A DC DC buck converter c on trolled by naturally sampled, constant frequency PWM is considered. The existe nce of chaotic solutions and the output performance of the system under differen t circuit parameters are s...A DC DC buck converter c on trolled by naturally sampled, constant frequency PWM is considered. The existe nce of chaotic solutions and the output performance of the system under differen t circuit parameters are studied. The transforming pattern of system behavior fr om steady state to chaotic is discovered by the cascades of period doubling bi furcation and the cascades of periodic orbit in V I phase space. Accordingl y, it is validated that change of values of the circuit parameters may lead DC DC converter to chaotic motion. Performances of the output ripples fro m steady state to chaotic are analyzed in time and frequency domains respective ly. Some important conclusions are helpful for opt imization design of DC DC converter.展开更多
As an integrated control unit that directly transfo rm s digital electric signals into analogy hydraulic signals, High-speed response solenoid valve (HSV) plays an important role in determining an electro-hydrauli c a...As an integrated control unit that directly transfo rm s digital electric signals into analogy hydraulic signals, High-speed response solenoid valve (HSV) plays an important role in determining an electro-hydrauli c automatic system’s overall performance. In the process of designing an HSV, o ne should well understand that various soft magnetic material properties and geo metries greatly affect HSV’s magnetic field design that accordingly has a direc t influence on HSV’s electric performance. As an approach of improving HSV perf ormance, this paper presents an optimal design method on HSV’s magnetic field b y making a full consideration of the effects of various soft magnetic material a nd geometries. The proposed optimal design method, based on HSV’s three-dimens ion solid modeling with the PRO/E software, simplifying from the previous three -dimension solid model to the axially symmetric plane model of the magnetic fie ld and the consequent the magnetic finite element method simulating within ANSYS analysis environment for obtaining accurate results on the distribution of HSV ’s magnetic field and flux-line as well as the magnetic force, can achieve lar ger magnetic force and lower power of an HSV by adjusting the structure paramete rs of the solenoid valve and selecting various soft magnetic materials which are of different B-H (flux density vs. field intensity) curves. Considering the no nlinearity and saturation of various soft magnetic materials, this paper process es the nonlinearity simulated calculation and experiment measure of three soft m agnetic materials and different structure parameters. The comparison of the simu lating and experimenting results proves that the simulating calculation and the proposed optimal design method are effective in HSV’s designing and its perform ance prediction. The researching results show that, for HSV’s designing, the pr oposed optimal design method can well simulate HSV’s the magnetic field, enhanc e the reliability and accuracy, reduce the cost, shorten the cycle, and henc e has practical value for engineering purpose.展开更多
With the development and widely used of the compute r technology, the CAD has been more and more used in the process of designing prod uct. The number of the engineering drawings will greatly increase because of the c...With the development and widely used of the compute r technology, the CAD has been more and more used in the process of designing prod uct. The number of the engineering drawings will greatly increase because of the continually appearance of the new products. As a result, it has become a badly needed to be solved problem for us that how to rapidly and efficiently search an d appropriately preserve and manage the drawings. In this paper, a method of bui lding the product drawing management system for extrusion aluminum-type materia ls is discussed. This system is designed for the profile graphic of the aluminou s section material management by using Group Technology (GT) principle. Accordin g to the GT, we developed a classifying-coding system and drawing management sy stem about the extrusion aluminum-type materials through analyzing a large numb er of extrusion aluminum-type materials section drawings. The coding system has realized the flexible coding and hidden coding of the extrusion aluminum-type materials and then enhanced the flexibility and the expansible of the system. By supplying the designer with the human-computer interaction interface the drawi ng management system has been able to resolve many difficult problems such as se arch and manage the existed drawings about the extrusion aluminum-type material s very well. At the same time, it also helps the developing work enhance the abi lity of inheriting by applying this kind of variant method. In a word, with the help of this system we can not only shorten the designing time greatly and reduc e the cost of the product but also research the designing drawings rapidly. In o rder to output the data information related to the part drawing, the system uses the data-exchange standard to which the drawing support-software adapted as d ata-exchange interface. The system is advantageous to building a standard of dr awing design and increasing the efficiency of searching drawing and enhancing th e information management, which have had a base for building the best management system in the future. In addition, the paper has a detailed analysis about the principle of flexible classification code and data structure.展开更多
文摘A DC DC buck converter c on trolled by naturally sampled, constant frequency PWM is considered. The existe nce of chaotic solutions and the output performance of the system under differen t circuit parameters are studied. The transforming pattern of system behavior fr om steady state to chaotic is discovered by the cascades of period doubling bi furcation and the cascades of periodic orbit in V I phase space. Accordingl y, it is validated that change of values of the circuit parameters may lead DC DC converter to chaotic motion. Performances of the output ripples fro m steady state to chaotic are analyzed in time and frequency domains respective ly. Some important conclusions are helpful for opt imization design of DC DC converter.
文摘As an integrated control unit that directly transfo rm s digital electric signals into analogy hydraulic signals, High-speed response solenoid valve (HSV) plays an important role in determining an electro-hydrauli c automatic system’s overall performance. In the process of designing an HSV, o ne should well understand that various soft magnetic material properties and geo metries greatly affect HSV’s magnetic field design that accordingly has a direc t influence on HSV’s electric performance. As an approach of improving HSV perf ormance, this paper presents an optimal design method on HSV’s magnetic field b y making a full consideration of the effects of various soft magnetic material a nd geometries. The proposed optimal design method, based on HSV’s three-dimens ion solid modeling with the PRO/E software, simplifying from the previous three -dimension solid model to the axially symmetric plane model of the magnetic fie ld and the consequent the magnetic finite element method simulating within ANSYS analysis environment for obtaining accurate results on the distribution of HSV ’s magnetic field and flux-line as well as the magnetic force, can achieve lar ger magnetic force and lower power of an HSV by adjusting the structure paramete rs of the solenoid valve and selecting various soft magnetic materials which are of different B-H (flux density vs. field intensity) curves. Considering the no nlinearity and saturation of various soft magnetic materials, this paper process es the nonlinearity simulated calculation and experiment measure of three soft m agnetic materials and different structure parameters. The comparison of the simu lating and experimenting results proves that the simulating calculation and the proposed optimal design method are effective in HSV’s designing and its perform ance prediction. The researching results show that, for HSV’s designing, the pr oposed optimal design method can well simulate HSV’s the magnetic field, enhanc e the reliability and accuracy, reduce the cost, shorten the cycle, and henc e has practical value for engineering purpose.
文摘With the development and widely used of the compute r technology, the CAD has been more and more used in the process of designing prod uct. The number of the engineering drawings will greatly increase because of the continually appearance of the new products. As a result, it has become a badly needed to be solved problem for us that how to rapidly and efficiently search an d appropriately preserve and manage the drawings. In this paper, a method of bui lding the product drawing management system for extrusion aluminum-type materia ls is discussed. This system is designed for the profile graphic of the aluminou s section material management by using Group Technology (GT) principle. Accordin g to the GT, we developed a classifying-coding system and drawing management sy stem about the extrusion aluminum-type materials through analyzing a large numb er of extrusion aluminum-type materials section drawings. The coding system has realized the flexible coding and hidden coding of the extrusion aluminum-type materials and then enhanced the flexibility and the expansible of the system. By supplying the designer with the human-computer interaction interface the drawi ng management system has been able to resolve many difficult problems such as se arch and manage the existed drawings about the extrusion aluminum-type material s very well. At the same time, it also helps the developing work enhance the abi lity of inheriting by applying this kind of variant method. In a word, with the help of this system we can not only shorten the designing time greatly and reduc e the cost of the product but also research the designing drawings rapidly. In o rder to output the data information related to the part drawing, the system uses the data-exchange standard to which the drawing support-software adapted as d ata-exchange interface. The system is advantageous to building a standard of dr awing design and increasing the efficiency of searching drawing and enhancing th e information management, which have had a base for building the best management system in the future. In addition, the paper has a detailed analysis about the principle of flexible classification code and data structure.
