Auto-tuned Admittance Control for Robot Drilling with Constrained Force Overshoot *

Drilling is a common and important task not only in industrial production but also in scientific exploration such as extraterrestrial drilling. It often involves large vibrations and contact force, which make it dangerous and difficult for robots. Our recent work focuses on stability and force overshoot issues of drilling control. We propose an admittance controlbased controller specially designed to regulate the force during drilling. It forms a second-order system with the environment. Detailed and complete theoretical analysis ensures its stability and shows that the force overshoot can be constrained with proper controller parameters. An adaptation system enabling the controller to auto-tune parameters is also included. Drilling experiments on slate and wood show that the controller can adapt to an unknown material and stably follow a reference drilling force without large force overshoot.