Nonlinear robot control based on improved joint model

The objective of our contribution is the unification of actuators, transmissions and linkages in the control design of a robotic manipulator. The joint model is extended with the reset integrator friction model and nonlinear elasticity. The nonlinear model parameters are identified on the basis of experimental data. A formalized procedure of exact input-output linearization that enables the introduction of linear local controllers is used for the nominal model. The robustness of the control law according to the class of parameter perturbations and unmodelled dynamics is improved by Lyapun's redesign. Simulation results are evaluated on a SCARA laboratory manipulator.