Combined grating micrometric displacement sensor and displacement measuring method using same

Abstract

The invention discloses a combined grating micrometric displacement sensor and a displacement measuring method using the same. The sensor comprises two groups of transmitting and receiving structures, a first moving grating, a second moving grating, a first fixed grating, a second fixed grating, a high reflecting layer, a first fixed base, a second fixed base, a zigzagged cantilever, an upper layer plate capacitor, a lower layer plate capacitor, a signal processing module and a current driving module. According to the invention, the volume of the system is reduced greatly, comb-type electrodes and plate capacitors are used as electrostatic forces recovery closed-loop devices to detect placement precisely and enlarge dynamic range of the detector, the maximum slope location of smooth light intensity changing signals produced by another group of grating is locked through pulse light intensity changing signals produced by a group of grating to detect the placement to realize miniaturization and high precision of sensing systems and the combined grating micrometric displacement sensor and the displacement measuring method using the same are wide in application prospect in the fields of aviation and military.

Description

technical field [0001] The invention relates to the technical field of sensors, in particular to a combined grating micro-displacement sensor and a method for measuring displacement thereof. Background technique [0002] In recent years, with the development of integrated circuit manufacturing technology and micro-machining technology, micro-mechanical sensors based on these two manufacturing technologies have developed rapidly. With its small size, light weight, low power consumption, low cost, easy integration, strong overload capability and mass production, micromechanical sensors have quickly occupied various sensor fields, such as micromechanical acceleration sensors. At present, with the improvement of the performance requirements of micro-mechanical displacement sensors, especially the continuous expansion of the application requirements of medium and high-precision displacement sensing, the research of high-precision micro-optical mechanical displacement sensors comb...

AI Technical Summary

Problems solved by technology

Although there are many types, the highest displacement accuracy of the current displacement sensor can only reach the nanometer level. A nanoscale micro-displacement measurement device is a double-grating MEMS displacement sensor designed by Sandia National Lab in the United States. To measure the small displacement, the grating is locked at the most sensitive position for measuring displacement through the change of signal light intensity. Since the light intensity change curve is relatively flat, it is impossible to accurately distinguish whether the change of light intensity is caused by the external environment or caused by displacement, so it is impossible to accurately measure the displacement. The grating is locked at the most sensitive position of displacement, and the measurement accuracy is not high

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