On the design and testing of a smart car damper based on electro-rheological technology

Abstract

This paper presents the different steps involved in designing, building and testing an intelligent damper, which is originally a classic passive damper retrofitted with electro-rheological (ER) technology, that can be used for semi-active car suspensions. Following an overview of the essential features of ER fluids, this paper examines the different design details required in building an efficient ER car damper. This particular model, filled with a ‘Rheobay VP AI3565’ ER fluid, was experimentally tested for different speeds and under different electric fields. The experimental results obtained clearly show that, when the high electric field is turned on, the generated dissipative force, and hence the damping characteristics, could be greatly increased. The dynamics of this first ER damper prototype model were numerically analysed, with an emphasis placed on evaluation of the influence of the electrical field on the resulting dynamic response. The results show that the damping ability could be easily increased by increasing the height of the moving electrode. However, this damping increase, which increases the stiffness of the ER damper, should be handled carefully by both the designer and the user. Indeed, there is always an optimal damping value which provides a compromise between car stability and ride comfort. Moreover, the simulation shows that the controller used to control the damper should not only apply an on/off policy but should also be able to deliver a variable value of the applied high voltage.

An electrorheological hydrostatic journal bearing for controlling rotor vibration

“…A reversible change in viscosity occurs in milliseconds with the fields applied. Since the study of the ER effect introduced in 1947 by Winslow [4], most related studies have been tried in order to increase rheological properties induced by the electric field [5][6][7]. The property of increasing the viscosity by applying an electric field to the ER fluid induced is termed the positive ER effect.…”

Combination of Homogeneous Electro-rheological Fluid and Multi- Electrodes Damper for A Better Control of Car Suspension Motion

“…The schematic configuration and photograph of a modified ER bitube hydraulic damper proposed in a previous work [16] are shown in Figure 3. The ER effect is induced into the classic damper by adding a 40-milimeter tall annular cupper electrode, tightly fitted to the axially movable rod.…”

“…The results collected from laboratory tests and numerical simulation [16] of the above ER damper clearly show that damping characteristics could be drastically changed whenever one of the following three parameters is modified:…”

Magnetorheological damper with external excitation for more efficient control of vehicles’ dynamics

“…Therefore, designing a good suspension is possible through making a compromise between stability and comfort (Sassi et al, 2003). The cost and efficiency of such a compromise rely on the type of implemented technology, which could be passive, active, or semi-active.…”