Optimizing stability bounds of finite-precision PID controllers using adaptive simulated annealing

Based on a lower bound stability measure for sampled-data controller structures subject to finite-word-length (FWL) constraints, the optimal realization of the digital PID controller with FWL considerations is formulated as a nonlinear optimization problem. An efficient strategy based on adaptive simulated annealing is adopted to solve this complex optimization problem. A numerical example of optimizing the finite-precision PID controller for a steel rolling mill system is used to demonstrate the effectiveness of the proposed method.