Research On Control Strategy Of Hoisting Manipulator Based On Joint Space

Modern warfare is developing to the direction of automation and intelligentization.The automatic lifting technology of launching box is a key factor to determine the efficiency of Battlefield supply.The key of using hydraulic heavy-duty manipulator to realize rapid and highprecision lifting of rocket launching box is to design a control strategy that is suitable for the actual use of hydraulic manipulator to deal with various nonlinearity of the hydraulic manipulator.In this paper,the control problem of the seven-degree-of-freedom hydraulic heavy-duty manipulator is studied in the following aspects:(1)The structure of hydraulic heavy-duty manipulator with seven degrees of freedom is introduced.The dynamics of each joint was analyzed in detail.The dynamic nonlinearity of each joint was reasonably dealt with,and the dynamic equation of each joint was given,which provided the foundation for the subsequent nonlinear controller design.(2)Aiming at the synchronous control problem caused by multiple hydraulic actuators driving a single joint of the manipulator,corresponding synchronous control strategies were designed respectively.For joint one,the actuator relationship is set as active-passive.By adding extra pressure difference control to the passive motor to provide a stable load to the joint,the pinion of the motor output shaft is always meshed with the large gear to achieve the purpose of dual-motor synchronous clearance.For joint two,the actuator relationship is active-active,and the force fight caused by the manufacturing deviation of the two actuators can be suppressed by using the position and pressure difference compound control strategy.(3)To overcome the strong coupling and nonlinear of hydraulic heavy-duty manipulator with seven degrees of freedom,design a control strategy which combine the disturbance observation with interference suppression.In the proposed controller design,an extended state observer(ESO)is constructed to estimate and compensate the lumped disturbance,and a robust integral of the sign of the error(RISE)feedback is synthesized to suppress the remaining estimation error to further improve the tracking accuracy.The use of the disturbance observer ensures the system has strong disturbance immunity and the use of RISE ensures that the controller has asymptotically stable tracking performance.The organic combination of the RISE and ESO ensures that the designed controller has strong disturbance immunity and theoretically asymptotically stable tracking performance.The effectiveness of the designed controller is verified by the joint simulation of Adams and Matlab.(4)The proposed synchronization control strategy and RISEESO control strategy are experimentally verified by the hydraulic heavy-duty manipulator with seven degrees of freedom.The excellences and effectiveness of the proposed control strategy are verified by comparing the different control methods.