Research On The Online Measurement System Of Large Square Steel

As a very important industrial raw material,square steel plays a significant role inthe field of building,energy,chemical,petroleum, machinery.As a result,the qualityof the square steel directly affects the performance of work pieces which are made ofsquare steel.How to achieve an efficient online detection becomes more and moreimportant in the production process of square steel.Generally speaking,the size andsurface quality are two typical parameters of the square steel.Though there are noshortage of square steel quality detection facilities,most of them are used for smallsize ones.While the rest of them are of great expensive.So the purpose of the paper isto find a low-cost as well as high stability instrument that could be used for thedetection of the large size steels. According to the instrument existed,we haveestablished the online detection system that consists of three structured lightsensors.The sensors could grasp different parts of the steel at the same time.After asimple calibration,we can calculate the parameters of the steel. The experimentsresults reveal that the system possesses a high precision and repeatability while thesize of the steel is large.The main work of this paper are as follows:1The overall framework of the measurement system is designed. According tothe design index and the scheme of system,we determined the components which areused.And then the whole optical mechanical layout is designed.2The image processing methods which are needed in the system isselected.Image process consists of median filter,Otsu image segmentation techniquesand the centerline positioning based on the Gauss curve fitting.What’s more,Welearn that the number of sampling points have an effect on the result of the Gausscurve fitting.It is proved by experiments that we can obtain a rather better result ofthe centerline positioning, when the number of sampling points is equal to the widthof stripe.3The calibrations of the sensors in the system are completed.According to theexisted technology, a new global calibration method of multi-sensors is designed Thenew method has no special requirements on the position of the target.It is convenientto use online. 4.The relevance experiments that are included of calibration and measurement arecarried out.The sensors’ Internal external parameters are calibrated.Through theexperiments we know that the number of the feature points collected will have aneffect on the calibration result.and then determined the optimal number of the featurepoints used in the calibration At last, the steel rolling quality experiments prove thatthe system designed have a high precision and stability.