Research And Design Of Switching Inductive Displacement Sensor

In the rapid development of science and technology society, human beings have been in theera of information explosion, informatization and automation have become an important directionof development in the world. Sensing and inspection technology is a forefront technology ofinformation science and technology, it will become one of the compete commanding heights in thefield of information science and technology of the21st century.As a device,which can convert a specific information into some available signal output with acertain rules, sensor is not only a component to realize automation, but also a bridge of electronicsystems and a variety of non-electric field,it is also the most important part of the test automaticcontrol, all of the accurately test and control will not be achieved if there is no sensor to accuratelycapture and convert the original information.Without accurate and reliable sensor, there is no accurate and reliable automatic detection and system control. So in the field of access toinformation, signal measurement, industrial automation and many others sensing technology playsa key pillar of the role, as one of the three pillars of modern information industry it has become theimportant development direction all over the world.In our daily life and work, we often measure small displacement with high-precision. The datawhich is obtained by using the traditional measurement tools such as vernier caliper、spiralmicrometer and others can not meet the needs of the measurement accuracy. Based on thisbackground, this paper studied a switching inductance displacement sensor, it uses switch chargeand discharge method to detect inductor signal, in order to achieve the measurement of thedisplacement signal. This sensor has a high accuracy and a high resolution, at the same time it hasa number of advantages,such as simple structure, strong anti-interference ability and reliable, andthus meet the needs of the general experimental and production conditions of the displacementmeasurement accuracy.First, this paper describes the background and significance of the research, and then elaborates the development situation and application prospect of inductance displacement sensor,inthe end,does a brief description of the displacement sensor types, principle and characteristics.Second, the working principle of switching inductance displacement sensor is introduced,afterthat, this paper does a illustration of the whole system architecture of sensor displacementmeasurement system, the system is composed with the following two parts:sensor displacementmeasurement part and the data signal collecting and processing section.After that,the traditional inductance detecting circuit is described in this paper,based on all ofthese,the principle of switch charge and discharge method inductance detection is proposed,andthen analysis the influence which may caused by the use of different core material.At the same time,the modules of switching inductance displacement sensor measurementcircuit are designed,the main parts of this modules are as follows: charge constant current sourcemodule,providing stable constant current for the charging process;diode dischargemodule,finishing the transformation of inductor signal to voltage signal;signal conditioningmodules,achieving the amplification comparison of voltage signal and the conversion into electrical signals;PWM signal generation module and signal acquisition module,single-chipoutputs a PWM signal to real-time control the switch, to complete the process of charging anddischarging of inductance, after the selection of enable signal,the electrical signal is sended intothe micro-controller,and then is converted into timer count value.Thirdly, using switch charge and discharge method to do inductive detection experiments ondifferent core materials, through the analysis of the experimental data has proved the feasibility ofswitching charge and discharge method, and then test the performance of the switching inductancedisplacement sensor, through the analysis of displacement measurement data, proving that theswitching inductance displacement sensor can meet the basic requirements of the displacementmeasurement.