Flight Dynamics and Control of an Unmanned Helicopter with Underslung Double Pendulum

Abstract

This paper presents systematic modeling and simulation of the dynamics and control of a carrier helicopter unmanned aerial vehicle (UAV) with a suspended net used for capturing target UAVs. The goal is to study the effect of key design parameters such as the weight of the net end rod, its length, and point of impact of the UAV on the swing angle of the underslung net. First, a net with an entangled target UAV is modeled as a planar double pendulum. Next, the coupled flight dynamic model of carrier UAV with underslung net with entangled target UAV is simulated and validated using the test data gathered for this purpose. From the simulations, it is identified that the length of the net and point of capture of the UAV on the net are critical parameters that govern the maximum swing angles of the double-pendulum system. Moving the point of impact of the target UAV by 10% of net length resulted in up to 23 and 43% reduction in swing angles of pendulums 1 and 2. The active swing suppression using proportional derivative (PD) controller is effective in attenuating the swing angles in the simulation for successful capture.