Self-organizing fuzzy control for motor-toggle servomechanism via sliding-mode technique

The dynamic response of a self-organizing fuzzy sliding-mode-controlled toggle mechanism, which is driven by a permanent magnet synchronous servo motor, is studied in this paper. First, based on the principle of fuzzy control, a self-organizing fuzzy control (SOFC) system is developed to control the position of a slider of the motor-toggle servomechanism. Moreover, to reduce the control rules in the design of the SOFC system and to strengthen the robust characteristics, a self-organizing fuzzy sliding-mode control (SOFSMC) is proposed to control the motor-toggle servomechanism. The proposed SOFC and SOFSMC systems contain two sets of fuzzy inference logic: one is the fuzzy controller and the other is the rule modifier. A new fuzzy learning method of the rule modifier is developed, where the modification value of each rule is based,on the fuzzy firing weight. The proposed SOFC and SOFSMC systems can automatically tune the rules bases to achieve satisfactory performance, so that they can be applied for on-line learning, real-time control. In addition, simulated and experimental results due to periodic step and sinusoidal commands show the dynamic behaviors of the proposed SOFC and SOFSMC systems are robust with regard to parameter variations and external disturbances. Comparison between SOFC and SOFSMC also shows that the SOFSMC can reduce implementation complex while defining the sliding surface. (C) 2002 Elsevier Science B.V. All rights reserved.