This paper studies, from a control engineering perspective, some problems in fuzzy logic control: the equivalence between fuzzy controllers and conventional ones, fuzzy controllers for high order processes, fuzzy supervisory control, and the stability of fuzzy logic control loops. The paper also summarizes applications in two closely related fields: automotive systems and mobile robots. In the first case applications to chassis control (active suspension) and engine control (idle speed regulation, antiknock) are reported . The second deals with automatic steering of wheeled mobile robots, and two different fuzzy logic strategies to solve the problem (direct fuzzy control and fuzzy auto-tuning of conventional path trackers) are presented.