The recently developed methods of explicit (multi-parametric) model predictive control (e-MPC) for hybrid systems provide an interesting opportunity for solving a class of nonlinear control problems. With this approach, the nonlinear process is approximated by a piecewise affine (PWA) hybrid model containing a set of local linear dynamics. Compared to linear-model-based MPC, a performance improvement is expected with the reduction of the plant-to-model mismatch; however at a cost of controller computation complexity. In order to reduce the computational load, so that desired horizon lengths may be used, we present an efficient sub-optimal solution. The feasibility of the approach for the application was evaluated in an experimental case study, where an output feedback, offset-free-tracking hybrid e-MPC controller was considered as a replacement for a PID-controller-based scheme for the control of the pressure in a wire-annealing machine.
COBISS.SI-ID: 23705895
The paper addresses the problem of numerical issues and degeneracies in the parametric quadratic programming (pQP) algorithm, used for computing partitions of explicit model predictive controllers (eMPC) with the Multi-Parametric Toolbox (MPT). We summarise the pQP problem setup and the basic algorithm, analyse its implementation in MPT, expose the numerical issues and suggest a series of improvements for more reliable operation, which are relevant also for other pQP solvers.
COBISS.SI-ID: 25004839