Constrain-based identification of a dynamic model

Dynamic simulation is potentially a powerful tool for studying complex contact interactions between robots and their environments. One of the main problems of such a simulation is the determination of the model parameters which provide realistic behavior for objects. This paper describes how to identify such parameters for a mass/spring based system. This identification process is composed of two main steps: 1) distributing the total mass of the object between different particles while respecting the inertial properties of the object; and 2) finding the values of the physical parameters of the model such as elasticity, viscosity, plasticity, etc. The numerical solution of the first step is described, while a genetic algorithm base approach is proposed for the second step. This approach allows us to find the values of the parameters which provide a consistent behavior under a set of given constraints (position, velocity, volume, etc.). It also allows us to minimize the computation time and to attach priorities with these constraints.