Research On The Slip Sensing Characteristics Of Fiber Bragg Grating

Slip perception is an important part of intelligent manipulator.Slip perception of manipulator is a physical quantity that describes the contact state between mechanical finger and gripped object.The sensor that detects this parameter is called slip sensing sensor.More and more scholars pay attention to the research on slip sensors.Fiber Bragg grating(FBG)sensor has the advantages of easy wavelength division multiplexing,space division multiplexing,small volume,low loss,anti-electromagnetic interference,low cost,etc.The advantages of fiber Bragg grating make it of great significance to develop a new type of slip sensor.Based on the principle of fiber Bragg grating,two kinds of fiber slip sensing units are developed in this dissertation.The main contents of this dissertation are as following:1.Describe the research status and sensing principle of slip sensors domestic and foreign.2.Elaborate the principle of fiber Bragg sensing.The sensing principle of fiber Bragg grating under temperature and strain is analyzed.When the fiber Bragg grating is stressed,only the stress along the axial direction of the fiber is considered,and the influence of tangential stress is ignored.The cross-sensitivity of fiber grating and the demodulation method are briefly described.3.Aiming at the problem of object sliding detection,a sliding sensor unit based on a cantilever beam structure is designed and manufactured.The sensing principle of the sliding sensor is theoretically analyzed,and a mathematical model of the sensor unit during sliding is established.This cantilever beam can perceive the slippage by displacement.The differences of the Bragg wavelength shift and variance analysis are employed to sense the start of the sliding,the end of the sliding,the sliding direction,the sliding speed and the fluctuation of the contact force.Experimental tests show that under the contact force of 0.2N?1N,the cantilever beam sensing unit has a good detection effect for small sliding.The average relative error between the experimental value and the theoretical value of the sliding sensitivity is 6%.The average relative error between the experimental value and the theoretical value is 14%,and the average relative error between the experimental value and the theoretical value of the contact force is 6.6%.4.Aiming at the problem that the cantilever beam slip sensor can not recognize the incipient slippage,it is proposed to realize the slip perception detection through the silicone rubber slip sensor unit.It is analyzed by SolidWorks Simulation.The experimental results show that the X-axis sensitivity of the sensor is 70 pm/N,and the average relative error between the experimental value and the simulated value is 13%;the Y-axis sensitivity is 74 pm/N,and the average relative error between the experimental value and the simulated value is 5.4%.The first derivative algorithm is used to identify the abrupt change of friction to realize the detection of sliding trend.The sliding sensor can realize the judgment of the sliding angle.The average error of the experiment is 2.40.5.Design demodulation system of fiber grating.FBG demodulation software is developed by LabVIEW software to realize data acquisition,display,storage and other functions,and MATLAB software is called to process the data.At last,it summarizes the research situation of the subject and the current deficiencies,puts forward the improvement methods and ideas,and looks forward to the future work.