Preliminary Study of Pressure Self-Sensing Miniature Magnetorheological Valves

Abstract

Magnetorheological (MR) valves have been included in many innovative engineering systems, such as dampers, clutches, or brakes, with different fields of application. Their role serves actuation purposes, while integrated displacement and velocity sensing in the actuators has been studied, as well.In this paper, we present the working principle, design, and preliminary results of a miniature MR valve with pressure selfsensing capabilities that exploits the electromagnetic induction phenomenon. The valve can work in a pressure range from 200 kP a to 700 kP a, supplied by a current of a maximum 0.3 A. The suggested valve design is realized with two coils, one for the current application and the magnetic field creation and one for the sensing of the electromagnetic induction. A specially designed test-bench, that facilitates MR fluid flow and pressure regulation, was used for the experimental procedures.

Microfluidic device for analysis of magnetorheological fluids’ properties

“…As reported in the literature, the permeance Λ mrf associated with a MRF is not constant. It varies with several parameters like the pressure applied to it or the flow rate of the MRF [9] [10]. In order to measure the variation of the magnetic properties of the MRF, the variation of the magnetic flux Φ is measured through the induced voltage V i on the sensing coil of Fig.…”

“…The valve is open by default, as the MRF has a low viscosity if no magnetic field is applied [8]. In our previous studies, we presented the design of a miniaturized MR valve that enables its self-sensing capabilities with regard to pressure and flow rate [9], [10]. This is achieved because the MRFs undergo a change in their magnetic properties, when pressure is applied to them or when their flow rate is changed, leading to electromagnetic induction phenomena.…”