Gabriel Zambrano

Multi-Agent Systems (MAS) are particularly adapted to deal with dynamic distributed environments and are typically used to manage business workflows or data flows in manufacturing systems. But, the lack of a global view and reference of the whole system by the low-level and physical parts, to actually guarantee optimal decision-making had been labelled by some researchers as ‘Myopia’. Thus, this paper intents to identify some Myopias, involved in a decentralised management of production systems. A HoloMAS (HolonicMultiAgent System), whose elementary parts show signs of myopia, is defined; and we validated our HoloMAS proposal using simulations and through a real implementation on a flexible assembly cell in our university lab.

This paper presents a formalization of a solution to control the myopia and its impact on performances of Flexible Manufacturing Systems (FMS) controlled by intelligent products. The model is based on the concept of the functional roles in Multi-Agent Systems which is described through a brief state of the art. Then this concept is applied to the control of a FMS. Entities, their roles, their knowledge and behaviors are explained in details. Finally, the proposed solution is implemented at the AIP-PRIMECA FMS of Valenciennes and some experimental results are given.

Mechanical and electrochemical surface properties of Si (100) and AISI D3 steel substrates-coated Ti–W–N, deposited by r.f. magnetron sputtering process from a binary (50% Ti, 50% W) target in an Ar/N2 (90%/10%) mixture, have been studied using nanoindentation, Tafel polarization curves and electrochemical impedance spectroscopy (EIS). The crystallinity of the coatings was analyzed via X-ray diffraction (XRD) and the presence of TiN(111), TiN(200), WN2(107), and W2N(220) phases were determined. Depth sensing nanoindentation measurements were used to investigate the elasto-plastic behavior of Ti–W–N coatings. Each group of samples was deposited under the same experimental conditions (power supply, Ar/N2 gas mixture and substrate temperature), except the d.c. negative bias voltage that varied (0, −50, and −100 V) in order to study its effect on the mechanical and electrochemical properties of AISI D3 steel coated with Ti–W–N coatings. The measurements showed that the hardness and elastic modulus increase from 19 to 30 GPa and from 320 to 390 GPa, respectively, as a function of the increasing negative bias voltage. Coating track and coating-substrate debonding have been observed with atomic force microscopy (Asylum Research MFP-3D®) on the indentation sites. Finally, the corrosion resistance of Ti–W–N coatings in 3.5 wt% NaCl solution was obtained from electrochemical measurements in relation to the increase of the negative bias voltage. The obtained results have shown that at the higher negative bias voltage (−100 V), the steel coated with Ti–W–N coatings presented the lower corrosion resistance. The corrosion resistance of Ti–W–N in 3.5 wt% NaCl solution was studied in relation to the increase of the bias voltage.

The mechanical and electrochemical properties of Ti-W-N films deposited onto Si and AISI D3 steel subtrates by d.c. magnetron co-sputtering process have been studied using nanoindentation, Tafel polarization curves and electrochemical impedance spectroscopy (EIS). The active vibration modes were studied using Fourier transformed infrared spectroscopy (FTIR), finding bands associated to Ti-W-N, δ(O-W-O) and W-N-W bonds for stretching vibrations of groups

Corrosion-resistance behavior of titanium carbon nitride (Ti-C-N) and titanium niobium carbon nitride (Ti-Nb-C-N) coatings deposited onto Si(1 0 0) and AISI 4140 steel substrates via r.f. magnetron sputtering process was analyzed. The coatings in contact with a solution of sodium chloride at 3.5% were studied by Tafel polarization curves and impedance spectroscopy methods (EIS). Variations of the bias voltage were carried out for each series of deposition to observe the influence of this parameter upon the electrochemical properties of the coatings. The introduction of Nb in the ternary Ti-C-N film was evaluated via X-ray diffraction (XRD) analysis. The structure was characterized by using Raman spectroscopy to identify ternary and quaternary compounds. Surface corrosion processes were characterized using optical microscopy and scanning electron microscopy (SEM). XRD results show conformation of the quaternary phase, change in the strain of the film, and lattice parameter as the effect of the Nb inclusion. The main Raman bands were assigned to interstitial phases and "impurities" of the coatings. Changes in Raman intensities were attributed to the incorporation of niobium in the Ti-C-N structure and possibly to resonance enhancement. Finally, the corrosion data obtained for Ti-C-N were compared with the results of corrosion tests of Ti-Nb-C-N coating. The results obtained showed that the incorporation of niobium to Ti-C-N coatings led to an increase in the corrosion-resistance. On another hand, an increase in the bias voltage led to a decrease in the corrosion-resistance for both Ti-C-N and Ti-Nb-C-N coatings.

Tungsten carbide/diamond like (W–C/DLC) multilayers have been investigated as low friction coatings on high-speed steel substrates. The coatings are composed of a W–C multilayer base and an upper lubricious DLC layer and they are obtained by reactive rf ...

TiC monolayers were deposited onto the AISI 4340 and 2311 steel substrates by using the Pulsed Laser Ablation PLA technique. A Nd: YAG laser 1064 nm, 500 mJ and 7 ns, with a repetition rate of 10 Hz was used. The topography and surface morphology of the samples were characterized by Scanning Electron Microscopy, SEM, and Atomic Force Microscopy AFM.

Ni doped Tungsten Carbide thin films (WC+Ni) were deposited onto stainless steel, WC–Co and glass substrates by non-reactive d.c. magnetron sputtering process using a sintered WC–6% Ni target. The WC+Ni hard coating films had thicknesses between 0.6 and 1.5 μm and were deposited at temperatures between 300°C and 550°C. The structure of the films was characterized using X-ray Diffraction (XRD),

In this work carbon nitrate CNx thin films have been deposited by a reactive r.f. magnetron sputtering technique. During the growth of the films bias voltage between 0 to -200V were applied to the substrate. In-situ Characterization of the plasma using a simple electrostatic Langmuir probe permitted determination of the electronic temperature Te (approximate 8 - 11 eV). The films