In this paper, an absolute time-grating displacement sensor with high accuracy and high resolution is proposed, where primary, secondary, and tertiary stage capacitor arrays with ${M}$ , ${N}$ , and ${N}$ –1 measurement periods, respectively, are combined by a multi-stage composite method that applies the four orthogonal traveling wave signals output by the primary-stage as the excitation signals of the secondary and tertiary stages. Combining the primary and secondary stages yields sensor A, with ${M}\,\,+\,\,{N}$ measurement periods. Similarly, sensor B, composed of the primary and tertiary stages, has ${M}\,\,+\,\,{N}$ –1 measurement periods. Sensor A is used as the fine measurement component, and the phase difference between sensors A and B is used as the coarse measurement component. Absolute positioning is realized in a similar manner to a Vernier caliper measurement. The output signal of each stage includes odd harmonics, such that the measurement error of each stage contains the fourth harmonic. This is retained in the synthesis stage by the multi-stage composite method. Experimental results for a prototype sensor yield an absolute positioning error of ±200 nm over a measurement range of 200 mm. Depending on the multi-stage composite method, the measurement accuracy and resolution of the same size time-grating are improved, and the connection of the input and output are focused on a stationary component. This compact and convenient sensor has wider application prospects for machine tools and automatic machine systems.

中文翻译：

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基于多级复合法的高精度电容式绝对时间光栅线性位移传感器


本文提出了一种高精度、高分辨率的绝对时间光栅位移传感器，其中初级、次级和第三级电容器阵列具有${M}$、${N}$和${N}$ – 1个测量周期分别采用多级复合的方法进行组合，将初级输出的四个正交行波信号作为二级和三级的激励信号。将初级和次级相结合产生传感器 A，具有 ${M}\,\,+\,\,{N}$ 测量周期。同样，传感器 B 由初级和第三级组成，具有 ${M}\,\,+\,\,{N}$ –1 个测量周期。传感器A作为细测分量，传感器A和B之间的相位差作为粗测分量。绝对定位的实现方式与游标卡尺测量类似。每级的输出信号都包含奇次谐波，使得每级的测量误差都包含四次谐波。通过多阶段复合方法将其保留在合成阶段。原型传感器的实验结果在 200 mm 的测量范围内产生 ±200 nm 的绝对定位误差。依靠多级复合方法，提高了同尺寸时间光栅的测量精度和分辨率，并且输入和输出的连接集中在静止组件上。这种紧凑、方便的传感器在机床和自动化机器系统中具有更广泛的应用前景。