STABILITY ANALYSIS OF THE INTERNAL DYNAMICS OF A WHEELED MOBILE ROBOT

The stability of the internal dynamics of a wheeled mobile robot is an alyzed. It is shown that the wheeled mobile robot exhibits unstable in ternal dynamics when moving backwards. Most control methods of wheeled mobile robots are designed based on input-output relations. Since the internal dynamics are not represented in input-output relations, stab ility properties of the internal dynamics are generally neglected. Nev ertheless, the internal dynamics do affect the behavior of mobile robo ts. Taking the look-ahead control method as an example, it is shown th at, by using a novel Liapunov function, the internal dynamics of a two -wheel differential-drive mobile robot are unstable when it is command ed to move backwards. Both simulation and experimental results are pro vided to verify the analysis. (C) 1997 John Wiley & Sons, Inc.