Lumped-Driven Method for Motion Control

Introduction

This chapter proposes motion control method for deformable machines consisting of actively deformable materials. If the problem is stated in inverse dynamics form, the required method is to move typical position of the robot on the objective trajectory by deforming its whole body. It was neither the selection of typical points nor objective trajectory was clear for the beginning.

In the previous chapter, morphogenetic method was proposed to control shape of gel robots. Their bodies grow from simple to complex forms. Degrees of freedom of the body are utilized at maximum. In this chapter, totally different approach is proposed to utilize deformability of the body. Motion control problem is dealt with referring to the motions of deformable living animals. The turning over motion control problem was selected as a typical example. Learning from a real starfish and other researches, the mechanism is made clear and motion is generated in high reliability.

A variety of motions of gel robots is derived by applying either spatially or time varying electric fields in the previous chapters. Both spatially and time alternating electric fields were not yet applied to them. For the purpose of generating turning over motion, both spatially varying time alternating electric fields are applied to them. Typical operators of electric fields are applied and switched to gel robots. This work is the first step towards motion control of gel robots and deformable machines in the future.

This chapter was adapted from in part, by permission, M. Otake, Y. Kagami, M. Inaba, and H. Inoue, “Motion design of a starfish-shaped gel robot made of electroactive polymer gel”, Robotics and Autonomous Systems, vol. 40, pp. 185–191, 2002; M. Otake, Y. Kagami, Y. Kuniyoshi, M. Inaba, and H. Inoue, “Inverse Dynamics of Gel Robots made of Electroactive Polymer Gel”, Proceedings of IEEE International Conference on Robotics and Automation, pp.2299–2304, 2003.