Research On Fiber Optic Pressure Tactile Sensors For Robot Finger

Robot tactile sensing technology is very important for the intelligent application of robot.With the increasingly complicated working environment of robots,the performance requirements of robots in touch tactile perception are getting higher and higher.Because of its advantages such as small size,good flexibility,high sensitivity,low electromagnetic interference and low cost,fiber optic sensor has advantages in micromation,flexibility and array of the tactile sensor.Applying optical fiber sensing to robot finger pressure tactile detection is one of the hotspots in the field of robot tactile perception.The main contents and research results of this paper are as follows:1)Through the retrieval and analysis of the current situation of robot finger tactile sensing technology,it is found that the existing electronic tactile sensors are difficult to be flexible and poor in electromagnetic interference.To solve this problem,the current research situation of fiber-optic tactile sensor is analyzed,and the sensing application of fiber-optic tactile sensor in robot finger pressure tactile is studied with the sensing mechanism of fiber bending characteristics.2)The bending deformation of the fiber will affect the transmission performance of the optical fiber.By analyzing the influence of the bending structure on the refractive index,the numerical aperture and the transmission loss of the optical fiber,the feasibility of the fiber bending application in finger pressure tactile perception is demonstrated,And the transmission performance of plastic optical fiber and quartz fiber were compared and analyzed.3)Combining the performance parameters of robot's finger shape and fiber bending,two kinds of optical pressure tactile sensors are designed,one is based on single-mode fiber pure bending structure of the pressure touch sensor,the other is based on the plastic fiber bending and displacement structure of the pressure Tactile sensor.The bending and force of the fiber are simulated by using the multi physics analysis software COMSOL,and the optimum structure parameters of the two kinds of tactile sensors are determined.At the same time,a simple design idea of fiber bending applied to the robot finger bending detection is made.Finally,the design and construction of the flexible tactile sensor structure are done.4)According to the principle of demodulation of pressure touch sensor,an experimental platform is built,and the performance parameters of the sensor are calibrated.A simple verification experiment was carried out on the finger bending test of the robot.The experimental results show that the design of two kinds of pressure touch sensor basically meet the requirements,the detection range of plastic optical fiber pressure tactile sensor is 0-20N,sensitivity is 0.839dBm/N,single-mode quartz fiber pressure touch sensor detection range of 0-4N,sensitivity is 0.125mW/N,the sensor linearity and repeatability is good.Finger bending degree detection effect is obvious,the detection range of 0-90 degrees,but showed a non-linear.At the end of the article,it summarizes the current research situation of the whole subject,analyzes the shortcomings of this research,and puts forward some suggestions for further improvement.