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
A robust control algorithm is proposed to focus on the non-linearity and variables of the hydraulic press machine with the proportional vatve. The proposed robust controller does not need to design stable compensator ...A robust control algorithm is proposed to focus on the non-linearity and variables of the hydraulic press machine with the proportional vatve. The proposed robust controller does not need to design stable compensator in advance, which is simple in design and has large scope of uncertainty applications. The feedback gains of the proposed robust controller are small, so it is easily implemented in engineering applications. The theoretical and experimental research on the position and speed control of the hydraulic press machine is carried out. The control requirements of the hydraulic press machine during the working process are met in the position and speed at the same time. Experimental results show that the proposed controller has better robustness subject to load variables and adaptability of parameter variations of the hydraulic press machine with the proportional valve.展开更多
Taking a new type of full-fiber crankshaft forging hydraulic press as the research object,an upsetting-bending stroke coordination control is studied to improve crankshaft forming accuracy.A master-slave proportion in...Taking a new type of full-fiber crankshaft forging hydraulic press as the research object,an upsetting-bending stroke coordination control is studied to improve crankshaft forming accuracy.A master-slave proportion integration differentiation(PID)coordination control strategy based on velocity feed-forward is proposed to improve the coordination control accuracy.The structure and working process of the full-fiber crankshaft forging hydraulic press are introduced,and a mathematical model of the upsetting and bending control system are established.The coordination control strategy is verified experimentally.The experimental results show that the maximum tracking error of the coordination control strategy is reduced by 66%compared with the traditional PID controller,and the coordination motion accuracy is improved effectively.展开更多
The reliability and robustness of the electro-hydraulic servo control system for heavy-duty forging machine play an important role in forging processes. A mathematic model of 50 MN water press for free forging was cre...The reliability and robustness of the electro-hydraulic servo control system for heavy-duty forging machine play an important role in forging processes. A mathematic model of 50 MN water press for free forging was created in this research. The dynamic robust compensator integrating with PID control method is designed and applied to the mathematical model simulation. The simulated results approved that the dynamic robust compensator application restrains interference from extra load and improves the electro-hydraulic position servo control system accuracy and stability.展开更多
For an ultra-high-pressure hydraulic transmission system of a large-size hydraulic forging press(LHFP),a 70 MPa two-way proportional cartridge valve has been developed to improve the power weight ratio of the hydrauli...For an ultra-high-pressure hydraulic transmission system of a large-size hydraulic forging press(LHFP),a 70 MPa two-way proportional cartridge valve has been developed to improve the power weight ratio of the hydraulic forging press.In this study,a nominal diameter 25 mm(DN25)cartridge valve is taken as the research object.A longer concentric cylindrical annular gap is set to effectively prevent the ultra-high-pressure oil from flowing to the pilot stage and a seated valve structure is set to form the linear sealing zone in the closing state of the main valve port.Electric-displacement feedback is adopted to realize precise control of the main valve port flow and the features of this valve are investigated.In order to verify the strength and static and dynamic characteristics,the finite element model and a simulation model of the valve proposed above are built.There is a little deformation which does not affect the main valve spool movement,and the main valve port flow meets the design demands.Then,the prototype of DN2570 TPCV is manufactured and a ultra-high-pressure experimental platform is developed.The experimental results show that the DN2570 TPCV designed in this study has the advantage of fast response,high control precision,and low leakage,which can meet the requirements of LHFPs.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Shanghai Municipal Natural Science Foundation of China (No.06111003)
文摘A robust control algorithm is proposed to focus on the non-linearity and variables of the hydraulic press machine with the proportional vatve. The proposed robust controller does not need to design stable compensator in advance, which is simple in design and has large scope of uncertainty applications. The feedback gains of the proposed robust controller are small, so it is easily implemented in engineering applications. The theoretical and experimental research on the position and speed control of the hydraulic press machine is carried out. The control requirements of the hydraulic press machine during the working process are met in the position and speed at the same time. Experimental results show that the proposed controller has better robustness subject to load variables and adaptability of parameter variations of the hydraulic press machine with the proportional valve.
基金Supported by the National Natural Science Foundation of China(No.51575471)Natural Science Foundation of Hebei Province(No.E2018203028)+2 种基金Open Foundation of the State Key Laboratory of Fluid Power and Mechatronic Systems(No.GZKF-201716)the Key Project of Science and Technology Plan of Higher Education of Hebei Education Department(No.ZD2017077)National Basic Research Program of China(No.2014CB046405)
文摘Taking a new type of full-fiber crankshaft forging hydraulic press as the research object,an upsetting-bending stroke coordination control is studied to improve crankshaft forming accuracy.A master-slave proportion integration differentiation(PID)coordination control strategy based on velocity feed-forward is proposed to improve the coordination control accuracy.The structure and working process of the full-fiber crankshaft forging hydraulic press are introduced,and a mathematical model of the upsetting and bending control system are established.The coordination control strategy is verified experimentally.The experimental results show that the maximum tracking error of the coordination control strategy is reduced by 66%compared with the traditional PID controller,and the coordination motion accuracy is improved effectively.
文摘The reliability and robustness of the electro-hydraulic servo control system for heavy-duty forging machine play an important role in forging processes. A mathematic model of 50 MN water press for free forging was created in this research. The dynamic robust compensator integrating with PID control method is designed and applied to the mathematical model simulation. The simulated results approved that the dynamic robust compensator application restrains interference from extra load and improves the electro-hydraulic position servo control system accuracy and stability.
基金Supported by the Natural Science Foundation of Hebei Province(E2018203028)。
文摘For an ultra-high-pressure hydraulic transmission system of a large-size hydraulic forging press(LHFP),a 70 MPa two-way proportional cartridge valve has been developed to improve the power weight ratio of the hydraulic forging press.In this study,a nominal diameter 25 mm(DN25)cartridge valve is taken as the research object.A longer concentric cylindrical annular gap is set to effectively prevent the ultra-high-pressure oil from flowing to the pilot stage and a seated valve structure is set to form the linear sealing zone in the closing state of the main valve port.Electric-displacement feedback is adopted to realize precise control of the main valve port flow and the features of this valve are investigated.In order to verify the strength and static and dynamic characteristics,the finite element model and a simulation model of the valve proposed above are built.There is a little deformation which does not affect the main valve spool movement,and the main valve port flow meets the design demands.Then,the prototype of DN2570 TPCV is manufactured and a ultra-high-pressure experimental platform is developed.The experimental results show that the DN2570 TPCV designed in this study has the advantage of fast response,high control precision,and low leakage,which can meet the requirements of LHFPs.
