Mobile robot motion control in partially unknown environments using a sliding-mode fuzzy-logic controller

• Published in: Robotics and autonomous systems 2000-10, Vol.33 (1), p.1-11
• Main Authors: Rigatos, G.G., Tzafestas, C.S., Tzafestas, S.G.
• Format: Article
• Language: English
• Subjects: Fuzzy rule base; Fuzzy-logic controller; Hybrid intelligent control; Motion planning; Sliding surface; Sliding-mode controller; Variable structure systems
• ISSN: 0921-8890; 1872-793X
• DOI: 10.1016/S0921-8890(00)00094-4

This paper studies the problem of motion and control law design for a mobile robot that moves inside a partially unknown environment with stationary obstacles and moving objects, under the assumption of parametric uncertainty in the model that describes the motion of the robot. A new variable structure system, that combines the basic principles of sliding-mode control with fuzzy logic, is presented which allows the robot to execute the desired motion. The proposed controller, named reduced complexity sliding-mode fuzzy-logic controller (RC-SMFLC), is characterised by its robustness and simplicity. The controller implements via fuzzy reasoning the following two rules: “IF sgn(e(t) e ̇ (t))< 0 THEN do not change the control action” and “IF sgn(e(t) e ̇ (t ))>0 THEN change the control action”, where control action can be either an increase or a decrease of the control signal. The stability of the method is verified and illustrative numerical simulation examples are included.