Genetic design of robust PID plus feedforward controllers

Evolutionary techniques are proposed in a new and novel paradigm to solve the problem of designing a robust fixed PID plus feedforward controller for a plant with prescribed plant parameter uncertainties. The evolutionary scheme used involves generating two separate populations, one representing the controller and the other the plant. The controller population is then evolved against a fixed population of plants representing the uncertainty space, such that the controller can control all these plants effectively. A cost function involving time-domain performance is then deployed, subject to a frequency domain stability constraint. The resulting paradigm results in a robust controller design with excellent time domain performance. This evolutionary approach is illustrated by evolving a PID plus feedforward controller for a linear plant which has a set of prescribed uncertainties