Impact control under elastic/plastic deformations

The paper deals with the problem of controlling the impact between a mechanical system, having n degrees of freedom, and a body possibly subject to elastic/plastic. deformations. Goal of the proposed control scheme is the regulation of the impact force to a desired value, while imposing a prescribed configuration to the system, even in presence of possible plastic deformations of the body. The behaviour of the controlled system is analysed in the three different situations that may occur: (i) non contact between the mechanical system and the body, (ii) contact with pure elastic impact, and (iii) contact with plastic deformation of the body. Simulation results, which confirm the theoretical analysis in the case of a planar 2-dof manipulator striking an external surface, are reported in the paper.