Mechanism and Machine Theory vol:28 issue:6 pages:741-749
This paper focuses on the problem of application of inverse dynamics control methods to robots with flexible joints. In Part I of the paper, there are answers presented to a number of questions related to the analytical formulation of nonlinear decoupling control laws. After discussion, the dynamic model of a robot with flexible joints and electrochemical actuators is chosen. The application of the extended computed torque technique together with the methods from the theory of differential-algebraic equations (DAE) to the developed fifth-order robot model gives a number of decoupled linear subsystems, which take robot task space commands as inputs. Due to drawbacks of the continuous-time inverse dynamics, discussed in the paper, a new control strategy in discrete-time is developed in Part II of the paper. The proposed control method is computationally efficient and admits low sampling frequencies. The results of extensive numerical experiments confirm the advantages of the designed control algorithm.