Direct computation of the performance index for an optimally controlled active suspension with preview applied to a half-car model

A quadratic integral performance index is defined for a linear active previ ew-type suspension and a series of matrix expressions derived for its evalu ation by means of MATLAB or some similar computer program in the case of a unit step input to the system. The computation, which is both fast and accu rate compared to simulation, requires the solution of Lyapunov- and Riccati -type equations. Some examples of numerical computation are given and these show excellent agreement with published results. The conclusion features a useful computer program.