New Type Timegrating Displacement Sensor

Precise measurement technique is an important means to guarantee product quality and also an important tool for scientific researches. Displacement measurement is the most basic geometrical quantity measurement. It exists massively in production practice and the science practice, especially in the manufacturing industry. The grating type sensor is widely applied in displacement measurement. Funded by National Natural Science Foundation of China(NSFC), this paper theoretically and practically develops the researchs on the principle fusion of optical grating, inductosyn and timegrating and new type timegrating sensor. The main contents and innovation are as follows:①Two essential methods of displacement measurement are discussed based on two mathematics description of displacement. And then, the concept of space grating sensor and time grating sensor is proposed. The space grating sensor takes spatial reference and uses the direct measurement method. The time grating sensor takes time reference and uses the indirect measurement method.②On the view of space and time, the essence of three working methods of tranditional grating type sensors are analyzed and compared with the principle of timegrating.③Magnetic field in field type timegrtaing sensor was analyzed. The traveling wave in timegrating is divided into"the spatial traveling wave"and"the time traveling wave". The former is a signal on space domain. Its'wave moves on the space when the time passes. The latter is a signal on time domain. Its'wave moves on the time when the displacement takes place. Explain the principle of timegrating with the traveling wave viewpoint. And takes a conclusion that the traveling wave on time domain is the key to realize space and time coordinates transform.④Two methods to generate traveling wave on time domain are proposed. According to these methods three types new timegrating sensor are designed and developed.1) G-E type timegrating sensor uses the two-lever construction. Two windings on the top and bottom lever are orthogonal on space domain and exert drive signals which orthogonal on time domain. They generate orthogonal standing wave magnetic field. The windings on stator induce electric current from both two magnetic fields at the same time and form an electricity traveling wave signal.2) V-C type timegrating sensor uses two plane gears and two transformers to generate the electricity standing waves and then add up to form a electricity traveling wave signal.3) O-E type timegrating sensor uses the low resolution optical grating as the signal generator of two orthogonal space signals. After modulated by two orthogonal time signals and added up each other, electricity traveling wave signal also formed.⑤Experiments were taken to prove the feasibility and test the performances of the new timegrating sensors.⑥Analyze the error of timegrating sensor. Discussed the processing error, the assembling error and the electrical parameter error how to influence the time grating sensor's final measuring accuracy.In summary, after analyzing the methods of displacement measurement, this paper proposes two new methods to generate traveling wave based on merge the technologies of tranditional grating sensor and timegrating sensor. Three new timegrating sensors are developed. It is not only an improvement to the existing timegrating using electromagnetic field, but also an attempt to extend research thought to optical field. Through the error analysis, point out the factors which influence the precision of timegrating sensor and the characteristic of error. According to the error characteristic, a new method to measure timegrating sensor's error was proposed.