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A web based remote monitor & control system for grinding process is presented. In this system, OPC/Socket drive technology, CAN bus technology, B/S structure, Java Applet and ActiveX etc. are used to realize the remote monitor & control, and grinding processes in different place can be monitored and controlled by remote grinding expert only through browser, so it overcomes the shortage that the grinding quality depends on skilled workers and variants with grinding operators. The data processing and feature releasing method of AE signals in grinding process also be discussed. The grinding state feature information can be updated automatically, and be browsed by remote experts through running the ActiveX in the browser. Therefore, it is of important significance for improving workers’ working environment and work-piece quality.

SummaryThe gradient preconditioning approach based on seismic wave energy can effectively avoid the huge storage consumption in the gradient preconditioning algorithms based on Hessian matrices in time-domain full waveform inversion (FWI), but the accuracy is affected by the energy of reflected waves when strong reflectors are present in velocity model. To address this problem, we propose a gradient preconditioning method, which scales the gradient based on the energy of the "approximated transmitted wavefield" simulated by the nonreflecting acoustic wave equation. The method does not require computing or storing the Hessian matrix or its inverse. Furthermore, it can effectively eliminate the effects caused by geometric diffusion and non-uniformity illumination on gradient. The results of model experiments confirm that the time-domain FWI using the gradient preconditioning based on transmitted waves energy can achieve higher inversion precision for high-velocity body and the deep strata below when compared with using the gradient preconditioning based on seismic waves energy.