| With the improvement of modern industrial level of the current society,industrial robots that work independently on a fixed base have been unable to meet the ever-changing manufacturing needs.A robot formed by installing a manipulator on a legged mobile platform can combine the flexibility of the legged motion and the maneuverability of the manipulator,so it has a broad application prospect.In this paper,the dual-mobile manipulator mounted on a quadruped robot is taken as the research object.Research is carried out on dual-arm modeling and kinematics analysis,real-time control system design,dual-arm operation motion planning,and compliant motion control.The main research contents are as follows:(1)For the layout and kinematics modeling of the robot’s dual-arm,the characteristics of the two layouts of the dual-arm operation system on the quadruped robot platform are analyzed.The-arm layout of the front and rear staggered left and right cooperation is determined,which has a large workspace coverage and has the least impact on the center of gravity of the quadruped robot in the standing state.According to this layout,the kinematic model of the dual-arm is established,the five-degree-of-freedom single-arm is abstracted into a link structure,the coordinate system is established by the D-H method,and the forward kinematics analysis is carried out in combination with the link parameters,and the single-arm inverse kinematics equation is derived.and the Jacobian matrix.(2)Aiming at the design of real-time control system for the multi-appendage and multi-joint quadruped robot,a control system based on CAN bus distributed structure is built and communication protocols covering various operation modes are given.The main controller is selected and analyzed,and the Compact-RIO 9039 controller of NI is used to complete the design of various service subprograms of the main controller,and realize the functions of remote control information reading,dual-arm motion planning and CAN bus communication.Secondly,the hardware and software design of the hydraulic servo motion controller based on DSP is introduced,which realizes the functions of joint angle servo control with control frequency up to 1Khz,six-dimensional force sensor information acquisition and joint angle position information acquisition.Finally,the experimental verification is carried out on a single-arm platform.(3)Research on the motion planning method for dual-arm.The operation modes of the dual-arm are divided into two modes:independent operation and cooperative operation.The kinematic constraint relationship between the arms and the target object to be operated under different operation modes is deduced respectively.Based on the above constraints,the motion planning based on the speed command is introduced.The method generates the motion trajectories of the arms in real time by giving the end speeds of the arms.Finally,the motion planning experiments of the arms under different operation modes are implemented on the Webots simulation software and experimental platform.(4)A compliant motion control method for a hydraulic manipulator for position control.The admittance control strategy based on the end six-dimensional force sensor is studied,the admittance control model of the five-degree-of-freedom hydraulic manipulator is established,the relationship between the load force and the moment in the six-dimensional force sensor is deduced,and the control of the end gripper load is realized.Gravity compensation and adding the gravity compensation term to the admittance control strategy improves the measurement accuracy of the six-dimensional force sensor.Finally,the compliance control experiment is carried out.The results show that the admittance control strategy can effectively improve the adaptability of the hydraulic manipulator to the external environment. |
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