An Extended Model for Ripple Analysis of 2–4 Phase Resonant Electrostatic Induction Motors

Fernando Carneiro,Masahiko Osada,Akio Yamamoto,Guangwei Zhang,Shunsuke Yoshimoto

doi:10.3390/act10110291

Abstract

Electrostatic motors are promising forms of actuation for future robotic devices. The study of their different implementations should accelerate their adoption. Current models for resonant electrostatic induction motors were found not to be able to properly describe their behavior, namely, with regard to changes with position. This paper reports a new analytical model for these motors, aiming to address this issue. The model is based on identification of all capacitance harmonics, through a simplified method. Using these, equations for different motor parameters, notably, thrust force, were obtained and compared to previous literature. The new equations model position dependent properties, such as force ripple. The outputs of this model were validated through experimentation with a prototype, with the results confirming the new model better describes motor behavior. An analysis into how to decrease this ripple was also discussed and tested. We concluded that the use of a higher number of harmonics resulted in a much more accurate model, capable of adequately characterizing motor outputs with changes in position.

Highlights

IntroductionAn actuated mechanism comprises a rigid structure and an actuator.For small-scale robots, this actuator is most times a conventional electromagnetic motor.there is an increasing demand for alternative forms of actuation, driven partly by attempts to replicate biological shapes and movements, in the pursuit of higher performance, lower weight or capabilities that go beyond simple manipulation or movement [1].There is an abundance of ongoing research on this topic, with recent results including robots capable of swimming [2], jumping [3,4], wall climbing [5,6] and flapping-wing flight [7]in a biologically-inspired manner, thanks to the application of unconventional forms of actuation
A subset of these is the field of soft robotics, which focuses on the development of robots with soft structures, for biomimetic purposes [8], and as a form of enhancing safety when interacting with human beings [9]
This paper reports the definition of a new model for 2–4 phase resonant electrostatic induction motors, exhibiting changes in slider voltage and thrust force with displacement, compatible with experimental observations

Summary

Introduction

An actuated mechanism comprises a rigid structure and an actuator.For small-scale robots, this actuator is most times a conventional electromagnetic motor.there is an increasing demand for alternative forms of actuation, driven partly by attempts to replicate biological shapes and movements, in the pursuit of higher performance, lower weight or capabilities that go beyond simple manipulation or movement [1].There is an abundance of ongoing research on this topic, with recent results including robots capable of swimming [2], jumping [3,4], wall climbing [5,6] and flapping-wing flight [7]in a biologically-inspired manner, thanks to the application of unconventional forms of actuation. A subset of these is the field of soft robotics, which focuses on the development of robots with soft structures, for biomimetic purposes [8], and as a form of enhancing safety when interacting with human beings [9]. These soft or compliant robots can be materialized in a number of ways using fluid [10,11,12,13], thermal [14,15] or electrostatic [6,16] actuation, on which the present paper will focus

Methods

Discussion

Conclusion