| With the continuous progress of One Belt and One Road,the total length of tunnels in China had exceeded 28,000 km,and the number of tunnels was about 29000 in 2016.With the emergence of more and more tunnels,a great of pressure and challenge had come to tunnel safety detection.In order to enrich the tunnel detection mode and reduce the labor intensity and danger of manual inspection,a new type of double-wheel-foot composite wall-climbing robot is proposed for tunnel detection.The designed climbing robot has a variety of motion modes,which not only has the ability of fast movement on the wall,but also has the ability of crossing surfaces and crossing over the barrier on the wall,so it can deal with the complicated wall environment of the tunnel.A multi-stage sealing device is designed so that the robot can be adsorbed on the rough tunnel wall.For special wall environment,the structure design of the wall climbing robot are carried out according to the design requirements.The motion analysis of the wall climbing robot,the forward / reverse kinematics analysis and the dynamic analysis on the process of crossing over the barrier on the wall are carried out.The stability criterion of wall climbing robot on the process of crossing over the barrier on the wall is established.The process of the wall-climbing robot crossing over the barrier on the wall is simulated and analyzed.The prototype is manufactured,and the prototype verification test is carried out to verify the rationality of the structure and the reliability of the motion of the designed wall-climbing robot.The specific contents of the study are as follows:1.A new type of wall climbing robot with double wheeled foot composite mechanism was designed for the special wall environment of tunnel.The special design requirements of the tunnel wall climbing robot are analyzed.The structure of each device is designed according to the demand.The 3D model of the virtual prototype is built by SOLIDWORKS and the degree of freedom of the mechanism is analyzed.2.The motion analysis of the designed wall climbing robot is carried out.The motion gait of the robot under each motion mode and the movement track of the obstacle-crossing process of the robot are described.The designed double-wheel-foot composite series mechanism is simplified based on the D-H method,and the forward kinematics is solved to obtain the position and pose equation of the end sucker,and then the inverse kinematics is solved by the analytic method.The expression of rotation angle of each joint is derived and the mapping relationship between the rotation of joints and the position of the suction disk at the end of the climbing robot is clarified.3.The dynamic analysis of wall climbing robot is carried out,the dynamic equations are established based on the Keyne method,and the stability criterion of wall climbing robot is established based on the equilibrium condition of spatial force system.ADAMS dynamic simulation and MATLAB numerical simulation are used to verify the correctness of the theoretical derivation and the stability of the climbing robot under the obstacle-crossing process.According to the simulation results,the relationship between the parameters of the climbing robot and the stability of the climbing robot is analyzed.4.According to the design of virtual prototype,the general parts of wall climbing robot are selected,and the size parameters of the structural parts are adjusted and optimized according to the result of selection.The adjusted parts are manufactured by 3-D printing,and then assemble the wall-climbing robot prototype.The ability of adsorption,load and obstacle-crossing of the climbing robot are verified through the prototype test.The experimental results show that the new wall-climbing robot with double-wheeled foot composite mechanism designed based on tunnel detection has reasonable structure,perfect function and outstanding advantages. |
