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Research On Acquisition And Processing Of The Signal From Disk-Shaped Grating Type Displacement Sensor

Posted on:2013-11-29Degree:MasterType:Thesis
Country:ChinaCandidate:J LuoFull Text:PDF
GTID:2248330395977155Subject:Measuring and Testing Technology and Instruments
Abstract/Summary:PDF Full Text Request
The grating type sensor is widely applied in displacement measurement, whichincludes grating, inductosyn, and magnetic grid. With the rapid development of scienceand technology, the displacement measurement requirements a higher accuracy, reliabilityand precision. The disk-shaped gate displacement sensor which we show in this paper is aoutcome of our group to explore high-precision displacement measurement. This sensor isnew type sensor based on MEMS processing technology. Theoretically, the original signalof the disk-shaped gate displacement sensor has a higher accuracy than inductosyn’s. Themain part of the thesis is Research the signal extracting and processing technology of thedisk-shaped grating type displacement sensor. Our work includes the following aspects.1. Through analyzing the disk-shaped gate displacement sensor measuring principle,the characteristics of the sensor principle and its output signal were introduced incomparison with inductosyn. Theoretical analysis indicates the original signal of thedisk-shaped gate displacement sensor has a higher accuracy than inductosyn’s. Throughanalyzing the characteristic of the sensor and the main division theories, we haveconstituted the measurement scheme of the sensor based on division theory of phasedemodulation which measuring space by time.2. The extraction of the tiny signal from the sensor was studied. Through building themodel of noise of the pre-amplifier, analyzing the impedance-match problem of the sensorand the pre-amplifying circuits for the purpose of the minimum SNR. Signal acquisitioncircuit was designed. Simulation results demonstrated the efficiency and consistency of thedesign by use NI multisim11.0.3. Displacement measurement system of the sensor is designed. FPGA is used as thesystem’s control and signal processing center, which not only reduce the volume of thecircuits and shorten period of development, but also make it’s to upgrade and improve theperformance of the system because of its programmability. FPGA’s hardware architecturecan make it has higher processing speed and reduce the signal disturbance.Anti-interference measures of the hardware circuit are designed.4. The measuring error of the disk-shaped gate displacement sensor is analyzed.Emphasis is laid on discussing the influence to measurement accuracy by processing errors,electrical parameter errors and installation error, and having taken certain measure toreduce the affection by these errors. 5. Static measuring accuracy test of the measurement system of the disk-shaped gatedisplacement sensor were studied. Grating with high accuracy is used as the measuringdatum. The results indicate that the static measuring accuracy can be±3.2".This studydemonstrated the validity of our sensor principle and proved feasibility of the measurementscheme.To sum up, the measurement scheme of the disk-shaped gate displacement sensorbased on division theory of phase demodulation has constituted which measuring space bytime. Tiny signal acquisition circuit and the measurement system of the sensor weredesigned. The measuring error of the sensor is analyzed and the static measuring accuracytest is analyzed. This study demonstrated the validity of our sensor principle and provedfeasibility of the measurement scheme. The usage of division theory of phasedemodulation and the study of tiny signal acquisition method have great reference insubsequent studies of this topic.
Keywords/Search Tags:grating type displacement sensor, tiny signal, noise model, measurementsystem
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