Fibre Bragg grating sensors for distributive tactile sensing

Abstract

Distributive tactile sensing is a method of tactile sensing in which a small number of sensors monitors the behaviour of a flexible substrate which is in contact with the object being sensed. This paper describes the first use of fibre Bragg grating sensors in such a system. Two systems are presented: the first is a one-dimensional metal strip with an array of four sensors, which is capable of detecting the magnitude and position of a contacting load. This system is favourably compared experimentally with a similar system using resistive strain gauges. The second system is a two-dimensional steel plate with nine sensors which is able to distinguish the position and shape of a contacting load, or the positions of two loads simultaneously. This system is compared with a similar system using 16 infrared displacement sensors. Each system uses neural networks to process the sensor data to give information concerning the type of contact. Issues and limitations of the systems are discussed, along with proposed solutions to some of the difficulties.

Optical Fiber Gratings in Perspective of Their Applications in Biomedicine

“…Existing systems of gait analysis use large numbers of sensors or complex imaging systems, whereas several FBGs on a single strand of fiber with one interrogation unit can be embedded within materials forming a surface without loss of material strength. Recently, FBG sensors have been investigated for distributed tactile sensing (Cowie et al 2006(Cowie et al , 2007 in a grid arrangement along with a neural network to detect the position and shape of a contacting load simultaneously in real-time.…”

Research Activities Arising From the University of Kent

“…We have investigated the use of neural processing with Bragg grating sensor networks [35]. In one demonstration experiment, a 25-cm-length thin cantilever was instrumented with four fiber Bragg gratings and clamped horizontally so that small weights could be placed along its length (Fig.…”

Tactile Sensor Array with Fiber Bragg Gratings in Quasi-Distributed Sensing

“…Such strategies include gluing grating-based transducers directly under the surface of a steel or polymethyl methacrylate (PMMA) plate [5,6], attaching gratings to iron rings [7], encapsulating FBGs in blocks of silicone positioned under a steel plate [8], or forming an array of sensors in a single silicone encapsulation [1,9].…”

“…Under these conditions, the cost and complexity of the sensing system also increase. Nevertheless, this number can be reduced if the responses of the sensor elements in the TSS are coupled, making such a system less expensive and more robust [6].…”