Compliance Control Using Hydraulic Heavy-Duty Manipulator

Active compliance control is one of the necessary prerequisites for the fine manipulation of hydraulic heavy duty manipulators (HHDMs). The establishment of a rigid–flexible coupling machine–hydraulic multibody dynamics model and an active compliance control algorithm for HHDM are the key problems to be solved urgently in the compliance control of heavy duty manipulators. In this paper, a multibody dynamics model of a machine–hydraulic system with seven degrees of freedom is developed with consideration of HHDM characteristics, such as multi-input multioutput, nonlinearity, and rigid-flexible coupling. Meanwhile, a position/force same loop control algorithm for the compliance control of HHDM is proposed based on genetic neural network. Specifically, the force control system is decomposed into subsystems, while the feedback position and force are output through the processing of the joint position controller, torque controller, and multibody dynamics model. Cosimulation results present the feasibility and effectiveness of the proposed dynamics model and control algorithm. Moreover, the experimental environment and the HHDM control system are also developed, while the operation experiment of the control system for HHDM is accordingly conducted. Experiment results show that the control system can realize precise control of position and force, and can successfully complete the function of active compliance control operation.