Modelling and computation of optimal task assignment for cooperative control

In this paper, task assignment for cooperative control of multiple UAV´s is studied. A model of linear programming is developed for multiple-tour assignment, both terminal and non-terminal tasks are included in the set of tasks. Although the problem is NP-hard, simulations show the possibility of real time computation for problems with small number of tasks. Examples of eleven tasks, including three terminal tasks, with four UAV´s are shown. Matlab based software program is developed to numerically compute the optimal task assignment. Using a relatively slow PC, the computation takes about four seconds only. In addition to the linear programming model, a result on task assignment using partial information is proved. The result implies that the size of the linear programming is determined by the number of tasks, independent of the number of UAV´s. For multiple-tour assignment with timing constraint but no terminal tasks, a scheduling process is added into the linear programming model so that tasks are serviced following a given sequence of time.