A new kind of volume control hydraulic press that combines the advantages of both hydraulic and SRM(switched reluctance motor) driving technology is developed.Considering that the serious dead zone and time-variant no...A new kind of volume control hydraulic press that combines the advantages of both hydraulic and SRM(switched reluctance motor) driving technology is developed.Considering that the serious dead zone and time-variant nonlinearity exist in the volume control electro-hydraulic servo system,the ILC(iterative learning control) method is applied to tracking the displacement curve of the hydraulic press slider.In order to improve the convergence speed and precision of ILC,a fuzzy ILC algorithm that utilizes the fuzzy strategy to adaptively adjust the iterative learning gains is put forward.The simulation and experimental researches are carried out to investigate the convergence speed and precision of the fuzzy ILC for hydraulic press slider position tracking.The results show that the fuzzy ILC can raise the iterative learning speed enormously,and realize the tracking control of slider displacement curve with rapid response speed and high control precision.In experiment,the maximum tracking error 0.02 V is achieved through 12 iterations only.展开更多
Co-based Co63Fe4B22.4Si5.6Nb5 amorphous ribbons with a width of 150 μm and a thickness of 50 μm were prepared by single-roller melt-spinning process.The giant magneto-impedance(GMI) effect of the stress-joule-heated...Co-based Co63Fe4B22.4Si5.6Nb5 amorphous ribbons with a width of 150 μm and a thickness of 50 μm were prepared by single-roller melt-spinning process.The giant magneto-impedance(GMI) effect of the stress-joule-heated ribbons under applied tensile stress ranging from 37 to 148 MPa was investigated.Experimental results show that the spectra of GMI ratio vs.external direct current(dc) field(Hex) of the samples changes dramatically with annealing tension() and driving frequency.The single-peak(SP) GMI curve with maximum GMI ratio of 260% and magnetic field sensitivity of 52%/Oe was obtained in the sample applied tensile stress of 74 MPa at frequency of 3.6 MHz.A three-peak behaviour appeared in the samples under σ of 111 and 148 MPa.The uncommon three-peak behaviour was attributed to several factors,which effectively originated from the balance between domain-wall movement and magnetization rotation.展开更多
基金Project(2007AA04Z144) supported by the National High-Tech Research and Development Program of ChinaProject(2007421119) supported by the China Postdoctoral Science Foundation
文摘A new kind of volume control hydraulic press that combines the advantages of both hydraulic and SRM(switched reluctance motor) driving technology is developed.Considering that the serious dead zone and time-variant nonlinearity exist in the volume control electro-hydraulic servo system,the ILC(iterative learning control) method is applied to tracking the displacement curve of the hydraulic press slider.In order to improve the convergence speed and precision of ILC,a fuzzy ILC algorithm that utilizes the fuzzy strategy to adaptively adjust the iterative learning gains is put forward.The simulation and experimental researches are carried out to investigate the convergence speed and precision of the fuzzy ILC for hydraulic press slider position tracking.The results show that the fuzzy ILC can raise the iterative learning speed enormously,and realize the tracking control of slider displacement curve with rapid response speed and high control precision.In experiment,the maximum tracking error 0.02 V is achieved through 12 iterations only.
基金supported by the National Natural Science Foundation of China(Grant Nos.50825103 and 51271194)Ningbo Science and Technology Innovation Team(Grant No.2011B82004)Equipment Project for Research of the Chinese Academy of Sciences(Grant No.Y2010010)
文摘Co-based Co63Fe4B22.4Si5.6Nb5 amorphous ribbons with a width of 150 μm and a thickness of 50 μm were prepared by single-roller melt-spinning process.The giant magneto-impedance(GMI) effect of the stress-joule-heated ribbons under applied tensile stress ranging from 37 to 148 MPa was investigated.Experimental results show that the spectra of GMI ratio vs.external direct current(dc) field(Hex) of the samples changes dramatically with annealing tension() and driving frequency.The single-peak(SP) GMI curve with maximum GMI ratio of 260% and magnetic field sensitivity of 52%/Oe was obtained in the sample applied tensile stress of 74 MPa at frequency of 3.6 MHz.A three-peak behaviour appeared in the samples under σ of 111 and 148 MPa.The uncommon three-peak behaviour was attributed to several factors,which effectively originated from the balance between domain-wall movement and magnetization rotation.
