Discrete time point to point position control of a system with actuator saturation

A method for developing a controller for point to point positioning of a single degree of freedom system with significant actuator saturation effects is developed and experimental results are presented. This method involves identifying the maximum stopping capacity of the actuator as a function of velocity and using this information to define a limiting state space trajectory associated with the fastest achievable deceleration and to compute a state to input mapping that will direct the system near to this limiting trajectory via discrete time control. The chief motivation for this work is to provide a simple, direct method to identify the crucial actuator limitation of a positioning system and use that information directly to achieve near minimum time point to point motion control despite significant nonlinear actuator characteristics. Experiments were conducted on a suitable system to verify the effectiveness of this technique and results are presented. This technique can also handle payload uncertainties easily and effectively.