Helicopter flight control with fuzzy logic and genetic algorithms

Researchers at the U.S. Bureau of Mines, in conjunction with researchers at the University of Alabama and the U.S. Army, have developed a fuzzy system for controlling the flight of UH-I helicopters through various maneuvers. Since flying a helicopter is an extremely difficult task, the fuzzy logic controller was necessarily quite complex. In fact, the control tasks were distributed over four individual control units, each of which had its own rules and associated membership functions. Because the fuzzy logic controller was large, and because the rules implemented in the individual control units were not necessarily those a human pilot would use, an efficient technique for writing the rules was required. A genetic algorithm was used to discover rules that provided for effective control of the helicopter. Genetic algorithms are search algorithms based on the mechanics of natural generics, and have demonstrated the ability to locate rules for fuzzy logic controllers. This paper describes the architecture of the helicopter fuzzy logic controller, provides the details of the genetic algorithm application, and presents the results of an actual flight test using the computer software. Copyright (C) 1996 Elsevier Science Ltd