Design And Compliance Control Of Dual Arm Robot System For Cooperative Task

Compared with the single arm robot,the dual-arm cooperative robot is more dexterous,can adapt to more complex tasks and cooperate with people better.However,at present,the cost of dual arm robot is high,which is not conducive to its industrialization.In most application scenarios,the coordination level of dual arms is low,and the advantages of dual arms cannot be fully utilized.Based on this,this paper developed a dual-arm cooperative robot,and carried out the research of compliance control under the tight coordination of dual-arm for cooperative tasks.According to the requirements of collaborative tasks such as transportation and assembly,the function and performance indexes of the dual-arm cooperative robot are determined,and the structure of the robot is designed accordingly.The robot is composed of three modular joints,adapters and bases.The single arm has 7 degrees of freedom,which makes it more dexterous;there are few machining parts in the modular joint,and an integrated double joint is designed,which makes the robot more integrated,more reliable and more maintainable.In this scheme,a low-cost and high integration dual arm robot is designed.Based on the configuration characteristics of the dual arm robot,a motion planning algorithm based on global graph search is proposed when the task is limited.In this algorithm,the configuration of the manipulator is represented by one parameter,and the planning path is represented by another parameter,so as to form a two-dimensional graph.The graph search algorithm is used to find the feasible solution,and finally the planning is carried out in the joint space.Under the premise of satisfying the planning path,the algorithm can simultaneously achieve sub goals such as obstacle avoidance and joint limit avoidance,and ensure the path consistency of multiple planning.An adaptive impedance control method is proposed to solve the complex problem of dual-arm forming a closed kinematic chain under the task of carrying.Firstly,the position level motion planning method under the tight coordination of dual-arm is given,and two effective ways are given for the decomposition of its common force.Based on this,the main arm and the slave arm are distinguished.The position control is adopted for the main arm and the adaptive impedance control based on RBF neural network is adopted for the slave arm.Due to the unknown environment parameters and other factors,the impedance parameters are difficult to determine.The problem of adjusting the impedance parameters is effectively solved by adaptive impedance parameters,so that the contact force error of the two arms is smaller.Finally,the assembly of the prototype is completed and the experimental system is built.Based on the system,the load and position tracking test of single joint and the load and accuracy test of single arm are carried out.The above-mentioned motion planning algorithm and adaptive impedance control algorithm based on global graph search are verified by experiments.The experimental results show that the performance of the designed and assembled dual arm robot meets the requirements,and the proposed planning and control algorithm is feasible.