The Hybrid Position/Force Control Based on Variable Impedance Model in the Dual-Arm Coordinated Transport

For the complex coupling motion with external disturbance and internal force constraint existing in the dual-arm coordinated transport, an internal and external hybrid position/force control strategy based on the variable impedance model is proposed. Firstly, the motion planning and dynamic model of the manipulated object in the closed-chain system are analyzed, and then the task space is orthogonally decoupled into the position free subspace at the outer loop and the force constrained subspace at the inner loop according to the coordinated transport characteristics. For the external disturbance in the position subspace, the impedance model is used for the trajectory tracking. For the internal force in the force constrained space, the variable impedance model is used for the force tracking. Finally, dual-arm coordinated transport experiments are carried out in the simulated environment and physical environment. The experimental results show that the proposed algorithm is flexible for external disturbance and satisfies internal force constraints.