International audience— This paper presents an easy-to-use sensor aimed for traffic safety applications using visible light communications. A central problem in this area is the design of a suitable sensor able to enhance the conditioning of the signal and to avoid disturbances due to the environmental conditions. The visible light communication sensor proposed in this article addresses these issues and enables a robust communication for short to medium distances. The presentation is focused on hardware aspects and low-level coding techniques. The experimental validation of the proposed sensor has been conducted by analyzing communication performances between a commercial traffic light and the sensor, for distances up to 50 m. The measurements exhibit bit error ratio lower than 10-7 in an outdoor configuration, using two well-known codes (Manchester and Miller) without any error-correcting codes or complex signal processing. The prototype is aimed for automotive applications but other outdoor configurations can also be addressed by slight changes in the system design. Index Terms— infrastructure to vehicle communication, robust sensor, smart lighting systems, vehicle safety applications, visible light communications

No abstract

Abstract-Since a few years, the vehicle industry tends to increase the performances of the lights based on led technologies. Nowadays, led systems are used as a standard by motor vehicles manufacturers. Led lights present higher reliability and are more flexible regarding the design or power adjustments. Furthermore, led systems are also very convenient for intensity modulation like in telecommunication fields. We developed a very simple data transmission system based on led that aims to be highly robust at short or medium distances -a few meters up to 15 meters. This visible light communication is dedicated to the cooperation between vehicles and road infrastructures to enhance the security of the traffic. This paper explains the choices and first results on the data transmission performances. In this paper, we present a first prototype of the system we made and experimental results.

Optical tweezers are a powerful tool for micromanipulation and measurement of picoNewton sized forces. However, conventional interfaces present difficulties as the user cannot feel the forces involved. We present an interface to optical tweezers, based around a low-cost commercial force feedback device. The different dynamics of the micro-world make intuitive force feedback a challenge. We propose a coupling method using an existing optical tweezers system and discuss stability and transparency. Our system allows the user to perceive real Brownian motion and viscosity, as well as forces exerted during manipulation of objects by a trapped bead.

No abstract

Actuation and sensing with electroactive polymers should be a chance for flexible MEMS but their micromachining and integration are still not mature. Some innovative materials and microfabrication processes are still expected. In this paper, a first full elaboration of polymeric microtransducers (MTs) including integration and operation has been described. The fabrication process relies on commercially available poly(3,4-ethyledioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) conductive ink, onto flexible SU-8 photoresist microchip. Batch-fabrication of complex flexible monolithic units comprising individually addressable MTs of different shapes, is demonstrated. The resulting polymeric MTs show both very promising bending actuation and strain sensing properties in open-air. Remarkably, the microfabrication process did not impact the performances compared to material fabricated with laser cutting. This work paves the way for flexible MEMS development for soft microrobotics, microfluidics in medical and spatial applications.

This article presents a novel visible light communications receiver architecture, designed for automotive applications. A central problematic in this area is the design of a suitable receiver able to face the problems caused by the dynamic situations, by the long distances and also by the environmental conditions. In such circumstances, a solution would be to adapt the communication's data rate to channel conditions, meaning that the communication would take place using different data rates depending on the signal to noise ratio (SNR) and the message priority. Considering the digital filtering better performances, the proposed architecture considers the usage of digital signal processing (DSP) as an alternative to the analog signal treatment. The visible light communication receiver proposed in this article addresses the upper mentioned issues and enables a robust communication even at low SNR.

To cite this version:Luc Perret, Luc Chassagne, Suat Topsu, Pascal Ruaux, Barthélemy Cagneau, et al.. Fiber optics sensor for sub-nanometric displacement and wide bandwidth systems. Sensors and Actuators A: Physical , Elsevier, 2010, pp.189-193 , 165, 189-193 (2011). AbstractIn this paper, we report fiber optics sensor with sub-nanometric resolution and wide bandwidth. It relies on an increase of the reception fibers number and on low-noise electronics. Moreover, a reference channel has been implemented using a semi-reflective plate to eliminate the source fluctuations and the fiber sensor was isolated to limit external influence of temperature and pressure. Thus we achieve both a sub-nanometric resolution on a 400 ms integration time and a long-term drift as low as 40 nm.h -1 . The setup has been also adapted to high speed applications by increasing the bandwidth up to 38 kHz. It can display a 28 nm peak-to-peak limit of resolution on an aluminized piezoactuator. It has been successfully used to test the resonance frequency of a vibrating plate actuated by two highfrequency prototypes of piezoactuators. These improvements lead to low cost fibers optic sensors interesting for non-contact displacement measurements with high sensitivity.