Manipulative operations of rheological objects can be found in many industrial fields such as food industry and medical product industry. Automatic operations of theological objects are eagerly required in these fields. In this paper, deformation transition graphs are proposed for the forming operations of rheological objects. First, a novel forming machine with multi degrees of freedom is developed for the automatic forming of rheological objects such as dough and paste. Second, we will introduce a deformation transition graph so that the forming process can be described. We will then develop a method to generate the deformation transition graph through experiments. Finally, we will explain a forming control method of a rheological object based on the deformation transition graph.

Since viscoelastic objects deform during operation processes, it is necessary to simulate the behavior of the objects and to estimate their deformation for the automatic operations. Consequently, a model of a viscoelastic object is needed for the simulation and the estimation of its deformation. We propose a lattice structure based modeling method for viscoelastic object deformation. First, the behavior of four element models is briefly explained. Next, a viscoelastic object is modeled as a lattice structure, where mass points are connected through four element models. We simulate shape deformation of the model when force input is applied to it. Validity of the model is then discussed. We also introduce a nonlinear damper (NLD) into a four element model in order to solve a discrepancy between an actual viscoelastic object and its linear model. By comparing the behavior of the two models, we show the validity of the model using NLDs.