Method for surmounting an obstacle by a robot vehicle

• US 5,372,211 A
• Filed: 10/01/1992
• Issued: 12/13/1994
• Est. Priority Date: 10/01/1992
• Status: Expired due to Term

• Current Assignee: The United States of America As Represented By The Secretary of Agriculture
• Original Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Inventors: Wilcox, Brian H., Ohm, Timothy R.
• Primary Examiner(s): Tyson, Karin L.
• Assistant Examiner(s): BOEHLER, ANNE MARIE M
• Application Number:
  US07/956,684
• Time in Patent Office: 803 Days
• Field of Search: 180/8.2, 180/8.3, 180/8.5, 280/5.2, 280/5.28, 280/5.32, 280/DIG. 10, 901/1
• US Class Current: 180/8.2
• CPC Class Codes: B62D 57/028 having wheels and mechanical legs B62D57/024 takes precedence; ground-engaging vehicle fittings for supporting, lifting or manoeuvring the vehicle, wholly or in part B60S9/00

Abstract

Surmounting obstacles in the path of a robot vehicle is accomplished by rotating the wheel forks of the vehicle about their transverse axes with respect to the vehicle body so as to shift most of the vehicle weight onto the rear wheels, and then driving the vehicle forward so as to drive the now lightly-loaded front wheels (only) over the obstacle. Then, after the front wheels have either surmounted or completely passed the obstacle (depending upon the length of the obstacle), the forks are again rotated about their transverse axes so as to shift most of the vehicle weight onto the front wheels. Then the vehicle is again driven forward so as to drive the now lightly-loaded rear wheels over the obstacle. Once the obstacle has been completely cleared and the vehicle is again on relatively level terrain, the forks are again rotated so as to uniformly distribute the vehicle weight between the front and rear wheels.

Claims

1. A method of operating a vehicle supported on front and rear wheels connected to the vehicle body by respective front and rear struts, the front struts and the rear struts being independently rotatable about respective forward and rear axes, wherein the axes intersect the vehicle body in a direction transverse to the direction of vehicle travel, said method comprising the steps of:

rotating the front struts simultaneously about their transverse axis with respect to the vehicle body from an original angular position to move the front wheels forward so as to shift most of the vehicle weight onto the rear wheels;

driving the vehicle forward by powered rotation of at least some of said wheels so as to drive the now lightly-loaded front wheels over an obstacle;

returning the front forks to their original angular position while rotating the rear struts simultaneously about their transverse axis with respect to the vehicle body to move the rear wheels rearward so as to shift most of the vehicle weight onto the front wheels; and

driving said vehicle forward by powered rotation of at least some of said wheels so as to drive the now lightly-loaded rear wheels over the obstacle.

2. The method of claim 1 further comprising, after the obstacle has been cleared and the vehicle is again on relatively level terrain, rotating the front and rear struts so as to uniformly distribute the vehicle weight between the front and rear wheels.

3. A method of operating a vehicle supported on front and rear wheels connected to the vehicle body by respective front and rear struts, the front struts and the rear struts being independently rotatable about respective forward and rear axes, wherein the axes intersect the vehicle body in a direction transverse to the direction of vehicle travel, said method comprising the steps of:

rotating the front struts simultaneously about their transverse axis with respect to the vehicle body from an original angular position to move the front wheels forward so as to shift most of the vehicle weight onto the rear wheels;

driving the vehicle forward by powered rotation of at least some of said wheels so as to drive the now lightly-loaded front wheels on top of an obstacle;

returning the front forks to their original angular position while rotating the rear struts simultaneously about their transverse axis with respect to the vehicle body from an original angular position to move the rear wheels rearward so as to shift most of the vehicle weight onto the front wheels;

driving said vehicle forward by powered rotation of at least some of said wheels so as to drive the now lightly-loaded rear wheels on top of the obstacle;

returning the rear forks to their original angular position while rotating the front struts simultaneously about their transverse axis with respect to the vehicle body to move the front wheels forward to provide stability during descent;

driving the vehicle forward by powered rotation of at least some of said wheels until clear of the obstacle; and

,

rotating the front and rear struts so as to uniformly distribute the vehicle weight between the front and rear wheels once the vehicle is again on relatively level terrain.