A Robot Joint Model with Minimal Order Controller and State Observer

Abstract

In this paper a novel control method and state observer are proposed for an autonomous humanoid robot joint model for fast tracking response and superior performance. The various movements of the robot for pre specified joint trajectories can be achieved using proposed controller. The controller is simple and is able to produce desirable results. The linearized robot joint model is controlled by a simpler order feedback control designed on the basis of quasi-linear feedback theory. Under this design, the pole of the lead-lag compensator depends on the gain of open loop system. A simulink model is developed to model single joint in the body. The proposed controller guarantees fast tracking of the desired trajectories, as well ensures the safety. Since the plant model involves differentiation of a state variable to generate another, resulting in a reduction of signal to noise ratio, a state observer is designed for the feedback system to ensure maximum safety and improved performance. The simulations are done showing the validity of the scheme. Poleplacement method is used to design the observer parameters. The
application of proposed controller and state observer is illustrated by linear model.