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ABSTRACT

Sliding Mode Control (SMC) is a robust control scheme based on the concept of

changing the structure of the controller in response to the changing state of the system in

order to obtain a desired response. A high speed switching control action is used to

switch between different structures of the controller and the trajectory of the system is

forced to move along a chosen switching manifold in the state space.

The standard sliding mode on which most variable structure systems are based is

of the first order. However, the standard sliding mode may be implemented only if the

relative degree of the sliding variable is 1. Also, it is associated with a high frequency

switching of the control or chattering. Therefore, the traditional notion of sliding mode

control has been extended and the concept of higher order sliding modes (HOSM) has

been developed in literature.

This report is a study of sliding mode control and its application to robotic

manipulator. The concept of higher order sliding mode control has also been studied and

simulated to these systems. Application of HOSM control to robotic manipulator is a

novel attempt. It involves study of various applications of sliding mode control, higher

order sliding mode control and the properties of robotic manipulator. Complete chattering

elimination by means of HOSM control has been demonstrated. An application of higher

order sliding mode control to robotic manipulator control has been considered and shown

to eliminate chattering completely. This is basically a comparative study of fuzzy sliding

mode and higher order sliding mode. Although both methods are used to eliminate the

chattering, tracking error performance is improved in higher order sliding mode.