In this paper,two lifting mechanism models with opposing placements,which use the same hydraulic hoist model and have the same angle of 50°,have been developed.The mechanical and hydraulic simulation models are e...In this paper,two lifting mechanism models with opposing placements,which use the same hydraulic hoist model and have the same angle of 50°,have been developed.The mechanical and hydraulic simulation models are established using MATLAB Simscape to analyze their kinetics and dynamics in the lifting and holding stages.The simulation findings are compared to the analytical calculation results in the steady state,and both methods show good agreement.In the early lifting stage,Model 1 produces greater force and discharges goods in the container faster than Model 2.Meanwhile,Model 2 reaches a higher force and ejects goods from the container cleaner than its counterpart at the end lifting stage.The established simulation models can consider the effects of dynamic loads due to inertial moments and forces generated during the system operation.It is crucial in studying,designing,and optimizing the structure of hydraulic-mechanical systems.展开更多
A kind of four degree-of-freedom （DOF） electrohydraulic lift system is studied in this pa- per, after analyzing the motion characteristics and the mathematic model of the hydraulic cylinders, a cross-coupled synchro...A kind of four degree-of-freedom （DOF） electrohydraulic lift system is studied in this pa- per, after analyzing the motion characteristics and the mathematic model of the hydraulic cylinders, a cross-coupled synchronization method with load force and synchronization error feedback had been proposed to solve the synchronization problem encountered when realizing the needed roll and pitch attitude of the lift system. In this paper, mathematic model of asymmetric hydraulic cylinder was es- tablished and the lift system had been simplified to a dual-cylinder system. By incorporating the load force and the displacement of each cylinder, a cross-coupled synchronized control method was pro- posed to fit each cylinder＇ s tracking performance and multi-cylinder＇ s trajectory synchronization property. The proposed method not only solved the synchronization problem when multi-cylinder had a same trajectory, but also could fit the coordinated synchronization need when different trajectories of multi-cylinder were desired. Simulations and experiments on a four DOF electrohydraulic lift sys- tem with load of 100 tons verified the effectiveness of the proposed method.展开更多
This paper presented a design of an automatic lifting system. It is used for large load powered support and improves the old method wherein powered support lifting depends on manual control. This system applies a high...This paper presented a design of an automatic lifting system. It is used for large load powered support and improves the old method wherein powered support lifting depends on manual control. This system applies a high accuracy gear shunt motor to match the flow for 4 lifting cylinders, and also allocates bypass throttles to realize automatic lifting. Through the dis- placement sensor feedback the height deviation among 4 lifting cylinders during the whole lifting process, when the deviation is up to the sitting value, the corresponding bypass throttle is operated immediately to reduce the deviation, so that the moving platform of the powered support would not be stuck. Through real application, it is shown that this system can realize automatic lifting of powered support; the lifting speed is controlled between 5 and 10 mm/s, and the final aligning accuracy is up to 1 mm.展开更多
The present study is concerned with the lifting of seabed materials by a BJT （bubble-jet-type） air-lift pump patented by Sadatomi. The targets are methane-hydrate rich muds on the bed about 200 m in depth around Jap...The present study is concerned with the lifting of seabed materials by a BJT （bubble-jet-type） air-lift pump patented by Sadatomi. The targets are methane-hydrate rich muds on the bed about 200 m in depth around Japan islands and rare-earth rich muds on the bed deeper than 4,000 m around Minami-Torishima islands in the Pacific Ocean. Feasibility studies were conducted using 50 mm I. D. （inner diameter） and 5.0 m long vertical pipe as the pump upriser, VC （vinyl chloride） particles and natural sands mixture in the methane-hydrate case, and ceramics particles with 3,761 kg/m^3 in density in the rare-earth case as the deposits. From the methane-hydrate simulation experiments, an efficient operation condition with high VC particles to sands lifting ratio has been clarified. In the rare-earth case, the air supplies from two different midways in the upriser pipe have been tested together with the bottom supply because the air supply from the upriser bottom is very hard in deep sea. The effects of the air supply position on the pump performance have been clarified by the experiments and the simulations with a revised model applicable to the midway air supply type.展开更多
At present, machine fixed up and down repeatedly work is done by human. Although it is low cost and easy to change plate, there are many shortcomings of the work injury and the low work efficiency. Foreign automatic l...At present, machine fixed up and down repeatedly work is done by human. Although it is low cost and easy to change plate, there are many shortcomings of the work injury and the low work efficiency. Foreign automatic loading and unloading device has been developed, but the principle is more complex, the cost is higher, the energy consumption is larger, so the automatic loading and unloading robot came into being. Aiming at the transportation of mechanical raw material, an automatic device is designed to transport the scheduled raw materials to the specified position according to the processing requirements. The device has the characteristics of the simple operation, the rapid response and the large range of activities, and has obvious economic and environmental benefits. There is certain popularization value.展开更多
基金Ho Chi Minh City University of Technology(HCMUT)Vietnam National University Ho Chi Minh City(VNU-HCM)for supporting this study。
文摘In this paper,two lifting mechanism models with opposing placements,which use the same hydraulic hoist model and have the same angle of 50°,have been developed.The mechanical and hydraulic simulation models are established using MATLAB Simscape to analyze their kinetics and dynamics in the lifting and holding stages.The simulation findings are compared to the analytical calculation results in the steady state,and both methods show good agreement.In the early lifting stage,Model 1 produces greater force and discharges goods in the container faster than Model 2.Meanwhile,Model 2 reaches a higher force and ejects goods from the container cleaner than its counterpart at the end lifting stage.The established simulation models can consider the effects of dynamic loads due to inertial moments and forces generated during the system operation.It is crucial in studying,designing,and optimizing the structure of hydraulic-mechanical systems.
文摘A kind of four degree-of-freedom （DOF） electrohydraulic lift system is studied in this pa- per, after analyzing the motion characteristics and the mathematic model of the hydraulic cylinders, a cross-coupled synchronization method with load force and synchronization error feedback had been proposed to solve the synchronization problem encountered when realizing the needed roll and pitch attitude of the lift system. In this paper, mathematic model of asymmetric hydraulic cylinder was es- tablished and the lift system had been simplified to a dual-cylinder system. By incorporating the load force and the displacement of each cylinder, a cross-coupled synchronized control method was pro- posed to fit each cylinder＇ s tracking performance and multi-cylinder＇ s trajectory synchronization property. The proposed method not only solved the synchronization problem when multi-cylinder had a same trajectory, but also could fit the coordinated synchronization need when different trajectories of multi-cylinder were desired. Simulations and experiments on a four DOF electrohydraulic lift sys- tem with load of 100 tons verified the effectiveness of the proposed method.
文摘This paper presented a design of an automatic lifting system. It is used for large load powered support and improves the old method wherein powered support lifting depends on manual control. This system applies a high accuracy gear shunt motor to match the flow for 4 lifting cylinders, and also allocates bypass throttles to realize automatic lifting. Through the dis- placement sensor feedback the height deviation among 4 lifting cylinders during the whole lifting process, when the deviation is up to the sitting value, the corresponding bypass throttle is operated immediately to reduce the deviation, so that the moving platform of the powered support would not be stuck. Through real application, it is shown that this system can realize automatic lifting of powered support; the lifting speed is controlled between 5 and 10 mm/s, and the final aligning accuracy is up to 1 mm.
文摘The present study is concerned with the lifting of seabed materials by a BJT （bubble-jet-type） air-lift pump patented by Sadatomi. The targets are methane-hydrate rich muds on the bed about 200 m in depth around Japan islands and rare-earth rich muds on the bed deeper than 4,000 m around Minami-Torishima islands in the Pacific Ocean. Feasibility studies were conducted using 50 mm I. D. （inner diameter） and 5.0 m long vertical pipe as the pump upriser, VC （vinyl chloride） particles and natural sands mixture in the methane-hydrate case, and ceramics particles with 3,761 kg/m^3 in density in the rare-earth case as the deposits. From the methane-hydrate simulation experiments, an efficient operation condition with high VC particles to sands lifting ratio has been clarified. In the rare-earth case, the air supplies from two different midways in the upriser pipe have been tested together with the bottom supply because the air supply from the upriser bottom is very hard in deep sea. The effects of the air supply position on the pump performance have been clarified by the experiments and the simulations with a revised model applicable to the midway air supply type.
基金Supported by The National College Students’Entrepreneurship Practice Project(201510359010)Science and Technology Research Project of Anhui Province(15czz02030)
文摘At present, machine fixed up and down repeatedly work is done by human. Although it is low cost and easy to change plate, there are many shortcomings of the work injury and the low work efficiency. Foreign automatic loading and unloading device has been developed, but the principle is more complex, the cost is higher, the energy consumption is larger, so the automatic loading and unloading robot came into being. Aiming at the transportation of mechanical raw material, an automatic device is designed to transport the scheduled raw materials to the specified position according to the processing requirements. The device has the characteristics of the simple operation, the rapid response and the large range of activities, and has obvious economic and environmental benefits. There is certain popularization value.
