In order to grasp the dynamic behaviors of 4-UPS-UPU high-speed spatial parallel mechanism, the stress of driving limbs and natural frequencies of parallel mechanism were investigated. Based on flexible multi-body dyn...In order to grasp the dynamic behaviors of 4-UPS-UPU high-speed spatial parallel mechanism, the stress of driving limbs and natural frequencies of parallel mechanism were investigated. Based on flexible multi-body dynamics theory, the dynamics model of 4-UPS-UPU high-speed spatial parallel mechanism without considering geometric nonlinearity was derived. The stress of driving limbs and natural frequencies of 4-UPS-UPU parallel mechanism with specific parameters were analyzed. The relationship between the basic parameters of parallel mechanism and its dynamic behaviors, such as stress of driving limbs and natural frequencies of parallel mechanism, were discussed. The numerical simulation results show that the stress and natural frequencies are relatively sensitive to the section parameters of driving limbs, the characteristic parameters of material on driving limbs, and the mass of moving platform. The researches can provide important theoretical base of the analysis of dynamic behaviors and optimal design for high-speed spatial parallel mechanism.展开更多
The high speed motor is effective to realize downsizing motor in an electric vehicle(EV).Switched Reluctance Motor(SRM)is possible to the high speed drive because the rotor structure has simple and robust.However,the ...The high speed motor is effective to realize downsizing motor in an electric vehicle(EV).Switched Reluctance Motor(SRM)is possible to the high speed drive because the rotor structure has simple and robust.However,the vibration and the acoustic noise are large from the drive principle.Moreover,the conventional complicated current excitation results in the difficulty of the torque controller design.To overcome these problems,the vector control has been proposed for SRM drive.However,the vector control has not been applied to the SRM in the high speed drive.In this paper,the drive conditions such as switching frequency,bus voltage for driving the SRM in the high speed region are clarified.It is shown that the proposed SRM can be driven by the vector control in the high speed region and can realize low vibration.展开更多
This research proposes a new theory in the field of physics and space technology, based on several scientific hypotheses and conclusions, as it plans to manufacture a “new magnetic focus” by means of high-speed cent...This research proposes a new theory in the field of physics and space technology, based on several scientific hypotheses and conclusions, as it plans to manufacture a “new magnetic focus” by means of high-speed centrifugal engines, by equipping a group of them, and installing heavy, dense fans, not for the purpose of air pressure, Rather, it works to rotate at a speed of up to 1000 kilometers per hour at an angle of 45 degrees, and is lined up in front of each other in a circle, so that the final result is to transfer the effort and weight of the propellers to an upper point in their midst, and this point will reach a large degree of density, size and mass, causing the generation of a point independent magnetic attraction, which pulls the motors upward, as a result of the mutual gravitational effect created by the motors. These hypotheses need a large number of experiments, applications, and analyze the use of specialists in physics, technology, technology, engine engineers, and others, and the correct results will cause a major revolution in the field of space technology, and this theory will be relied upon in many means of land, air, and space transportation and different fields.展开更多
基金Project(51005138) supported by the National Natural Science Foundation of ChinaProject(BS2012ZZ008) supported by Shandong Young Scientists Award Fund,China+2 种基金Project(J09LD54) supported by the Natural Science Foundation of Shandong Education Department of ChinaProject(2011KYJQ102) supported by the Science Foundation of Shandong University of Science and Technology,ChinaProject(HGDML-1104) supported by Jiangsu Key Laboratory of Digital Manufacturing Technology,China
文摘In order to grasp the dynamic behaviors of 4-UPS-UPU high-speed spatial parallel mechanism, the stress of driving limbs and natural frequencies of parallel mechanism were investigated. Based on flexible multi-body dynamics theory, the dynamics model of 4-UPS-UPU high-speed spatial parallel mechanism without considering geometric nonlinearity was derived. The stress of driving limbs and natural frequencies of 4-UPS-UPU parallel mechanism with specific parameters were analyzed. The relationship between the basic parameters of parallel mechanism and its dynamic behaviors, such as stress of driving limbs and natural frequencies of parallel mechanism, were discussed. The numerical simulation results show that the stress and natural frequencies are relatively sensitive to the section parameters of driving limbs, the characteristic parameters of material on driving limbs, and the mass of moving platform. The researches can provide important theoretical base of the analysis of dynamic behaviors and optimal design for high-speed spatial parallel mechanism.
文摘The high speed motor is effective to realize downsizing motor in an electric vehicle(EV).Switched Reluctance Motor(SRM)is possible to the high speed drive because the rotor structure has simple and robust.However,the vibration and the acoustic noise are large from the drive principle.Moreover,the conventional complicated current excitation results in the difficulty of the torque controller design.To overcome these problems,the vector control has been proposed for SRM drive.However,the vector control has not been applied to the SRM in the high speed drive.In this paper,the drive conditions such as switching frequency,bus voltage for driving the SRM in the high speed region are clarified.It is shown that the proposed SRM can be driven by the vector control in the high speed region and can realize low vibration.
文摘This research proposes a new theory in the field of physics and space technology, based on several scientific hypotheses and conclusions, as it plans to manufacture a “new magnetic focus” by means of high-speed centrifugal engines, by equipping a group of them, and installing heavy, dense fans, not for the purpose of air pressure, Rather, it works to rotate at a speed of up to 1000 kilometers per hour at an angle of 45 degrees, and is lined up in front of each other in a circle, so that the final result is to transfer the effort and weight of the propellers to an upper point in their midst, and this point will reach a large degree of density, size and mass, causing the generation of a point independent magnetic attraction, which pulls the motors upward, as a result of the mutual gravitational effect created by the motors. These hypotheses need a large number of experiments, applications, and analyze the use of specialists in physics, technology, technology, engine engineers, and others, and the correct results will cause a major revolution in the field of space technology, and this theory will be relied upon in many means of land, air, and space transportation and different fields.
