Frequency-shaped sliding mode control using output feedback and application to follow-up control of process system

摘要

This paper proposes a design method of frequency shaped Sliding Mode Control System using output feedback and application to follow-up control of a fluid temperature and liquid level interacting plant to a time dependent reference input. This method is characterized as that the Moore-Penrose's inverse matrix is used to deduce the equivalent control input because the numbers of inputs and outputs are not equal in general, then the order of the reduced system is equal to the number of outputs, and the chattering can be suppressed by introducing the switching hyperplane with dynamics. First, switching hyperplane is introduced as that it includes an integral element for the controlled deviation to remove the steady-state error, and a switching condition of the reachability to the switching surface is deduced using the eventual sliding mode. Next, a linear operator with dynamics is introduced to the switching hyperplane, and a frequency dependent weight matrix is introduced as that controlled deviation can be suppressed for certain frequencies. The switching hyperplane has frequency characteristics, so that the chatter motion is decreased. Finally, the frequency-shaped sliding mode system is applied to follow-up control of 2inputs-3outputs carriages, and a fluid temperature and liquid level interacting plant to confirm the effectiveness.