Motion control of mechanical systems with a cable subjected to contact forces

Abstract

The usage of unmanned aerial vehicles (UAVs) varies from construction inspection to disaster response. Cable attachment benefits the UAV with longer operation time and larger data transmission, while the tension, inertia, and contact forces of the cable work to disturb its operation. This paper introduces a numerical modelling method of a cable with frictional contact forces using an absolute nodal coordinate formulation (ANCF), and extracts and evaluates the influences of the cable on the mechanical system’s motion. The contacting cable length, that affects frictional contact forces, is derived using the catenary curve. The numerical analysis results present errors and vibrations at the connection point of the cable and the rigid body. These are the influences when the cable contacts the ground. In this paper, the compensation system, and its validity for mitigating these influences, using an unscented Kalman filter (UKF) to estimate the state of the cable, are presented. Although there was a small error in the mechanical system’s final position in relation to the target position, the numerical analysis indicated that the proposed control system stabilizes the mechanical system’s motion.