The Perception Mechanism And Experiment Research On Robot Fiber-optic Array Skin

Research on the artificial skin, which is able to perceive and feedback the external information, has an extremely important significance to the collision problem of human-machine cooperative security in the robot field. Comparing to the traditional electrical sensors, optical fiber has many advantages such as small size, light weight, high sensitivity, anti-electromagnetic interference and high re-usability. So it is easier for optical fiber to realize the miniaturization, integration and distributed sensing of the artificial skin. Application of fiber Bragg grating (FBG) sensor to robot artificial skin is a hot topic in the robot perceptual field.Main research contents of this article are as follows:The deficiencies can be found in the existing research on fiber artificial skin through the analysis on current research status of artificial skin and optical fiber artificial skin. Combining with the transverse strain sensing and axial strain sensing principles of fiber Bragg grating (FBG), researches are done on the perception structure and information processing techniques of the array optical fiber artificial skin.Firstly, we design 3*3 array sensing unit with simple structure to verify the feasibility of encapsulating the array fiber sensor into polydimethylsiloxane (PDMS) and the feasibility of utilizing wavelength demodulation scheme to demodulate the array sensing unit based on multiplexing technology. The scheme of the array sensor static and dynamic testing is also presented.To tackle the problem that the 3*3 array sensing unit with simple structure has a low sensitivity because of the lateral sensing strain, we carry on key research to analyze the single node micro-structure of the 3*3 array sensing unit. The micro-structure is designed to be able to transform external force into the deformation of axial tension. After simulating 5 kinds of micro-structures by using finite element analysis software ANSYS, we optimally select 2 kinds of them through statics analysis for development. We also carry on the physical production, set up the experimental platform and test the system performance to demonstrate feasibility of the micro-structures.In view of the spatial localization problem of the 3*3 array sensing unit and the array information demodulation during its practical application, we conduct study on array arrangement and algorithm for array strain location of the sensing unit. We conduct experimental tests on the array sensing unit after prototype fabrication and give an empirical demonstration to the algorithm for array strain location.We apply the fiber sensing unit to silicone gloves and do the calibration test, contrast test and grabbing test. Through above tests, we can verify the feasibility of detecting force in the gloves grasping action by utilizing fiber sensing unit encapsulated in it.At the end is the summation of the project situation. We also analyze the limitation in current study; propose area need for improvement and point out aspects to be further studied.