第一篇：畢業(yè)設(shè)計英文 翻譯(原文)

編號：

畢業(yè)設(shè)計(論文)外文翻譯

（原文）

院（系）：桂林電子科技大學(xué)

專 業(yè)： 電子信息工程

學(xué)生姓名： xx 學(xué) 號： xxxxxxxxxxxxx 指導(dǎo)教師單位：桂林電子科技大學(xué) 姓 名： xxxx

職 稱： xx

2014年x月xx日

桂林電子科技大學(xué)畢業(yè)設(shè)計（論文）報告用紙

Timing on and off power supply uses

The switching power supply products are widely used in industrial automation and control, military equipment，scientific

equipment，LED

lighting，industrial medical equipment,communications

equipment,electrical

equipment,instrumentation, equipment, semiconductor cooling and heating, air purifiers, electronic refrigerator, LCD monitor, LED lighting, communications equipment, audio-visual products, security, computer chassis, digital products and equipment and other fields.Introduction

With the rapid development of power electronics technology, power electronics equipment and people's work, the relationship of life become increasingly close, and electronic equipment without reliable power, into the 1980s, computer power and the full realization of the switching power supply, the first to complete the computer Power new generation to enter the switching power supply in the 1990s have entered into a variety of electronic, electrical devices, program-controlled switchboards, communications, electronic testing equipment power control equipment, power supply, etc.have been widely used in switching power supply, but also to promote the rapid development of the switching power supply technology.Switching power supply is the use of modern power electronics technology to control the ratio of the switching transistor to turn on and off to maintain a stable output voltage power supply, switching power supply is generally controlled by pulse width modulation(PWM)ICs and switching devices(MOSFET, BJT)composition.Switching power supply and linear power compared to both the cost and growth with the increase of output power, but the two different growth rates.A power point, linear power supply costs, but higher than the switching power supply.With the development of power electronics technology and innovation, making the switching power supply technology to continue to innovate, the turning points of this cost is increasingly move to the low output power side, the switching power supply provides a broad space for development.The direction of its development is the high-frequency switching power supply, high frequency switching power supply miniaturization, and switching power supply into a wider range of application areas, especially in high-tech fields, and promote the miniaturization of high-tech products, light of.In addition, the development and application of the switching power supply in terms of energy conservation, resource conservation and environmental protection are of great significance.桂林電子科技大學(xué)畢業(yè)設(shè)計（論文）報告用紙

classification

Modern switching power supply, there are two: one is the DC switching power supply;the other is the AC switching power supply.Introduces only DC switching power supply and its function is poor power quality of the original eco-power(coarse)closed the voltage surge, RC or LC buffers can be used, and the current surge can be caused by the diode stored charge of amorphous and other core made of magnetic buffer.However, the high frequency more than 1MHz, the resonant circuit to make the switch on the voltage or current through the switch was a sine wave, which can reduce switching losses, but also to control the occurrence of surges.This switch is called the resonant switch.Of this switching power supply is active, you can, in theory, because in this way do not need to greatly improve the switching speed of the switching losses reduced to zero, and the noise is expected to become one of the high-frequency switching power supply The main ways.At present, many countries in the world are committed to several trillion Hz converter utility.the principle of Introduction

The switching power supply of the process is quite easy to understand, linear power supplies, power transistors operating in the linear mode and linear power, the PWM switching power supply to the power transistor turns on and off state, in both states, on the power transistor Vthe step-down chopper, the average output voltage U0 is less than the input voltage Ui, the same polarity.Boost Circuitbuck or boost chopper, the output average voltage U0 is greater than or less than the input voltage Ui, the opposite polarity, the inductance transmission.Cuk circuit-a buck or boost chopper, the output average voltage U0 is greater than or less than the input voltage Ui, the opposite polarity, capacitance transmission.The above-mentioned non-isolated circuit, the isolation circuit forward circuits, feedback circuit, the half-bridge circuit, the full bridge circuit, push-pull circuit.Today's soft-switching technology makes a qualitative leap in the DC / DC the U.S.VICOR company design and manufacture a variety of ECI soft-switching DC / DC converter, the maximum output power 300W, 600W, 800W, etc., the corresponding power density(6.2 , 10,17)W/cm3 efficiency(80-90)%.A the Japanese Nemic Lambda latest using soft-switching technology, high frequency switching power supply module RM Series, its switching frequency(200 to 300)kHz, power density has reached 27W/cm3 with synchronous rectifier(MOSFETs instead of Schottky diodes), so that the whole circuit efficiency by up to 90%.AC / DC conversion

AC / DC conversion will transform AC to DC, the power flow can be bi-directional power flow by the power flow to load known as the “rectification”, referred to as "active inverter power flow returned by the load power.AC / DC converter input 50/60Hz AC due must be rectified, filtered, so the volume is relatively large filter capacitor is essential, while experiencing safety standards(such as UL, CCEE, etc.)and EMC Directive restrictions(such as IEC, FCC, CSA)in the AC input side must be added to the EMC filter and use meets the safety standards of the components, thus limiting the miniaturization of the volume of AC / DC power, In addition, due to internal frequency, high voltage, current switching, making the problem difficult to solve EMC also high demands on the internal high-density mounting 桂林電子科技大學(xué)畢業(yè)設(shè)計（論文）報告用紙

circuit design, for the same reason, the high voltage, high current switch makes power supply loss increases, limiting the AC / DC converter modular process, and therefore must be used to power system optimal design method to make it work efficiency to reach a certain level of satisfaction.AC / DC conversion circuit wiring can be divided into half-wave circuit, full-wave circuit.Press the power phase can be divided into single-phase three-phase, multiphase.Can be divided into a quadrant, two quadrant, three quadrants, four-quadrant circuit work quadrant.he selection of the switching power supply

Switching power supply input on the anti-jamming performance, compared to its circuit structure characteristics(multi-level series), the input disturbances, such as surge voltage is difficult to pass on the stability of the output voltage of the technical indicators and linear power have greater advantages, the output voltage stability up to(0.5)%.Switching power supply module as an integrated power electronic devices should be selected

第二篇：采礦工程本科畢業(yè)設(shè)計英文翻譯

Use of Mineral Coal for Sorption Sewage Treatment

A.V.Mozolkova Russian University of People’s Friendship.Moscow, Russia E.V.Chekushina Russian University of People’s Friendship.Moscow, Russia A.A.Kaminskaya Russian University of People’s Friendship.Moscow, Russia

Treatment of mining, industrial, household and other sewage is an actual problem for many mining and processing enterprises.Coal-mining industry is not an exception.Usually, at coal enterprises, treatment of mine sewage before it is dumped consists in settling and subsequent filtering.Many pollutants are not removed from the sewage by this method.Hence, dumped water frequently does not satisfy sanitary requirements regarding the permissible content of oil products, dissolved substances and other parameters.For additional cleaning of sewage it is possible to use sorption methods.By these methods water is cleaned of oil products, heavy metals, a number of organic substances and other polluting substances, depending on the used sorbent properties.Both natural and artificial materials can be used as sorbents.Constraint for wide use of sorption methods of sewage treatment in the coal industry is high cost of the majority of sorbents.A number of technologies for obtaining inexpensive and good quality sorbents from coal minerals have been developed.These sorbents can be manufactured directly in coal mines which has additional advantage of reducing transport costs.The processes sorbents may be recycled or burnt.Apart from that production and sale of sorbents can serve the coal-mining enterprises as an additional source of income.One of the most widespread sorbents is activated coal.Quality activated coals are carbon sorbents, having an internal specific surface of more than 500㎡/g, and characterized by iodine adsorption(iodine value)of more than500mg/g.mineral coal, peat and wood can serve as raw materials for activated coal production.Traditional production techniques of activated coal include two basic stages of thermal processing of the initial carbon-containing raw material-carbonization and activation, done in different devices.Both stages are energy-consuming and ecologically dangerous, which explains the high cost of activated coal, received through this technology(1200-4000 dollars/MT).Carbonization is the elimination of volatile substances by heating up to the temperature of 600-900℃, because with volatile components there are basically formed the oxygen and hydrogen, and increase carbon content in initial raw material.Carbonization is done in mining or rotating furnaces with utilization of external form-holder, as a rule, waste gases with temperatures of 600℃ and higher.Activation means increasing the volume and pore surfaces of carbonized material at heterogeneous reaction.The most used reagent is water vapour with the temperature of 900℃ and higher, and the process takes 15-20 hours.Both stages are energy consuming and pose threat to environment.For one tonne of activated coal from 2 up to 4 tonnes of specific fuel like crude oil and natural gas are consumed.From 1000 up to 1500 m3 of processed gasses with high content of SOx(1-2 g/ m3), H2S(200-250mg/ m3), resinous substances(10-40mg/ m3), phenols(50-70mg/ m3), carbon oxides(up to 5%)and also other substances which are carcinogenic and mutagenic are formed and released into the atmosphere during both stages.High-energy consumption and environmental danger, which requires large investments in nature protection activities, result in the high cost of quality-activated coal.Another group of carbon sorbents, which was widespread in the 80’s, consists of inexpensive carbon sorbents used in nature protection technologies and industry.Such sorbents are produced by a one-phase technology, without additional activation.Their adsorption activity is not high(iodine value less than 300mg/g)but the cost is low(250-700 USD/MT).because the price of these sorbents is comparable to the cost of their regeneration, they are used only once and are burnt after saturation.The leaders in the production of such sorbents are Rheinbraun AG(Germany, 200 thousand MT per year)and Australian Char Ltd(Australia, 150 thousand MT per year), which produce brown coal semi-coke used for treatment of wastewater and smoke.In Russia research work in this direction is conducted, but only test works have been done so far, although the quality of carbon sorbents obtained from Kansk-Achinsk coals did not concede to production from Rheinbraun AG and Australian Char.One of the directions of utilization of semi-coke from Kansk-Achinsk coals, production of which was planed at Krasnoyarsc thermal power station 2(device ETX-175), was its utilization as carbon sorbent.The reason for production of inexpensive carbon sorbents by one-phase technologies being not developed in Russia is the absence of demand for this product.This production is basically used for cleaning of sewage, however there is no effective ecological service in Russia, and the penal sanctions of the environmental protection legislation are so insignificant that industrial enterprises do not have ant motivation to invest in nature protection.In1992-1994 the employees from Joint-Stock Company “Carbonica-F”(at that time Open Company “Sibtermo”)have developed a new method of production of carbon sorbents, which considerably from all known technologies.During the research of dynamic effects in a layer evaporator the regime conditions were defined under which the effect of “thermal wave” could be observed in the device.Using this effect, the authors created a layer evaporator in which volatile components of coal were exposed to gasification(incomplete oxidation), and the degree of carbon conversion was adjusted by the mode of injection feed.By changing the regime parameters it was possible to conduct the process as fuel gasification(with only ashes remaining in the end)without any residue, and also as gasification of volatile components of coal, thus receiving so-called semi-coke containing solid coal.From one tonne of Kansk-Achinsk coal with calorific content of 3600-3800 kcal/kg can be produced about 0.33 tonnes of semi-coke with calorific content up to 7000 kcal/kg(as anthracite)and up to 1700 m3 of combustible gas with calorific content of 800-900 kcalJm3, suitable for use as an energy source.Technological process of Joint-Stock Company “Carbonika-F” has a large number of advantages in comparison to the already known methods of obtaining activated coal and semi-coke

1.Simplicity of hardware.One-phase process.The stages of drying, pyrolysis, thermal decomposition of volatile substances and semi-coke cooling are incorporated in one device.The device is auto-metric;it means that external heat-carrier for coal heating is not used.2.Ecological safety.In the technology of Joint-Stock Company “Carbonica-F” all hydrocarbons, including resinous substances, are broken down and gasified inside the device during the formation of combustible gas containing only CO, H2, CO2, N2, H20, H2S and insignificant quantity CH4.Sludge, pyroligneous waters, phenols and other harmful impurities are not formed in this process.3.Because the speed of gas filtration from a layer reactor is low(0,02-0,03 m/s in comparison to 0,5-2,5 m/s for mine furnaces), the process is less dependent on fractional composition of coal, hydraulic resistance of the layer and allows to process fine-grained coals.4.As a result of low speed of filtration the phenomenon of carrying out of fly ashes from the layer does not occur, because the device works as a granular filter.Combustible gas is moved in user-boiler or can move to the gas turbine without preliminary cleaning.The volume of SOx, NOx, CO contained in waste gases is lower than that produced when obtaining equivalent quantity of heat by burning coal.Combustible gas without prior cleaning can be used to produce electric and/or thermal power or as an energy carrier for thermal processes.5.Unlike the already existing technologies, in the given process there is no dump（排空孔）of gaseous heat-carrier(氣體熱載體)into the atmosphere and consequently（因此）the construction of other additional gas purification systems（更多的天然氣凈化系統(tǒng)工程）and catalytic burning of carbon oxide(CO)（催化燃燒的碳氧化物）is not required.與現(xiàn)有的技術(shù)不同，在以上給出的過程呢個中，沒有氣體熱載體排放的到空中的排空孔，因此，更多的天然氣凈化系統(tǒng)和催化燃燒的碳氧化物的工程是不必要的。

Test of the solid residue(semi-coke)have revealed, that this material is characterized by large specific surface(more than 500㎡/g)and high adsorption activity(iodine value 500mg/g and higher), and because of these parameter does not concede to quality-activated coal.經(jīng)過試驗的固體殘渣（半焦）表明：這種材料的特點(diǎn)是表面積大（大于五百平方米）并且有很強(qiáng)的吸附性（碘值是500毫克每克甚至更高）而且因為這些參數(shù)并不退讓與高質(zhì)量的活性炭。

The product received with the technology of Joint-Stock Company “Carbonica-F” is certificated as activated coal ABG(active, brown coal of gasification), for it there were developed technical conditions TU 6-00209591-443-95.The characteristics of ABG activated coal produced from the coal of 62 mark from “Berezovsky-1” opencast colliery.獲得技術(shù)聯(lián)合股份公司“Carbonica-F認(rèn)證的產(chǎn)品被認(rèn)證為ABG類活性炭（就是具有活性的棕色的氣化煤）為此，在此基礎(chǔ)上又發(fā)展了TU 6-00209591-443-95技術(shù)條件。ABG活性炭的特點(diǎn)來自于出產(chǎn)它的來自”Berezovsky-1“露天煤礦的62號煤。

High specific surface and adsorption activity of ABG coal is explained by the fact that both gasification of coal volatile components, and activation of carbon-containing solid residue of gaseous products occur in the device simultaneously.Because gasification products contain up to 20%n of hydrogen whose molecules are smaller than the ones of water vapour, and hence their permeability in pores of semi-coke is higher, activation(heterogeneous reaction)is done not only with vapor, but also with hydrogen, which practically is not present in the traditional technologies.Thus, carbonization stages and activation are combined in one device.氣化煤揮發(fā)性成分和激活含碳固體殘留氣體產(chǎn)品同時在裝置上發(fā)生的事實(shí)就解釋了ABG煤的高比表面積和強(qiáng)大的吸附特性。因為氣化產(chǎn)品包含了20%以上的氫，而這些氫分子比那些水蒸汽要小一些，因此他們在半焦氣孔的滲透率就高一些，激活（異構(gòu)反應(yīng)）就完成了，不僅與蒸汽，還與氫，而這些實(shí)際上是傳統(tǒng)技術(shù)中不存在的。因此，碳化階段和激活是在同一裝置中同步進(jìn)行的（相結(jié)合的）。

Other positive effect of application of this method of coal processing is that in ”thermal wave“ mode the products of thermal decomposition which contain very toxic resinous substances(coal tar pitch used in experimental medicine for the inoculation of cancer in experiments on mice, brown coal is more toxic), passing through a hot layer of semi-coke(500-700℃)are completely broken down into two and three-nuclei gases H2O, CO2, CO, H2.Measurements done at the working production plant of Joint-Stock Company ”Carbonica-F“ have shown that the gas does not contain hydrocarbons of lines above methane, and also carcinogens, including benzo(a)pirene.其他應(yīng)用到這種方法的積極效果是在“熱波”模式中產(chǎn)品的熱分解含有劇毒物質(zhì)的樹脂（煤瀝青用于實(shí)驗醫(yī)學(xué)的接種癌癥的實(shí)驗小鼠，褐色碳毒性更強(qiáng)。）經(jīng)過一個半焦的熱層（500到700攝氏度）完全分解成雙核或三核氣體：水，二氧化碳，一氧化碳，氫氣。測量工作在”Carbonica-F“聯(lián)合股份公司的工作生產(chǎn)廠完成，這表明了這種氣體不僅包含了碳?xì)浠衔锛淄橐陨系男?，也包含了致癌物質(zhì)，包括：

Cooling of the activated coal from 550 up to 70℃ before discharging is carried out by compulsory circulation of gaseous heat-carrier(waste gases)through a layer of the product and further through shell-and-tube heat exchanger in which water used in closed circuit is also provided.Total process efficiency reaches 95% due to the high degree of utilization, which is associated with utilizing the thermal energy.在把活性炭從高于550攝氏度冷卻到70攝氏度的過程以前，Departing waste gases do not undergo any cleaning;there are even no cyclones.Nevertheless, the content of harmful mixtures(NOx 150 mg/m3, SOx 50 mg/m3, ash less than 10 mg/m3)is essentially lower than the established norms and parameters of working boiler and thermal power stations, even those equipped with modern multistage systems of gas purification including electro filters.This is explained by a insignificant ablation of ash from devices, sorption of sulfur compounds in activated corner, and also focus temperature from the user-boiler is lower than 1600℃-“threshold（” 閾值）temperature at which begins the formation of nitrogen oxides due to the oxidation of nitrogen from the air.汽車尾氣不經(jīng)過任何清理，也沒有分離器。然而，有害混合物的含量（NOx 150 mg/m3, SOx 50 mg/m3,含灰塵少于10 mg/m3)實(shí)質(zhì)上比規(guī)定和工作鍋爐和熱電站的參數(shù)都要低。甚至是那些配備了現(xiàn)代化多級系統(tǒng)的氣體凈化過濾器。這是用來自儀器燃燒產(chǎn)生的毫無意義的灰塵來解釋的，硫磺混合物的吸附作用在激活的一角進(jìn)行，并且也把用戶鍋爐法制溫度低于1600℃作為重點(diǎn)，而這個溫度是空氣中的氧化氮形成氮氧化物的開始。

The technology of Joint-Stock Company ”Carbonica-F“ can be used for any not conglomerating coals.”Carbonica-F“聯(lián)合股份公司的技術(shù)可以被用在任意的非聚合煤上。

Similar sorbents or slightly conceding in quality to activated coal are formed by semi-coking of unconglomerated coal.Semi-coke received by using the technology developed and patented at Joint-Stock Company ”Carbonika-F“ is characterised by large specific surface(above 500 m2/g)and high adsorption activity(iodine value 500 mglg and more), and with these parameters does not concede in quality to activated coal.The production of this sorbent is ecologically safe.The producon by-product-combustible gas can be burnt in boilers of thermal power station.類似的吸附劑或是質(zhì)量稍微差一點(diǎn)的活性炭油由聚合碳的半焦形成。半焦被使用該技術(shù)發(fā)展和專利的”Carbonika-F"聯(lián)合股份公司使用，特點(diǎn)是表面積大（大于500平方米/ g），和高吸附活性（碘值500 mglg等）而且這些參數(shù)不會影響到活性炭的質(zhì)量。生產(chǎn)這些吸附劑是具有生態(tài)安全性的。產(chǎn)品的副產(chǎn)品會在熱電站的鍋爐里被燃燒。

Some mineral coals(called mesoporous)have internal pores accessible to water, having the size 3.5-4 manometers(mesopores), forming active surface, sized 50-120 m2/g(unlike all other natural coals with surface of 0.5-1 m2/g).These coals can be used as sorbents without additional activation.They clear water of undissolved and dissolved mineral oil, deep dispersing mixtures, iron, phenol, ions of heavy metals, ammonia, nitrates, benzo(a)pirene and so forth.Sorbent MIU-S received from poorly metamorphosed mesopore coal can be used for 3-7 years with periodic regeneration.Alkali regeneration solution is removed from the fitter without other additional neutralization, because in alkali and acid medium MIU-S presents buffer properties, neutralizing these media.一些礦產(chǎn)煤（叫做孔）有內(nèi)部吸水孔，面積在50-120 m2/g（不像其他自然界的煤表面積是0.5-1 m2/g）。這些煤無需激活就可以被用作吸附劑。他們可以清理不溶水和融化的礦物油，深層分散混合物，鐵，酚，重金屬離子，氨，硝酸鹽，苯等等。MIU-S吸附劑來自劣質(zhì)變形孔煤，可以在定期更改新的情況下用3-7年。堿再生解決方案從管工上移除而沒有其他而外的失效，因為酸和堿的中介MIU-S存在緩沖性能，能夠中和這些媒介。

Specific porous structure of mesopore coals assures sorption extraction of dissolved mineral oil products with concentration lower than 1 mg/l, and thus is not always reachable even with activated coals.具有特殊滲透結(jié)構(gòu)的孔酶能夠吸附提取溶解濃度低于1毫克/升的礦物油產(chǎn)品，因此并非總是能獲得活性炭。

Using MIU-S filters in drinking water supply systems made the stability of their work in conditions of continuous exploitation evident, maintaining the properties of sorbents at null and sub-zero temperatures and absence of biomass formation.使用MIU-S filters在飲水供應(yīng)系統(tǒng)中使用MIU-S filters可以使系統(tǒng)工作具有穩(wěn)定性?？梢詾閮π铋_采創(chuàng)造條件，保證吸附劑在零度或是零下溫度條件下都可以持續(xù)進(jìn)行且沒有生物的形成。

Besides the abovementioned technologies, sorbents can be obtained from material coal by its briquetting and activation.Raw mineral for briquettes can be coals of any rank.除了上述提到的技術(shù)，吸附劑可以從礦物煤中通過成型和活化獲得。制作煤球的礦物原料可以是任何一種煤。Thus , sorbents suitable for additional cleaning of sewage are possible to be produced from mineral coals by special processing, and sometimes directly.Production of own sorbents may solve the problem of additional cleaning of sewage in coal enterprises.Mesopore coals can be used as sorbents without additional processing;the other coals need additional activation.The studied sorbents can be used for cleaning sewage water from mineral oil products, organic substances and metal ions.因此，適合附加清洗下水道里的)污物的吸附劑可以通過特殊處理從礦物煤中得到，并且有時候是可以直接得到的，不需要特殊處理。制作自己的吸附劑可以解決煤炭企業(yè)附加清洗污水的問題。有孔煤不經(jīng)過額外的處理就可以直接被用作吸附劑；其他的煤需要額外的處理才行。吸附劑的研究能被用于礦物油產(chǎn)品，有機(jī)物質(zhì)和金屬離子的污水處理中。

REFERENCES Kovaleva LB., Matvienko N.G., Solovyeva E.A., Tarnopolskaya M.G.: The Application of Natural Mineral Coal in the Technology of Sewage Treatment from Mineral Oil.World n Mining Ecology.Works of the Congress 1999, pg.310-315.2.Congress o For the preparation of the article have been used materials from the site 004km.cn.ru, www.miu-sorb.ru

第三篇：安徽理工大學(xué)畢業(yè)設(shè)計英文翻譯

安徽理工大學(xué)

自動化專業(yè)本科畢業(yè)設(shè)計英文翻譯

學(xué)院(部)：電氣與信息工程學(xué)院 專業(yè)班級： 自動化0 班 學(xué)生姓名： x x x 指導(dǎo)教師： 講師

年 月 日 Implementation of Fuzzy-PID in Smart Car Control

Abstract—An unmanued smart car control system and the fuzzy-PID control algorithm are produced.A design scheme of fuzzy-PID controller is put forward.The simulation analysis from matlab indicated that the dynamic performance of fuzzy-PID control algorithm is better than that of usual PID.Experimental result of smart car show that it can follow the black guide line well and fast-stable complete running the whole trip.Keywords — fuzzy-PID;smart car;fuzzy controller;fuzzy control 1 Introduction In recent years, many countries are developing unmanned vehicle technology.This gives birth to many new theories and applied technology.Reference[1] presents the theory of turn ahead which uses real-time monitoring speed to change the turn-in point dynamically, then it implements the control strategy to achieve a perfect characteristics of steering.Reference[2] uses edge detection algorithm to extract track information and adopt P control.Reference[3] proposes a efficient, good anti-jamming and adaptive image processing dynamic algorithm which effectively solves the out of track caused by the changes of ambient light and track.Reference[4] reconstructs spatial relationships of track and calibrates camera using nonlinear optimization, then it can measure lateral deviation accurately.The above improve vehicle performance in one way but they are all lack of characteristics of car movement and based on lots of experiments.A fuzzy-PID control algorithm and a design scheme of fuzzy-PID controller are put forward in this paper.At last, the experimental result is given out to prove the validity of fuzzy-PID.2 Hardware system design To implement the design of fuzzy-PID algorithm, it’s necessary to design a hardware system of smart car.Smart car would have a smart control unite which contain detection of guide line, steering angle value, speed value and so on.See details in Fig.1.1

Fig.1 The functional block diagram of smart car 3 Basic principle of fuzzy-PID It’s difficult for usual PID control algorithm to achieve the best effect.Because, the parameters Kp, Ki, Kd can’t adjust to different object or different state of the same object.Fuzzy control is based on fuzzy set and fuzzy logic.Without precise mathematical model it can determine the size of controlled variable according the rule table organized by experience.In general, fuzzy control input variables are based on system error E and error change EC, which is similar to PD control.Such control might have a good dynamic characteristic, but the static performance is not satisfactory.Combining fuzzy control and PID control, this would make a system have both flexibility-adaptablity of fuzzy control and high accuracy of PID control.Fig.2 shows the structure diagram of fuzzy-PID control system, in which fuzzy controller is responsible for selecting a different PID parameter to improve the local performance thus increasing over all performance.2 Design of fuzzy-PID controller Speed drive motor controller design is similar to the following example for steering gear controller design.Fuzzy controller consists of fuzzification, fuzzy-inference and defuzzification, which are based on the knowledge base.[6] Controller input error and error change, output the parameters Kp,Ki,Kd.Suppose the fuzzy set for E is{NB,NM,NS,NO,PO,PS，PM,PB};the fuzzy set for EC、Kp、Ki and Kd is{NB,NM,NS,ZO,PS,PM,PB}.The linguistic meanings are: NB = negative big, NM = negative middle, NS = negative small, NO = negative zero, ZO = zero, PO = positive zero, PS = positive small, PM = positive middle, PB = positive big.So the membership function curves of fuzzy variables E、EC、Kp、Ki and Kd are shown in the Fig.3-Fig.7: 3

It’s necessary to establish rule table after finishing fuzzification.According the description of rule table, 56 fuzzy conditional statements can be summed, which look like If(E is PB)and(EC is PB)then(Kp is PB)(Ki is ZO)(Kd is PB).See details in Tab.1-Tab.3.Then, the last step is defuzzification and making a lookup table.During fuzzy control, the lookup table would be embed into the program.Suppose input value is fixed, the corresponding output value would be found in the table.Actually, this would save much computing time, and the control would become simply.Analysis of experimental results

Experiment used the steering gear model.The simulation circuit were shown in Fig.2.The usual PID and fuzzy PID algorithm were all simulinked in the Matlab.Responding curves obtained were shown in Fig.8 and Fig.9.The experimental result show that compared with the usual PID, the responding time of fuzzy-PID algorithm is shorter without over swing.The system dynamic performance is improved significantly.6 Conclusion and outlook This paper provided a design scheme for controlling a smart car, which is proved practically and superlatively though experiments.Unmanned smart car is due to the development of computer technology, pattern recognition and intelligent control technique.Many countries and research groups are doing research in the area.But it’s a complicated system, which involves a number of technologies.So the development of each technology is important, for it would become the bottleneck of the development of smart car.Stepper motor Stepper motor is the electric pulse signals into angular displacement or linear displacement of the open-loop stepper motor control element pieces.In the case of 8 non-overloaded, the motor speed, stop position depends only on the pulse frequency and pulse number, regardless of load changes, when the driver receives a step pulse signal, it will drive a stepper motor to Set the direction of rotation of a fixed angle, called the “step angle”, which the angle of rotation is fixed step by step operation.Number of pulses can be controlled by controlling the angular displacement, so as to achieve accurate positioning purposes;the same time by controlling the pulse frequency to control the motor rotation speed and acceleration, to achieve speed control purposes.1 Work Induction motor is a stepper motor, does it work is the use of electronic circuits, the DC power supply into a time-sharing, multi-phase timing control current, this current stepper motor power supply, the stepper motor to work properly , The drive is sharing power supply for the stepper motor, the polyphase timing controller.Although the stepper motor has been widely used, but the stepper motor does not like a normal DC motor, AC motor in the conventional use.It must be double-ring pulse signal;power driver circuit composed of the control system can be used.Therefore, it is not easy with a good stepping motor, which involves mechanical, electrical, electronics and computers, and much other specialized knowledge.As the stepper motor actuators, electromechanical integration, one of the key products, widely used in a variety of automatic control systems.With the development of microelectronics and computer technology, increasing demand for stepper motor has applications in all areas of the national economy.2 Categories Now more commonly used include the reaction of step motor stepper motor(VR), permanent magnet stepper motor(PM), hybrid stepper motors(HB)and single-phase stepper motor.3 Permanent magnet stepper motor Permanent magnet stepper motor is generally two-phase, torque, and smaller, usually 7.5 degree step angle or 15 degrees;Permanent magnet stepper motor output torque, dynamic performance, but a large step angle.4 Reaction Stepper Motor

Reaction is generally three-phase stepping motor can achieve high torque output, step angle of 1.5 degrees is generally, but the noise and vibration are large.Reaction by the stepper motor rotor magnetic circuit made of soft magnetic materials, a number of the stator phase excitation winding, the use of permeability changes in torque.Step Motor simple structure, low production costs, step angle is small;but the dynamic performance is poor.Hybrid Stepping Motor Hybrid Step Motor combines reactive, permanent magnet stepper motors of both, it's a small step angle, contribute a large, dynamic performance, is currently the highest performance stepper motor.It is also sometimes referred to as Permanent Magnet Induction Stepping Motor.It consists of two phases and the five-phase: the general two-phase step angle of 1.8 degrees and the general five-phase step angle 0.72 degrees.The most widely used Stepper Motor.Stepper motor drive for energy saving 6 Three-phase stepper motor drive special features: ? 180% low torque output, low frequency characteristics of a good run ? Maximum output frequency 600Hz, high-speed motor control ? full range of detection of protection(over voltage, under voltage, overload)instantaneous power failure restart ? acceleration, deceleration, such as dynamic change in the stall protection function to prevent ? Electrical dynamic parameters of automatic recognition function to ensure stability and accuracy of the system ? quick response and high-speed shutdown ? abundant and flexible input and output interface and control, versatility ? use of SMT production and three full-mount anti-paint treatment process, product stability and high ? full range of Siemens IGBT power devices using the latest, to ensure the quality of high-quality 7 Basic principles Usually for the permanent magnet rotor motor, when current flows through the stator windings, the stator windings produce a magnetic field vector.The magnetic field will lead to a rotor angle of the magnetic field makes the direction of a rotor and the stator's magnetic field direction.When the stator magnetic field vector rotating at an angle.As the rotor magnetic field is also transferred from another perspective.An electrical pulse for each input, the motor turning a point forward.It is the angular displacement of the output and input the number of pulses proportional to speed and pulse frequency is proportional to.Power to change the order of winding, the motor will reverse.Therefore, the number of available control pulse, frequency and power the motor windings of each phase in order to control the stepper motor rotation.8 Induction Stepping Motor 8-1 features: Induction, compared with the traditional reactive, structural reinforced with a permanent magnet rotor, in order to provide the working point of soft magnetic materials, and the stator excitation magnetic field changes only need to provide to provide the operating point of the consumption of magnetic materials energy, so the motor efficiency, current, low heat.Due to the presence of permanent magnets, the motor has a strong EMF, the damping effect of its own good, it is relatively stable during operation, low noise, low frequency vibration.Induction can be seen as somewhat low-speed synchronous motor.A four-phase motor can be used for four-phase operation, but also can be used for two-phase operation.(Must be bipolar voltage drive), while the motor is not so reactive.For example: four phase, eight-phase operation(A-AB-B-BC-C-CD-D-DA-A)can use two-phase eight-shot run.Not difficult to find the conditions for C =, D =.a two-phase motor's internal winding consistent with the four-phase motors, small power motors are generally directly connected to the second phase, the power of larger motor, in order to facilitate the use and flexible to change the dynamic characteristics of the motor, its external connections often lead to eight(four-phase), so that when used either as a four-phase motors used, can be used for two-phase motor winding in series or parallel.8-2 classification：Induction motors can be divided in phases: two-phase motor, three phase motor, four-phase motor, five-phase motor.The frame size(motor diameter)can be divided into: 42BYG(BYG the Induction Stepping motor code), 57BYG, 86BYG, 110BYG,(international standard), and like 70BYG, 90BYG, 130BYG and so are the national standards.8-3 the stepper motor phase number of static indicators of terms: very differently on the N, S the number of magnetic field excitation coil.Common m said.Beat number: complete the necessary cyclical changes in a magnetic field pulses or conducting state with n said, or that turned a pitch angle of the motor pulses needed to four-phase motor, for example, a four-phase four-shot operation mode that AB-BC-CD-DA-AB, shot eight four-phase operation mode that A-AB-B-BC-C-CD-D-DA-A.Step angle: corresponds to a pulse signal, the angular displacement of the rotor turned with θ said.θ = 360 degrees(the rotor teeth number of J * run shot), the conventional two, four-phase, the rotor teeth 50 tooth motor as an example.Four step run-time step angle θ = 360 ° /(50 * 4)= 1.8 degrees(commonly called the whole step), eight-shot running step angle θ = 360 ° /(50 * 8)= 0.9 degrees(commonly known as half step.)Location torque: the motor is not energized in the state, its locked rotor torque(as well as by the magnetic field profile of harmonics caused by mechanical error)static torque: the motor under the rated static electricity, the motor without rotation, the motor shaft locking torque.The motor torque is a measure of volume(geometry)standards, and drive voltage and drive power, etc.has nothing to do.Although the static torque is proportional to the electromagnetic magnetizing ampere turns, and fixed air gap between the rotor teeth on, but over-use of reduced air gap, increase the excitation ampere-turns to increase the static torque is not desirable, this will cause the motor heating and mechanical noise.12 智能小車控制中模糊-PID控制的實(shí)現(xiàn)

摘要：本文設(shè)計了一個自動智能小車控制系統(tǒng)和模糊-PID控制算法。提出了一個設(shè)計模糊PID控制器的方案。通過matlab的仿真分析表明,模糊-PID控制算法的性能比一般的PID控制更好。智能小車的試驗結(jié)果表明它會隨黑色的引導(dǎo)線快速并且穩(wěn)定的走完整個行程。關(guān)鍵詞：模糊PID；智能小車；模糊控制器；模糊控制。

1．簡介

近年來,許多國家正在研制無人駕駛的車輛技術(shù)。產(chǎn)生了許多新的理論和應(yīng)用技術(shù)。文獻(xiàn)[1]中提出了一個采用實(shí)時檢測速度從而準(zhǔn)確、動態(tài)改變小車轉(zhuǎn)向的理論，從而實(shí)現(xiàn)轉(zhuǎn)向完美特性的控制策略。文獻(xiàn)[2]中采用邊緣檢測算法來提取道路信息，并采用了比例控制。文獻(xiàn)[3]提出了一種有效、具有良好抗干擾性的、適應(yīng)性強(qiáng)的動態(tài)圖像處理算法。這種算法有效的解決了由環(huán)境光線變化以及軌道變化所引起的小車偏離軌道現(xiàn)象。文獻(xiàn)[4]利用非線性最優(yōu)化重建了軌道和攝像調(diào)整間的空間關(guān)系，從而使它能夠精確的測量出橫向偏差。上述方案都從某種意義上改善了小車的性能，但他們都缺少以小車運(yùn)動和大量實(shí)驗為基礎(chǔ)的小車的特性。這篇文章中提出了一個模糊控制算法以及模糊PID控制器的設(shè)計方法。在本文最后,給出了實(shí)驗結(jié)果來證明模糊PID算法的有效性。

2．硬件系統(tǒng)設(shè)計

要實(shí)現(xiàn)模糊PID控制算法的設(shè)計，有必要設(shè)計一個智能小車硬件系統(tǒng)。智能小車應(yīng)該有由道路檢測，轉(zhuǎn)角檢測，速度檢測等構(gòu)成的智能控制單元。詳見圖1。

圖1 智能小車原理框圖 3．模糊PID控制的基本原則

用一般的PID控制算法來獲得最好的響應(yīng)是不容易的。因為參數(shù)Kp、Ki、Kd不適應(yīng)于不同的對象，或者同一個對象的不同狀態(tài)。模糊控制是以模糊集合和模糊邏輯為機(jī)車的。不需要精確的數(shù)學(xué)模型，它可以由用經(jīng)驗建立起來的規(guī)則表來確定控制變量的大小。一般來說，模糊控制的輸入變量基于系統(tǒng)的誤差E和系統(tǒng)的誤差變化量Ec。這和比例－微分控制相似。這樣的控制可能可以獲得較好的動態(tài)性能，但獲得的靜態(tài)性能不能讓人滿意。

將模糊控制于PID控制結(jié)合起來，這就會使系統(tǒng)即具有模糊控制所具有的靈活的適應(yīng)特性，又具有PID控制的所具有的較高的精確度。圖2給出了模糊PID控制系統(tǒng)的結(jié)構(gòu)圖，其中模糊控制器的作用是選擇不同的PID參數(shù)來改善局部響應(yīng)，進(jìn)而改善整體的響應(yīng)。

圖2 模糊PID控制仿真框圖

4．模糊PID控制器的設(shè)計

速度驅(qū)動電機(jī)控制器的設(shè)計和下面給出的轉(zhuǎn)向機(jī)構(gòu)控制器設(shè)計是相似的。模糊控制器由模糊化、模糊推理、去模糊化組成，這些都是以知識庫為基礎(chǔ)的?？刂破鬏斎霝檎`差及誤差變化量，輸出為參數(shù)Kp、Ki、Kd。

假設(shè)誤差E的模糊集合為{NB NM NS NO PO PS PM PB};誤差變化量Ec、參數(shù)Kp、Ki、Kd的模糊集合為{NB NM NS ZO PS PM PB}。他們表示的意義為：NB=負(fù)大、NM=負(fù)中、NS=負(fù)小、NO=負(fù)零、ZO=零、PO=正零、PS=正小、PM=正中、PB=正大。得到模 糊變量E、EC、Kp、Ki、Kd的隸屬度函數(shù)曲線如圖3至圖7所示：

圖3 Kp隸屬函數(shù)響應(yīng)曲線

圖4 Ki隸屬函數(shù)響應(yīng)曲線

圖5 Kd隸屬函數(shù)響應(yīng)曲線

圖6 E隸屬函數(shù)響應(yīng)曲線

圖7 Ec隸屬函數(shù)響應(yīng)曲線

在模糊化完成后需要建立規(guī)則表，根據(jù)規(guī)則表的描述，可以總結(jié)出56個模糊條件語句，形式例如：如果(E 是 PB)并且(Ec 是 PB)那么(Kp 是 PB)(Ki 是 ZO)(Kd是 PB)。詳見表1—表3。

最后一個步驟是去模糊化和建立查詢表。在模糊控制中查詢表應(yīng)該嵌入到程序中。假設(shè)輸入的值是固定的那么可以在表中查出相應(yīng)的輸出值。實(shí)際上，這可以節(jié)省許多計算時間并使控制簡化。

表1 Kp規(guī)則表

表2 Ki規(guī)則表

表3 Kd規(guī)則表

5．實(shí)驗結(jié)果分析

圖8 PID控制響應(yīng)曲線

圖9 模糊PID控制響應(yīng)曲線

實(shí)驗利用了轉(zhuǎn)向機(jī)構(gòu)模型，它的仿真回路已經(jīng)由圖2給出。我們已經(jīng)用MATLAB仿真出了一般PID控制算法和模糊PID控制算法，獲得的響應(yīng)曲線如圖

8、圖9所示。

實(shí)驗結(jié)果表明，同一般得PID控制相比模糊控制的響應(yīng)時間要短且沒有超調(diào)的。系統(tǒng)的動態(tài)性能有了重大的提高。

6．總結(jié)和展望

這篇文章給出了一個控制智能小車的設(shè)計方案，并且通過實(shí)驗從實(shí)際上很好的驗證了這個方案。

無人駕駛智能小車是以計算機(jī)技術(shù)、模式識別以及智能控制技術(shù)的發(fā)展為基礎(chǔ)的。許多國家和機(jī)構(gòu)都在做這一方面的研究，但它是一個復(fù)雜的系統(tǒng)，它包含了許多方面的技術(shù)，所以任何一個技術(shù)的發(fā)展都是重要的，這可能成為智能車發(fā)展的瓶頸。

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步進(jìn)電機(jī)

步進(jìn)電機(jī)是將電脈沖信號轉(zhuǎn)變?yōu)榻俏灰苹蚓€位移的開環(huán)控制元步進(jìn)電機(jī)件。在非超載的情況下，電機(jī)的轉(zhuǎn)速、停止的位置只取決于脈沖信號的頻率和脈沖數(shù)，而不受負(fù)載變化的影響，當(dāng)步進(jìn)驅(qū)動器接收到一個脈沖信號，它就驅(qū)動步進(jìn)電機(jī)按設(shè)定的方 向轉(zhuǎn)動一個固定的角度，稱為“步距角”，它的旋轉(zhuǎn)是以固定的角度一步一步運(yùn)行的?？梢酝ㄟ^控制脈沖個數(shù)來控制角位移量，從而達(dá)到準(zhǔn)確定位的目的；同時可以通過控制脈沖頻率來控制電機(jī)轉(zhuǎn)動的速度和加速度，從而達(dá)到調(diào)速的目的。工作原理

步進(jìn)電機(jī)是一種感應(yīng)電機(jī)，它的工作原理是利用電子電路，將直流電變成分時供電的，多相時序控制電流，用這種電流為步進(jìn)電機(jī)供電，步進(jìn)電機(jī)才能正常工作，驅(qū)動器就是為步進(jìn)電機(jī)分時供電的，多相時序控制器

雖然步進(jìn)電機(jī)已被廣泛地應(yīng)用，但步進(jìn)電機(jī)并不能象普通的直流電機(jī)，交流電機(jī)在常規(guī)下使用。它必須由雙環(huán)形脈沖信號、功率驅(qū)動電路等組成控制系統(tǒng)方可使用。因此用好步進(jìn)電機(jī)卻非易事，它涉及到機(jī)械、電機(jī)、電子及計算機(jī)等許多專業(yè)知識。步進(jìn)電機(jī)作為執(zhí)行元件，是機(jī)電一體化的關(guān)鍵產(chǎn)品之一, 廣泛應(yīng)用在各種自動化控制系統(tǒng)中。隨著微電子和計算機(jī)技術(shù)的發(fā)展，步進(jìn)電機(jī)的需求量與日俱增，在各個國民經(jīng)濟(jì)領(lǐng)域都有應(yīng)用。分類

現(xiàn)在比較常用的步進(jìn)電機(jī)包括反應(yīng)式步進(jìn)電機(jī)（VR）、永磁式步進(jìn)電機(jī)（PM）、混合式步進(jìn)電機(jī)（HB）和單相式步進(jìn)電機(jī)等。永磁式步進(jìn)電機(jī)

永磁式步進(jìn)電機(jī)一般為兩相，轉(zhuǎn)矩和體積較小，步進(jìn)角一般為7.5度 或15度； 永磁式步進(jìn)電動機(jī)輸出力矩大，動態(tài)性能好，但步距角大。反應(yīng)式步進(jìn)電機(jī)

反應(yīng)式步進(jìn)電機(jī)一般為三相，可實(shí)現(xiàn)大轉(zhuǎn)矩輸出，步進(jìn)角一般為1.5度，但噪聲和振動都很大。反應(yīng)式步進(jìn)電機(jī)的轉(zhuǎn)子磁路由軟磁材料制成，定子上有多相勵磁繞組，利用磁導(dǎo)的變化產(chǎn)生轉(zhuǎn)矩。

反應(yīng)式步進(jìn)電動機(jī)結(jié)構(gòu)簡單，生產(chǎn)成本低，步距角??；但動態(tài)性能差。混合式步進(jìn)電機(jī)

混合式步進(jìn)電動機(jī)綜合了反應(yīng)式、永磁式步進(jìn)電動機(jī)兩者的優(yōu)點(diǎn)，它的步距角小，出力大，動態(tài)性能好，是目前性能最高的步進(jìn)電動機(jī)。它有時也稱作永磁感應(yīng)子式步進(jìn)電動機(jī)。它又分為兩相和五相：兩相步進(jìn)角一般為1.8度而五相步進(jìn)角一般為 0.72度。這種步進(jìn)電機(jī)的應(yīng)用最為廣泛。變頻器對步進(jìn)電機(jī)的節(jié)能改造 三相步進(jìn)電機(jī)專用變頻器特點(diǎn)：

■低頻轉(zhuǎn)矩輸出180%，低頻運(yùn)行特性良好 ■輸出頻率最大600Hz，可控制高速電機(jī)

■全方位的偵測保護(hù)功能(過壓、欠壓、過載)瞬間停電再起動

■加速、減速、動轉(zhuǎn)中失速防止等保護(hù)功能

■電機(jī)動態(tài)參數(shù)自動識別功能，保證系統(tǒng)的穩(wěn)定性和精確性 ■高速停機(jī)時響應(yīng)快

■豐富靈活的輸入、輸出接口和控制方式，通用性強(qiáng) ■采用SMT全貼裝生產(chǎn)及三防漆處理工藝，產(chǎn)品穩(wěn)定度高 ■全系列采用最新西門子IGBT功率器件，確保品質(zhì)的高質(zhì)量 基本原理

通常電機(jī)的轉(zhuǎn)子為永磁體，當(dāng)電流流過定子繞組時，定子繞組產(chǎn)生一矢量磁場。該磁場會帶動轉(zhuǎn)子旋轉(zhuǎn)一角度，使得轉(zhuǎn)子的一對磁場方向與定子的磁場方向一致。當(dāng)定子的矢量磁場旋轉(zhuǎn)一個角度。轉(zhuǎn)子也隨著該磁場轉(zhuǎn)一個角度。每輸入一個電脈沖，電動機(jī)轉(zhuǎn)動一個角度前進(jìn)一步。它輸出的角位移與輸入的脈沖數(shù)成正比、轉(zhuǎn)速與脈沖頻率成正比。改變繞組通電的順序，電機(jī)就會反轉(zhuǎn)。所以可用控制脈沖數(shù)量、頻率及電動機(jī)各相繞組的通電順序來控制步進(jìn)電機(jī)的轉(zhuǎn)動。感應(yīng)子式步進(jìn)電機(jī)

1、特點(diǎn)： 感應(yīng)子式與傳統(tǒng)的反應(yīng)式相比，結(jié)構(gòu)上轉(zhuǎn)子加有永磁體，以提供軟磁材料的工作點(diǎn)，而定子激磁只需提供變化的磁場而不必提供磁材料工作點(diǎn)的耗能，因此該電機(jī)效率高，電流小，發(fā)熱低。因永磁體的存在，該電機(jī)具有較強(qiáng)的反電勢，其自身阻尼作用比較好，使其在運(yùn)轉(zhuǎn)過程中比較平穩(wěn)、噪音低、低頻振動小。感應(yīng)子式某種程度上可以看作是低速同步的電機(jī)。一個四相電機(jī)可以作四相運(yùn)行，也可以作二相運(yùn)行。（必須采用雙極電壓驅(qū)動），而反應(yīng)式電機(jī)則不能如此。例如：四相，八相運(yùn)行（A-AB-B-BC-C-CD-D-DA-A）完全可以采用二相八拍運(yùn)行方式.不難發(fā)現(xiàn)其條件為C=,D=.一個二相電機(jī)的內(nèi)部繞組與四相電機(jī)完全一致，小功率電機(jī)一般直接接為二相，而功率大一點(diǎn)的電機(jī)，為了方便使用，靈活改變電機(jī)的動態(tài)特點(diǎn)，往往將其外部接線為八根引線（四相），這樣使用時，既可以作四相電機(jī)使用，可以作二相電機(jī)繞組串聯(lián)或并聯(lián)使用。

2、分類

感應(yīng)子式電機(jī)以相數(shù)可分為：二相電機(jī)、三相電機(jī)、四相電機(jī)、五相電機(jī)等。以機(jī)座號（電機(jī)外徑）可分為：42BYG(BYG為感應(yīng)子式步進(jìn)電機(jī)代號）、57BYG、86BYG、110BYG、（國際標(biāo)準(zhǔn)），而像70BYG、90BYG、130BYG等均為國內(nèi)標(biāo)準(zhǔn)。

3、步進(jìn)電機(jī)的靜態(tài)指標(biāo)術(shù)語 相數(shù)：

產(chǎn)生不同對極N、S磁場的激磁線圈對數(shù)。常用m表示。拍數(shù)：完成一個磁場周期性變化所需脈沖數(shù)或?qū)щ姞顟B(tài)用n表示，或指電機(jī)轉(zhuǎn)過一個齒距角所需脈沖數(shù)，以四相電機(jī)為例，有四相四拍運(yùn)行方式即AB-BC-CD-DA-AB，四相八拍運(yùn)行方式即 A-AB-B-BC-C-CD-D-DA-A.步距角：對應(yīng)一個脈沖信號，電機(jī)轉(zhuǎn)子轉(zhuǎn)過的角位移用θ 20 表示。θ=360度（轉(zhuǎn)子齒數(shù)J*運(yùn)行拍數(shù)），以常規(guī)二、四相，轉(zhuǎn)子齒為50齒電機(jī)為例。四拍運(yùn)行時步距角為θ=360度/（50*4）=1.8度（俗稱整步），八拍運(yùn)行時步距角為θ=360度/（50*8）=0.9度（俗稱半步）。定位轉(zhuǎn)矩：電機(jī)在不通電狀態(tài)下，電機(jī)轉(zhuǎn)子自身的鎖定力矩（由磁場齒形的諧波以及機(jī)械誤差造成的）靜轉(zhuǎn)矩：電機(jī)在額定靜態(tài)電作用下，電機(jī)不作旋轉(zhuǎn)運(yùn)動時，電機(jī)轉(zhuǎn)軸的鎖定力矩。此力矩是衡量電機(jī)體積（幾何尺寸）的標(biāo)準(zhǔn)，與驅(qū)動電壓及驅(qū)動電源等無關(guān)。雖然靜轉(zhuǎn)矩與電磁激磁安匝數(shù)成正比，與定齒轉(zhuǎn)子間的氣隙有關(guān)，但過分采用減小氣隙，增加激磁安匝來提高靜力矩是不可取的，這樣會造成電機(jī)的發(fā)熱及機(jī)械噪音。

第四篇：采礦工程畢業(yè)設(shè)計英文翻譯

Underground Mining

Most present-day mining in Europe occurs under 2000 to 4000 ft of overburden, as more easily mined coal deposits have been depleted.At this depth most mines are developed as shaft mines.All personnel, material, and coal have to be hoisted trough these shaft.Considering the two factors of hoisting capacity and required length of shaft, a considerable investment is necessary to reach the coal-bearing strata.The requires huge investments.Openings at this depth have to be equipped with costly supports, and periodic reworking and repair is necessary.Mines not only extend horizontally but also vertically through the development of new levels.The life of the mines is thus extend considerably, and surface installations can be amortize over a longer period.The more limited reserves have forced companies into mining less favorable deposits, and European government require that all possible deposits be mined to conserve the nation’s energy resources.These factor and the large percentage of inclined seams and faults make mining very difficult and costly.The population density and the heavy surface buildup cause additional expense in the form of payments for subsidence damage to surface structures.Therefore, backfilling is frequently practiced to reduce subsidence.The close spacing of faults often severely limits the size of a mining section, forcing frequent moves and excessive development work.The thickness of the overburden results in very high ground pressure.This would require extremely large pillars if the room and pillar method was applied.Additionally, support is required for any opening, adding prohibitive costs to a multiple-entry room and pillar operation.As a result, single-entry longwall operations requiring the minimum number of entries and allowing maximum recovery of resources is the mining method almost exclusively practiced.Shaft mines dominate the European coal mining industry.Shafts 20 to 30 ft in diameter, with circular cross section, lined with masonry, concrete, or steel are the dominant means of gaining access to the coal-bearing strata.They are often extended beyond the last mining level to provide for future expansion.As in the Unite States, shafts are developed by drilling, blasting, and excavating or by large-diameter shaft-boring equipment.Shaft boring is more frequently used, particularly on the smaller and shorter subshaft, which connect the different levels but do not extend to the surface.Haulage in the shaft is usually accomplished by hoisting of the filled mine cars on multistage cages or by skips.Pumping of coal slurry is also done in special cases.The complex system of forces and the resulting rock mechanical problems developed by mining activities at different levels result in significant differences between European and US underground development.The rock mechanical interaction of the extraction operations at the various levels require that all deposits be mined as completely as possible.Pillars left after mining create zones of extreme and often unmanageable ground control problem, as well as a high probability of roof bounce.Since the number of entries is kept to a minimum because of cost, no bleeder systems are provided.If retreat mining is practiced, only two entries are advanced in to a new mining area.Panels are laid out as large as possible.The large-panel layout is used as another means of reducing the number of entries.Minded–out panels are sealed off to prevent spontaneous combustion through the removal of oxygen.The main levels, with extensive entry systems, are used for coal, supply, and personnel haulage and for ventilation.They are often spaced with little regard to the position of the coal seams, because the deposits are reached selectively through other means.In the past, 165-or330-ft intervals were selected while increasing ground pressures and development and maintenance increase substantially, requiring large volumes of air for cooling.As a result, entry cross sections at these levels have to be increase.Fig.9.1 German multilevel, multiseam shaft-type coal mine.Underground facilities：

(1)main shaft with skip hoisting;(2)exhaust ventilation shaft with multistage cage;(3)third-level station;(4)blind shaft with cylindrical storage bin;(5)blind shaft with car-hoisting facilities;(6)main entry;(7)main entry;(8)section or panel entry;(9)road heading machine(10)longwall section with plow;(11)longwall section with shearer;(12)longwall section in a steeply pitching seam mined manually with air picks;(13)longwall section in steeply pitching seam with plow;(14)minded-out gob area;(15)ventilation lock;(16)belt conveyor as main haulage;(17)main car haulage;(18)storage bin and skip-loading facilities;(19)supply haulage with a mono-rail;(20)supply haulage with mine cars;(21)monorail system as personnel carrier;(22)worker-trip cars;(23)pump station.Surface facilities:(a)hoisting tower with overhead hoist;(b)shaft building;(c)head frame;(d)main exhaust fan and diffuser;(e)coal preparation plant with loading facilities;(f)coking coal silo;(g)container vehicle for filling of coke ovens;(h)coke oven battery;(i)coke watering car;(k)coke quenching tower;(l)gas tank;(m)water-treatment plant;(n)refuse pile;(o)power plant;(p)cooling tower;(q)water tower;(r)supply storage area;(s)sawmill;(t)training and teaching center.地下采煤

目前，大部分歐洲的煤礦開采都已經(jīng)達(dá)到了2000到4000英尺，主要是因為淺部容易開采的煤層都已經(jīng)采完。在這個深度的大部分煤層都已經(jīng)發(fā)展成為要用相關(guān)井筒進(jìn)行開采的地步。所用的人員、材料、煤炭都不得不從井筒采用絞車等提升進(jìn)行運(yùn)輸。考慮到絞車提升容量以及所需要的井筒長度的兩個因素，一個相當(dāng)大的資金投入對于開采到煤層所處的地層是必需的。這些大范圍的地下巷道或隧道的網(wǎng)絡(luò)的開拓和維護(hù)費(fèi)用需要一筆巨大的投資。在這個深度進(jìn)行開拓不得不裝備一些很昂貴的支架和一些循環(huán)型的改造和返修，這些也都是必要的。

采礦不單單是拓寬水平方向而且通過開拓新的水平來拓寬來延深。所以礦井的服務(wù)年限被極大地拓寬，并且地表的安裝設(shè)備費(fèi)用也能夠在很長的一個時期內(nèi)得以緩沖。

有限的資源儲備迫使公司開采要去開采那些并不是很樂觀的煤層，并且歐洲各國政府要求采出所有可采的煤層以保護(hù)國家的能源。這些因素由于大比率的煤線和斷層以至于煤炭的開采非常困難并且價格昂貴。由于人口密度的增長和地表建筑的增加，從而造成地表的沉陷對于建筑物的破壞，以至于增加了額外的成本。因此，采空區(qū)填充是最常用的防治地表沉陷的實(shí)踐措施。過小的斷層間距常常嚴(yán)重地限制采區(qū)的尺寸，因而不得不頻繁搬家，并造成過大的開拓工程量。

上部覆蓋層的厚度導(dǎo)致了相當(dāng)大的地層壓力。如果采用房柱式開采方法，就需要留異常巨大的煤柱。另外，任何一個工作面都需要支 架，并且增加了額外的費(fèi)用對于多種平巷峒室的支撐措施。

地下開采統(tǒng)治著歐洲的煤炭開采工業(yè)。井筒直徑大約20到30英寸，一般采用鋼筋混凝土砌碹的圓形斷面，作為主要的連接巷道連接到含煤地層。他們一般被延深到超過最后一個開采水平來滿足未來的拓展。如在美國，立井是用打眼、放炮和挖掘方法或用大直徑鉆井設(shè)備來開鑿的。鉆井時經(jīng)常被采用的，尤其對于小型的長度較短的連接各個水平但不通往地面的暗井。

井筒中一般采用罐籠中承載礦車或箕斗進(jìn)行提升。在特殊情況下采用煤泥泵出的形式開采。

這種力的復(fù)雜的系統(tǒng)和巖石力學(xué)的合成的問題在煤礦開采活動不同的水平在歐洲和美國存在巨大的不同。

在多個水平煤層進(jìn)行開采時，巖石之間相互力的作用要求盡可能的將煤全部采出。煤礦開采后留下的煤柱形成了一個壓力極高并且相當(dāng)難以維護(hù)的空間，具有很高的發(fā)生頂板巖石突出的可能性。

由于資金成本的問題，巷道入口的數(shù)目保持在最小值。沒有回風(fēng)巷的系統(tǒng)開始形成。如果采用后退式的開采方法，在采煤區(qū)段只有兩個入口。

區(qū)段一般被盡可能的大。大區(qū)段的布置方式其實(shí)從另一個角度說就是為了減少入口的數(shù)目。開采過后的區(qū)域一般打上封閉，以切斷氧氣的來源從而防止采空區(qū)煤層自燃。

在布置有眾多巷道主要的水平，它被用來運(yùn)送煤炭、供給以及人員的運(yùn)輸和通風(fēng)。他們經(jīng)?？粘鲆徊糠治恢玫拿褐徊?，因為儲量已 經(jīng)達(dá)到并通過別的方法進(jìn)行有選擇性的開采。在過去，165或330英尺的間隔被有選擇的當(dāng)逐漸增加的礦山壓力和開拓的維護(hù)費(fèi)用迫使增加到660或990英尺。溫度隨著深度的增加也急劇增加，需要大容量的空氣從而達(dá)到降溫的目的。以至于這些水平的采區(qū)巷道也就要求增加。

圖9.1 德國多水平、多工作面立井井筒式礦井

地下設(shè)備：

(1)箕斗提升主井；

(2)擔(dān)負(fù)抽出式通風(fēng)的并配有多層罐籠的副井；(3)第三水平井底車場;(4)帶有圓柱形煤倉的暗井;(5)有礦車提升設(shè)備的暗井;(6)主要大巷;(7)主要大巷;(8)采區(qū)或盤區(qū)平巷;(9)掘進(jìn)機(jī)；(10)采用刨煤機(jī)的長壁工作面采區(qū);(11)采用采煤機(jī)的長壁工作面采區(qū);(12)采用人工風(fēng)鎬的急傾斜煤層的長壁工作面采區(qū)；(13)采用刨煤機(jī)的急傾斜煤層的長壁工作面采區(qū);(14)采空區(qū);(15)風(fēng)門;(16)膠帶輸送機(jī)作為主要運(yùn)輸設(shè)備;(17)主要礦車運(yùn)輸;(18)煤倉和箕斗裝載峒室設(shè)備;(19)材料運(yùn)輸采用單軌運(yùn)輸;(20)材料運(yùn)輸采用礦車運(yùn)輸;(21)單軌礦車用于人員運(yùn)輸;(22)人車;(23)泵房及地表設(shè)備:(a)帶有高架天輪的提升塔;(b)井筒;(c)井架;(d)主扇和擴(kuò)散管;(e)有裝載設(shè)備的洗選廠;(f)焦炭倉罐;(g)運(yùn)送焦炭冶煉的運(yùn)送機(jī);(h)焦炭爐電池;(i)焦炭水車;(k)焦炭冷卻塔;(l)瓦斯容器箱;(m)水處理裝置;(n)矸石堆;(o)動力廠;(p)冷卻塔;(q)水塔;(r)倉儲區(qū)域;(s)鋸木廠;(t)培訓(xùn)中心.

第五篇：畢業(yè)設(shè)計(論文)外文翻譯(原文)

畢業(yè)設(shè)計（論文）——外文翻譯（原文）

NEWAPPLICATIONOFDATABASE

Relational databases have been in use for over two decades.A large portion of the applications of relational databases have been in the commercial world, supporting such tasks as transaction processing for banks and stock exchanges, sales and reservations for a variety of businesses, and inventory and payroll for almost of all companies.We study several new applications, which have become increasingly important in recent years.First.Decision-support system

As the online availability of data has grown, businesses have begun to exploit the available data to make better decisions about increase sales.We can extract much information for decision support by using simple SQL queries.Recently however, people have felt the need for better decision support based on data analysis and data mining, or knowledge discovery, using data from a variety of sources.Database applications can be broadly classified into transaction processing and decision support.Transaction-processing systems are widely used today, and companies have accumulated a vast amount of information generated by these systems.The term data mining refers loosely to finding relevant information, or “discovering knowledge,” from a large volume of data.Like knowledge discovery in artificial intelligence, data mining attempts to discover statistical rules and patterns automatically from data.However, data mining differs from machine learning in that it deals with large volumes of data, stored primarily on disk.Knowledge discovered from a database can be represented by a set of rules.We can discover rules from database using one of two models:

In the first model, the user is involved directly in the process of knowledge discovery.In the second model, the system is responsible for automatically discovering knowledge from the database, by detecting patterns and correlations in the data.Work on automatic discovery of rules has been influenced strongly by work in the artificial-intelligence community on machine learning.The main differences lie in the volume of data handled in databases, and in the need to access disk.Specialized data-mining algorithms have been developed to handle large volumes of disk-resident data efficiently.The manner in which rules are discovered depends on the class of data-mining application.We illustrate rule discovery using two application classes: classification and associations.Second.Spatial and Geographic Databases

Spatial databases store information related to spatial locations, and provide support for efficient querying and indexing based on spatial locations.Two types of spatial databases are particularly important:

Design databases, or computer-aided-design(CAD)databases, are spatial databases used to store design information about how objects---such as buildings, cars or aircraft---are constructed.Other important examples of computer-aided-design databases are integrated-circuit and electronic-device layouts.Geographic databases are spatial databases used to store geographic information, such as maps.Geographic databases are often called geographic information systems.Geographic data are spatial in nature, but differ from design data in certain ways.Maps and satellite images are typical examples of geographic data.Maps may provide not only location information-such

as boundaries, rivers and roads---but also much more detailed information associated with locations, such as elevation, soil type, land usage, and annual rainfall.Geographic data can be categorized into two types: raster data(such data consist a bit maps or pixel maps, in two or more dimensions.), vector data(vector data are constructed from basic geographic objects).Map data are often represented in vector format.Third.Multimedia Databases

Recently, there has been much interest in databases that store multimedia data, such as images, audio, and video.Today multimedia data typically are stored outside the database, in files systems.When the number of multimedia objects is relatively small, features provided by databases are usually not important.Database functionality becomes important when the number of multimedia objects stored is large.Issues such as transactional updates, querying facilities, and indexing then become important.Multimedia objects often have descriptive attributes, such as those indicating when they were created, who created them, and to what category they belong.One approach to building a database for such multimedia objects is to use database for storing the descriptive attributes, and for keeping track of the files in which the multimedia objects are stored.However, storing multimedia outside the database makes it harder to provide database functionality, such as indexing on the basis of actual multimedia data content.It can also lead to inconsistencies, such a file that is noted in the database, but whose contents are missing, or vice versa.It is therefore desirable to store the data themselves in the database.Forth.Mobility and Personal Databases

Large-scale commercial databases have traditionally been stored in central computing facilities.In the case of distributed database applications, there has usually been strong central database and network administration.Two technology trends have combined to create applications in which this assumption of central control and administration is not entirely correct:

1.The increasingly widespread use of personal computers, and, more important, of laptop or “notebook” computers.2.The development of a relatively low-cost wireless digital communication infrastructure, base on wireless local-area networks, cellular digital packet networks, and other technologies.Wireless computing creates a situation where machines no longer have fixed locations and network addresses.This complicates query processing, since it becomes difficult to determine the optimal location at which to materialize the result of a query.In some cases, the location of the user is a parameter of the query.A example is a traveler’s information system that provides data on hotels, roadside services, and the like to motorists.Queries about services that are ahead on the current route must be processed based on knowledge of the user’s location, direction of motion, and speed.Energy(battery power)is a scarce resource for mobile computers.This limitation influences many aspects of system design.Among the more interesting consequences of the need for energy efficiency is the use of scheduled data broadcasts to reduce the need for mobile system to transmit queries.Increasingly amounts of data may reside on machines administered by users, rather than by database administrators.Furthermore, these machines may, at times, be disconnected from the network.Summary

Decision-support systems are gaining importance, as companies realize the value of the on-line data collected by their on-line transaction-processing systems.Proposed extensions to SQL, such as the cube operation, help to support generation of summary data.Data mining seeks to discover

knowledge automatically, in the form of statistical rules and patterns from large databases.Data visualization systems help humans to discover such knowledge visually.Spatial databases are finding increasing use today to store computer-aided design data as well as geographic data.Design data are stored primarily as vector data;geographic data consist of a combination of vector and raster data.Multimedia databases are growing in importance.Issues such as similarity-based retrieval and delivery of data at guaranteed rates are topics of current research.Mobile computing systems have become common, leading to interest in database systems that can run on such systems.Query processing in such systems may involve lookups on server database.畢業(yè)設(shè)計（論文）——外文翻譯（譯文）

數(shù)據(jù)庫的新應(yīng)用

我們使用關(guān)系數(shù)據(jù)庫已經(jīng)有20多年了，關(guān)系數(shù)據(jù)庫應(yīng)用中有很大一部分都用于商業(yè)領(lǐng)域支持諸如銀行和證券交易所的事務(wù)處理、各種業(yè)務(wù)的銷售和預(yù)約，以及幾乎所有公司都需要的財產(chǎn)目錄和工資單管理。下面我們要研究幾個新的應(yīng)用，近年來它們變得越來越重要。

1、決策支持系統(tǒng)

由于越來越多的數(shù)據(jù)可聯(lián)機(jī)獲得，企業(yè)已開始利用這些可獲得的數(shù)據(jù)來對自己的行動做出更好的決策，比如進(jìn)什么貨，以及如何最好的吸引顧客以提高銷售額。我們可以通過使用簡單的SQL查詢語句提供大量用于決策支持的信息。但是，人們最近感到需要使用多種數(shù)據(jù)源的數(shù)據(jù)，以便在數(shù)據(jù)分析和數(shù)據(jù)挖掘（或知識發(fā)現(xiàn)）的基礎(chǔ)上，更好的來做決策支持。

數(shù)據(jù)庫應(yīng)用從廣義上可分為事務(wù)處理和決策支持兩類。事務(wù)處理系統(tǒng)現(xiàn)在正被廣泛使用，并且公司已經(jīng)積累了大量由這類系統(tǒng)產(chǎn)生的信息。

數(shù)據(jù)挖掘這個概念廣義上講是指從大量數(shù)據(jù)中發(fā)現(xiàn)有關(guān)信息，或“發(fā)現(xiàn)知識”。與人工智能中的知識發(fā)現(xiàn)類似，數(shù)據(jù)挖掘試圖自動從數(shù)據(jù)中發(fā)現(xiàn)統(tǒng)計規(guī)則和模式。但是，數(shù)據(jù)挖掘和機(jī)器學(xué)習(xí)的不同在于它處理的是大量數(shù)據(jù)，它們主要存儲在磁盤上。

從數(shù)據(jù)庫中發(fā)現(xiàn)的知識可以用一個規(guī)則集表示。我們用如下兩個模型之一從數(shù)據(jù)庫中發(fā)現(xiàn)規(guī)則：

● 在第一個模型中，用戶直接參與知識發(fā)現(xiàn)的過程

● 在第二個模型中，系統(tǒng)通過檢測數(shù)據(jù)的模式和相互關(guān)系，自動從數(shù)據(jù)庫中發(fā)現(xiàn)知識。有關(guān)自動發(fā)現(xiàn)規(guī)則的研究很大程度上是受人工智能領(lǐng)域在知識學(xué)習(xí)方面研究的影響。其主要的區(qū)別在于數(shù)據(jù)庫中處理的數(shù)據(jù)量，以及是否需要訪問磁盤。已經(jīng)有一些具體的數(shù)據(jù)挖掘算法用于高效地處理放在磁盤上的大量數(shù)據(jù)。

規(guī)則發(fā)現(xiàn)的方式依賴于數(shù)據(jù)挖掘應(yīng)用的類型。我們用兩類應(yīng)用闡述規(guī)則發(fā)現(xiàn)：分類和關(guān)聯(lián)。

2、空間和地理數(shù)據(jù)庫

空間數(shù)據(jù)庫存儲有關(guān)空間位置的信息，并且對高效查詢和基于空間位置的索引提供支持。有兩種空間數(shù)據(jù)庫特別重要：

● 設(shè)計數(shù)據(jù)庫或計算機(jī)輔助設(shè)計（CAD）數(shù)據(jù)庫是用于存儲設(shè)計信息的空間數(shù)據(jù)庫，這些信息主要是關(guān)于物體（如建筑、汽車或是飛機(jī)）是如何構(gòu)造的。另一個計算機(jī)輔助設(shè)計數(shù)據(jù)庫的重要例子是整合電路和電子設(shè)備設(shè)計圖。

● 地理數(shù)據(jù)庫是用于存儲地理信息（如地圖）的空間數(shù)據(jù)庫。地理數(shù)據(jù)庫常稱為地理信息系統(tǒng)。

地理數(shù)據(jù)本質(zhì)上是空間的，但與設(shè)計數(shù)據(jù)相比在幾個方面有所不同。地圖和衛(wèi)星圖像是地理數(shù)據(jù)的典型例子。地圖不僅可提供位置信息，如邊界、河流和道路，而且還可以提供許多和位置相關(guān)的詳細(xì)信息，如海拔、土壤類型、土地使用和年降雨量。地理數(shù)據(jù)可以分為兩類：光柵數(shù)據(jù)（這種數(shù)據(jù)由二維或更高維的位圖或像素圖組成）、矢量數(shù)據(jù)（由基本幾何對象構(gòu)成）。地圖數(shù)據(jù)常以矢量形式表示。

3、多媒體數(shù)據(jù)庫

最近，有關(guān)多媒體數(shù)據(jù)（如圖像、聲音和視頻）的數(shù)據(jù)庫的研究很熱門。現(xiàn)在多媒體數(shù)據(jù)通常存儲在數(shù)據(jù)庫以外的文件系統(tǒng)中。當(dāng)多媒體對象的數(shù)目相對較少時，數(shù)據(jù)庫提供的特點(diǎn)往往不那么重要。但是當(dāng)存儲的多媒體對象數(shù)目較多時，數(shù)據(jù)庫的功能就變得重要起來。總之，事務(wù)更新、查詢機(jī)制和索引也開始變的很重要。多媒體對象常常有描述屬性，如指明它們是何時創(chuàng)建的、誰創(chuàng)建的，以及它們屬于哪一類。構(gòu)造這種多媒體對象的數(shù)據(jù)庫的方法之一是用數(shù)據(jù)存儲描述屬性，并且跟蹤存儲這些媒體對象的文件。

但是，將多媒體數(shù)據(jù)存儲在數(shù)據(jù)庫之外，使得難于提供數(shù)據(jù)庫的功能，譬如基于實(shí)際多媒體數(shù)據(jù)內(nèi)容的索引。此外這種情況還會造成不一致，譬如一個文件在數(shù)據(jù)庫中做了記錄，但其內(nèi)容卻丟失了；或其相反情況。因此我們更希望將數(shù)據(jù)本身存儲在數(shù)據(jù)庫中。

4、移動性和個人數(shù)據(jù)庫

大型商用數(shù)據(jù)庫傳統(tǒng)上是存儲在中央計算設(shè)備上的。在分布式數(shù)據(jù)庫應(yīng)用中，通常有強(qiáng)大的中央數(shù)據(jù)庫和網(wǎng)絡(luò)管理。然而以下這兩個技術(shù)趨勢的結(jié)合產(chǎn)生了一些應(yīng)用，這些應(yīng)用使中央控制和管理不再完全正確：

● 個人計算機(jī)越來越廣泛的使用，其中更重要的 是便攜式或“筆記本”計算機(jī)的使用?！?基于無限局域網(wǎng)、蜂窩數(shù)字包網(wǎng)絡(luò)，以及其他技術(shù)成本相對低廉的無線數(shù)字通信基礎(chǔ)設(shè)

施的發(fā)展。

無線計算使得計算機(jī)不必有固定的位置和網(wǎng)絡(luò)地址這使得查詢處理更加復(fù)雜，因為它難于決定實(shí)體化查詢結(jié)果的最佳位置。某些情況下，用戶的位置是一個查詢參數(shù)。例如，一個旅客信息系統(tǒng)提供關(guān)于酒店、路邊服務(wù)的信息及類似信息給乘車的旅客。有關(guān)當(dāng)前道路前放服務(wù)的查詢必須根據(jù)用戶的位置、移動的方向及速度進(jìn)行處理。

能源（電池能源）對應(yīng)動計算機(jī)來說是有限的資源，這一限制影響了系統(tǒng)設(shè)計的許多方面。能源效率需求最有趣的結(jié)果之一的使用計劃的數(shù)據(jù)廣播來減少傳輸查詢中移動系統(tǒng)的需求。越來越多的數(shù)據(jù)會放在由用戶管理、而不是由數(shù)據(jù)庫管理員管理的計算機(jī)上，并且這些計算機(jī)有時可能與網(wǎng)絡(luò)斷開連接。

5、總結(jié)

隨著企業(yè)認(rèn)識到聯(lián)機(jī)事務(wù)處理系統(tǒng)收集的聯(lián)機(jī)數(shù)據(jù)的價值，決策支持系統(tǒng)也越發(fā)變得重要了?，F(xiàn)已提出SQL擴(kuò)展，如cube操作，能幫助系統(tǒng)生成匯總數(shù)據(jù)。數(shù)據(jù)挖掘致力于從大數(shù)據(jù)庫中自動發(fā)現(xiàn)統(tǒng)計規(guī)律和模式等知識。數(shù)據(jù)可視化系統(tǒng)幫助人們從視覺上發(fā)現(xiàn)這些知識。

目前，空間數(shù)據(jù)庫正越來越多的被應(yīng)用于存儲計算機(jī)輔助設(shè)計數(shù)據(jù)和地理數(shù)據(jù)。設(shè)計數(shù)據(jù)基本上是以矢量數(shù)據(jù)的形式存儲，而地理數(shù)據(jù)則包含矢量數(shù)據(jù)和光柵數(shù)據(jù)。

多媒體數(shù)據(jù)庫正變得越來越重要?；谙嗨菩缘牟樵円约鞍纯梢源_保的速率傳送數(shù)據(jù)是當(dāng)前研究的重要課題。

移動計算系統(tǒng)的普及使人們對這類系統(tǒng)上運(yùn)行的數(shù)據(jù)庫產(chǎn)生了濃厚的興趣。在這類系統(tǒng)上的查詢處理可能會設(shè)計在服務(wù)器端數(shù)據(jù)庫上的查找。