compression-release type engine brake auxiliary device 13 and a first
It comprises a stage retarder 14 and a second stage retarder 15. The exhaust brake 12 obtains a braking force by the flow resistance of the exhaust according to the restriction of the exhaust pipe. The compression-pressure releasing engine brake auxiliary device 13 compresses, for example, a third valve provided in an appropriate engine cylinder. The braking force is obtained by weakening the downward force of the open piston from the stroke to the expansion stroke. The first-stage retarder 14 and the second-stage retarder 15 obtain a braking force by, for example, changing the blade angle of the stator in the fluid retarder to adjust the flow rate of the retarder and increasing the rotational resistance of the propeller shaft. The retarder is not limited to the fluid type because the electric resistance type and the like may be used in addition to the fluid type.

The auxiliary brake 11 operates as the deviation between the actual vehicle speed and the set vehicle speed increases, and
2 and the compression-pressure-release type engine brake auxiliary device 13 and the first-stage retarder 14 and the second-stage retarder 15 are additionally operated sequentially, respectively, to increase the braking force. Conversely, as the deviation between the actual vehicle speed and the set vehicle speed decreases, the respective operations are released in the reverse order to the above, and the braking force decreases. The order of operation and release of the operation of the auxiliary brake 11 is appropriately changed, and the means and number of the auxiliary brake 11 are variously changed.

When the vehicle reaches a desired speed after the main switch 2 is closed while the vehicle is running, the vehicle speed at this time is set as a set vehicle speed (target vehicle speed) by closing the set switch 3 so that auto cruise is performed. Control is started. When the auto cruise control is started, the output of the diesel engine is adjusted by the control of the electronic governor 10 by the control unit 1, and the current vehicle speed Vh is maintained at the set target vehicle speed Vo. Note that the target vehicle speed Vo is not limited to the vehicle speed when the vehicle reaches the desired speed, that is, the target vehicle speed itself, as long as it is a predetermined value set according to the desired vehicle speed.

For example, when the vehicle runs downhill during execution of the auto cruise control, the vehicle speed increases even when the diesel engine is in the engine braking state. in this case,
The auxiliary brake 11 is operated by the control unit 1 in the order described above, and the braking force is applied to maintain the current vehicle speed Vh at the target vehicle speed Vo (auxiliary brake control). The control when the foot brake is operated during the auxiliary brake control will be described with reference to FIG.

As shown in FIG. 2, it is determined in step S1 whether or not auto cruise control is being performed. If it is during auto cruise, it is determined in step S2 whether or not the foot brake has been operated. If it is determined in step S2 that the foot brake has not been actuated, the driver does not intend to brake, so the process proceeds to step S3 to continue the auto cruise control. If it is determined in step S2 that the foot brake is being operated, it is determined in step S4 whether or not the auxiliary brake control is being executed. If it is determined in step S4 that the auxiliary brake control is not being executed, it is assumed that the foot brake is being operated on a flat ground or an uphill slope other than a downhill slope, and the process proceeds to step S5 to cancel the auto cruise control.

On the other hand, if it is determined in step S4 that the auxiliary brake control is being executed, for example, it is estimated that the driver has operated the foot brake while traveling downhill,
In step S6, the current vehicle speed Vh and the target vehicle speed Vo are compared.
When it is determined in step S6 that the current vehicle speed Vh is equal to or lower than the target vehicle speed Vo, it is estimated that the vehicle is stopped or a foot brake is activated due to a large deceleration on a downhill, and the process proceeds to step S5 to cancel the auto cruise control. You. If it is determined in step S6 that the current vehicle speed Vh is higher than the target vehicle speed Vo, it is estimated that, for example, the foot brake is operated for a slight deceleration due to approaching a curve while traveling downhill. Then, the process proceeds to step S3 to continue the auto cruise control as it is.

As described above, when the driver operates the foot brake during auto cruise traveling of the vehicle, the control unit 1 controls the operation of the auxiliary brake 11 (estimated that the vehicle is traveling on a downhill). When the current vehicle speed Vh is higher than the target vehicle speed Vo (slight deceleration), the automatic cruise control is not released. Further, even when the foot brake is operated when the operation control of the auxiliary brake 11 is not performed, or when the operation control of the auxiliary brake 11 is performed, the current vehicle speed Vh becomes lower than the target vehicle speed Vo due to the operation of the foot brake. In this case, the automatic cruise control is released.

Therefore, when the driver operates the foot brake during the auto cruise travel, the auto cruise control is not immediately released depending on the vehicle speed. In the case of a foot brake operation for deceleration, the auto cruise control is not released. For this reason, by simply changing the software of the control unit 1 without adding a special device, the frequency of the automatic cruise control being released under a stable release condition is reduced to maintain continuous automatic cruise traveling. It becomes possible.

[0021]

Automatic cruise control method of the present invention, according to the present invention is, Oh
When running under auto cruise control, use the foot brake
When the auxiliary brake is in operation control,
When the current vehicle speed exceeds the set vehicle speed corresponding to the target vehicle speed, the automatic cruise control is not released, and when the auxiliary brake is not operated, or when the auxiliary brake is operated and the current vehicle speed is equal to the target vehicle speed. Since the automatic cruise control is released when the vehicle speed is equal to or less than the set vehicle speed corresponding to the vehicle speed, the automatic cruise control is not released in the case of a foot brake operation for slightly decelerating. As a result, the frequency at which the auto cruise control is canceled is reduced, continuous auto cruise control is possible without adding a special device, and useless operation is greatly reduced while suppressing an increase in cost. Further, since the condition for canceling the auto cruise control is set according to the vehicle speed, the auto cruise control is executed in a stable state irrespective of the loaded state of the vehicle or the driving operation state of the driver.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of an auto cruise device that implements an auto cruise control method according to one embodiment of the present invention.

FIG. 2 is a flowchart of an auto cruise control method.

FIG. 3 is a flowchart of a conventional auto cruise control method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Control unit 2 Auto cruise main switch 3 Set switch 4 Resume switch 5 Auto cruise release switch 6 Accelerator switch 7 Stop lamp switch 8 Vehicle speed sensor 9 Cruise lamp 10 Electronic governor 11 Auxiliary brake 12 Exhaust brake 13 Compressed pressure release type engine brake auxiliary Apparatus 14 First stage retarder 15 Second stage retarder

Continuation of the front page (56) References JP-A-61-175130 (JP, A) JP-A-63-180530 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60K 31 / 00 B60K 41/00-41/20 B60T 8/32 F02D 9/06 F02D 13/04 F02D 29/02 301

Claims (2)

(57) [Claims] Claims: 1. An engine output control by increasing or decreasing a fuel supply amount
Control and foot brake
Target vehicle speed with vehicle speed set in cooperation with auxiliary brake
While performing auto cruise control to match
When the foot brake is activated, the auto cruise system
In the auto cruise control method for canceling the control, while the vehicle is traveling by the auto cruise control,
When the rake is activated, the auxiliary brake
If the current vehicle speed exceeds the target vehicle speed , the automatic cruise control is not released.
Auto cruise control wherein the configured it will be. 2. The auxiliary brake includes an exhaust brake, a pressure
Shrink release engine brake, hydraulic or electromagnetic litter
2. The auto cruise control method according to claim 1, wherein the control method includes at least one of the following .