A simple discrete-time robot model and its control application

This paper presents a new discrete-time robot model. In general, the discrete-time robot models are derived by using discretizing methods to robot dynamical differential equations. The obtained models are very complex in structure, and are thus difficult to implement in practical applications. In this study, a simple discrete-time robot model is developed by using the trapezoid rule to approximate the integration part of continuous-time robot equation, and then successfully eliminating the nonlinear force terms and external force term from the robot equation. The proposed discrete-time robot model has very simple structure, and the controller based on this model owns inherent robustness to external forces. Both pole placement control and adaptive control schemes are designed for a 2-link manipulator. Simulation results demonstrate the validity of the proposed model, and verify its property of robust to external forces.