Non-Iterative nonlinear model predictive approach applied to the control of helicopters’ group formation

Abstract

Two geometrical formation schemes that allow the definition of any desired three-dimensional formation mesh for a group of helicopters are presented. Each formation scheme, which defines the leader–follower geometry of the formation mesh, has four parameters. These formation parameters are directly used as the output of decentralized controllers that independently control each helicopter in the group. The decentralized controllers are designed using a non-iterative Nonlinear Model Predictive Control (NMPC) method. The Continuation method is used for solving, in real-time, for future control actions that minimize a NMPC cost function. It is shown by analyzing the number of floating point operations per calculation cycle that the calculation load of the NMPC method for this application is quite manageable for today’s industrial embedded computers. Simulations show that the formation schemes along with the NMPC controller can initialize and keep the formation of a group of helicopters even in the presence of bounded parameter uncertainty and environmental disturbance.