The implementation problems by a digital computer for a well-designed linear continuous-time variable structure control system are considered. By using the zero-order-hold of the designed continuous-time VSS controller, a corresponding discrete-time controlled system is obtained. For the discrete-time system a new definition, the discrete-time weak-pseudo-sliding mode, is given to describing the zigzag behaviour corresponding to the continuous-time VSS sliding mode. An upper bound of the sampling period is given to guarantee the existence of the weak-pseudo-sliding mode along the prescribed hyperplane for the discrete-time system. If the chosen sampling period is not greater than this upper bound, the zero-order-hold of the continuous-time VSS controller can still stabilize sampled data system without any modification. Finally, simulation results are presented to show the effectiveness of the decision of the upper bound.
ASJC Scopus subject areas
- Control and Systems Engineering
- Computer Science Applications