Date of Award
Master of Science in Electrical Engineering (MSEE)
Electrical, Computer, and Biomedical Engineering
Richard J. Vaccaro
The problem considered is the design of a digital control system for precision tracking control of a fully-coupled non-minimum phase MIMO plant. The first step is to design a 2-degree-of-freedom feedback tracking system using standard pole-placement or linear quadratic regulator techniques. The result is a stable closed-loop system having zero steady-state error to step inputs. In order to obtain precision tracking for other types of inputs, some kind of feedforward control is needed. Two different tracking architectures are considered in this thesis, both feature a feedforward inverse filter to enable precision tracking. The filters are the inverse of a closed-loop system. The derivations of the filters are given; for non-minimum phase systems the result is approximately a decoupled system of delays over a certain bandwidth. Two different possibilities to design the inverse filters are considered: the first one is based on a novel frequency approximation, while the other one relies on the addition of feedback. Several options to design the feedback are discussed. The tracking performances of the resulting precision tracking architectures are demonstrated and evaluated for several non-minimum phase example systems via simulations.
Schurig, Roland G., "APPROXIMATE INVERSION OF MIMO SYSTEMS FOR PRECISION TRACKING" (2020). Open Access Master's Theses. Paper 1871.