Abstract
In this paper, a new anti-swing controller for helicopter slung load system near hover flight is proposed. This controller is based on time-delayed feedback of the load swing angles. The output from this controller is additional displacement that was added to the helicopter trajectory in the longitudinal and lateral directions. Hence, its implementation is simple and it only needs a small modification to the software of helicopter position controller. The parameters of the controllers are determined using the method of particle swarms by minimizing an index, which is a function of the load swing history. The simulation results show the effectiveness of the proposed controller in suppressing the swing of the suspended load and the stabilization of the helicopter .