Control System Design of a Multi-Rod Drilling Robot for Planetary Exploration

Extraterrestrial bodies sampling is a crucial objective in planetary exploration missions. As an efficient and convenient sampling method, drilling robots have been widely used in various sampling missions. However, current sampling missions have limitations in terms of sampling depth and automation level. Multi-rod drilling robots are efficient for deep drilling, but the coordination and control of multiple degrees of freedom (DOFs) must be considered to achieve full automation of sampling. To meet the requirement of autonomous deep-drilling control of a multi-rod drilling robot, this paper proposes a control system based on a multi-rod drilling robot. Firstly, a motion sequence planning for the robot is presented. Then, a prototype of the control system is designed on this plan. A state machine control strategy based on fixed and input parameters is adopted to realize deep autonomous drilling. Finally, the automated drilling process is verified by performing process tests on the developed multi-rod drilling robot, using the control system. The results show that the proposed motion planning process is effective and the control system works stably.