Design Of 3-D Fingertip Flexible Tactile Sensor

Flexible tactile sensor is the main direction of research and development in robot technology. Three-dimensional fingertips flexible tactile sensor, one of the important sensor of dexterous hand intelligent, can sense the full information of three-dimensional space. Intelligent dexterous hand mainly includes six dimensional wrist sensors and three-dimensional fingertips flexible tactile sensor. So far, the study of six dimensional wrist sensors at home and abroad has been more thorough, but the research on 3-D fingertips flexible tactile sensor is not serious. As the demand for intelligent dexterous hand in grasping stability and reliability is higher and higher in the engineering. Redundant information about three-dimensional fingertips flexible tactile sensor is an unavoidable question.This article designed Three-dimensional fingertips flexible tactile sensor that manufactured by using 3D modeling technical and 3D printer technical. The axial force mathematical model and tangential force mathematical model of three-dimensional fingertips flexible tactile sensor is set based on elasticity theory to show haptic mechanism and lay the theory foundation of the established of the method to detect tactile force. According to tactile information detection scheme, it designed the signal switch and amplification circuit. Applying P-control which automatically match charge injection error produced by analog switch to effectively overcome the key technical difficult in parasitic capacity refrain. It is mainly manifested as follows:1) Mathematical model of three-dimensional fingertips flexible tactile sensor is established by using Matlab and ProE.3d printer is utilized to implement sensing mechanism and sensor unit sample.2) This paper is set mathematical model of three-dimensional fingertips flexible tactile sensor axial force based on elasticity. The static charge leaking problem of PVDF is analyzed by piezoelectricity. This article is built a distortion model could compensate low frequency distortion by borrowing pre-distortion theory. The tangential force applies on sensor is solute by comparison with the deflection curve equation of sensor connecting is calculated by using girder flexural deformation theory in engineering mechanics and stress curve equation of the sensor unit is fitted on the least squares principle.3) By adopting capacity amplifier, it built micro-capacity switching circuit. By using PID control strategies, a P-control is designed for automatic match charge injection error produced by analog switch to effectively overcome the key technical difficult in parasitic capacity refrain. Finally, it analyses the cause of parasitic capacity production by elaborate experiments.4) It explores the effect that the geometric distribution of capacitor dielectric and capacitor electrode has on sensor sensitivity and designs a butterfly plate condenser to improve sensor sensitivity. It proposes a new detection strategy, which can effectively suppress the cross-axis sensitivities of three-dimensional fingertips flexible tactile sensor units.The main innovation of this paper is:1) A distortion model compensate the low frequency distortion is set up. It solved problems such as low frequency signal distortion, leakage fast and impedance matching difficult in the PVDF piezoelectric film measuring.2) A P-control is designed for automatic match charge injection error produced by analog switch. It effectively overcomes the key technical difficult in parasitic capacity refrain.3) New test strategy and the new structure are proposed to effectively improve the sensitivity of the sensor and eliminate the coupling effect of the positive pressure and tangential force.Author:GeWeidong (School of Mechanical and Automotive Engineering)...