Development of low-level control system for the KuupKulgur rover

Abstract

Modern extraterrestrial exploration relies on unmanned planetary rovers capable of conducting experiments on cosmic bodies autonomously. This work is a part of the Estonian microrover project KuupKulgur, a lunar explorer which requires a low-level control system for on-board motors as a part of its larger autonomy software stack. This thesis presents development of the control system for the rover’s 6 skid-steering wheels by implementing and enhancing a per-wheel PID controller. The algorithm is configurable to match frequent system improvements and constantly changing requirements of the project. It is developed as a Robot Operating System (ROS) node written in C++ to be easily integrated into the project’s ROS architecture. PID controller utilizes wheel encoder data for control input calculation, and features terrain adaptation and per-wheel correction logic aimed at handling terrain inconsistency. The control system was extensively tuned and tested on several surfaces including lunar regolith analogue at Tartu Observatory, with results presented in this thesis.