管道外壁机器人全向行走机构设计与仿真

Design and Simulation of Omni-Directional Walking Mechanism for Pipe Outer Wall Robot

针对石油输送管道焊接作业需求,提出一种用于管道外壁行走的新型轮式机器人行走机构,并能实现管道过弯。设计了采用水平布置的全向轮和预紧弹簧组成的悬挂机构,过弯时在弹簧力的作用下能够适应弯道轮廓。将水平面内的全向轮过弯运动等效为平面两轮小车转弯模型,分析了机器人在过弯时倾覆力矩产生的原因。在Solidworks中建立三维虚拟样机模型,利用ADAMS动力学软件对机器人过弯运动进行仿真,分析了行走机构中弹簧的刚度对机器人过弯稳定性的影响以及不同管道表面条件下机器人行走稳定性。结果表明,弹簧刚度在(800~1400)N/m范围内取值,机器人能稳定过弯;在管道表面干燥以及附着有雨水时湿滑的条件下,即全向轮辊子与管道外壁的摩擦因数大于0.1时,机器人能展现出良好的行走性能。该研究结果可为后续机器人结构优化设计提供依据。

Aiming at the welding operation requirements of petroleum transportation pipelines,a new wheeled robot walking mechanism for walking on the outer wall of the pipeline is proposed,which can realize the pipeline bending.A suspension mechanism composed of horizontally arranged omnidirectional wheels and pre-tensioned springs is designed,which can adapt to the curve contour under the action of spring force when cornering.The turning motion of the omnidirectional wheel in the horizontal plane is equivalent to the turning model of a flat two-wheeled trolley,and the reason for the overturning moment of the robot when turning is analyzed.A three-dimensional virtual prototype model was established in Solidworks,and the ADAMS dynamics software was used to simulate the turning movement of the robot.The influence of the stiffness of the spring in the walking mechanism on the turning stability of the robot and the walking stability of the robot under different pipe surface conditions were analyzed.The results show that if the spring stiffness is within the range of(800~1400)N/m,the robot can make stable corners;when the pipe surface is dry and wet and slippery with rain,it is the friction factor between the omnidirectional wheel roller and the outer wall of the pipe.When it is greater than 0.1,the robot can show good walking performance.The research results can provide a basis for the subsequent optimization design of the robot structure.