Design, simulation and synthesis of wheelchair controller using Fuzzy logic

Abstract

This paper describes a Fuzzy Logic Controller (FLC) algorithm for designing a Wheelchair Controller (WC). The controller enables the movement of wheelchair and makes brake in an unstructured environment by the WC sensor to avoid any encountered obstacles. The WC is found to be able to react to the environment appropriately during its navigation to avoid crashing with obstacles by turning to the proper angle while moving. To design the controller unit, a speed sensor and a distance sensor etc are placed in front of the wheelchair for its functionality. The numerous data is used to evaluate the algorithm which control an output signal for the brake-power, using by the input signals of speed sensor and distance sensor. The Fuzzy logic algorithm has proven a commendable solution in dealing with certain control problems when the situation is ambiguous. One of the main difficulties faced by conventional control systems is the inability to operate in a condition with incomplete and imprecise information. As the complexity of a situation increases, a traditional mathematical model will be difficult to implement. Fuzzy logic is a tool for modeling uncertain systems by facilitating common sense reasoning in decision-making in the absence of complete and precise information. In this paper, the WC is designed and simulated based on the theories of Fuzzy logic in MATLAB software. The MATLAB codes of WC have been written using VHDL language for implementing the separate modules of the Fuzzifier, Fuzzy Rule Base, Inference mechanism and Defuzzifier as hardware blocks. The generated VHDL codes have synthesized using synthesis tool for VLSI implementation.