Mamdani based Fuzzy Logic Controller for A Wheeled Mobile Robot with Obstacle Avoidance Capability

Mobile robot is a type of robot that can move freely because it is equipped with motion elements such as wheels or legs. In guiding its motion, a mobile robot is equipped with a navigation system so that it can avoid obstacles. This paper describes the design and implementation of a wheeled mobile robot using fuzzy logic principles with Mamdani's fuzzy inference system so that the robot has the obstacles avoidance capability. Mobile robot is equipped with three pairs of HC-SR04 ultrasonic sensors to detect the distance between the robot and the obstacles. Fuzzy logic controller is installed in the Arduino microcontroller to generate an actuating signal for the DC motor mounted on each robot wheel. The whole fuzzy system is designed using three distance inputs obtained from ultrasonic sensors with each variable having three fuzzy sets with triangular and trapezoidal membership functions. Meanwhile, the output variable is the speed of movement of each wheels with each output variable has three fuzzy sets with triangular and trapezoidal membership functions. Based on the appropriate rule bases, fuzzy logic controllers are designed to achieve robot motion with the obstacle avoidance capability. The experimental results show the wheeled mobile robot can move along the trajectory without hitting the walls so that it has an obstacle avoidance capability. Compared to simulation results from Matlab, the accuracy of the speed value that rendered by the fuzzy inference system installed in Arduino microcontroller for some experimental data is approximately 96 %.