Frequency Shaped Variable Structure Control

This paper describes a systematic approach to Variable Structure Control wherein a frequency shaping filter is inserted so that high frequency vibrational modes are not excited due to the switching phenomena inherent in such controllers. This is accomplished by considering a Quadratic Regulator problem during sliding mode. It has been shown earlier that the weights in the quadratic cost criterion are related to the definition of the switching surface. The introduction of frequency weighted Quadratic Regulators supplies the filter design approach suggested. Applications discussed are related to slewing flexible structures in general and flexible manipulator control in particular.