Robotic Chemotaxis Controller

This project uses biologically inspired chemotactic movements to navigate a robot towards the source of a chemical spill. These movements are inspired by organisms like the bacterium Escherichia coli (E. coli) and the silkworm moth Bombyx mori that react to stimulants in an observable way. For these organisms, stimulants might include food sources or pheromones that signal mating readiness, and others. E. coli for example use the intracellular signaling pathway to process the temporal change in the chemical concentration to determine if the E. coli should run (move forward) or tumble (spin in place). In our project, we introduced a robotic controller mediator that is responsible for processing information that exists in the environment. The robotic controller that was developed uses a finite state machine to decide which specific control algorithms to use such as waypoint navigation, plume tracking, or plume recovery algorithms at various environment readings. The controller has been simulated as well as tested on a small-scale robot that imitates E. Coli chemotaxis in order to locate the source of a chemical cloud. The robotic controller utilizes the Robot Operating System (ROS) to separate different parts of this project into interdependent modules that communicate with each other. This robotic controller can be adapted to other situations with various plume configurations and be made compatible with different sensors. By making the robotic controller general, chemotaxis algorithms can be tested on different environments with minimal customization to the back-end code. The overall goal of this project is to use the robotic controller as an effective way to select the most appropriate algorithm to find the source of a chemical leak in various environments.