Active Sling Load Stabilization

A control strategy for stabilization of single-point sling loads and hoists is proposed. Nonlinear oscillations of an elastically suspended mass are described by a suitable nonlinear dynamic model that incorporates delayed position feedback for active stabilization of both sling loads and hoist. Helicopter maneuvers are described by assigned trajectories of the mass suspension point to model oscillations of the payload. For the sling load case, stability analysis is performed to estimate optimal control gains. For the hoist case, a genetic algorithm is adopted to estimate optimal control parameters. The controlled system is simulated via time integration of the nonlinear equations of motion