Rigid–flexible coupling dynamics with contact estimator for robot/PTL system

Abstract

In order to enhance sampling efficiency and security when robot maintains power transmission line (PTL), this article develops a new approach for the rigid-flexible coupling dynamics of robot/PTL system, which decouples the large system into two small systems and solves them separately by estimating the contact force. The robot is modelled as a system of rigid bodies by screw theory, while the PTL system is modelled using absolute node coordinate formulation (ANCF). The integration of screw theory, ANCF and contact estimator trained by artificial neural network has not been accomplished before in the literature. The main contribution of this paper is to achieve this integration with the goal of developing a new and general approach for the nonlinear dynamic analysis of the interaction of the rigid maintenance robot with flexible PTL cable. A simplified two-dimensional example is used to compute the effect of the robot/PTL interaction under different operating conditions to have an understanding of the coupling approach between the two systems. A more detailed three-dimensional model was developed, and the results obtained validate the utility and effectiveness of our approach.

Robust stabilization control of live working robot under wind load based on angular momentum conservation principle

“…Similarly, according to equation ( 13), the rotation angle u 2 of the momentum wheel under the generalized coordinates of the robot body can be obtained as shown in equation (14).…”

“…Few methods of robust stabilization control [10][11][12][13] for the robot under wind load have been mentioned, especially the precisely wind load action and protection of the robot in the complex field environment which is the key to the robot practical technology. 14,15 Based on the above, a momentum wheel balance method based on the conservation of angular momentum has been proposed, so that the live operation robot side tilt effect caused by wind load on the high altitude transmission line can be eliminated so as to achieve a stable posture and spread out the operation. Firstly, the principle of conservation of angular momentum is described, the mechanical structure and installation position of momentum wheel has been designed according to this theory.…”

Kinodynamic planning with reachability prediction for PTL maintenance robot

“…One of the prominent issues for the establishment of the simulation platform is the dynamic characteristics of rigid–flexible coupling for robot/PTL system (Figure 1), which considers the robot as a system of rigid bodies and the PTL as an assembly of finite elements. The rigid–flexible coupling model and solver introduced in the previous work 15 are thus applied, which can well reflect the actual states of the robotic bodies in close contact with PTL and is the key to the RST planner for responding quickly to the rigid–flexible coupling environment. For the robot/PTL system, it generates hundreds of dynamical states per second on the multi central processing unit (CPU)–graphics processing unit (GPU) workstation accelerated by parallel technique and runs at 20 Hz on the ground station (GS) or personal computer (PC) used in this article.…”

Hierarchical Reinforcement Learning Considering Stochastic Wind Disturbance for Power Line Maintenance Robot

“…Based on the previous research work [25,28] and Equation ( 6), the fluid-rigid-flexible coupling dynamical equation of the robot/PTL system under wind load can be obtained:…”