An Application Of Wavelet In The Surface Evaluation

The technology of electrospark maching is an important maching technology, which plays a very important role both in civilian and military equipment producting. Whether the maching technology of accessories is advanced or not, is determined by the level of surface roughness mostly. A mashing technology is advanced with a low level of surface roughness, otherwise the technology is disadvanced. A accessory with a low level of surface roughness not only looks beauty and durable, but also gives an guarantee to work well. So it is very important to evaluate the level of surface roughness of a accessory, which is processed by eletrospark maching technology. However, there is no uniform standard for 3D surface roughness evaluation, the work is very difficult.Traditional surface roughness evaluation has a limited capability to deal with the multi-scale of the surface; however, the wavelet does well by separateing roughness form surface with different scales. The basis of wavelet is continuous and there is no specific function form. The decomposion is easy to put in practice. Because of the capability of multi-scales and local time-frequancy, the wavelet deals with defferent roughness by distinguishing, separating and constructing.The innovative work in the pater is listed as follow:1. We get eigiht groups 2D datas by lineation and separate them into different scales by using the methord of multi-scale annlysis in wavelet theory, then dispose and construct them. The smoothness of new datas are much better.2. The roughness parameters which are calculated by the new datas are ideal.3. We do a lot of researches in the 2D roughness parameters and extent them into 3D situation, they are 3D arithmetic average warp parameter and 3D surface maximum height parameter. Then we do some computing by simulaition and discuss the meaning and establishing for the 3D roughness parameters.4. We do some 3D roughness parameters' approximation by 2D methords. And we compare two 2D measure methords, and then do some analysis.