Abstract：To meet the practical requirements of light weight and fewer driving motors, a novel unit module driven by a single motor and cables is proposed for the multi-link inspection robot for transmission lines, and the switching method of the supporting stands is presented by taking the advantage of the light weight characteristic of the cable driving. Afterwards, the concrete mechanism and the principle prototype of robot unit module are designed and the kinematic model of unit mechanism is established. The unit pitching motion experiment and the supporting stand switching experiment verify that the pitching angles of the unit are consistent with the simulation results, and the switching process of the supporting stands is stable. The experimental results show that the single motor cable driving method can reduce the number of robot driving motors, realize the switching of the supporting stands, and satisfy the requirements of robot crossing obstacles.
 Sawada J, Kusumoto K, Maikawa Y, et al. A mobile robot for inspection of power transmission lines[J]. IEEE Power Engineering Review, 1991, 11(1):57.
 Nicolas P, Pierre-Luc R, Serge M. LineScout technology opens the way to robotic inspection and maintenance of high-voltage power lines[J]. IEEE Power and Energy Technology Systems Journal, 2015, 2(1):1-11.
 Paulo D, Michele G. Expliner-From prototype towards a practical robot for inspection of high-voltage lines[C]//1st International Conference on Applied Robotics for the Power Industry. Piscataway, USA:IEEE, 2010:6pp.
 朱兴龙,周骥平,王洪光,等. 输电线巡检机器人越障机理与试验[J].机械工程学报,2009,45(2):119-125.Zhu X L, Zhou J P, Wang H G, et al. Experiments and mechanism of obstacle negotiation of an inspection robot for transmission lines[J]. Journal of Mechanical Engineering, 2009, 45(2):119-125.
 孙翠莲,赵明扬,王洪光. 风荷载下越障巡检机器人结构参数优化[J].机械工程学报,2010,46(7):16-21.Sun C L, Zhao M Y, Wang H G. Structural parameters optimization of a navigating inspection robot under the wind load[J]. Journal of Mechanical Engineering, 2010, 46(7):16-21.
 Wu G P, Xiao H, Xiao X H, et al. Transmission line inspection robot and deicing robot:Key technologies, prototypes and applications[C]//1st International Conference on Applied Robotics for the Power Industry. Piscataway, USA:IEEE, 2010:6pp.
 房立金,魏永乐,陶广宏. 一种新型带柔索双臂式巡检机器人设计[J].机器人,2013,35(3):319-325.Fang L J, Wei Y L, Tao G H. Design of a novel dual-arm inspection robot with flexible cable[J]. Robot, 2013, 35(3):319-325.
 Wang J D, Sun A Q, Zheng C D, et al. Research on a new crawler type inspection robot for power transmission lines[C]//1st International Conference on Applied Robotics for the Power Industry. Piscataway, USA:IEEE, 2010:5pp.
 Liang Q K, Wang Y N, Zhang D, et al. Multifunctional robotic system for live power transmission lines[J]. International Journal of Robotics and Automation, 2014, 29(2):175-183.
 Yang D W, Feng Z R, Ren X D, et al. A novel power line inspection robot with dual-parallelogram architecture and its vibration suppression control[J]. Advanced Robotics, 2014, 28(12):807-819.
 Aoshima S, Tsujimura T, Yabuta T. A wire mobile robot multi-unit structure[C]//IEEE/RSJ International Conference on Intelligent Robots and Systems. Piscataway, USA:IEEE, 1989:414-421.
 Nakamura H, Shimada T, Kobayashi H. An inspection robot for feeder cables-snake like motion control[C]//International Conference on Industrial Electronics, Control, Instrumentation, and Automation. Piscataway, USA:IEEE, 1992:849-852.
 Perrot Y, Gargiulo L, Houry M, et al. Long-reach articulated robots for inspection and mini-invasive interventions in hazardous environments:Recent robotics research, qualification testing, and tool developments[J]. Journal of Field Robotics, 2012, 29(1):175-185.
 陶广宏,房立金. 三臂式巡检机器人重力平衡及其转向越障方法[J].中国机械工程,2016,27(9):1150-1157.Tao G H, Fang L J. Gravity balance and steering and obstacle-crossing of three-arm inspection robots[J]. China Mechanical Engineering, 2016, 27(9):1150-1157.
 Tao G H, Fang L J. A novel inspection robot moving on high-voltage power transmission line[C]//18th International Conference on Climbing and Walking Robots and the Support Technologies for Mobile Machines. Hangzhou, China:World Scientific Publishing, 2015:275-282.
 Liu X J, Li J, Zhou Y H. Kinematic optimal design of a 2-degree-of freedom 3-parallelogram planar parallel manipulator[J]. Mechanism and Machine Theory, 2015, 87:1-17.
 孙龙飞,房立金.机械手臂结构设计与其性能分析[J].农业机械学报,2017,48(9):402-410.Sun L F, Fang L J. Design and performance analysis of novel robotic arm[J]. Transactions of the Chinese Society for Agricultural Machinery, 2017, 48(9):402-410.