Contact Stiffness Estimation Techniques for Robotic Manipulation

This work addresses the problem of stiffness estimation for robotic tasks. Online stiffness estimation can be used to improve force tracking in explicit force control schemes being also important for realistic haptic feedback in telemanipulation tasks. It also enables accurate stiffness mapping and simulation of environment dynamics. Many robotic applications involving contact with the environment can benefit from stiffness estimation. Examples can be found in the medical and industrial areas.In this book, three new online stiffness estimation algorithms are developed for robotic interaction tasks. These algorithms completely prevent the dependency on environment position-based data, relying instead on force-based data to obtain the stiffness estimation. Theoretical analysis, simulation and experimental results are provided, demonstrating that these techniques can effectively achieve environment stiffness estimation. These algorithms represent a contribution to online stiffness estimation in robotic tasks involving interactions with unstructured and unknown environments where contact geometrical data is unavailable or unreliable.