Force control system with nonlinear oscillator for manipulator in oscillatory motion

A force control system for a manipulator equipped with a spring as the end-effector is presented in this paper. The manipulator exploits its oscillatory motion, applying a force through the spring. It has been investigated that the manipulator driven by the van der Pol oscillator can generate a large force efficiently. In this paper, the authors design a force control system to control the amplitude of a force generated by the manipulator. The force control system achieves the desired force by adjusting the natural frequency of the van der Pol oscillator. The performance of the force control system is evaluated using simulations.