A hybrid control allocation strategy for aircraft with multiple effectors

A hybrid strategy for control allocation of aircraft with multiple effectors is described in this paper. Pseudo inverse method for solution of the control allocation problem is able to find a feasible solution only on a subset of the feasible region. Some other methods, like direct control allocation is able to find the feasible solution on the entire feasible region but have heavy computation burden. A novel, hybrid approach for control allocation, proposed in this paper, is based on integration of the pseudo inverse and the sequential least squares method. It is implemented as a two-step process: The pseudo inverse solution is found in the first step; then the feasibility of the solution is examined analyzing its individual components. If violation of actuator constraint is detected, the sequential least squares method is activated in the second step. In this way, the hybrid approach is able to allocate the exact solution, optimal in the l₂ sense, inside the entire feasible region. This solution minimizes a control energy cost function, the most suitable criteria for aircraft with multiple effectors applications.