Research On Trajectory Planning And Soft Dragging Control Of Supernumerary Robotic Limb

In fields such as nuclear industry,aerospace manufacturing,and construction engineering,the working space of tasks is usually very small,extremely dangerous and complex.Traditional robots are overwhelmed by these constraints,while purely manual operations tend to lead to inefficiencies and physical injuries to workers.Therefore,Supernumerary Robotic Limbs(SRL)have become an effective solution.As a wearable human assistive device,supernumerary robots can help the wearer to perform tasks such as support and handling,and enhance single-person operation and operational range,and thus have a wide range of applications in aviation,medical,construction,and military fields.In this paper,we focus on the trajectory optimization and soft dragging of the supernumerary robotic limbs arm as the research object.Firstly,the structure of the outer limb robot arm is analyzed,and the kinematic modeling is carried out by the improved DH parameter method to complete the derivation of the forward and inverse kinematic equations.Subsequently,the robotic arm simulation model is built in CoppeliaSim,and the correctness of the kinematic model and the forward and inverse kinematic solutions are verified by using MATLAB Robotics Toolbox.Meanwhile,the Monte Carlo method is used to determine the working space range of the supernumerary robotic limbs arm to provide basic data for the subsequent trajectory planning and control.With the goal of shortening the system operation time,the joint space trajectory planning of the supernumerary robotic limbs arm is optimized.Under the limitation of the maximum running speed,to ensure the smoothness of the robot arm trajectory,the 3-5-3 segmented polynomial is proposed to interpolate the joint space trajectory and combine with the improved white shark optimization algorithm to shorten the interpolation time to achieve the optimization of the joint space trajectory.The feasibility of the trajectory optimization algorithm of the supernumerary robotic limbs arm is verified by completing simulation validation in CoppeliaSim and MATLAB software.Considering the demand of the supernumerary robotic limbs arm in the application scenario of soft dragging,this paper adopts the position-based impedance control method to realize the soft control of the robotic arm by comparing the existing soft control methods.The impedance parameters,namely inertia coefficient,damping coefficient and stiffness coefficient,which affect the impedance control effect,are analyzed in conjunction with the simulation model.The impedance parameters are optimized by using a white crowned chicken optimization algorithm for the problem of impedance parameter finding.The impedance control system of the robot arm is built in MATLAB/Simulink to verify the effectiveness of the algorithm in impedance parameter optimization.Finally,an experimental platform based on the Aubo_i5 robotic arm is built,and the robotic arm trajectory optimization experiment and the soft dragging experiment are carried out.The trajectory optimization experiment verifies the effectiveness of the improved white shark optimization algorithm for the temporal optimization of the robot arm joint space;the soft dragging experiment verifies the effectiveness of the white crown chicken optimization algorithm for the impedance parameter finding of the position-based impedance control.