Application Of Linear Control Theory Research Articles

Discrete Linear Time Invariant Analysis of Digital Fluid Power Pump Flow Control

A fundamental part of a digital fluid power (DFP) pump is the actively controlled valves, whereby successful application of these pumps entails a need for control methods. The focus of the current paper is on a flow control method for a DFP pump. The method separates the control task concerning timing of the valve activation and the task concerning the overall flow output control. This enables application of linear control theory in the design process of the DFP pump flow controller. The linearization method is presented in a general framework and an application with a DFP pump model exemplifies the use of the method. The implementation of a discrete time linear controller and comparisons between the nonlinear model and the discrete time linear approximation shows the applicability of the control method.

Fuzzy modeling of vibration of a smart CFRP composite beam and control effect by using the model

Vibration control for a smart carbon fiber reinforced plastics (CFRP) composite beam actuated by piezoceramics (PZT) and electro-rheological fluids (ERF) is investigated in this paper. Since the application of linear control theory to the vibration control is very difficult due to the intensive nonlinearity of the ERF actuator, a fuzzy model of the controlled element containing two actuators is constructed. In this study, the time delay of the response of the actuator is also taken into consideration. A controller for vibration suppression of the composite beam is designed based on the fuzzy model for guaranteeing stability of the vibration control system. The effect of the control system is verified by experiment and simulation.

Controller design for vibration of a smart CFRP composite beam based on the fuzzy model

In the present study, vibration control is investigated for a smart carbon fibre reinforced plastics (CFRP) composite beam actuated by piezoceramics (PZT) and electro-rheological fluid (ERF) actuators. A fuzzy model of the controlled element containing two actuators is formed because the application of linear control theory to the vibration control is very different due to the intensive nonlinearity in the ERF actuator. The fuzzy model is identified based on the result of system identification test by using a hybrid neuro-fuzzy system. A controller for guaranteeing bounded input-bounded output (BIBO) stability of the vibration control system of the composite beam is designed by solving linear matrix inequalities (LMI) obtained based on Lyapunov's stability theory. The effect of vibration control system is verified by simulation and experiment.