Closed Loop System Identification of a Torsion System
A model is developed for the Quanser torsion system available at Control Systems
Research Laboratory at Chulalongkorn University. The torsion system is a laboratory
equipment that is designed for the study of position control. It consists of a
DC motor that drives three inertial loads that are coupled in series with the motor,
and where all components are coupled to each other through torsional springs.
Several nonlinearities are observed and the most significant one is an offset in
the input signal, which is compensated for. Experiments are carried out under
feedback as the system is marginally stable. Different input signals are tested
and used for system identification. Linear black-box state-space models are then
identified using PEM, N4SID and a subspace method made for closed-loop identification,
where the last two are the most successful ones. PEM is used in a second
step and successfully enhances the parameter estimates from the other algorithms.
Senast uppdaterad: 2013-06-17