Synchronized altitude tracking control of multiple unmanned helicopters

In this paper, we consider the synchronized altitude tracking control for multiple helicopters, when the desired trajectory is only available to the leaders. By using the weighted average of the neighbors´ states as the reference signal, the adaptive neural network (NN) tracking control is designed for each helicopter. It is shown that, the output tracking error of each helicopter converges to an adjustable neighborhood of origin under the proposed NN control, although some of them do not access the desired tracking trajectory directly. Simulation results are provided to demonstrate the effectiveness of the approach presented.