Flatness calculation of metal stream

Abstract: This thesis project comprises a review of documentation/programmer code, and the creation of the algorithm for calculation of the flatness. The old program "PLANHETSMÄTNING 839:2" is written in DOS. The algorithm has now been applied in LabVIEW and the performance has been compared with the old program. In this thesis project I have examined the definition for the available flatness calculation program. Flatness is defined as the space between maximum and minimum value at the flatness curve. To get the maximum and minimum value, you must calculate, evaluate and adjust the collected data. This is done with "PLANHETSMÄTNING 839:2". The restriction in the old DOS-program was the number of samples and the max breadth. The max number of sample was 2 600 and the maximum breadth at stream was 260 mm. The measurement is now done with an inductive sensor, which gives an optimal linearity, high resolution and accuracy. The analogue exit from the inductive sensor A/D-transforms with a collector card. In the new program "PLANHETSMÄTNING 839", already existing functions are used. These functions convert volt to mm, calculate the maximum and minimum value on the plot curve, and work on already collected data. These functions are adjusted, depending on how you want them to work. There are some restrictions in the thesis project. One is that the saved measure files are not processed, and that the inductive sensors only manage very careful measurements on flatness, at the intervals of 0-1 mm. The movement stretch, which the inductive sensor does during the measurement, is limited to 350 mm, which means that the max breadth on strip bit can not exceed 350 mm. The performance was compared by measuring a calibrated strip bit with both programs, but where the flatness was compared. Approximately 40 measurements were done on the calibrated bit, and the flatness was calculated. The arrow peak with the old program was calculated to 0,07+/- 0,01 mm compared to 0,06 + 0,01 and 0,06 – 0,00 mm, which was calculated with measurements from the new program. The flatness measured with the new program lies within the intervals.