Design And Experiment Research On Measurement And Control System Of Snake-like Robot Arm

The kinematics of the serpentine robot arm have super redundant degrees of freedom when compared to traditional rigid manipulators,making it easier to transport operating tools into narrow and obstructed semi enclosed spaces to complete tasks.It has a wide range of applications,including aviation engines,non-disassembly endoscopic examination and maintenance of aerospace complicated structural components,and so on.A serpentine robot arm with 22 degrees of freedom in kinematics is examined in this paper in terms of kinematics modeling and control,closed-loop control algorithms,and motion control system software and hardware design.Endoscopic motion control and environment interaction functions of the serpentine robot arm are applied in complex structural environments.First,the overall structure of the robot is briefly presented based on the application scenarios and fundamental characteristics of the snake-shaped robot arm.A kinematic model of the mechanism was created based on the structural characteristics of the serpentine arm,and the mapping relationships between the serpentine arm’s drive space,joint space,and task space were analyzed and simulated.The serpentine arm’s homogeneous transformation matrix is provided,and the forward kinematics solution from joint space to task space and the inverse kinematics solution from joint space to drive space are investigated.The serpentine arm path planning problem is studied using B-spline interpolation and end following algorithms,setting the groundwork for realizing the serpentine arm to complete the endoscopic operation task in a complex and narrow space.Secondly,in order to improve the safety of system operation,the adaptive impedance control problem of serpentine robot arm is studied.In order to improve the interaction ability between the serpentine arm and the environment,a servo stiffness control method for the serpentine arm was designed.Based on the dynamic modeling and controlled model establishment of a single actuator in a parallel mechanism joint,a new adaptive impedance control law design method is proposed.By constructing integral functions related to the system state and estimated parameters,an update law of estimated parameters and a closed-loop system control law are established,which reduce the negative impact of model uncertainty on control performance.In the redundant drive parallel mechanism,adaptive impedance control is used for each driver.Coordinated and stable control within the drive space of the parallel mechanism may be achieved by leveraging the characteristics of bounded stability of the force position signals of each driver under adaptive mechanism and impedance control.The implementation technique of the designed adaptive impedance control law was detailed,and simulation was used to validate the algorithm’s stability,closed-loop control effect,and the influence of different parameters on controller performance.The adaptive impedance coordination control algorithm may increase the snake arm’s force position coordination control ability and dynamic response characteristics,as well as its motion flexibility and interaction operation safety.Experiments were used to confirm the engineering viability of the adaptive impedance controller.During the paper’s study process,a complete snake-shaped robot arm measurement and control system was conceived and built.The measurement and control system employs a control mode that combines a PC and a motion control card,primarily consisting of a communication module,servo drive module,and sensing module,to achieve information monitoring,motion control,and human-machine separation operation mode of the snake-shaped robot arm.The software includes the overall architecture and functional composition,control process design,closed-loop control algorithm implementation,system status monitoring and recovery,as well as humancomputer interaction interface design for the upper computer,providing a good platform for completing the desired operational tasks.To improve the stability of the control algorithm,a Kalman filter is designed to filter the rope tension in real time;To solve the problem of solving nonlinear equations,a joint angle observer based on extended Kalman filter is designed and validated.Experiments on the simulation motion control,trajectory tracking accuracy,and adaptive impedance control of the serpentine arm were performed to verify the correctness of the modeling,feasibility of algorithm design,and rationality of the measurement and control system construction plan.Experiments of single joint and multi-joint cooperative motion control,open space and narrow semi closed space endoscopic detection simulation control,and so on are used to validate the validity of kinematics modeling and the stability of the measurement and control system.Experiments on trajectory tracking accuracy were used to validate the snake-shaped robot arm’s actual operating performance.Adaptive impedance control experiments were used to validate the control algorithm’s technical viability,and the influence of controller design parameters on the motion performance of the controlled system was investigated.The serpentine arm’s safety control performance in challenging situations has been verified.Finally,the report discusses future research and experimental work that can be conducted.