Design And Implementation Of Portable Flatness Measurement System For Steel Plate

Flatness is a key index that reflects the shape quality of plate(strip).In the production process of steel enterprises,the flatness of plates usually needs to be measured and evaluated.However,due to the production batch etc,there are a lot of phenomena that the flatness measurement object and place are not fixed,and the flatness measurement equipment installed on the base no longer meets the measurement requirements.On this background,this paper has carried on the related research of the portable flatness measurement system,aiming to provide technology and method support for the research and development of the portable flatness measurement system.Firstly,the contact and non-contact flatness measurement methods were introduced.Then the research status of contact and non-contact flatness measurement technology was stated,the actual demand and existing problems of flatness measurement in China’s steel enterprises were summarized.According to the definition of flatness,the flatness measurement was transformed into the measurement of plate surface height.A flatness measurement method based on laser dot matrix was proposed,the calculation model was established,and the overall design scheme of portable plate flatness measurement system was given.Secondly,the principle prototype of the portable plate flatness measurement system was developed.On the basis of determining the overall scheme of the portable plate flatness measurement system,hardware selection have been done.After that,the connecting and debugging of the hardware system have been performed.The mechanical structure and parts were designed according to the selected hardware,and the deformation and stress of the main bearing structure were analyzed through the finite element analysis software to guide the structural design and selection of structural materials.The principle prototype of the measurement system was manufactured.According to the requirements of measurement,the upper computer software of measurement system was developed based on the multi-threaded programming method.Thirdly,the error factors of the measurement system were studied and the error was compensated.As one of the main error sources of distance sensors,the relationship between its tilt angle and measurement error was studied,and the error compensation was carried out according to the change law.The two degree of freedom platform is another main error source,the position error model of two degree of freedom platform was established based on the error modeling theory of multi-body system,and the influence of each error on the measurement accuracy was compared by simulation.According to the simulation results,the design and manufacture of the flatness measurement system were required,and the error angle obtained was compensated to the three-dimensional coordinate transformation model of the laser dot through the calibration experiment of the platform.Finally,the flatness study of plate was carried out.The rubber block was added at different positions at the bottom of the plate to cause different deformation of the plate.Then,the system was used to measurement the deformed plate.The three-dimensional shape and contour curve of the results are consistent with the actual plate,so the system meet the measurement requirements.The feasibility of the practical application of the portable plate flatness measurement system was verified by experiments.