JPH08282328A - Automatic cruise controlling 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 a vehicle auto-cruise control method involving 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 auto-cruise device with operation control of an auxiliary brake. This is to use the control of the fuel supply amount and the braking control of the exhaust brake and the retarder when the vehicle is traveling at a constant speed. By using an auto-cruise device that controls the operation of the auxiliary brake, it is difficult to drive at a constant speed when controlling the fuel supply amount. It will be possible to keep running at a constant speed.

[0003]

Generally, in the automatic cruise control system, as shown in FIG. 3, when the driver operates the foot brake during the automatic cruise control, the automatic cruise control is released. There is. When the driver actuates the foot brake during the control by the auto cruise device accompanied by the above-mentioned operation control of the auxiliary brake, the auto cruise control is released regardless of the traveling state of the vehicle. For this reason, during auto cruise control, even if the foot brake is lightly actuated to the extent that the driver does not want to decelerate significantly before the curve on the downhill, the auto cruise control is canceled and the continuous constant speed is maintained. It becomes impossible to drive.

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

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

[0006]

An automatic cruise control method of the present invention for achieving the above object is to provide an automatic cruise control of a vehicle accompanied by an operation control of an auxiliary brake.
When the foot brake is operated while the auxiliary brake is operating, the automatic cruise control is continued when the current vehicle speed exceeds the set vehicle speed corresponding to the target vehicle speed. The set vehicle speed is a target vehicle speed.

[0007]

[Function] When the foot brake is operated, the automatic cruise control is continued when the auxiliary brake is operating and the current vehicle speed exceeds the set vehicle speed corresponding to the target vehicle speed, and when the auxiliary brake is not operating, or , The automatic cruise control is released 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 auto cruise apparatus for carrying out an auto cruise control method according to an embodiment of the present invention, and FIG. 2 is a flowchart of the auto cruise control method.

A schematic structure of the automatic cruise device will be described with reference to FIG. A main switch 2 for auto cruise is connected to a control unit 1 of a vehicle such as a truck, and an operation signal for auto cruise control is input to the control unit 1 by operating the main switch 2. A set switch 3 and a resume switch 4 are connected to the control unit 1. The set switch 3 is for setting the auto cruise vehicle speed and decreasing the auto cruise vehicle speed, and the resume switch 4 is for returning from the temporary cancellation of the auto cruise and increasing 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 actuation signal or a transmission neutral signal. Furthermore, the auto cruise release switch 5
Is also closed based on the operating condition of the auxiliary brake, the operating condition of the foot brake, and the vehicle speed, which will be described later.

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

The control unit 1 lights the cruise lamp 9 during the automatic cruise control traveling, and at the same time sends a signal to the electronic governor 10 of the diesel engine (not shown) to increase or decrease the fuel supply amount to the diesel engine.
The vehicle speed is controlled so as to be maintained at the set vehicle speed. Further, the control unit 1 controls the operation of the auxiliary brake 11 so that the actual vehicle speed approaches the set vehicle speed when the vehicle speed exceeds the set vehicle speed during the operation of the engine brake.

The auxiliary brake 11 includes an exhaust brake 12, a compression pressure release type engine brake auxiliary device 13 and a first brake.
It comprises a stage retarder 14 and a second stage retarder 15. The exhaust brake 12 obtains a braking force by the exhaust flow resistance according to the throttle of the exhaust pipe, and the compression pressure release type 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 opening piston from the stroke to the expansion stroke. The first-stage retarder 14 and the second-stage retarder 15 obtain braking force by 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 electrical resistance type or the like may be used in addition to the fluid type.

The auxiliary brake 11 uses the exhaust brake 1 as the deviation between the actual vehicle speed and the set vehicle speed increases.
2 and the compression pressure release type engine brake auxiliary device 13, the first-stage retarder 14 and the second-stage retarder 15 are sequentially additionally operated to increase the braking force. On the contrary, as the deviation between the actual vehicle speed and the set vehicle speed becomes smaller, the respective operations are released in the reverse order to the above, and the braking force decreases. The order of actuation and deactivation 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 traveling, the vehicle speed at this time is set as the set vehicle speed (target vehicle speed) by closing the set switch 3, and the 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. It should be noted that the target vehicle speed Vo is not limited to the vehicle speed at the time of reaching 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 travels on a downhill while the automatic cruise control is being executed, the vehicle speed increases even if the diesel engine is in the engine brake 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 exerted to maintain the current vehicle speed Vh at the target vehicle speed Vo (auxiliary brake control). 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 the automatic cruise control is being performed, and if it is in the automatic cruise, it is determined in step S2 whether or not the foot brake is operated. If it is determined in step S2 that the foot brake is not operated, the driver has no intention of braking, so the process proceeds to step S3 to continue the automatic cruise control. When it is determined in step S2 that the foot brake is operated, it is determined in step S4 whether or not the auxiliary brake control is being executed. When it is determined in step S4 that the auxiliary brake control is not being executed, it is estimated that the foot brake is operating on a downhill slope such as a flat ground or an uphill slope, and the process advances to step S5 to cancel the automatic cruise control.

On the other hand, when it is judged in step S4 that the auxiliary brake control is being executed, it is estimated that the driver actuated the foot brake while traveling on a downhill, for example.
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 on a downhill or the foot brake is activated due to a large deceleration, and the process proceeds to step S5 to release the auto cruise control It 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 actuated for a slight deceleration due to approaching a curve while traveling on a downhill. Then, the process proceeds to step S3 to continue the automatic cruise control as it is.

As described above, when the driver operates the foot brake during the automatic cruise traveling of the vehicle, the control unit 1 controls the operation of the auxiliary brake 11 (estimated that the vehicle is traveling downhill). When the current vehicle speed Vh is higher than the target vehicle speed Vo (slight deceleration), the auto cruise control is not released. Further, even if the foot brake is operated while the operation control of the auxiliary brake 11 is not being performed or even when the operation control of the auxiliary brake 11 is being performed, the current vehicle speed Vh becomes equal to or less than the target vehicle speed Vo due to the operation of the foot brake. If so, the automatic cruise control is released.

Therefore, when the driver operates the foot brake during the automatic cruise traveling, the automatic cruise control is not immediately released depending on the vehicle speed. For example, when the driver approaches a curve on a downhill, it may be mild. The auto cruise control is not released in the case of a foot brake operation for deceleration. Therefore, 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 travel. It will be possible.

[0021]

According to the automatic cruise control method of the present invention, when the foot brake is operated while the auxiliary brake is operating, the automatic cruise control is performed when the current vehicle speed exceeds the set vehicle speed corresponding to the target vehicle speed. When the auxiliary brake is not operating, or when the auxiliary brake is operating and the current vehicle speed is less than or equal to the set vehicle speed corresponding to the target vehicle speed, the automatic cruise control is released.
The auto cruise control is not released in the case of a foot brake operation that causes a slight deceleration. As a result, the frequency of canceling the auto-cruise control is reduced, continuous auto-cruise control can be performed without adding a special device, and wasteful operations are significantly reduced while suppressing an increase in cost. Further, since the condition for canceling the automatic cruise control is set according to the vehicle speed, the automatic cruise control is executed in a stable state regardless of the loading state of the vehicle and the driving operation state of the driver.

[Brief description of drawings]

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

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

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

[Explanation of symbols]

 1 Control Unit 2 Main Switch for Auto Cruise 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 Device 14 First stage retarder 15 Second stage retarder

Claims (2)

[Claims] 1. When the foot brake is operated while the auxiliary brake is operating during the automatic cruise control of the vehicle accompanied by the operation control of the auxiliary brake, the current vehicle speed is set to a set vehicle speed corresponding to the target vehicle speed. An automatic cruise control method, characterized in that the automatic cruise control is continued when it exceeds. 2. The automatic cruise control method according to claim 1, wherein the set vehicle speed is a target vehicle speed.