油罐检测爬壁机器人结构设计与运动分析

Structure design and motion analysis of wall-climbing robots for oil-tank detection

为解决大型化工容器石油储油罐罐体缺陷检测问题,文中设计了一种适应其内部结构且可调节工作间隙的四轮四轴式磁力吸附爬壁机器人,该机器人可在化工容器储油罐罐体上完成前进、后退、越障、90°转向及调节工作间隙等动作,同时也能够实现罐底与罐立壁之间的爬壁转换。通过对机器人静力学与越障性能分析,得出机器人正常工作所需的最小磁吸附力并采用40块(单块尺寸为6 cm×6 cm×2.5 cm)Halbach阵列布局的永磁铁构成磁吸附装置(提供磁吸附力)。使用ANSYS软件对该机器人在不同工作间隙下进行磁吸附力计算,得出合理的磁吸附力范围与工作间隙范围,并以此为依据,在ADAMS软件中完成各动作及跨越焊缝、罐底与罐立壁之间的爬壁转换等仿真试验。仿真结果表明,针对储油罐等大型化工容器的罐体缺陷检测,该四轮四轴式磁力吸附爬壁机器人设计方案可行。

In this article,in order to deal with defect detection of the large-scale chemical vessel of oil-storage tank,a fourwheel-four-axis magnetic-adsorption climbing robot is designed.With adjustable working gap,it can adapt to the storage tank's internal structure.It realizes many tasks on the wall of the chemical vessel of oil-storage tank,such as moving forward and backward,crossing obstacles,90°turning and adjusting the working gap.At the same time,it ensures wall-climbing conversion between the tank bottom and the tank vertical wall.Based on the analysis on robot statics and obstacle-crossing performance,the minimum magnetic-adsorption force for the robot's normal operation is worked out.A total of 40 pieces(the size of single piece of 6 cmx6 cmx2.5 cm)of permanent magnet in the Halbach array layout constitutes the magnetic-adsorption device(a source of the magnetic-adsorption force).The ANSYS software is used to calculate the magnetic-adsorption force of the robot with different working gaps,and the reasonable range of the magnetic-adsorption force and its working gap are identified.Based on this,the simulation experiments such as various actions and weld-crossing as well as wall-climbing conversion between the tank bottom and the tank vertical wall are completed in the ADAMS software.The simulation results show that the design of the four-wheel four-axis magnetic-adsorption wall-climbing robot is feasible for defect detection of the large-scale chemical vessels of oil-storage tank.