Design of a Fuzzy Logic Controller(FLC) for mobile robot navigation in an unknown environment.

Implemented the Tracking FLC and Obstacle Avoidance FLC on TurtleBot2 robot in simulation

Project Outline:

Accessed stereovision point-cloud data and laserscan data. Defined membership functions for Obstacle Avoidance FLC and Tracking FLC inputs - distance between the robot and the target, distance between the robot and obstacle and the angular presence of the same.It included the design of If-Else fuzzy rules for OAFLC and TFLC. Fuzzy Inference System design was performed and defuzzification techniques were implemented.

Methodology

The Takagi-Sugeno-Kang fuzzy inference technique and the Centroid defuzzification methods are used to implement our proposed controller.The TSK approach computes the output of the If-Else rules as a linear expression made up of weighted conditional components. Elaborately, the FIS setup processes all If-Else conditional statements with the weights generated on the basis of the membership functions and computes a new weight for execution of the condition. The Centroid defuzzification process computes a normalized weight distribution for conditions and thereafter their weighted sum to generate final numerical output values.The Gazebo simulation environment was used with a customized design of the world cluttered with obstacles. Weighted behavior fusion for both FLCs to obtain final robot commands.

Results:

The robot was successfully able to navigate through the environment and avoid obstacles enroute reaching the target.The controller was tested on several terminal states as well as environments

Complete Project Report