Orthogonalization Principle for Haptic Interaction

Abstract

Haptic exploration for high precision applications such as surgical training stations, represent a challenge in kinesthetic force feedback methods with deformable virtual objects. In this contribution, a methodology to compute the contact forces for haptic interfaces with high performance, is presented to define the force in the human interaction with the virtual environment. To this end, the method is based on the orthogonal decomposition principle applied to robot force controllers, in this case, to generate deformable viscoelastic and tangent friction properties on the virtual surface, during haptic exploration. The dynamics of the normal plane is defined by a spring-damper system, and the dynamics of the tangent plane from a viscous-Coulomb friction model. The experimental platform corresponds to a haptic device based on the impedance principle (compute of force as a function of the movement) of 6 degrees of freedom, 3 degrees of freedom fully actuated for position and force control. The interaction task consists of two phases: i) numerical validation in Matlab, the forward and inverse kinematics of the position and veocity of the haptic device are used., and ii) validation in a virtual environment programmed in CHAI 3D and Visual C++, described by a virtual sphere with deformable and tangent dynamics.