A Novel Fractional Order Impedance Control and Its Performance Analysis

In traditional impedance control model, the contact force can be reduced effectively. However, there exists a tracking error at the stable state due to the existence of stiffness, which is not conducive to tackle tasks based on high performance position control for robots. Therefore, this paper proposes a novel dynamic interaction model: fractional order impedance control, to address this issue. Firstly, an integral item is added into the traditional impedance model to eliminate the tracking error. Secondly, the idea of fractional order is introduced to make the orders of inertia, damping, and stiffness change from integers to fractions to achieve more significant compliant performance. Finally, simulation results validate the advantages of proposed fractional order impedance control and it can be also employed to absorb/increase, hold/keep, and dissipate/decrease system energy to achieve jumping, bouncing and friendly contact, respectively. Besides, stability analysis and three criterions of choosing and tuning 6 classic parameters in the proposed fractional order impedance control are both given out.