Research On Movement And Control Of Snake-Like Manipulators

With the popularization and application of robots,robot application scenarios are being more and more complicated and diversified,which demands quite a few new requirements for the structure and operation modes of robots.Robots should have the adaptability to the industrial operation environments with complex structure and compact layout or non-institutional natural environments,which needs to research and develop more flexible robots to meet such needs.The unique athleticism of a living creature gives the bionic robot the ability to adapt to a variety of complex environments.The snake-like robot which holds advantages like high flexibility,excellent accessibility and stable performance characteristics can be used to accomplish complex and difficult operations such as detection and maintenance in small and confined space of the industry.In this paper,a series of explorations and experimental research on bionic snake-like manipulators are carried out,involving bionics structure research,kinematics modeling and control,control system software and hardware design,prototype development and other aspects.First,the structure and motion characteristics of the biological snake are analyzed,and the general structure and detailed design principle of the snake-like manipulator is discussed.Through the virtual coordinate transformation method and the geometric method,the mathematical relationship between the posterior joint posture,the driving rope variable and the joint angle variable is established,and the positive solution and the inverse solution of the single joint are determined.The multi-joint decoupling method is established based on the analysis of the single-joint motion.Next,the redundant kinematics algorithm for the snake-like manipulator is studied and the improved backbone mode method is analyzed to make it suitable for the structure of the snake-like manipulator.Besides,the different design methods of backbone line in two-dimensional space and three-dimensional space are studied.The kinematics modeling and solving in the two cases are discussed and analyzed.Finally,two kinds of fitting methods of backbone lines and snake-like robots are studied.Then,based on the discussion of the structure and algorithm of the snake-like manipulator,the hardware and software of the manipulator control system are designed and realized according to the two-level hierarchical control strategy.From the bottom to the upper layer of the hardware platform,the selection and debugging of the motor driver,CAN communication structure,sensors,embedded controllers and other parts are completed.One PC and embedded control board use UART communication structure,control board,sensor information acquisition board and the motor controller use CAN communication design.On this basis,the software system design is completed,the complex kinematic solution and underlying driving control are layered,and the system computing load is rationally distributed.Finally,according to the system design of the manipulator,the whole system of the manipulator is processed,installed and debugged.The experiment platform of snake-like manipulator is established.According to the prototype system completed at present,the research on the snake-like manipulator system is carried out.The unilateral joint movement test verified the correctness of the algorithm single joint motion of the manipulator.The control accuracy of the manipulator is improved by the improvement of the angle error control experiment.Multi-joint decoupling experiment verifies the correctness of the multi-joint motion decoupling method.The experiment of space motion proves the flexibility and broad application prospect of the snake-like manipulator.