Research On Large-angle Contact Force Sensing Method With Bionic Compound Eye

Human cognition of the world is largely dependent on the sense of touch.With the rapid development of artificial intelligence,high-precision measurement of contact force is playing an increasingly important role in contact state detection,adhesion phenomenon detection,and physical properties(shape,size,stiffness,etc.)recognition.However,it is difficult for the existing contact force sensor to achieve large sensing angle,high sensitivity,and isotropy at the same time.Under this background,a large-angle 3D(three-dimensional)contact force sensing method with bionic compound eye is proposed in this paper.And a 3D tactile force measurement and adhesion contact measurement system are researched and built to measure contact force.The details are as follows:1.The mechanical simulation of two different elastic specimens was carried out to verify the force-deformation conversion by using ABAQUS finite element software.The electromagnetic analysis and optical simulation by using Tracepro software are used to verify the generation mechanism of leaking light in theory and simulation.So,the deformation-light conversion is verified.The bionic compound eye and light cone structure was used to receive the leaked light isotropically.And the mechanical decoupling model was established to verify the light-force conversion.Finally,the force-light-force conversion is realized.2.Based on the bionic compound eye,the 3D tactile force measurement system is built and the calibration experiment is carried out.The experiment results show that there is piecewise linear relationship between the normal force and the gray value of the image.And there is also piecewise linear relationship between the tangential force and the centroid displacement of the image.The detection angle of the 3D tactile force measurement system is 90°,and the characteristics of tactile perception of this system is proved by the press switch experiment.3.Adhesion contact force measurement system and calibration experiment are carried out.The experiment results show that the system can measure the normal loading force during loading,pull-off force and adhesion work of silicone rubber during unloading.The adhesion work of silicone rubber with different hardness can be obtained based on JKR adhesion contact theory.The typical detection angle of the adhesion contact force measurement system is 100°.Through the hydrogel indentation experiment,it is proved that the adhesion contact force system can measure the normal force,pull-off force and adhesion work.The 3D tactile force measurement setup has been successfully built with a sensitivity of 0.006 m N/Gray for normal force and 0.022N/μm for shear force.The relative uncertainty in 3D tactile force measurement system is under 5%.The adhesion contact force measurement system performs experiments five different hardnesses of silicone rubber,and the experimental results show that there is a linear relationship between the gray value and the load.The relative uncertainty in adhesion contact force measurement system is under 4%.