Compliant Predictive Tracking Control of Space Manipulator Under Safety Assessment

Space manipulators perform a crucial role in on-orbit tasks of spacecraft, and the control accuracy and safety performance are the factors that are often emphasized. Typically, the uncertainties caused by the complex space environment will result in the control system for the space manipulator having off-nominal values of the responses and decrease the reliability in the on-orbit task, thus affecting the safety performance. To tackle these drawbacks, a compliant predictive tracking control method of a space manipulator with uncertainties under safety assessment is proposed to further improve and evaluate the tracking accuracy, compliance, and safety performance of the manipulator. Considering the optimization problem constructed by the model predictive tracking control method and impedance control constraints, a nominal compliant predictive tracking control method is developed, thereby achieving compliance of space manipulator system while guaranteeing the tracking accuracy. Based on the interval dimensionwise analysis method and uncertainty quantization process, the control system with uncertainties is established to realize the estimation of the control system’s uncertain responses. A non-probabilistic reliability metric is introduced that can assess the safety performance of the entire space manipulator toward uncertain response bounds. Finally, the validity of the proposed method is demonstrated in simulation using a manipulator for task.