A hierarchical fuzzy controller using line-curvature feature extraction for a single link flexible arm

A two-level hierarchical fuzzy controller is developed for a single flexible link. The second level of hierarchy monitors the behavior of the robot arm and extracts features such as straight, oscillatory, gently curved. This is accomplished using a fuzzy feature extraction technique which incorporates line-curvature data computed over a finite number of discrete points along the length of the robot arm. The line-curvature data are computed from measurements of a finite number of strain sensors. The fuzzy features such as straight, oscillatory, gently curved, the angular position measurements of the tip of the robot arm, and the torque of the motor constitute a basis of information for the first level of the hierarchical fuzzy controller