Simulation of the dynamic retrieval process of a towed target system under towing airplane’s wake and atmospheric turbulence

Abstract

This paper studies the dynamic retrieval process of a towed target system under perturbation by simulating the reel-in operation under the towing airplane’s wake and atmospheric turbulence. To settle the computational problem of cable tension, the constant-length method is proposed to transform this variable-mass problem into a constant-length problem based on a mass-spring model that discretizes the cable. A three-dimensional atmospheric turbulence field is built using a recursive function to model the complex perturbation field along the cable. A horseshoe vortex model is adopted to simulate the towing airplane’s wake. Simulation analysis shows that both the reel-in speed and turbulence significantly affect the retrieval deviation, whereas the airplane’s wake has little influence. The reel-in speed should be chosen in concert with the turbulence intensity to achieve a high retrieval success rate. Moreover, a higher reel-in speed is preferred to maintain cable strain and smoothen the process when the retrieval tolerance is satisfied.

Design and Optimization of UAV Aerial Recovery System Based on Cable-Driven Parallel Robot

“…Additionally, in the study of airborne flexible towing systems, some researchers have modeled the towing cables as continuum models [42][43][44][45], typically analyzing the cable elements to construct partial differential dynamic equations. Other studies have established cable models as concentrated mass models, subdivided into concentrated mass rigid body models [46][47][48][49] and concentrated mass elastic body models [50][51][52]. These models reflect the real motion of the cables, but the equations are complex and difficult to solve for multi-cable CDPRs.…”