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In this paper an observer based on measured and estimated currents and a kinematic model is designed to estimate the velocity and direction angle of an unmanned vehicle (UV). The Lyapunov stability theory is used to establish the stability conditions for the observer. It is shown that the observer will converge in a finite time and the observer gains satisfy the constraints of the stability conditions. The observed velocity and direction angle are used in the closed loop instead of measured ones for sensorless control of the UV. The velocity and direction angle control of the UV are carried out by a well-tuned PI controller. The experimental results show that the proposed observer can be perfectly implemented for sensorless control without using a mechanical sensor, and satisfying results are obtained. In the experiment, command voltages are used rather than measured ones, and therefore only current sensors are needed for the proposed algorithm. [ABSTRACT FROM AUTHOR]

In this paper a fuzzy controller is applied to velocity and direction angle control of a certain type of wheeled mobile robots called Automated Guided Vehicles (AGVs). The velocity and direction angle of the AGV are controlled to keep the vehicle on desired path. A PI controller is also applied to AGV in order to show the robustness of the fuzzy controller. Experimental results prove that the fuzzy controller shows better tracking performance than the PI controller in terms of robustness, smoothness and fast dynamics. Results are also given for sudden disturbance and extra load conditions and satisfied results are obtained. [ABSTRACT FROM AUTHOR]