Preceding vehicle follow-up control system

• US 6,389,351 B1
• Filed: 06/12/2000
• Issued: 05/14/2002
• Est. Priority Date: 06/15/1999
• Status: Expired due to Term

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Tange, Satoshi, Egawa, Kenichi, Higashimata, Akira, Asada, Tetsuya
• Primary Examiner(s): Nguyen, Tan
• Assistant Examiner(s): Donnelly, Arthur D.
• Application Number:
  US09/592,566
• Time in Patent Office: 701 Days
• Field of Search: 701/96, 701/93, 701/300, 701/301, 340/903, 340/904, 342/70, 342/71, 342/72, 180/167, 180/169
• US Class Current: 701/93
• CPC Class Codes: B60K 31/0008 including means for detecting potential obstacles in vehicle path
• CPC Class Codes: B60W 2050/146 Display means
• CPC Class Codes: B60W 2510/0604 Throttle position
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2720/106 Longitudinal acceleration
• CPC Class Codes: B60W 30/16 Control of distance between vehicles, e.g. keeping a distance to preceding vehicle

Abstract

A preceding-vehicle follow-up control system is arranged to calculate a target vehicle speed employed for bringing a detected vehicle-to-vehicle distance closer to a target vehicle-to-distance, to control the controlled-vehicle speed to bring a controlled-vehicle speed closer to the target vehicle speed, to decelerate the controlled-vehicle speed to a set vehicle speed at a rate of a preset deceleration when the controlled-vehicle speed is greater than a control continuation decision value greater than an upper limit of the set vehicle speed and when the accelerating operation is terminated. This arrangement provides a smooth drive feeing to a driver even after an acceleration of the controlled vehicle is executed during a follow-up control and is terminated.

Claims

1. A preceding vehicle follow-up control system for a vehicle, comprising:

a vehicle-to-vehicle distance detector that detects a distance between a controlled vehicle and a preceding vehicle and outputs a signal indicative of the vehicle-to-vehicle distance;

a vehicle speed detector that detects a vehicle speed of the controlled vehicle and outputs a signal indicative of the controlled-vehicle speed;

an accelerating operation detector that detects whether an accelerating operation based on a driver'"'"'s demand is executed; and

a controller connected to said vehicle-to-vehicle distance detector, said vehicle speed sensor and said accelerating operation detector, said controller being arranged

to calculate a target vehicle speed employed for bringing the vehicle-to-vehicle distance closer to a target vehicle-to-distance on the basis of the vehicle-to-vehicle distance and the controlled-vehicle speed,

to control the controlled-vehicle speed to bring the controlled-vehicle speed closer to the target vehicle speed,

to detect whether the controlled-vehicle speed is greater than a control continuation decision value which is greater than an upper limit of a settable range of a set vehicle speed,

to decelerate the controlled-vehicle speed to the set vehicle speed at a rate of a preset deceleration when the controlled-vehicle speed is greater than the control continuation decision value and when the accelerating operation is not executed.

2. The preceding vehicle follow-up control system as claimed in claim 1, wherein said acceleration detector includes one of a detector for detecting a depression of an accelerator pedal and a depression detecting means for detecting the depression of the accelerator pedal on the basis of a difference between an actual throttle opening and a throttle opening command value outputted from said controller during when said controller executes controlling the vehicle speed.

3. The preceding vehicle follow-up control system as claimed in claim 1, wherein the driver sets the set vehicle speed within the settable range.

4. The preceding vehicle follow-up control system as claimed in claim 1, wherein said controller is connected to a brake control unit for controlling a braking force generated by disc brakes, an engine output control unit for controlling an output of an internal combustion engine and a transmission control unit for controlling a shift position of an automatic transmission.

5. The preceding vehicle follow-up control system as claimed in claim 1, wherein

said controller stores a first control continuation value greater than the upper limit in the settable range of the set vehicle speed and a second control continuation value greater than the first control continuation value,

said controller decelerates the controlled-vehicle speed to the set vehicle speed at a rate of a preset deceleration when the controlled-vehicle speed is greater than the first control continuation decision value and smaller than the second control continuation decision value and when the accelerating operation is not executed,

said controller stops calculating the target vehicle speed and controlling the controlled-vehicle speed when the controlled-vehicle speed is greater than the second control continuation decision value, and

said controller resumes calculating the target vehicle speed and controlling the controlled-vehicle speed to be executed based on the set vehicle speed stored in the storage region said after calculating the target vehicle speed and controlling the controlled-vehicle speed are stopped and when the controlled-vehicle speed is smaller than the upper limit of the settable range of the set vehicle speed and when a driver'"'"'s demand for resuming the follow-up control is inputted to said controller.

6. The preceding vehicle follow-up control system as claimed in claim 5, wherein said controller limits the shift position of the automatic transmission through the transmission control unit on the basis of a magnitude of a deceleration of the controlled-vehicle speed and a relative speed between the controlled vehicle and a preceding vehicle.

7. The preceding vehicle follow-up control system as claimed in claim 5, wherein said controller calculates a target braking pressure for generating a target acceleration of the controlled vehicle by outputting a control command to the brake control unit.

8. A preceding vehicle follow-up control system for a vehicle, comprising:

a vehicle-to-vehicle distance detector that detects a distance between a controlled vehicle and a preceding vehicle and outputs a signal indicative of the vehicle-to-vehicle distance;

a vehicle speed detector that detects a vehicle speed of the controlled vehicle and outputs a signal indicative of the controlled-vehicle speed;

an accelerating operation detector that detects whether an accelerating operation based on a driver'"'"'s demand is executed;

a control resume switch through which a driver of the controlled vehicle outputs a control resume command; and

a controller connected to said vehicle-to-vehicle distance detector, said vehicle speed sensor, said accelerating operation detector and said control resume switch, said controller being arranged

to calculate a target vehicle speed employed for bringing the vehicle-to-vehicle distance closer to a target vehicle-to-distance on the basis of the vehicle-to-vehicle distance and the controlled-vehicle speed,

to control the controlled-vehicle speed to bring the controlled-vehicle speed closer to the target vehicle speed,

to detect whether the controlled-vehicle speed is greater than a control continuation decision value which is greater than an upper limit of a settable range of a set vehicle speed,

to store the set vehicle speed in a storage region,

to stop calculating the target vehicle speed and controlling the controlled-vehicle speed when the controlled-vehicle speed is greater than the control continuation decision value, and

to resume calculating the target vehicle speed and controlling the controlled-vehicle speed to be executed based on the set vehicle speed stored in the storage region after calculating the target vehicle speed and controlling the controlled-vehicle speed are stopped and when the controlled-vehicle speed is smaller than the upper limit of the settable range of the set vehicle speed and when said control resume switch outputs the control resume command.

9. A preceding vehicle follow-up control system for a vehicle, comprising:

vehicle-to-vehicle distance detecting means for detecting a distance between a controlled vehicle and a preceding vehicle;

controlled-vehicle speed detecting means for detecting a vehicle speed of the controller vehicle;

vehicle-to-vehicle distance controlling means for calculating a target vehicle speed for bringing the detected vehicle-to-vehicle distance closer to a target vehicle-to-vehicle distance on the basis of the vehicle-to-vehicle distance and the controlled-vehicle speed; and

controlled-vehicle speed controlling means for controlling the controlled-vehicle speed to bring the controlled-vehicle speed closer to the target vehicle speed;

decision-speed achievement detecting means for detecting that the controlled-vehicle speed is greater than a control continuation decision value which is greater than an upper limit of a settable range of a set vehicle speed;

acceleration detecting means for detecting whether an accelerating operation of a driver'"'"'s demand is executed;

prior deceleration controlling means for decelerating the controlled-vehicle speed to the set vehicle speed by a preset deceleration when the controlled-vehicle speed is greater than the control continuation decision value and when said acceleration detecting means detects that the accelerating operation is not executed.

10. A preceding vehicle follow-up control system for a vehicle, comprising:

vehicle-to-vehicle distance detecting means for detecting a distance between a controlled vehicle and a preceding vehicle;

controlled-vehicle speed detecting means for detecting a vehicle speed of the controller vehicle;

vehicle-to-vehicle distance controlling means for calculating a target vehicle speed for bringing the detected vehicle-to-vehicle distance closer to a target vehicle-to-vehicle distance on the basis of the vehicle-to-vehicle distance and the controlled-vehicle speed; and

controlled-vehicle speed controlling means for controlling the controlled-vehicle speed to bring the controlled-vehicle speed closer to the target vehicle speed;

decision-speed achievement detecting means for detecting that the controlled-vehicle speed is greater than a control continuation decision value which is an upper limit of a settable range of a set vehicle speed;

set vehicle speed storing means for storing the set vehicle speed;

control resume commanding means for commanding resuming the execution of said vehicle-to-vehicle distance controlling means and said vehicle speed controlling means;

control canceling means for canceling the execution of said vehicle-to-vehicle distance controlling means and said vehicle speed controlling means when the controlled-vehicle speed is greater than the control continuation decision value; and

control resuming means for resuming the execution of said vehicle-to-vehicle distance controlling means and said vehicle speed controlling means executed based on the set vehicle speed stored in said set vehicle speed storing means after the execution of said vehicle-to-vehicle distance controlling means and said vehicle speed controlling means is cancelled and when the controlled-vehicle speed is smaller than the upper limit of the settable range of the set vehicle speed and when said control resume commanding means commanding the resume of the execution of said vehicle-to-vehicle distance controlling means and said vehicle speed controlling means.

11. A method for following-up a preceding vehicle, comprising:

detecting a distance between a controlled vehicle and a preceding vehicle and outputs a signal indicative of the vehicle-to-vehicle distance;

detecting a vehicle speed of the controlled vehicle and outputs a signal indicative of the vehicle speed;

detecting whether an accelerating operation of a driver'"'"'s demand is executed;

calculating a target vehicle speed employed for bringing the vehicle-to-vehicle distance closer to a target vehicle-to-distance;

controlling the controlled-vehicle speed to bring the controlled-vehicle speed closer to the target vehicle speed;

detecting whether the controlled-vehicle speed is greater than an upper limit of a settable range of a set vehicle speed; and

decelerating the controlled-vehicle speed to the set vehicle speed by a preset deceleration when the controlled-vehicle speed is greater than the upper limit and when the accelerating operation is not executed.