【機械類畢業(yè)論文中英文對照文獻翻譯】21世紀制造業(yè)和計算機的結合與創(chuàng)新

【機械類畢業(yè)論文中英文對照文獻翻譯】21世紀制造業(yè)和計算機的結合與創(chuàng)新,機械類畢業(yè)論文中英文對照文獻翻譯,機械類,畢業(yè)論文,中英文,對照,對比,比照,文獻,翻譯,21,世紀,制造業(yè),以及,計算機,結合,創(chuàng)新,立異 LINKING AND CREATTION OF MANUFACTURE INDUSTRY WITH COMPUTER IN 21 CENTRY Modern Machinery Abstract:The concept and connotation of manufacturing automation is always in development, and has become quite extensive The State of the art on manufacturing automation are analysed, and the developing trends are summed as six aspects: global manufacturing,agile manufacturing, manufacturing based on network, virtual manufacturing, intelligent manufacturing and green manufacturing. The vertical bearing drill combination machine, which is widely used for its high efficiency. It also analyzes the selections of the positioning of parts, clamps, cutters, and electromotor, as well as the design calculation. Key word: CAD/CAM, Modular machine tool，Modular design, PLC. Computer-aided design/computer-aided manufacturing (CAD/CAM) refer to the integration of computers into the design production procees to improve productivity .The heart of the CAD/CAM system is the design terminal and related hardware,such as computer ,printer,plotter,a tape reader,and digitizer.The design is constantly monitored on the terminal until it is completed.A hard copy can be generated if necessary.A computer tape or other control medium containing the design data guides computr-controlled machine tools during the manufacturing,testing,and quality control. The software for CAD/CAM is a collection of computer programs stored in the system to make the various hardware componrnts perform specific tasks.Examples of software are programs developed to generate a NC tool path,to assembel a bill of materials,or to create nodes and elements on a finite element model.Some of these software packages are referred to as sofware modules and can be classified into four categories:operating systems,generl-purpose programs,application programs and user programs.Although there are other kinds of software,these are suffcient for an explanation of the complexities in developing a CAD/CAM system. User A system structure and model for a manufacturing service enterprise is developed on Intranet/Internet The system has two tiers: the bottom function tier provides the network for the internal manufacturing environment and integrates the manufacturing processes, the top service tier supports the agility of the networked manufacturing enterprise and manages the workflow of the manufacturing processes. The proposed system is targeted to Rapid prototyping (RP) manufacturing services. Flexible manufacturing system (FMS) has become an important production manner by its flexibility, but many firms have failed to solve the problem to improve the average station utilization through allotting various tasks equally. This paper describes the basic construction and the scheduling control method of FMS. To take into account the workload of the bottleneck workstation, a basic method of the task assignment based on the workload equality in distribution was given. The flexible automation manufacture technology is developing rapidly, flexible manufacture system can be the most representation, the processing system in the flexible manufacture system is the actual execution system to change and finish the task. In flexible manufacturing environment, various internal and external disturbances occur stochastically and dynamically and a requirement for fast and effective rescheduling is needed. In such cases, to realize dynamic scheduling effectively, a structure model of dynamic scheduling decision system was presented and a filtered-beam-search based heuristic algorithm was proposed as the kernel of the model. The proposed algorithm makes improvement in the generation procedures of branches and the local/global. Flexible assembled fixture was designed. With the fixture, the goal of integrating the lathing and welding process in one machine was achieved. This can simplify the whole process and improve the welding quality. Review the research actuality and fixing methods toward flexible manufacturing. Discuss the principle, chief components and process of the reference free part encapsulation (RFPE) technique. Point out the weakness of this technique in production practice. Put forward and develop a universal fixture system with rapid locating and state memory and promote its practical application in agile manufacturing. Flexible manufacturing technology is novelty concept pattern and new developing trends to realize unborn factory, it is also strategic action to decide developing future of manufacturing enterprises. Based on flexible manufacturing technology, design scheme of new MCCB technical equipment system was brought forward to realize machinery flexibility, technology flexibility, producing capacity flexibility, extending flexibility, maintenance flexibility and control the coherence of product. It brings new product. According to modularization design theory, the modules of aggregate machine tool are divided in this paper on the basis of function analysis. Taking UG software as developing flat, the parametric 3D modeling module bank is set up. The database for storing the data used in design is also set up at the same time. Under the guiding of the system, users can complete such tasks as module choice, module combination, and calculation, etc. Therefore, computer aided modularization design of aggregate machine tool can be realize. Through synthetical application of CAD technology and various design methods，a theory of the quick-responded adaptive design is put forward based on feature-based parame-terized modeling system and modular design method ．Taking spindle box of modular machine tool for example，the quick re-construction of modular moz3hine tool is realized by using UG software．This paper gives a feasible technology routine for design of modular machine tool． Based on the characteristics of the design of machine tool, the modular designing technology is applied to CAD system for modular machine tool. The modules of machine tool are divided according to their different functions. The interface between the modules is designed based on the principle of assembly. The system which is developed on UG supports the modular designing technology and includes parametric-driving 3-D models which correspond to every module of machine tool. When designing aggregate machine tool, many clamps are general and standard parts. This paper describes how to use AutoCAD as the developing tool to design and develop. the clamp components library and achieve parameter drawing. This method can be extended to the other parts of aggregate machine tool and set up the parts library. So it makes the design simple and the efficiency improved and brings considerable benefits. According to modularization design principle, the modules of multi-spindle box of modular machine tool are divided on the basis of function analysis. By combining 3-D CAD technology with modularization technology and taking Unigaphics (UG)as the software development flat, the parametric 3-D modeling module bank of multi-spindle box is set up by means of its strong 3-D modeling function and assembling function. The database for storing the data used in design is also set up at the same time. This paper has developed the system of training CAD and boxes CAM of major axis boxes by VB. It may finish the procedure of obtaining the data, training CAD and boxes CAM. The characteristics of the system is more optimization and more high—speed of the design. It improves the productivity and accuracy of boxes. Put forward a mode of developing three-dimensional variational CAD for the multispindle box of modular machine, and developed a set of practical three-dimensional variational CAD system for the multispindle box by using existing CAD software-Solid Edge. This provides an efficient tool for improving efficiency of designing the multispindle box. The standardized and assembled fixture of machine tools is created in Pro/Engineer, s mass of function and method of group technology, and establishing a library of component includes standardized parts and generalized parts, forming a design, s library on fixtures of machine tools, Designing fixtures of machine tools. This kind of design, s library on fixtures of machine tools applies simply and expands easily. A numerical control machining-oriented box CAPP system was developed based on Pro/E, which solves the problem of conversion between CAD and CAPP, achieves automatic recognition and extraction from design feature to manufacturing feature, and integrates with CAD. In the view of the mass customization several manufacturing systems including the modular production system are compared in this paper. The characteristics, design method and application foreground of the modular production system are analysed. The research results showed that the modular production system with higher productivity and better flexibility, lower investment and higher benefit is much suitable to the Chinese situation. Parallel Machine Tool (PMT) whose principal axis is connected with machine base adopts multi-poles parallel structure, which breaks traditional concept. Thus, the rigidity of Machine Tool, the precision and quality of process are improved. Moreover, the high-speed process can be done easily. It conquers many shortcomings of the traditional machine tool, such as tool processing only along fixed path, the lower degree of freedom of tool-task and so on. CNC system of PMT is based on the open architecture,. The over-restriction of a parallel kinematic machine (PKM) is simplified and through analysis the 1-differential and 2-differential kinematic equation, the identified parameters among which there are strong relationships are eliminated and it proves that the vertical tolerance along z axis is approximately only related with the non-vertical coefficient of the two columns, so that the parameter errors are classified from the view of output errors. A novel parallel machine-tool mechanism based on the compound-sphere-joint is presented. The parallel machine tool consists of a moving spindle system and a fix base connected by 5-SPS serial chains. The moving spindle system is made up of two compound-sphere-joints, one of them is a three-layer sphere-joint connecting three SPS serial chains; the other is a two-layer sphere-joint connecting two SPS serial chains. The two-sphere-joints spindle system replaces the general moving platform and the main axis. Dynamics of a type of 3-HSS parallel kinematic machine is dealt with, and the research on the trail tracking control method is also done at the same time. First, the reverse solution model of position, velocity and acceleration of parallel kinematic machine is deduced including parallelogram strut structure and the outer translation pair driving fashion. Parallel machine tool numerical system needs kinematics transform module to perform coordinates transform between Cartesian space and joint space. In order to increase design efficiency and quality of parallel machine tool (PMT),a main process of PMT virtual concept design is researched. Based on ADAMS, a design platform of PKM virtual prototype is developed. A parallel mechanism case base and a modular component base are built. The management of the parallel mechanism case base and the modular component base and virtual assembly of PMT are realized. By using animated technique and simulating analysis function of ADAMS, kinematic simulation and analysis of PMT. Conventionally mechanical engineers design the schematic 3D layout at first, and then represent it in 2D, assembly drawing. This 3D layout can be only expressed in 3D isometric projection by quite a few masters. But it can be hardly used as precise engineering drawing. In the last decades, researchers undertook works on 3D reconstruction. Nowadays, computer-aided 3D assembly drawing can be implemented by using CAD software systems. Accordingly, the unit assembly and detail drawing can be done automatically. A parametric drawing software of combination machine project CAD System is developed based in using HIGH C/C++3.04 and ADS (AutoCAD Development System) language. It makes design simple, decreases design cycle and improves design quality. The probability and necessity of combination machine applying CAD technique, the program framed box, the two key problem in program design, the characteristic and reliability in program design is introduced. The vertical bearing drill combination machine, which is widely used for its high efficiency. It also analyzes the selections of the positioning of parts, clamps, cutters, and electromotor, as well as the design calculation. References: [1] LI Yugui, YANG Xiaoming, GAO Xuejie. Study on static characteristic of PWM high speed on/off valve[3]. Joumai of Taiyuan Heavy Machinery Institute, 2002, 23(1): 68-71. (In Chinese) [2] DENG Xiaohang. Design of the fluid pulse modulation digital testing and control laboratory bench[.Machine tool&hydraulics，2004(12):120-122. (In Chinese). 21世紀制造業(yè)和計算機的結合與創(chuàng)新 現代機械 摘要：分析了計算機輔助設計/計算機輔助制造的內涵，論述了制造自動化的研究現狀，總結了制造自動化的“六化”發(fā)展趨勢，即制造全球化、制造敏捷化、制造網絡化、制造虛擬化、制造智能化和制造綠色化。 關鍵詞：CAD/CAM, 組合機床，模塊化設計，PLC。 計算機輔助設計/計算機輔助制造（CAD/CAM）指的是將計算機應用于設計和生產過程中以提高生產率。CAD/CAM系統的核心是設計終端和相應的硬件，諸如計算機、打印機、繪圖儀、磁帶機和數字化儀等，設計在被完成之前始終在終端顯示器上被監(jiān)視，如果需要還可以進行硬拷貝。含有設計數據的計算機磁帶或其他控制媒介在制造、測試和質量控制過程中驅動著數控加工設備。 用于CAD/CAM的軟件是儲存在計算機系統中的程序集合，用來驅動各種構成硬件完成特定任務。如生成NC（數控）加工路徑、裝配材料清單、在有限元模型中生成節(jié)點和單元的程序。有些軟件包指的是軟件（程序）模塊，可分為一下四類：操作系統、通用程序、應用程序和用戶程序。雖然還有其他功能模塊軟件，但這足以說明研發(fā)CAD/CAM系統的復雜性了。 CAD/CAM系統中的用戶程序是為產生專用輸出結果的專業(yè)針對性極強的軟件包，如用戶只要輸入一些像齒數、節(jié)圓直徑之類的參數，就可由用戶程序自動生成齒輪。還可用另一類程序在給出刀具尺寸、材料、切削深度等信息后，計算切削時的最佳進給和轉速。這類程序通常都是用戶在通用軟件供應商提供的軟件模塊基礎上自己開發(fā)的。盡管用戶程序可大大節(jié)約時間和精力，但不是所有的CAD/CAM軟件包都有用戶程序。 ① 計算機圖形 計算機圖形系統計算并儲存物理相關數據，以確定精確位置、尺寸標注及每個設計單元的其他征。借助于這些相關設計數據，用戶設計人員可在工件制品加工前進行復雜的工程分析、生成材料清單、生產報告、檢查設計的不相容性。 利用計算機圖形學，可將二維圖轉成三維線框和實體模型。 ② 線框模型 簡單的線框模型是表示幾何模型最經濟的一種方法，在檢驗圖形的基本屬性和模型的連續(xù)性時很有用，但在開發(fā)復雜模型時，線框模型就有局限性，實體模型可解決線框模型中出現的大部分問題。 ③ 實體模型 主要有三種結構實體的技術：構造實體幾何法（CSG）、邊界表示法（B-Rep）、和分解實體模型。 構造實體幾何法（CSG）是用各種幾何體諸如圓柱、球面、圓錐等經過布爾運算后生成的實體。 邊界法中，先定出物體輪廓，在通過線性或徑向掃描，用其中所包含的區(qū)域表示實體。 分解實體模型與邊界法相似，但加強了構造時有限元模型。商業(yè)化軟件包中，并不單純使用某一中方法，例如，在構造實體表達法中可能會用到邊界法技術生成初始模型，而在邊界法或分解法中可能會用布爾代數法，利用圓柱或圓錐去修剪模型，生成孔洞。 計算機輔助制造側重于一下四方面：數控、工藝規(guī)程編制、自動化操作和生產管理。 ① 數控 計算機輔助制造（CAM）中數控的重要體現在：可用計算機從幾何模型或制品直接生成數控程。 目前，這種自動化能力還僅僅限于非對稱和其他特殊形狀制品。未來，有些公司可能根本不用圖紙，就可以通過數據庫將產品信息直接從設計傳送到制造工序。由于計算機設計與制造使用同一個集成數據庫，生成的計算機模型數是一樣的，所以隨著圖紙的消失，好些問題也會隨之而去。這樣即便部門之間在地域上離得很遠也不影響工作，因為實際上他們是通過辦公桌上的終端連在一起的。 ② 工藝規(guī)程 制定工藝規(guī)程包括從生產到結束的每一個工序，與計算機輔助制造相連的工藝制定系統幾乎不用人工參與就可直接從幾何模型數據庫生成工藝過程。 ③ 自動化 制造系統自動化機器人完成了許多改進，如在線裝配、在線焊接和線噴涂等。 ④ 生產管理 生產管理用于交互的工業(yè)數據收集以便及時獲得和生產相關的信息，并用該數據計算出制造的先后次序，動態(tài)的確定下一步要做的工作，從而保證標準制造程序的正常執(zhí)行。另外，為適應特殊要求，可直接對系統進行修改，無需召集計算機編程專家。 網絡技術特別是Intranet/Internet 技術的迅速發(fā)展,正在給企業(yè)制造活動帶來新的變革,并給未來的CAD/CAM環(huán)境開辟了一個新的領域。未來的CAD/CAM環(huán)境將是全球化、網絡化、敏捷化的制造群體,不同成員提供各自的制造設備及其分布式設計制造過程的管理。本文介紹了作者在Intranet/Internet下建立的Internet服務企業(yè)的系統結構和模式。該系統包括兩層結構:底層功能層實現制造環(huán)境內部的網絡化,完成制造過程的集成;上層服務層實現網絡制造企業(yè)的敏捷化,完成制造過程中工作流信息管理。本文以快速成形制造服務作為實現對象。在快速成形制造服務中,功能層采用分布結構提供設計制造功能單元,包括CAD插件、截面數據提取單元。服務層采用工作流機制,實現客戶、設計人員、工藝人員、加工人員和管理人員之間的協作和協同工作。目前本系統架構于微軟的分布式DNA=,未來將采用跨平臺的JAVA/CORBA并且引入智能設計和制造。 柔性制造系統(FMS)以其靈活性成為現代企業(yè)非常重要的生產方式,但如何均衡分配各設備的負荷以提高系統的利用率一直沒能很好地解決。柔性自動化制造技術迅速發(fā)展,其中柔性制造系統最具代表性,柔性制造系統中的加工系統是實際完成改變物性任務的執(zhí)行系統. 針對柔性制造環(huán)境中內外擾動的動態(tài)隨機發(fā)生和快速、高效的重調度需求,構建了動態(tài)調度決策系統結構模型,提出了一種基于過濾定向搜索的啟發(fā)式算法作為模型的核心算法.為了更好地搜索調度解空間和更好地集成作業(yè)的交貨期、優(yōu)先權重和資源負載平衡,算法改進了節(jié)點分枝策略和局部、全局評價函數.以作業(yè)交貨延遲時間加權平方和最小為性能指標,通過實例仿真,對算法性能進行了分析評價和比較,結果表明了該算法對實現柔性制造系統動態(tài)調度的有效性和實用性.柔性組合夾具,達到了將車削加工工藝和焊接加工工藝同時在同一個專用設備上完成的目的,簡化了制造工序,提高了焊接質量。回顧國內外關于面向柔性制造系統的工件安裝方法及其研究動態(tài)，無基準零件密封技術的基本原理、組成和工藝過程，指出了該項技術用于生產實際尚存在的不足，提出并研制了快速尋位與狀態(tài)記憶通用夾具系統，以促進RL&SM安裝技術在敏捷制造中的應用。 柔性制造技術是實現未來工廠的新穎概念模式和新的發(fā)展趨勢,是決定制造企業(yè)未來發(fā)展前途的具有戰(zhàn)略意義的舉措。基于柔性制造技術,提出了新塑殼斷路器工藝裝備系統的設計方案,實現了機器柔性、工藝柔性、生產能力柔性、擴展柔性、維護柔性,控制了產品的一致性。使傳統塑殼斷路器有了新的生產模式,同時對其他低壓電器的柔性制造也具有借鑒意義。 根據模塊化設計原理,在功能分析的基礎上劃分組合機床的各級模塊。以三維設計軟件UG為開發(fā)平臺,建立了組合機床各級模塊的參數化三維造型模板庫,同時還建立了存放設計過程中所需數據的數據庫。用戶在系統的引導下可完成設計過程中的模塊選擇、模塊組合和設計計算等環(huán)節(jié),從而實現了計算機輔助組合機床模塊化設計,提高了設計效率。為綜合運用CAD技術和各種設計方法，建立了以模塊化設計為基礎，采用參數化特征造型，進行快速響應的變型設計的理論。以組合機床主軸箱為例，以UG軟件為平臺．實現了組合機床的快速重構，為組合機床的設計提供了可行的技術路線。 根據組合機床設計特點,將模塊化設計技術應用于組合機床CAD系統。以分級模塊化為主導思想,在功能分析的基礎上劃分組合機床的各級模塊并按照面向裝配設計的原則設計了模塊接口。以三維設計軟件UG為開發(fā)平臺,針對組合機床的每一級模塊建立相應的全參數化三維模型庫,開發(fā)出支持模塊化設計的組合機床CAD系統。針對設計組合機床的夾具元件都是通用件、標準件，利用 Auto CAD軟件開發(fā)工具、設計、開發(fā)了夾具元件庫，實現了參數化繪圖．此方法可以擴展到組合機床其它元件上，建立 相應元件庫，從而簡化了設計，提高了效率，具有實用價值和可擴展性．根據模塊化設計原理,在功能分析的基礎上劃分了組合機床多軸箱的各級模塊。將三維CAD技術與模塊化技術相結合,以UG為軟件開發(fā)平臺,利用其強大的三維造型功能和裝配功能,建立了組合機床多軸箱參數化三維造型模板庫,同時還建立了存放設計過程中所需數據的數據庫。設計人員在系統界面的引導下可完成模塊選擇、模塊組合和設計計算等環(huán)節(jié),從而實現了計算機輔助組合機床多軸箱三維模塊化設計,提高了設計效率。 用VB開發(fā)了主軸箱傳動CAD及其箱體CAM一體化系統。該系統利用人機交互的方式完成數據的獲得、傳動系統的CAD和箱體的CAM工作,它的使用可使主軸箱傳動系統的設計更優(yōu)化、更快捷 ,使箱體的加工生產率提高 ,準確性增加。提出了一種組合機床多軸箱三維變量化CAD的開發(fā)模式,并利用現有的CAD軟件—Solid Edge開發(fā)出實用的多軸箱三維變量化CAD系統,為提高多軸箱的設計效率提供有效的工具。應用PRO/Engineer強大的功能模塊,用成組技術的分類方法,創(chuàng)建機床標準組合夾具,建立和開發(fā)相應的標準件、通用件元件庫,成形機床夾具設計庫,進行機床夾具應用設計。這種機床夾具設計庫開發(fā)應用簡單,拓展容易。以Pro/E為開發(fā)平臺,開發(fā)一種面向數控加工的箱體零件CAPP系統,解決CAD信息向CAPP系統的轉換,實現從設計特征到制造特征的自動識別與提取和CAD/CAPP的集成。 對包括模塊化制造系統在內的幾種制造系統模式從滿足大批量定制生產需求的角度進行了比較,對模塊化制造系統的特點、設計方法和在中國的應用前景進行了分析。研究結果表明 ,模塊化制造系統具有高生產率和高柔性的特點,投資小、效益高,比較適合中國的國情 并聯機床完全打破了傳統機床結構的概念,采用了多桿并聯機構驅動,即機床的主軸與機座之間為多桿并聯連接,從而大大提高了機床的剛度,使加工精度和加工質量都有較大的改進。另外,其進給速度的提高,也使高速加工更容易實現。它克服了傳統機床刀具只能沿固定導軌進給,刀具作業(yè)自由度偏低等固有缺陷。并聯機床數控系統基于開放式數控系統體系結構,增加了軟件的可重用性,方便用戶進行二次開發(fā)。 針對一臺實際的并聯機床,簡化過約束結構,在運動學方程一次微分和二次微分的基礎上,進行相關性分析,整合相關性強的辨識參數,推導出z向垂直度誤差近似唯一相關于立柱傾斜系數,從輸出誤差測量的角度實現對誤差源的分類。同時利用簡單可行的相對誤差測量方案,基于相關性分析的結論,采用分步標定方案,顯著提高精度,大工作空間內達到±0.04 mm以內,局部在±0.02 mm以內,滿足了工程需要。該方法基于參數間以及參數和輸出誤差間的相關性分析,有效簡化標定過程,實現參數的分步辨識,為并聯機床標定提供了新思路。一種基于新型運動副——復合球鉸的虛擬軸機床,它是由5-SPS分支組成的并聯機構,其中3個分 支匯交于一個三重球鉸,另2個分支匯交于一個二重球鉸,兩個球鉸固接在一起形成一個復合球鉸,代替了并聯 機構的活動平臺,而且機床主軸位于復合球鉸中心線上。這種基于復合球鉸的5個分支新型虛擬軸機床與基于 Stewart平臺機構的6個分支的虛擬軸機床相比具有同樣多的實用自由度,并且機床結構簡單、解耦,其正反解 計算及控制亦相對簡單。探討了5分支機床的結構形式,尤其對關鍵結構——復合球鉸的結構,機構位置反解, 以及一定姿態(tài)下的可達工作空間進行了分析和計算。這種新型虛擬軸機床在空間曲面加工領域將有著廣泛的應用前景。3-HSS并聯機床動力學建模及魯棒軌跡跟蹤控制方法。首先導出了外移動副驅動,含平行四邊形支鏈結構的并聯機構位置、速度及加速度逆解模型,并利用虛功原理建立其剛體動力學逆解模型。在此基礎上,考慮其運動部件重力及模型誤差,為保證其跟蹤精度,設計了一種魯棒軌跡跟蹤控制器,確保了跟蹤誤差的一致終值有界性，該控制方法具有很好的穩(wěn)定性和有效性。 并聯機床由于完全摒棄了傳統機床固定導軌的刀具導向方式,其數控系統中必然需要添加運動學變換模塊,以實現加工代碼中的直角坐標與其可控制的關節(jié)空間坐標之間的轉換。以提高并聯機床設計效率和質量為目標,研究了并聯機床虛擬概念設計的主要內容,開發(fā)出基于ADAMS的并聯機床虛擬概念設計平臺,建立并聯機構型譜庫和功能模塊組件庫,并實現對型譜庫和模塊組件庫的管理。開發(fā)并聯機床虛擬裝配人機交互界面,以幫助設計者完成并聯機床的虛擬裝配。利用ADAMS的動畫技術和仿真分析功能,實現了對樣機模型的運動學仿真和分析。 傳統的機械設計模式是工程師首先有三維的整體布局,然后用二維的裝配圖表達。只有少數設計師能夠直接描繪示意性的三維軸測圖,但是也難于作為精確的設計圖紙。上世紀后期,研究者致力于二維裝配圖的“三維”重建?，F在有了條件,可利用Autodesklnventor實現人機交互的三維總圖設計,以及零部件的二維表達本文以組合機床設計為例,闡述該計算機輔助設計系統的開發(fā),詳述各個部分的功能。為進一步完善這個系統提供條件。 參考文獻: [1] LI Yugui, YANG Xiaoming, GAO Xuejie. Study on static characteristic of PWM high speed on/off valve[3]. Joumai of Taiyuan Heavy Machinery Institute, 2002, 23(1): 68-71. (In Chinese) [2] DENG Xiaohang. Design of the fluid pulse modulation digital testing and control laboratory bench[月.Machine tool&hydraulics, 2004(12):120-122. (In Chinese)