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Title: Method for controlling a vehicle with two or more independently steered wheels

A method (10) for independently controlling each steerable drive wheel (W.sub.i) of a vehicle with two or more such wheels (W.sub.i). An instantaneous center of rotation target (ICR) and a tangential velocity target (v.sup.G) are inputs to a wheel target system (30) which sends the velocity target (v.sub.i.sup.G) and a steering angle target (.theta..sub.i.sup.G) for each drive wheel (W.sub.i) to a pseudovelocity target system (32). The pseudovelocity target system (32) determines a pseudovelocity target (v.sub.P.sup.G) which is compared to a current pseudovelocity (v.sub.P.sup.m) to determine a pseudovelocity error (.epsilon.). The steering angle targets (.theta..sup.G) and the steering angles (.theta..sup.m) are inputs to a steering angle control system (34) which outputs to the steering angle encoders (36), which measure the steering angles (.theta..sup.m). The pseudovelocity error (.epsilon.), the rate of change of the pseudovelocity error ( ), and the wheel slip between each pair of drive wheels (W.sub.i) are used to calculate intermediate control variables which, along with the steering angle targets (.theta..sup.G) are used to calculate the torque to be applied at each wheel (W.sub.i). The current distance traveled for each wheel (W.sub.i) is then calculated. The current wheel velocities (v.sup.m) and steering angle targets (.theta..sup.G) are used to calculatemore » the cumulative and instantaneous wheel slip (e, ) and the current pseudovelocity (v.sub.P.sup.m).« less
Inventors:
 [1];  [2]
  1. (Oak Ridge, TN)
  2. (Knoxville, TN)
Issue Date:
OSTI Identifier:
869808
Assignee:
Martin Marietta Energy Systems, Inc. (Oak Ridge, TN) ORNL
Patent Number(s):
US 5402344
Contract Number:
AC05-84OR21400
Research Org:
LOCKHEED MARTIN ENRGY SYST INC
Country of Publication:
United States
Language:
English
Subject:
method; controlling; vehicle; independently; steered; wheels; 10; steerable; drive; wheel; instantaneous; center; rotation; target; icr; tangential; velocity; inputs; 30; sends; steering; angle; theta; pseudovelocity; 32; determines; compared; current; determine; error; epsilon; targets; angles; control; 34; outputs; encoders; 36; measure; rate; change; slip; pair; calculate; intermediate; variables; torque; applied; distance; traveled; calculated; velocities; cumulative; drive wheels; control variable; control variables; drive wheel; angle encoder; /701/180/

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