Load Vibration Mitigation in Unmanned Aerial Vehicles With Cable Suspended Load

Abstract

This paper addresses the problem of pointtopoint path planning of a 3D model of a quadcopter carrying a suspended load by parameterizing its differentially flat outputs. The flat outputs are the Cartesian coordinates of the suspended load and the yaw angle of the quadcopter. The time integral of the absolute angular rate of the suspended load is minimized to synthesize a trajectory which minimizes the pendular oscillations of the suspended load while the quadcopter transition from one point of rest to another. An established feedback controller and an input shaped profile for the closed loop system dynamics using position as reference and also velocity as reference are also developed to compare the performance of the proposed controller. Experimental results validate results obtained via simulation showing that the differential flat solution outperforms the pure feedback and the feedback system with input shaping prefilters.