Fuzzy sliding mode control for trajectory tracking of an electric powered wheelchair

Various controllers have been applied to control the dynamics of Electric Powered Wheelchair (EPW) for people whose walking are difficult or impossible, due to illness or disability. This paper deals with the nonlinear control of an electric wheelchair based on the hybridization between fuzzy logic and sliding mode control called Fuzzy Sliding Mode Control (FSMC). The EPW is powered by two Permanent Magnet Synchronous Motors (PMSM) due to some advantageous features, such as high efficiency, high torque to the current ratio, low noise and robustness. This research aims to present the dynamic modelling of both EPW motors with Lagrangian method in the first step, and the application of fuzzy sliding mode control in the second. This control technique was presented in order to consider the full dynamic model while alleviating the chattering phenomenon and to increase trajectory tracking performance of the EPW in the presence of disturbances. However, the reference trajectory used is that generated by the fifth-degree polynomial interpolation, which ensures a regular trajectory that is continuous in positions, velocities and accelerations. Finally, numerical simulations are presented to show the evolution of electrical and mechanical quantities in order to verify the effectiveness of the control strategy.