Data-Driven Anomaly Diagnosis for Machining Processes

To achieve zero-defect production during computer numerical control(CNC)machining processes,it is imperative to develop effective diagnosis systems to detect anomalies efficiently.However,due to the dynamic conditions of the machine and tooling during machining processes,the relevant diagnosis systems currently adopted in industries are incompetent.To address this issue,this paper presents a novel data-driven diagnosis system for anomalies.In this system,power data for condition monitoring are continuously collected during dynamic machining processes to support online diagnosis analysis.To facilitate the analysis,preprocessing mechanisms have been designed to de-noise,normalize,and align the monitored data.Important features are extracted from the monitored data and thresholds are defined to identify anomalies.Considering the dynamic conditions of the machine and tooling during machining processes,the thresholds used to identify anomalies can vary.Based on historical data,the values of thresholds are optimized using a fruit fly optimization(FFO)algorithm to achieve more accurate detection.Practical case studies were used to validate the system,thereby demonstrating the potential and effectiveness of the system for industrial applications.

The Design, Development and Implementation of the Integrated EMS/DMS for the Project of Beijing Power System

In line with the developing trend in the 90’s [1] and the requirements of the power dispatching center of BEPB(Bejing Electric Power Bureau),the open and distributed EMS/DMS SD-6000E is developed as the master station of BEPB project. Because the power system of BEPB, either the capacity of peak load, or the quantity of substations under monitoring and number of subsidiary control centers in hierarchical structure, is the largest district power system in China, in view of this situation and the significance of capital power supply, the comprehensive dispatch automation system with high reliability was planned, the integrated EMS/DMS SD6000E with multi-screen video graphic systems has been developed. This project was planned from December of 1992, started on April 30,1996, and will be completed by the end of 1998.This project is the largest EMS/DMS project in China up to now.The overview of this project, including the comprehensive requirement of EMS/DMS from BEPB, the hardware configuration design of EMS master station, the software design of SD-6000E, the integrated multi-screen video graphic systems with EMS/DMS is described in this paper. The implementation of this project is briefly described as well.

Microstructure,mechanical property and corrosion behavior of porous Ti-Ta-Nb-Zr

In this paper,biomedical porous Ti-Nb-Ta-Zr with 40%porosity and 166±21μm macro-pore size was successfully fabricated by space holder method.The microstructure,Vickers hardness,compressive and electrochemistry behavior were studied.It results that a few second phases exist inβmatrix of the porous Ti-Nb-Ta-Zr.Its Young's modulus is 0.8 GPa,close to 0.01-3 GPa for trabecular bone.The total recovery strain ratio and pseudoelastic strain ratio are 8.8%and 2.7%,respectively.It fails mainly by brittle cleavage with the fan-shaped and smooth cleaved facets.Although,local ductile fracture by a few dimples and a small amount of transcrystalline fracture with the cleavage of similarly oriented laths in a colony are observed on the fracture surface.The impedance spectrum of porous Ti-Nb-Ta-Zr has the characteristics of half capacitive arc resistance,showing good corrosion resistance in SBF solution.

Synergistic O^(2-)/Li^(+) Dual Ion Transportation at Atomic Scale

Te ion migration during electrochemical process is a fundamental scientifc issue for phase transition behavior and of technical importance for various functional devices,where cations or anions are active under electrical bias.Usually only one type of functional ion,O^(2-)or Li^(+),is activated due to their diferent migration energy barriers,cooperated by the valence change of other immobile ions in the host lattice matrix,e.g.,Co^(2+)/Co^(3+)and Mn^(3+)/Mn4+redox couples,owing to the charge neutralization.Here we select spinel Li4Ti5O12 as anode and construct an all-solid-state battery under a transmission electron microscope;a synergistic transportation of O^(2-)and Li^(+)driven by an electrical bias was directly observed at the atomic scale.A small amount of oxygen anions was extracted frstly as a result of its lowest vacancy formation energy under 2.2 V,leading to the vertical displacement of oxygen.Up to 2.7 V,an ordered phase with both Li-and O-defciency formed.Te Li^(+)and O^(2-)ions are simultaneously extracted out from the[LiO_(4)]tetrahedra due to the electroneutrality principle.Te migration paths of O and Li have been proposed and verifed by frst-principles calculations.Tese results reveal a brand new synergistic ion migration manner and may provide up-to-date insights on the transportation process of lithium ion conductors.