A Robust Control Strategy for Linear Systems Having Uncertainties

摘要

As the robust control strategy which assures stability for linear systems having uncertainties caused by parameter variations, the one using linear and nonlinear laws by G. Leitmann and others based on the second method of Lyapunov has been known in these ten years.For this control strategy, however, saturating function approximating discontinuous function is used and it has been pointed out when implemented to existing plant that chattering may be generated at the manipulating variable due to the input delay caused by the sampling time in the computer system.This paper proposes a new algorithm of Moving Attractor to reduce this chattering effect. The control deviation is not evaluated by using the existing deviation but by using the deviation between the Moving Attractor and controlled variables. Position of Moving Attractor is first given at a prescribed place and then is moved to the position of real command under some given rule. The rule of Moving Attractor which assures uniform boundedness and uniform ultimate boundedness is derived.It is shown by an example of a robotic arm that the chattering at the manipulating variable is remarkably reduced under this proposed system.