OPTOELECTRONIC IMPLEMENTATION OF REAL-TIME CONTROL OF AN INVERTED PENDULUM BY FUZZY-LOGIC-CONTROL UNITS BASED ON A LIGHT-EMITTING-DIODE ARRAY AND A POSITION-SENSING DEVICE

We have realized a novel optoelectronic implementation of an analog fu zzy-inference architecture, using the movement of the center of gravit y of a far-field pattern. In the inference process Gaussian-like membe rship functions and a product-sum-gravity method are used. Antecedent membership functions and the grade evaluations are realized by combini ng light-emitting-diode (LED) arrays for sequential light emission and position-sensing devices for center-of-gravity detection. Consequent and defuzzification operations are realized by a LED array and a posit ion-sensing device. High-speed fuzzy inference of more than several te ns of mega fuzzy logical inference per second is possible with these u nits. The usefulness of the system is demonstrated by the real-time st anding control of an inverted pendulum. (C) 1997 Optical Society of Am erica