A nonlinear trajectory tracking controller for mobile robots with velocity limitation via fuzzy gains

• A new nonlinear trajectory tracking controller for mobile robots is proposed.
• The proposed controller can also be used to position the robot.
• The proposed controller uses fuzzy rules to determine its gains.
• The fuzzy rules are designed to reduce the errors arising from the robot dynamics.
• The fuzzy rules are designed aiming at limiting the control signals as well.

This paper proposes a fuzzy controller for trajectory tracking with unicycle-like mobile robots. Such controller uses two Takagi–Sugeno (TS) fuzzy blocks to generate its gains. The controller is able to limit the velocity and control signals of the robot, and to reduce the errors arising from its dynamics as well. The stability of the developed controller is proven, using the theory of Lyapunov. Experimental results show that the use of the proposed controller is attractive in comparison with the use of a controller with fixed saturation function.