Research On Several Problems Of High Precision Differential Inductive Transducer For Roundness Or Cylindricity Measuring Instrument

Measurement technology has become the main technology which restricted thedevelopment of machining. Roundness or cylindrical measuring instrument hasprovided an effective means of measuring in aerospace, automotive, bearings,optical and other Ultra-precision machining manufacturing. Because of its highresolution, noise immunity, and simple structure, the inductive transducer has beenthe core technology in roundness or cylindrical measuring instrument. Therefore,the study of high-precision sensor technology has become a very important task.Against this background, the inductive transducer used in roundness or cylindricalmeasuring instrument was talked about in this paper; the main contents are asfollows:Firstly, the differential coil of inductive transducer that used in roundness orcylindrical measuring instrument was studied in this paper. And analyzed how thequality of the differential coils impact transducer’s resolution, sensitivity and range.So more attention was paid to differential coils’ study. And for the conventionalmethod of uniformly wound coil, introduce a new type of step wingding coil.Because of the differential coil contains two coils, the bad effect on the sensor’soutput voltage due to the differential coil’s asymmetry parameter was also discussedin this article. And some simple ways was listed in the test to eliminate the badimpact on sensor’s output voltage caused by the differential coil’s asymmetricparameters.After that, transducer’s static and dynamic characteristics, was researched inthe paper. And the static and dynamic characteristics of transducer directly reflectits quality. But in the process of sensor’s manufacturing, it’s inevitably willimporting errors and deviate from the ideal design. In view of this deviation, thecompensation method was considered in the text. The measurement accuracy can beimproved in the actual measurement process, by compensating the sensor’scharacteristics. The dynamic model of the sensor system should be created beforecompensate the sensor’s characteristics. And errors will be inevitably generatedfrom the modeling process. Therefore, the article discussed how the sensor’smodeling error affect the compensation effect.Furthermore, this paper optimized the signal processing of the differentialinductive sensor. In this part, the stability of filter, circuit design optimization andhow signal processing of the sensor works were mainly talked about, and improvedthe performance of previous acquisition card. At last of this part, the effect was compared between the latest and previous acquisition card.Finally, in this paper, is the experimental section. During the experiment, thesensor’s static and dynamic characteristics were mainly verified. Through theexperiments we know that the resolution of sensor is15nm in460μm range and5nm in70μm range. It can meet the high-precision measurement requirements ofroundness or cylindricity measuring instrument. The compensation of sensor’sdynamic characteristic was verified at the same time during the experiment. And thesensor’s dynamic response frequency was increased from312Hz to381Hz aftercompensation. And finally decreases the measuring time.