Study On New Type Variable Reluctance Measurement System Of Time Grating Based On Construction Of Standard Parts

Precision measurement technology to ensure that the processing quality is one of important means,which results directly determine the quality of the product.Displacement as a fundamental physical quantity,mass production practices need to be precision measured.To the grating as the representative in the traditional grating type displacement sensors,the measurement accuracy of which is mainly dependent on the scoring accuracy of precision scoring techniques.Magnetic field time grating sensor by the establishment of relative motion with double coordinate system,completed the conversion with time to measure the displacement of space,realized precision measurement under the big pitch,avoided the drawbacks of traditional grating type displacement sensor which relies on precise scoring to realize the high precision measurement.But magnetic field time grating sensor proposed certain requirements to equal divided of a whole week of slotted,magnetic field time grating in all week slotted equal division is difficult to guarantee by currently mechanical grooving accuracy constraints,thereby restricted the further improvement of the measurement accuracy.Also it is difficult to assurance consistency throughout the week winding due to disadvantages which the groove spacing is small and need manual winding,then the sensor is introduced new sources of error,restricted the improvement of accuracy of sensor once again.In view of the above problems,this paper put forward a new idea with standard parts to construct the time grating,the new idea of using standard parts-needle roller which can achieve metering aliquots precision as magnetic coupling unit of the time grating,so as to improve the equal division of the entire week magnetic coupling unit of standard parts construction of the new variable reluctance type time grating,at the same time,the standard parts construction of time grating can realize the mechanization of winding of sensor,increase the winding efficiency,eliminating manual winding the introduced error,so as to achieve the purpose of improving the measurement accuracy.The main research contents of this paper are as follows: First,intensive study of space-time measurement principle,magnetic field type time grating sensing mechanism and the traveling wave synthesis method,establish the standard parts of new variable reluctance type time grating circuit mathematical model.Second,used electromagnetic simulation software,established simulation model of new variable reluctance type time grating of which is constructed by standards parts.Optimized the effective radius and the magnetic air gap length focus on the sensor.And summarized the design rules of both,established the simulation model of 90 poles,compared the simulation results between the sensor and field type time grating to get the differences between of the two.Finally,designed new variable reluctance type time grating principle prototype of 90 poles which constructed by standards parts according to the results of simulation and optimization.Third,designed the signal processing system based on SOPC technology and made the measurement system more compact,the performance of signal processing higher.At the same time,designed resistor chain phase-shift circuit to solve the problem under the low-frequency excitation source,of which the sensor' measurement rate is slower because of.which the frequency' response speed is slow.Fourth,through experimental study,verified the signals' generation of standing wave and traveling wave of the principle prototype;tested stability,precision and frequency response of new type variable reluctance type time grating measuring system by performance test experiment.The experimental results shows that time grating constructed by the standard parts can effectively improve the all week magnetic coupling unit of aliquots,which make the raw error ratio field type time grating reduced by about 50%.Finally,the accuracy of the time grating achieved within±2"after correction.At the same time,measurement rate of the design of signal processing system can be increased by 32 times to solve the problem under low-frequency excitation source of which the sensor' measure rate is slow.