1. A control system for controlling the operation of a machine or process, comprising: a plurality of actuators that receive a set of output control signals in order to control the operation of the machine or process; a plurality of sensors that produce input sensor signals indicative of the operation of the machine or process; a processor programmed to produce the control signals from the sensor signals by: creating an input vector of difference signals by subtracting a number of input sensor signals from a number of output signals created by a fixed model of the machine or process; storing a sequence of prior input vectors; reducing the number of input signals produced by the plurality of sensors based on a singular value decomposition of the fixed model of the machine or process and on a principal component analysis of the stored sequence of prior input vectors; applying the reduced number of input signals to a reduced order controller, that is a function of the principal component analysis to calculate a reduced number of output control signals; and increasing the number of output control signals based on the principal component analysis of the stored sequence of prior input vectors and the singular value decomposition in order to create the set of output control signal supplied to the actuators.