Method and device for speed and distance control for a motor vehicle

• US 5,871,062 A
• Filed: 04/15/1996
• Issued: 02/16/1999
• Est. Priority Date: 04/13/1995
• Status: Expired due to Fees

• Current Assignee: Daimler Chrysler Company LLC (Stellantis NV)
• Original Assignee: Mercedes-Benz AG (Mercedes-Benz Group AG)
• Inventors: Hahn, Stefan, Desens, Jens, Zomotor, Zoltan
• Primary Examiner(s): Jordan, Charles T.
• Assistant Examiner(s): DUCKER JR, CHARLES R
• Application Number:
  US08/635,265
• Time in Patent Office: 1,037 Days
• Field of Search: 180/169, 180/170, 180/167, 364/461, 364/424.083, 367/909, 340/435, 340/436, 340/903
• US Class Current: 180/169
• CPC Class Codes: B60K 31/0008 including means for detecting potential obstacles in vehicle path
• CPC Class Codes: B60W 2540/20 Direction indicator values
• CPC Class Codes: B60W 2720/106 Longitudinal acceleration
• CPC Class Codes: B60W 2754/30 Longitudinal distance
• CPC Class Codes: B60W 30/16 Control of distance between vehicles, e.g. keeping a distance to preceding vehicle

Abstract

A method and a device for controlling the speed of a motor vehicle and its distance from a vehicle travelling in front are provided. The speed is controlled as long as no vehicle travelling in front is located within a prescribed detection area in front of the vehicle and the distance from the vehicle travelling in front is controlled if a vehicle is located in the detection area. The desired distance for the distance control is set after an instruction for a lane change to the left has been triggered, to a value which is smaller than the value before this instruction was triggered, but is at least as large as a prescribed minimum distance. Alternatively, the actual acceleration of the vehicle is limited to a prescribed maximum value if a vehicle travelling in front moves out of the prescribed detection area in front of the vehicle during the time that an instruction for a lane change to the right is set. In this way, fast overtaking maneuvers can be performed within the control and/or lane changes to the right can be carried out without undesired acceleration effects.

Claims

1. A method of operating a vehicle speed and distance control unit for automatically controlling a speed of a motor vehicle and its distance from a vehicle travelling in front, said speed and distance control unit having a device for entry of lane change instructions by a vehicle operator, the method comprising the steps of:

controlling the speed about a prescribed desired speed as long as no vehicle travelling in front is located within a prescribed detection area in front of the vehicle;

controlling the distance from a vehicle travelling in front about a prescribed desired distance as long as a vehicle travelling in front is located within the prescribed detection area in front of the vehicle; and

after an instruction for a lane change in a predetermined lateral direction has been entered, setting a desired distance for the distance control to a value (d_s1) which is smaller than a value (d_sn) before the instruction for a lane change to the left was triggered, but which is at least as large as a prescribed minimum distance (d_min).

2. The method according to claim 1, wherein the desired distance value (d_s1) after the instruction for a lane change in said predetermined lateral direction has been entered is set to the larger value of the prescribed minimum distance (d_min) and a value (d_sn /k) which is smaller by a prescribed factor (1/k) than the value (d_sn) before the instruction for a lane change to the left was triggered.

3. A method of operating a vehicle speed and distance control unit for automatically controlling a speed of a motor vehicle and its distance from a vehicle travelling in front, said speed and distance control unit having a device for entry of lane change instructions by a vehicle operator, the method comprising the steps of:

controlling the speed about a prescribed desired speed as long as no vehicle travelling in front is located within a prescribed detection area in front of the vehicle;

controlling the distance from a vehicle travelling in front about a prescribed desired distance as long as the vehicle travelling in front is located within the prescribed detection area in front of the vehicle; and

after an instruction for a lane change in a predetermined lateral direction has been entered, changing over from a distance control to an acceleration control, and prescribing a minimum distance, wherein acceleration control is terminated and distance control is implemented when the distance drops below the prescribed minimum distance.

4. A method for controlling a speed of a motor vehicle and its distance from a vehicle travelling in front, said motor vehicle having a device for detecting lane change instructions which are entered by a vehicle operator, the method comprising the steps of:

controlling the speed about a prescribed desired speed as long as no vehicle travelling in front is located within a prescribed detection area in front of the vehicle;

controlling the distance from a vehicle travelling in front about a prescribed desired distance as long as the vehicle travelling in front is located within the prescribed detection area in front of the vehicle; and

limiting an actual acceleration of the vehicle to a maximum value (a_max) if the vehicle travelling in front moves out of the prescribed detection area in front of the vehicle during a time that an instruction for a lane change in a predetermined lateral direction is set.

5. The method according to claim 4, wherein the maximum value (a_max) which limits actual acceleration is set equal to the actual acceleration (a_i) when the vehicle travelling in front moves out of the prescribed detection area in front of the vehicle, if the actual acceleration (a_i) is positive, and otherwise the maximum value is set to zero.

6. A device for automatically controlling a speed of a motor vehicle and its distance from a vehicle travelling in front, the device comprising:

a speed control unit for controlling motor vehicle speed about a prescribed desired speed as long as no vehicle travelling in front is located within a prescribed detection area in front of the motor vehicle;

a distance control unit for controlling distance of the motor vehicle from the vehicle travelling in front about a prescribed distance as long as a vehicle travelling in front is located within the prescribed detection area in front of the motor vehicle;

means for detecting entered lane change instructions from an operator of said vehicle; and

means which, after entry of an instruction for a lane change in a predetermined lateral direction has been detected, set the desired distance for the distance control to a value which is smaller than the value before the instruction for a lane change in said predetermined lateral direction was entered, but is at least as large as a prescribed minimum distance.

7. A device for controlling a speed of a motor vehicle and its distance from a vehicle travelling in front, the device comprising:

a speed control unit for controlling motor vehicle speed about a prescribed desired speed as long as no vehicle travelling in front is located within a prescribed detection area in front of the motor vehicle;

a distance control unit for controlling distance of the motor vehicle from the vehicle travelling in front about a prescribed desired distance as long as the vehicle travelling in front is located within the prescribed detection area in front of the motor vehicle;

means for detecting entered lane change instructions from an operator of said vehicle;

means which, after entry of an instruction for a lane change in a first predetermined lateral direction has been detected, set the desired distance for the distance control to a value which is smaller than the value before the instruction for a lane change in said first predetermined lateral direction was entered, but is at least as large as a prescribed minimum distance; and

means for limiting actual acceleration of the motor vehicle to a maximum value during detection of an entered instruction for a lane change in a second predetermined lateral direction if a vehicle travelling in front moves out of the prescribed detection area in front of the motor vehicle.

8. A device for automatically controlling a speed of a motor vehicle and its distance from a vehicle travelling in front, the device comprising:

a speed control unit for controlling motor vehicle speed about a prescribed desired speed as long as no vehicle travelling in front is located within a prescribed detection area in front of the motor vehicle;

a distance control unit for controlling distance of the motor vehicle from the vehicle travelling in front about a prescribed desired distance as long as the vehicle travelling in front is located within the prescribed detection area in front of the motor vehicle;

means for detecting entered lane change instructions from an operator of said vehicle; and

means for limiting actual acceleration of the motor vehicle to a maximum value during detection of a set instruction for a lane change in a predetermined lateral direction if a vehicle travelling in front moves out of the prescribed detection area in front of the motor vehicle.