关键词:
Bang-bang
Fuzzy logic control
Sliding mode controller
Optimal control
Pneumatic rotary actuator
Real-time control
摘要:
In this paper, we propose a new fuzzy bang-bang relay controller (FBBRC). The bang-bang control systems use switching relays or hard limiter saturation functions with fixed parameters, and their input does not have the flexibility to control the non-linear system over its entire range of operation. The conventional fuzzy bang-bang controllers have an analog output and an external hard limiting device to convert the output to bang-bang action. The new integrated FBBRC proposed here directly output two-level state. The inputs to the FBBRC are configured on standard fuzzy sets on the basis Mamdani implications. The largest of maxima defuzzification method is used for two-level state output. The stability and optimality of the FBBRC can be established with the Lyapunov stability criterion and Pontrygin minimum principle, respectively. Non-linear bang-bang control action is inherently time-optimal and endows this property to the FBBRC. Because of its design simplicity and cost-effectiveness, the bang-bang control is desired for control applications such as spacecraft-satellite attitude, heating controls, and on/off valve controls. Comparison between the proposed FBBRC and the fuzzy bang-bang controller (FBBC) show that FBBRC gives a better response. Finally, we demonstrate a practical application of FBBRC by controlling the angular position of a single-axis pneumatic rotary actuator in real-time, using the Matlab-Simulink xPC target environment. (C) 2009 Elsevier Ltd. All rights reserved.