Research On Motion Control Of Rope Driven Snake Like Manipulator In Complex Environment

The rope-driven snake-shaped manipulator is a continuous manipulator that imitates a biological snake.Compared with traditional industrial robotic arms,snake-shaped robotic arms can work flexibly in small spaces.At the same time,the separation of the drive and the working arm is conducive to the anti-radiation and underwater sealing design of the robotic arm.In this paper,a snake-shaped robotic arm robot is designed for the use environment of nuclear power plant pools,which can meet both the radiation resistance requirements and the underwater operating environment.At this time,it was the first domestic attempt to apply a rope-driven snake-shaped manipulator to underwater operations in a nuclear environment.Compared with the existing research,the manipulator in this paper pays more attention to the function,reliability and user experience in the actual environment,and at the same time,it has made innovations in the kinematics algorithm.First,this paper designs a rope-driven snake-arm robot with 18+1 degrees of freedom.The snake-shaped mechanical arm has 9 full-drive cross universal joints,each of which has two degrees of freedom.The mechanical arm is driven by 27 ropes and is integrally mounted on a linear guide.Compared with other snake-shaped manipulators studied in China,the manipulator has a smaller diameter and a larger number of degrees of freedom,which can adapt to a narrower working environment and perform more flexible movements.At the same time,this paper combines the characteristics of underwater motion sealing to design a driving structure suitable for underwater work.Finally,the lighting module,camera module,and suction pump module are integrated at the end of the robotic arm,so that the robotic arm can perform video surveillance and small foreign body processing under water.On the basis of the design scheme,the positive kinematics model of the manipulator was established using the traditional DH method,and based on this,the working space of the snake-shaped articulated arm was solved based on the Monte Carlo method.Then,in order to solve the problem of low real-time performance of the inverse kinematics solution of the mechanical arm based on the Jacobian algorithm,the FABRIK algorithm is used for the inverse kinematics solution.At the same time,combining the FTL algorithm and the force touch mechanical pen,a practical solution to the movement of the snake-shaped mechanical arm in a complex environment is proposed with a low computational complexity.Next,the solution process of the FTL algorithm is improved,and the problem that the terminal pose cannot be constrained during the solution process of the FABRIK algorithm and the FTL algorithm is solved.Finally,a motion simulation is performed based on the above algorithm to verify the effect of the algorithm.The traditional snake-shaped mechanical arm control requires manual setting of the target point,which is not convenient,safe and precise.For this reason,this paper introduces binocular positioning technology and hand-eye calibration technology to realize the 3D point cloud reconstruction of the target area,which can not only easily obtain the 3D coordinates of the target point,but also realize data collection and measurement.Finally,this paper writes software based on the Cloud Compare framework to implement the above algorithms and operating procedures,and conducts related experiments to verify the measurement results.Finally,the electronic control system of the serpentine manipulator was designed and built.Then,the upper computer control software was written by WPF framework and the lower computer control software was realized by Twin CAT soft PLC programming.Compared with the existing research,an independent monitoring module is added to the electronic control to enhance the reliability of the equipment.At the same time,to strengthen the human-computer interaction ability in the upper computer software,the 3D animation of the real-time posture of the robotic arm is realized based on Direct X.In order to test the reliability of the algorithm and the basic design,this paper builds a test platform for testing.The test results prove the practicability of the kinematic algorithm and provide ideas for further improvements in machinery.