Research on pressure tactile sensing technology based on fiber Bragg grating array

Abstract

A pressure tactile sensor based on the fiber Bragg grating (FBG) array is introduced in this paper, and the numerical simulation of its elastic body was implemented by finite element software (ANSYS). On the basis of simulation, fiber Bragg grating strings were implanted in flexible silicone to realize the sensor fabrication process, and a testing system was built. A series of calibration tests were done via the high precision universal press machine. The tactile sensor array perceived external pressure, which is demodulated by the fiber grating demodulation instrument, and three-dimension pictures were programmed to display visually the position and size. At the same time, a dynamic contact experiment of the sensor was conducted for simulating robot encountering other objects in the unknown environment. The experimental results show that the sensor has good linearity, repeatability, and has the good effect of dynamic response, and its pressure sensitivity was 0.03 nm/N. In addition, the sensor also has advantages of anti-electromagnetic interference, good flexibility, simple structure, low cost and so on, which is expected to be used in the wearable artificial skin in the future.

Recent Progress in Technologies for Tactile Sensors

“…Their tactile sensor is able to measure external strain in a high solution by analyzing the reflected light spectrum, as shown in Figure 19 . One fiber Bragg grating tactile sensor array introduced by Song et al in [ 139 ] is implanted in flexible silicon. This array has a good dynamic response and is suitable for large-area fabrication because of its high flexibility, but the size needs further miniaturization.…”

Theoretical and experimental investigation of fiber Bragg gratings with different lengths for ultrasonic detection

“…where s w is the ultrasonic wave frequency, m  is the amplitude of sound wave, z is the sound path, and k=2π/s is the ultrasonic wave number [12]. The transfer matrix method is utilized to analyze the FBG multilayered structure.…”

Tactile Sensing and Control of Robotic Manipulator Integrating Fiber Bragg Grating Strain-Sensor

“…State-of-art regarding applications adopting FBGs as transducers provide evidence of tactile sensors used in different scenarios. Compared to related works (i.e., soft tactile sensors embedding FBGs) (Heo et al, 2006; Saccomandi et al, 2015; Song et al, 2015; Jiang and Xiang, 2017; Negri et al, 2017; Li et al, 2018; Pedroso et al, 2018), the present sensor shares the concept of encapsulating the optical fiber in a soft matrix. Such cover not only protects the fiber from mechanical ruptures but also affects the transduction of the signal by mediating the transmission of pressure to the buried FBGs.…”

“…In comparison to previous studies embedding FBGs in prototypical matrices (e.g., parallelogram bricks), the location of our FBGs were based on the design of the robotic hand, expressly functional to gripping tasks. One common elastomer used as encapsulating material is PDMS (Heo et al, 2006; Saccomandi et al, 2015; Song et al, 2015; Jiang and Xiang, 2017), while in this study a soft Dragon Skin silicone (20 medium, Smooth-on, USA) was used, due to its higher flexibility and lower delamination between layers. Further details on the adopted elastomer, are given in the Materials and Methods section.…”