T. Urbancic et I. Bratko, CONSTRUCTING CONTROL RULES FOR A DYNAMIC SYSTEM - PROBABILISTIC QUALITATIVE MODELS, LOOKAHEAD AND EXAGGERATION, International Journal of Systems Science, 24(6), 1993, pp. 1155-1164
Citations number
19
Categorie Soggetti
System Science","Computer Applications & Cybernetics","Operatione Research & Management Science
Dynamic systems have sometimes to be controlled in circumstances that
are very inconvenient for classical control methods. In such cases, us
e of qualitative controllers seems to be a promising alternative, as t
hey can be designed without having an exact mathematical model. A meth
od for synthesizing control rules is presented, in which a probabilist
ic qualitative model is used together with a decision strategy that ta
kes into account the results of qualitative simulation. As a case stud
y, the problem of the inverted pendulum control is considered. By comb
ining the model simulation lookahead and a decision criterion, an inte
resting phenomenon of 'exaggerated simulation' has emerged. Experiment
al results show that in certain cases, using an exaggerated force in t
he process of simulation considerably improves the performance of gene
rated control rules. The exaggeration helps to detect some trends of t
he system's behaviour that would otherwise have remained hidden. Exper
iments and mathematical analysis show that the improvement due to the
exaggeration is comparable to that achieved by a deeper lookahead in t
he state transition graph.