Time-grating principle Time-grating principle
Core technology
Core technology
High precision | High resolution | Strong adaptability to the environment | Low process difficulty
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Original thought

Time is currently the physical quantity with the highest measurement accuracy for human beings, six orders of magnitude higher than space. In the International System of Units, "meter" is defined in terms of time, and the highest length datum is traced back to time.

In 1996, Professor Peng Donglin initially proposed the new idea of "Building a high-speed uniform motion as a time reference and achieving displacement measurement through the time comparison ", the original academic idea of "Using time pulses to form a reference for space displacement measurement" and the significant invention of "Time-grating Sensing" gradually formed. Generally speaking, it is to observe each other in two coordinate systems, and the difference in position (displacement) of one side is shown as the difference in time observed by the other side.

Professor Liu Xiaokang and his team have continuously iterated the time-grating sensing technology. In 2010, they proposed to use an electric field which is orthogonally changed  to construct an equivalent spatial domain motion as a motion reference system which was called "Nanometer Time-grating". By simplifying and optimizing the transfer process of time reference, scientifically shortening the length of the time reference transfer chain, and improving the uniform velocity of the motion reference system, the measurement accuracy has improved and the leap of precision from millimeter to micron to nanometer has gradually realized.

development history
The concept of time-grating was proposed for the first time, forming the original academic thought of "Space-time transformation";
Using the motor rotation to form a motion reference system, the prototype based on the time-grating principle was developed with an accuracy of ±34". Many experts from the National Fund Commission fully affirmed the originality of the time-grating technology;
Using the rotating magnetic field to form a motion reference system, the second generation of magnetic-field time-grating was developed with an accuracy of ±0.8" and evaluated by the National Fund Commission as" Internationally advanced, and the principle is the initiate at home and abroad";
The first prize of the Technological Invention Award in Chongqing, China;
The gold medal of China Patent;
The second prize of National Technology;
The thought of nanometer time-grating was proposed for the first time, and the third generation electric-field time-grating was developed by using alternating electric field to form a motion reference system;
Time-grating technology was listed as one of the 27 typical achievements of the Department of Engineering and Materials by the National Natural Science Foundation during the "11th Five-Year Plan" period, and was incorporated into many classic universities textbooks in the field of mechanical precision measurement;
The error curve of the horizontal grating with the world's highest precision was measured for the first time by using the angular nanometer time-grating displacement sensor;
Verified by the National Institute of Metrology, China, the nanometer linear time-grating displacement sensor had an accuracy of ±96 nm and a resolution of 1nm within the range of 400 mm, and the performance index had reached a globally leading level;
Verified by National Institute of Metrology, China, the nanometer angular time-grating had an accuracy of ±0.06" and a resolution of 0.01" within any range of 360°, and the performance index had reached globally leading level in an all-round way;
In April 2011, Genertec Guoce Time Grating Technology Co., Ltd was established;
As 35 representative key projects, nanometer time-grating technology was selected for China’s "13th Five-Year Plan" Science and Technology Achievement Exhibition as well as won the first prize of Chongqing Technology Invention Award in China;
The nanometer time-grating technology was selected into the promotion activities of "Coordinate China", and was widely reprinted by powerful media platforms;
The nanometer time-grating technology, as one of the landmark achievements of the decade, was selected for the exhibition "Forging Ahead in the New Era".
technical advantage
High precision
using the orthogonal electric field to improve the uniform speed of the moving reference system, with the theoretical basis for achieving high precision displacement measurement;
High resolution
The use of high-frequency time pulse to achieve the subdivision of the spatial grating-surface, providing a scientific basis to achieve the measurement resolution of nanometer level;
Strong environmental adaptability
The non-contact sensing method with electric field coupling provides the principle guarantee to adapt to harsh environments such as oil, dust, shock, and vibration;
Low process difficulty
The sensing structure of sinusoidal "grating-surface" avoids the dependence of high-precision displacement measurement on high-precision "grating-line" manufacturing.