Electrically Actuated Antiglare Rear-View Mirror Based on a Shape Memory Alloy Actuator

Abstract

This article focuses on the experience of Centro Ricerche FIAT (CRF) regarding the development of shape memory alloy (SMA) actuators, and addressed some new design approaches which have been defined. Specific characteristics of shape memory materials, such as the efficiency of the transformation, have oriented the design of actuators toward occasionally used devices. The antiglare manual mechanism, incorporated in the internal rear-view mirror of a car, fits this new approach well. An antiglare rear-view mirror is a system capable of detecting a glare situation during night-time driving in order to automatically switch the mirror plane so as not to distract the driver. The low forces required, together with the silent, bistable movement are suitable for the use of a SMA actuator in this application. In the first part of the paper, the conceptual design is illustrated and a preliminary overview of the working principle is provided together with a series of considerations regarding the kinematics and the layout of electronic sensors in order to realize a fully controlled mechatronic prototype. Before concluding, the description of the realization of a working prototype is presented. The prototype of the EAGLE (Electrically Actuated antiGLare rEar-view mirror) system has provided experimental confirmation that such a device can satisfy fatigue and functional test requirements, thus offering the opportunity to spread the use of SMA devices in the automotive field.

Analysis of One-Dimensional Ivshin–Pence Shape Memory Alloy Constitutive Model for Sensitivity and Uncertainty

“…The first GM vehicle was seventh generation Chevrolet Corvette with SMA actuator in which SMA was used to actuate the hatch vent for closing the trunk lid easily [30]. Centro Ricerche Fiat (CRF) has developed numerous patented applications of SMA for devices such as electrically actuated antiglare rear-view mirror, headlamp actuators, fuel filling lid actuator, and locking mechanism [31][32][33][34].…”

Design and experimental characterization of a NiTi-based, high-frequency, centripetal peristaltic actuator

“…A possible solution is the use of a mobile heat sink that comes off the SMA during heating, reducing the power amount compared to an equivalent fixed heat sink [28]. Luchetti et al [29] reduced the thermal hysteresis by using a silicone cover to uniform the conductivity coefficient on the heat exchanging surface. In the case of jet fluid cooling, very rapid heat transfer occurs between the jet fluid and the SMA actuator.…”

Solution processable neutral state colourless electrochromic devices: effect of the layer thickness on the electrochromic performance

“…1 These materials are used in different technological applications, such as anti-glare rear-view mirrors, 2 electrochromic displays, 3,4 earth tone chameleon materials, 5 and smart windows for buildings or cars. 6,7 The first applications of electrochromic materials started with semiconductors based on inorganic materials such as IrO 2 and WO 3 8-10 and then continued with organic small molecules based on viologens. [11][12][13][14] Finally, conjugated polymers have gained quite an importance over the course of time 15 owing to their superior features of tunable HOMO-LUMO band gap and also potential application in low-cost, large-area flexible devices.…”