Research On Climbing Gait Of Snake Robot For Truss Structure

In recent years,China has focused on the development of infrastructure based on the real economy,and the truss structure has been used as the skeleton structure of various types of large-scale equipment and buildings(such as large stadiums,bridges,and heavy-load equipment),so that its reliability has become particularly important.Most truss structures are exposed to harsh environments for a long time.With repeated changes in the surrounding climate and possible rigid collisions,failures such as corrosion,deformation,joint loosening,etc.may occur in the truss structure.The current maintenance of truss structures is mainly manual.In addition to taking into account the dangers of working conditions,the manual inspection process must also consider the human error caused by long-term work fatigue.This method not only consumes a lot of human resources,but also it is difficult to guarantee the accuracy of maintenance.In order to realize the safe,long-distance and high-reliability maintenance work of complex truss structures,snake robots with the advantage of high flexibility and operability are used instead of manual inspection.The research in this paper focuses on the following three directions:1)The structure and mechanical properties of a snake robot suitable for climbing were studied.In combination with the climbing environment of complex truss structure,a new PR joint was proposed.Through the differential module,the design of joints with two degrees of freedom was achieved and flexibility requirements were met.The static analysis of the winding process and the stretching process of the snake robot was performed,and the key performance parameters of the robot's winding posture were obtained,which provides guidance for the structural design of the snake robot.2)The method of generating the climbing gait of snake robot was studied,and the performance of the generated gait is analyzed.A gait climbing method was proposed through the transformation from plane climbing to cylindrical climbing,and two kinds of accordion climbing gaits were obtained in combination with the climbing of the biological snake,and two kinds of accordion climbing gaits were obtained in combination with the climbing of the biological snake.Through the analysis of the key steps and the extraction of key parameters in the exercise process,the simulation analysis of the four typical climbing gaits,including the two existing rolling gaits,was performed mainly for the climbing speed,and the respective advantages of each gait when climbing different diameter rods were determined.In addition,the respective advantages of each gait when climbing different diameter rods are determined,and the applicable environment for each gait is summarized,which provides a basis for the climbing robots in complex truss structures.3)The method of generating the obstacle avoidance gait of snake robot was studied.The problem of generating the obstacle avoidance movement gait of snake robot on the truss is transformed into the motion planning problem of the redundant manipulator with using RRT algorithm as a planning tool.According to the characteristics of obstacle avoidance movement of snake robot,the convergence method,physical constraints and cost function of the planning algorithm are redefined,which accelerates the planning speed of the algorithm and reduces the torque demand during the movement.Finally,the results of planning algorithm were verified by simulation.