Plate Shape Detection Based On Eddy Current

Cold rolled strip is a main product with high technology and high added value in iron and steel industry.It provides strong support for the production and processing of many industries.Flatness is an important index for measuring the quality of cold rolled strip.Therefore,the study of flatness detection device is an essential part in the production process of cold rolled strip.Shape detection is a more complex detection process.In addition to all kinds of high precision sensors,exciter,roller shaft and other auxiliary equipment,various theoretical algorithms are needed to support.At present,with the deepening of the research on the shape detection,people have studied a variety of detection methods,such as thickness measurement,vibration measurement,electromagnetic method,tensiometry,electromagnetic method,temperature measurement,optical method,water column method,etc.According to the different location of detection,it can be divided into contact detection method and non-contact detection method.At present,our country's plate testing instrument is still mainly imported from foreign countries,mainly using the section detection roll type plate meter of air bearing of DAVY company of England and the section detection roll type detector of Sweden ABB company.Most of the domestic plate testing instruments are still in the stage of theoretical research and experimental development,but through the unremitting efforts of various scientific research units for many years,our country has basically had the ability to produce a variety of plate testing equipment.From the point of view of detection means,the current contact shape tester still dominates the main market and the market share of the contactless flatness detection device is still less.However,from the perspective of future development,the contactless flatness instrumient occupies the advantages of simple structure,convenient installation and low maintenance cost.Basecd on the above factors,we will study the plate shape tester based on eddy current.The plate type detector is classifiecd according to the detection method ancd belongs to the vibration measurement method.According to the detection principle,it belongs to a non-contact plate shape detector.According to the Euler beam model of vibration mechanics,the basic inspection principle of the detector is divided into 20 longitudinal fiber strips,which are 1 meters long.The plate is excited by an electromagnetic exciting array,and the amplitude of 20 longitudinal fiber strips is measured by 20 electric eddy current sensor arrays with a diameter of 5 centimeters.According to the difference of the length of the 20 longitudinal fibers,the distribution of the amplitude and the residual stress inside the plate is different,so that the shape defects can be obtained.On the basis of the above principles,the first part of this paper is mainly about the research background and significance of the shape detection,the status of the plate shape research at home and abroad,the concept of plate shape and the shape defect of the plate.In the second part of the article,the basic principle of shape detection is briefly introduced,and the relation between amplitude and inductance,internal stress and amplitude is established,and the relationship between inductance and amplitude is established.The third part of the article mainly introduces and analyses the design of the eddy current sensor,including the background and significance of the research on the eddy current sensor,the classification of the non-contact displacement sensor,the winding method of the eddy current sensor coil,the detection principle and the hardware circuit of the electric eddy current sensor.The design,the upper computer and the measurement process.The fourth part of the article is mainly about the construction of the experimental platform based on the eddy current plate detector,which mainly includes the construction of the eddy current sensor array,the measurement of the eddy current coil and the hardware circuit design of the electromagnetic vibration exciter.