提高容栅位移传感器精度的有效方法

为解决环境温度变化、尺体导轨加工误差以及边缘效应等因素对容栅位移传感器测量精度的影响,提出了三极板结构、周期比较测量以及分段采用正余弦极板分段数据处理的方案。三极板结构中动极板仅起屏蔽作用,可以降低对尺体导轨加工精度的要求;周期比较测量在提高系统温度稳定性的同时,由于采用了全数字电路的实现方式能有效降低专用集成电路的设计、制作成本;交替使用正余弦极板的读数避开边缘效应的影响。理论分析和实验结果证明了该方案的可行性。

Effective ways to improve accuracy of capacitive grating displacement sensor

To eliminate or reduce the influence of temperature,manufacturing tolerance and edge effect,etc. on measuring accuracy of the sensor,tri-electrode setup,period-compare measurement and sine-cosine electrode scheme are put forward.The slide electrode of tri-electrode is just for shielding,and this structure can reduce the requirement of manufacturing tolerance;period-compare measurement can improve the sensor's temperature stability;digital circuit is used to reduce the design and manufacture cost of IC effectively;alternately using the data of sine or cosine electrode can avoid the influence of edge effect.Theoretical analysis and experimental data show the feasibility of the scheme of capacitive grating system.