Flight Control Design using Polynomial Eigenstructure Assignment

This paper examines the use of polynomial eigenstructure assignment for the design of output feedback control. An algorithm which provides solutions to the general polynomial eigenproblem is formulated. The unique feature of this algorithm is that, unlike many eigenstructure assignment techniques, parameterisation of the eigenproblem is not restricted by an a priori choice of closed-loop eigenvalues. Instead, all free parameters made available by a given system triple (A,B,C) are retained until a final solution is selected according to some desired performance criterion/criteria. If more than one performance objective is to be satisfied, the algorithm allows each objective to be satisfied in a systematic manner. Metrics to assess input/output decoupling, gain matrix norm minimisation and time response are presented. The algorithm is applied to a flight control example to demonstrate the use of these metrics in locating a closed loop solution which meets a multi-objective design criterion.