Computation and approximation of piecewise affine control laws via binary search trees

Abstract
We present an algorithm for generating a binary search tree that allows efficient computation of piecewise affine (PWA) functions defined on a polyhedral partition. This is useful for PWA control approaches, such as explicit model predictive control (MPC), as it allows the controller to be implemented on-line with small computational effort. The computation time is logarithmic in the number of regions in the PWA partition. A method for generating an approximate PWA function based on a binary search tree is also presented, giving further simplification of PWA control.