Communications: electrical – External condition vehicle-mounted indicator or alarm – Transmitter in another vehicle
Reexamination Certificate
1999-07-15
2001-07-24
Pope, Daryl (Department: 2632)
Communications: electrical
External condition vehicle-mounted indicator or alarm
Transmitter in another vehicle
C340S435000, C340S436000, C701S301000
Reexamination Certificate
active
06265990
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus and a method for controlling a distance between two traveling vehicles and a recording medium for storing the control method.
To improve the safety in a vehicle driving operation and reduce the driver's burden, an apparatus for automatically controlling a distance between two traveling vehicles is conventionally proposed. For example, a relative speed between the system's vehicle and a preceding vehicle is obtained. A target distance is determined in accordance with the detected relative speed (i.e., speed deviation between two vehicles). An actual distance between the system's vehicle and the preceding vehicle is detected. To eliminate the distance deviation between the actual distance and the target distance, an appropriate target acceleration is set to control an internal combustion engine of the vehicle and/or a braking apparatus so as to realize the target acceleration.
In an automotive vehicle, there are a plurality of deceleration devices which are independently operable to decelerate the vehicle. To adjust the distance between two traveling vehicles, appropriate one or plural deceleration devices are generally selectable in accordance with the target acceleration.
Meanwhile, there is a warning device which generates a warning or alarm to caution the driver against upcoming danger when the distance between two traveling vehicles becomes short. For example, the warning is a buzzer, an indicator or the like, in response to which the driver depresses a braking pedal to give a sufficient braking force to wheels.
However, the warning operation is conventionally independent from the automatic distance control. The condition of the deceleration devices actuated during the automatic distance control is not taken into consideration in the judgement of the warning operation. In some cases, the warning may be issued awkwardly or unexpectedly even if the automatic control apparatus has a sufficient capability of recovering the distance between two vehicles by continuing the automatic distance control. In such cases, the warning operation may not fit to driver's feeling.
SUMMARY OF THE INVENTION
In view of the foregoing, the present invention has an object to solve the problems caused by the conventional distance control method.
An object of the present invention is to provide a control apparatus and a method capable of optimizing the relationship between the automatic distance control and the warning operation so as to fit to driver's feeling.
An object of the present invention is to provide an apparatus and a method for judging and generating a warning with reference to the condition of the deceleration devices actuated for controlling the distance between two traveling vehicles.
An object of the present invention is to provide an apparatus and a method for performing the automatic distance control considering the presence of the warning.
An object of the present invention is to provide a recording medium for storing a computer program relating to the distance control method realized by the present invention.
To accomplish the above and other related objects, one aspect of the present invention provides a distance control apparatus and a related method for controlling a distance between two traveling vehicles. A plurality of deceleration devices, capable of acting as acceleration/deceleration means, are independently operable and different from each other in degree of attainable deceleration. An automatic distance control is performed by obtaining a control value required for controlling the distance between the two traveling vehicles based on a relationship between an actual value and a target value as well as a relative speed between the two traveling vehicles, and by actuating the acceleration/deceleration means based on the control value to control the distance between the two traveling vehicles. A warning operation is performed with reference to the deceleration devices actuated for the distance control. The warning is producible when the distance between the two traveling vehicles is shorter than a predetermined warning distance under the condition where the automatic distance control is in progress. At least one of the plurality of deceleration devices is selected to decelerate the succeeding vehicle. The warning operation is prohibited when a deceleration level attainable by the selected single or plural deceleration devices is lower than a predetermined maximum level even if the distance between the two traveling vehicles is shorter than the predetermined warning distance.
In other words, the present invention allows the activation of the warning device, only when the distance control apparatus is already using the available maximum deceleration obtained from the specific deceleration device or designated combination among the various deceleration devices which is capable of producing a predetermined maximum deceleration for the automatic distance control.
When the distance control apparatus has not used the available maximum deceleration, no warning is generated. Instead, the distance control apparatus activates the braking device so as to obtain the predetermined maximum deceleration for the automatic distance control.
When the braking device is already been used for decelerating the system's vehicle, the warning is generated. In response to the warning, the driver can depress the braking pedal strongly or abruptly with intent to immediately decelerate the vehicle.
It is preferable to judge that the deceleration level is higher than the predetermined maximum level when a deceleration device capable of generating a largest deceleration is already activated.
It is also preferable to judge that the deceleration level is higher than the predetermined maximum level when the control value for the automatic distance control is equivalent to an available maximum deceleration level.
Another aspect of the present invention provides a distance control apparatus and a related method for controlling a distance between two traveling vehicles characterized in that a deceleration control capable of obtaining an available maximum deceleration is performed in response to the warning operation.
In short, the warning operation and the automatic distance control are not independent from each other. Rather, the warning operation is closely correlated with the automatic distance control as an integrated vehicle behavior control system. It becomes possible to realize an optimized and cooperative operation of the automatic distance control and the warning generation so as to match with the driver's feeling.
Preferably, the deceleration control is performed by selecting a deceleration device capable of generating a largest deceleration.
Preferably, the deceleration control is performed by setting the control value to a value corresponding to the available maximum deceleration.
In practical automotive vehicles, the deceleration device capable of generating the largest deceleration is a braking device for applying a braking force to wheels of the succeeding vehicle.
In this case, the deceleration degree attainable by the driver's depression of the braking pedal (such as emergency braking) is fairly higher than the deceleration degree attainable by the automatic braking control performed in the automatic distance control. Thus, by forcibly applying the emergency braking, the driver can escape from the dangerous situation, such as a collision with the preceding vehicle. Otherwise, the driver may change the traveling lane by turning the steering wheel to avoid the collision. In this manner, the warning or alarm is generated only when it is truly necessary. The present invention thus realizes the effective warning generation by considering the condition of the automatic distance control.
Besides the braking device, an ordinary automotive vehicle has at least one additional deceleration device performing another function selected from the group consisting of a fuel cut control for partly o
Isogai Akira
Nishimura Takao
Teramura Eiji
Denso Corporation
Pillsbury & Winthrop LLP
Pope Daryl
LandOfFree
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