Modeling and Calibration of Contact, Friction and Deformation between a Rigid Object and another Rigid or Rheology Object

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The purpose of this research is to construct contact (including friction) model between rigid bodies and also design deformation model of pushed rhelogy (complex viscous - elastic) object. These models are quite useful for manipulating many kinds of materials by robotic manipulator in a real world and also for manipulating them by haptics in a virtual world.Concerning to the former problem, we propose an impulse-momentum-based approach to generate an arbitrary impulse (sequence of forces) artificially. This is a modified version of Mirtich's famous approach. Our new approach has enough parameters to express several physical phenomena. For example, there are static and kinetic friction coefficients between two encountered objects, restitution coefficient in the Poisson's contact model, and so on. The unknown parameters are efficiently calibrated by two kinds of near-optimal probabilistic search algorithms such as the randomized algorithm and genetic algorithm under many experimental dat … More a. The calibration is based on the conservative law of momentum variation. For this purpose, we should exactly measure velocities before and after collision by high-speed camera. Finally, we check the feasibility of our new approach in the air hokey and billiard games.Concerning to the latter problem, we propose smart MSD (Mass-Spring-Damper) model to represent the viscosity, elasticity, and residual displacement of deformed object. In general, there are many kinds of rheology objects in our living life. Therefore for each material, we calibrate many uncertain parameters of MSD model by the genetic algorithm. Each MSD element consists of Voigt and damper parts serially. Therefore, parameters to calibrate are two coefficients of dampers, one coefficient of spring, length ratio of Voigh and damper and so on. In order to calibrate all the parameters, we minimize the shape difference between real and virtual rheology objects. The shape deformation of real rheology object is precisely captured by two or more stereo vision camera systems Digiclops and its software development kit (SDK) Triclops (provided by Point Grey Research Inc, Canada). Each captures about three or more thousand points as shape of real rheology object in the real-time manner. Less