Development Of The Measuring Circuit And Digital Display System Of An Inductive Micrometer

Inductance sensor has high resolution,high reliability and extremely long service life.Inductive micrometer is a kind of developed products based on inductance sensor,has been applied to the measurement of micro-displacement for along experience.The product made abroad has very high accuracy and reliability due to the ripe technology,but it is very expensive.There are some defects in domestic inductive micrometer such as low accuracy and reliability,don't suit to precise processing technology today.The measurement system of inductance micrometer is designed in this subject on the basis of analyzing the current development of the measuring head and measuring circuit of the inductor micrometer at home and abroad and in view of the existing problems in the domestic existing system.The standard half bridge inductor probe of the Swiss TESA company is used as the sensor.The main work includes: 1.According to the working principle of the inductor micrometer,the overall analysis and design of the system are carried out,and the design ideas and plans of the combination of the software and the hardware are determined.2.Design hardware circuit.The basic function of the measuring system of the inductance micrometer is realized.The main contents include the power circuit,the application of direct digital frequency synthesis(DDS)sine signal generating circuit,AD9850 chip set AC signal amplifying circuit,band-pass filter circuit,phase sensitive detection circuit,AD sampling circuit,signal processing circuit and man-machine interface circuit MCU;3.Design software system.Coordinate a number of functions of the hardware circuit.The main contents include the control of sinusoidal signal generator,the control and communication of AD acquisition circuit,the digital filtering function of AD sampling program and the software development of humanmachine interaction function.4.First,the functions of each module are verified by experiments.Then the measurement system is fitted and calibrated by measuring the standard parts,and the accuracy and stability of the system are verified.