Speed Control System and Method Having a Distance Sensor, Intended for a Motor Vehicle

• US 20130204505A1
• Filed: 03/14/2013
• Published: 08/08/2013
• Est. Priority Date: 09/15/2010
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG
• Original Assignee: Bayerische Motoren Werke AG
• Inventors: SAUER, Thomas
• Granted Patent: US 9,026,335 B2
• Time in Patent Office: Days
• US Class Current: 701/96
• CPC Class Codes: B60K 2031/0016 Identification of obstacles; Selection of a target vehicle
• CPC Class Codes: B60K 2310/26 Distance setting methods, e.g. determining target distance to target vehicle
• CPC Class Codes: B60K 31/00 Vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed, i.e. preventing speed from exceeding an arbitrarily established velocity or maintaining speed at a particular velocity, as selected by the vehicle operator fittings acting on two or more sub-units B60W30/14; speedometers G01P; systems or devices for controlling speed in general G05D13/00 ; in traffic anti-collision system for road vehicles G08G1/16
• CPC Class Codes: B60W 2050/0095 Automatic control mode change
• CPC Class Codes: B60W 2554/4041 Position
• CPC Class Codes: B60W 2554/801 Lateral distance
• CPC Class Codes: B60W 2554/804 Relative longitudinal speed
• CPC Class Codes: B60W 30/17 with provision for special action when the preceding vehicle comes to a halt, e.g. stop and go
• CPC Class Codes: B60W 50/0098 Details of control systems ensuring comfort, safety or stability not otherwise provided for

Abstract

A motor vehicle speed control system having a distance sensor operates in a first mode when the vehicle is traveling on a clear stretch of road in which a predetermined desired vehicle speed is set. In a second mode when the vehicle is following another vehicle, a predetermined minimum distance from a selected target object is set. The target object is selected by a first selection process that screens out stationary objects. When a defined condition prevails, the first mode switches into a third mode in the form of deceleration, wherein a second selection process is started which also evaluates stationary target objects. Until a target object is selected, the vehicle travels on a clear road with deceleration initiated which is reduced relative to following another vehicle. If a target object is selected by the second selection process, the system switches over without delay from the third mode into the second mode.

Claims

1. A method of operating a speed control system having a distance sensor for a motor vehicle, the method comprising the acts of:

providing a first mode of operation when the vehicle is traveling on a clear stretch of road, in which a predefined desired vehicle speed is settable;

providing a second mode of operation when the vehicle is following another vehicle, in which a predefined minimum distance to a selected target object is settable, the target object in the second mode being selected according to a first selection process that screens out stationary objects as target objects;

in an event of a presence of at least one defined condition, changing the operation of the speed control system when in the first mode of operation into a third mode of operation, in which the motor vehicle undergoes decelerated travel; and

in the third mode of operation, starting a second selection process that evaluates stationary objects, wherein until a selection of a target object is made, the vehicle operates in the third mode as a vehicle traveling on a clear road with an initiated deceleration which is reduced with respect to following travel.

2. The speed control method according to claim 1, wherein a defined condition is a vehicle speed of the motor vehicle below a first predefined motor vehicle speed threshold.

3. The speed control method according to claim 1, wherein a defined condition is a recognition of a minimum number of objects in a predefined distance range.

4. The speed control method according to claim 1, wherein a defined condition is a recognition of a minimum number of objects in a predefined distance range, speeds of said number of objects being below a predefined object speed threshold.

5. The speed control method according to claim 2, wherein a defined condition is a recognition of a minimum number of objects in a predefined distance range, speeds of said number of objects being below a predefined object speed threshold.

6. The speed control method according to claim 5, wherein at least one of the motor vehicle speed threshold and the object speed threshold is definable as a function of an actual vehicle speed of the motor vehicle.

7. The speed control method according to claim 1, wherein a transition takes place from the third mode in the form of the decelerated travel into the first mode when at least one of the following occurs:

(a) a manual operating action is carried out by a driver;

(b) an accelerator pedal is operated;

(c) the motor vehicle falls below a second lower motor vehicle speed threshold; and

(d) the third mode exceeds a defined time period.