Vehicle steering angle control device

• US 5,781,870 A
• Filed: 05/08/1997
• Issued: 07/14/1998
• Est. Priority Date: 11/10/1994
• Status: Expired due to Term

• Current Assignee: Komatsu Ltd.
• Original Assignee: Komatsu Ltd.
• Inventors: Okawa, Yukio
• Primary Examiner(s): NGUYEN, TAN QUANG
• Application Number:
  US08/836,133
• Time in Patent Office: 432 Days
• Field of Search: 364/424.029, 364/424.027, 364/424.031, 364/444.2, 364/447, 364/449.2, 364/450, 364/424.051, 364/424.07, 180/169, 180/408, 180/409, 180/410, 180/415, 180/422, 180/445, 318/587
• US Class Current: 701/25
• CPC Class Codes: B62D 1/28 non-mechanical , e.g. following a line or other known markers
• CPC Class Codes: G05D 1/0891 specially adapted for land vehicles

Abstract

A vehicle steering angle control device which accurately guides a vehicle along a predetermined drive course by accurately controlling a steering angle of the vehicle based on a degree of curvature of a curved course on which the vehicle is currently running and a current speed of the vehicle in which the degree of curvature of the curved course on which the vehicle is currently running is determined by calculating a degree of deviation of the vehicle relative to a vehicle advancing direction corresponding to current vehicle advancing direction data or an integration of the degree of deviation and a current speed of the vehicle is detected; a steering angle suitable for the degree of curvature of the curved course and the current speed of the vehicle is found and the steering angle of the vehicle is controlled to realize the suitable steering angle, whereby the vehicle is guided along the predetermined driving course.

Claims

1. A vehicle guidance system for storing position data pertaining to a predetermined driving course and for guiding the vehicle along the predetermined driving course by controlling the steering angle of the vehicle on the basis of this position data, comprising:

memory means for storing, for each point on the aforementioned predetermined driving course, data indicating the coordinate position for the point in question and the direction in which the vehicle should advance;

position detection means for detecting the current coordinate position of the vehicle;

speed detection means for detecting the current speed of the vehicle;

selection means for selecting from the memory contents of the memory means coordinate position data for the point on the predetermined driving course that is closest to the current coordinate position detected by the position detection means and direction of advance data for this closest point;

deviation calculation means for calculating the current deviation of vehicle position in the direction perpendicular to the direction of vehicle advance corresponding to the selected direction of advance data on the basis of the coordinate position data and direction of advance data selected by the selection means and the current coordinate position detected by the position detection means;

steering angle calculation means for calculating the vehicle steering angle so as to decrease with increased detected travel speed on the basis of the deviation calculated by the deviation calculation means and the current speed detected by the speed detection means in order to reduce deviation to zero; and

control means for controlling the steering angle of the vehicle on the basis of the vehicle steering angle calculated by the steering angle calculation means.

2. A vehicle guidance system for storing position data pertaining to a predetermined driving course and for guiding the vehicle along the predetermined driving course by controlling the steering angle of the vehicle on the basis of this position data, comprising:

memory means for storing, for each point on the aforementioned predetermined driving course, data indicating the coordinate position for the point in question and the direction in which the vehicle should advance;

position detection means for detecting the current coordinate position of the vehicle;

speed detection means for detecting the current speed of the vehicle;

selection means for selecting from the memory contents of the memory means coordinate position data for the point on the predetermined driving course that is closest to the current coordinate position detected by the position detection means and direction of advance data for this closest point;

deviation calculation means for calculating the current deviation of vehicle position in the direction perpendicular to the direction of vehicle advance corresponding to the selected direction of advance data on the basis of the coordinate position data and direction of advance data selected by the selection means and the current coordinate position detected by the position detection means;

integration operation means for performing integration operations on the deviation calculated by the deviation calculation means;

steering angle calculation for calculating the vehicle steering angle so as to decrease with increased detected travel speed on the basis of the deviation calculated by the deviation calculation means, the integral calculated by the integration operation means, and the current speed detected by the speed detection means in order to reduce the deviation to zero; and

control means for controlling the steering angle of the vehicle on the basis of the vehicle steering angle calculated by the steering angle calculation means.

3. A vehicle guidance system for storing position data pertaining to a predetermined driving course and for guiding the vehicle along the predetermined driving course by controlling the steering angle of the vehicle on the basis of this position data, comprising:

memory means for storing, for each point on the aforementioned predetermined driving course, data indicating the coordinate position for the point in question and the direction in which the vehicle should advance;

position detection means for detecting the current coordinate position of the vehicle;

speed detection means for detecting the current speed of the vehicle;

selection means for selecting from the memory contents of the memory means coordinate position data for the point on the predetermined driving course that is closest to the current coordinate position detected by the position detection means and direction of advance data for this closest point;

deviation calculation means for calculating the current deviation of vehicle position in the direction perpendicular to the direction of vehicle advance on the basis of the coordinate position data and direction of advance data selected by the selection means and the current coordinate position detected by the position detection means;

integration operation means for performing integration operations on the deviation calculated by the deviation calculation means;

first steering angle calculation means for calculating a first vehicle steering angle so as to decrease with increased detected travel speed on the basis of the deviation calculated by the deviation calculation means, the integral calculated by the integration operation means, and the current speed detected by the speed detection means in order to reduce the deviation to zero;

second steering angle calculation means for calculating a second vehicle steering angle on the basis of the radius of curvature of the predetermined course at the closest point;

third steering angle calculation means for calculating a third vehicle steering angle by adding the value obtained by multiplying the first vehicle steering angle calculated by the first steering angle calculation means by a prescribed coefficient with a value obtained by multiplying the second vehicle steering angle calculated by the second steering angle calculation means by a prescribed coefficient; and

control means for controlling the steering angle of the vehicle on the basis of the third vehicle steering angle calculated by the third steering angle calculation means.