Weldan - Online welding inspection on flat products
Weldan (Weld-Analizer) is a density based analyzer and therefore non-contact, useful for the analysis of strip/coil/ sheet welding in industrial rolling processes. The analysis is based on the different local transparency due to thermal processes to which a given material is subjected during welding operation, so a blow or impurity inside the part which is not visible externally, as well as an uneven heating or partial fusion of the two sheets of the coils are highlighted as defects from the analysis process.
The system uses a 64, 128 or 256 linear linear sensor depending on the model and an amplitude of 5 or 10 cm can detect with a maximum precision of 0.2 mm possible imperfections following the welding process. The sensor is slid across the weld at a speed of up to 50 cm / s and acquires a linear array of values every 0.2 mm. The result is therefore a matrix of values
which with a maximum accuracy of 0.2x0.2 mm represents the virtual projection of the sheet metal portion of the solder, across the width of the coil/strip.
The analysis algorithm operates on this matrix to evaluate, by different parameters, the goodness of the welding by reconstructing from this intensity values matrix a map of values
of density, which with good approximation in a homogeneous material, represents it continuity.
The sensor is interconnected by a dual high-speed digital analog converter speed (up to 5MHz to 2x12 bit) to an ARM Cortex M7 processor with floating point processing (FPU) capable of piloting high - speed signals sensor and perform the local data analysis.
The availability of digital, Ethernet and serial inputs and outputs completes the availability of read head resources, heart of the system.
The systems requires a "learning time" with information provided by the operator which are suitable to set up "rules" to identify future similar conditions and behaviors.