Stability enhancement of hybrid PTLIR on flexible transmission lines: Mechanism design, corrected force analysis, and dynamic modeling

Abstract The hybrid Power Transmission Line Inspection Robot (PTLIR) provides the core driving force for establishing a new model of safe, efficient, and sustainable grid operation. One critical challenge in promoting its application is the accurate attitude and slope estimation of the robot in complex natural environments. This paper first investigates the operational conditions of transmission line inspection, and develops a walking device prototype based on the evolution of a single-degree-of-freedom eight-link mechanism. Second, it establishes an analytical model of the robot’s line-walking motion to explore the influence of robot weight on transmission line slope, proposes a corrected force analysis method, and evaluates the maximum climbing capacity of the walking device. Finally, considering the influence of line flexibility characteristics on the hybrid PTLIR, it analyzes the dynamic response of the whole system during the robot’s line-walking motion, and reveals the intrinsic physical mechanism driving vibration in the transmission line system. Comparative results show that the walking device can carry a 30 kg load, and is capable of traversing power line inclines up to 20°. The improved method achieves a slope calculation accuracy of 96.53% at the robot positioning points, with an average improvement of 14.67% along the whole route. In addition, it preliminarily verifies the stable operational performance of the device in practical engineering applications of transmission line inspection. The significance of this study is not limited to improving the robot’s mobility and solving the practical application bottlenecks of such inspection equipment, but also lies in providing systematic engineering insights for the design and analysis of hybrid PTLIRs.