畢業(yè)論文基于plc的飲料灌裝機控制系統(tǒng)設(shè)計

1、畢業(yè)設(shè)計說明書題 目 基于plc的飲料灌裝機控制系統(tǒng)設(shè)計 專 業(yè) 機械制造與自動化 班 級 1001 班 學(xué)生姓名 指導(dǎo)老師 2016年1月3日目 錄摘要 1第一章 緒論31.1 設(shè)計內(nèi)容31.2 控制要求31.3 設(shè)計要求3第二章 控制系統(tǒng)方案設(shè)計42.1 飲料灌裝流水線的基本結(jié)構(gòu)42.2灌裝流水線的工作原理 5第三章 硬件控制設(shè)計63.1 PLC的選擇 6 3.2 傳感器的選擇 73.3 硬件電路的設(shè)計 7第四章 軟件控制設(shè)計84.1 系統(tǒng)流程圖 8 4.2 I/O分配表 104.3 I/O接線圖 114.4梯形圖 124.5指令表 14第五章 調(diào)試說明15 第六章 總結(jié)15致謝 16 參

2、考文獻 17 摘要隨著計算機和網(wǎng)絡(luò)通訊技術(shù)的發(fā)展，企業(yè)對生產(chǎn)過程的自動控制和信息通訊提出了更高的要求。飲料生產(chǎn)線比較復(fù)雜，生產(chǎn)環(huán)節(jié)也很多。其中飲料的灌裝就是飲料生產(chǎn)線上重要的生產(chǎn)環(huán)節(jié)?？刂葡到y(tǒng)主要由一臺PLC、交流異步電機、液罐、多個灌裝狀態(tài)檢測傳感器、故障報警蜂鳴器、產(chǎn)量統(tǒng)計顯示器等組成。其中電機用來控制運送飲料瓶的傳送帶部分。本控制系統(tǒng)有兩個特點：一是輸入、輸出設(shè)備比較多；二是所需實現(xiàn)的控制是順序邏輯控制、模塊控制以及計算統(tǒng)計功能。采用PLC控制飲料灌裝生產(chǎn)線，實現(xiàn)了飲料生產(chǎn)線的自動化、智能化。對勞動生產(chǎn)率的提高，飲料質(zhì)量和產(chǎn)量的提高具有深遠的意義。關(guān)鍵詞 可編程序控制器（PLC）/自動化

3、/智能化 AbstractWith the computer and network communication technology, business-to-production process automation and information and communication put forward higher requirements. Beverage production line more complex production processes are also numerous. One drink is a beverage filling production l

4、ine's most important production areas.Control system mainly by a single PLC, AC asynchronous motor, tank, multiple filling state detection sensor, fault alarm buzzer, the output statistics displays so on. One motor is used to control the delivery of beverage bottles conveyor belt parts.The contr

5、ol system has two characteristics: First, input and output devices are more; second is required in order to achieve control is logic control, module control, and computing statistical functions.Use of PLC control beverage filling production line, to achieve the soft drink production line automation

6、and intelligence. On labor productivity gains, improve beverage quality and yield far-reaching significance.Key words: PLC ，Automation ，Intelligence第一章 緒 論 1.1設(shè)計內(nèi)容飲料灌裝機控制系統(tǒng)設(shè)計1.2控制要求（1）系統(tǒng)通過開關(guān)設(shè)定為自動操作模式，一旦啟動，則傳送帶的驅(qū)動電機啟動并一直保持到停止開關(guān)動作或灌裝設(shè)備下的傳感器檢測到一個瓶子時停止；瓶子裝滿飲料后，傳送帶驅(qū)動電機必須自動啟動，并保持到又檢測到一個瓶子或停止開關(guān)動作。（2） 當(dāng)瓶子定位

7、在罐裝設(shè)備下時，停頓1秒，罐裝設(shè)備開始工作，罐裝過程為5秒鐘，罐裝過程應(yīng)有報警顯示，5秒后停止并不再顯示報警（報警方式為紅燈以0.3秒時間間隔閃爍）。（3） 灌裝完一瓶須進行稱重比較：若大于或等于700克為正品，并計數(shù)1次，計數(shù)滿24瓶為一箱，并令蜂鳴器報警一次（鳴響1s）；若小于700克則為次品，同時也計數(shù)1次，計滿24瓶為一箱，并令蜂鳴器報警一次（鳴響2s）瓶裝飲料的重量以模擬量的形式自模擬量通道A/D輸入（重量Kg與模擬量電壓輸入及數(shù)字量的對應(yīng)值可以自己設(shè)定）。（4）可以手動對計數(shù)值清零（復(fù)位）。1.3設(shè)計要求（1）I/O編址（2）I/O端子接線圖（3）編程與調(diào)試第二章 控制系統(tǒng)方案設(shè)計

8、2.1飲料灌裝流水線的基本結(jié)構(gòu)飲料灌裝流水線的基本結(jié)構(gòu)圖1-1所示：圖1-1飲料灌裝流水線的基本結(jié)構(gòu)2.2灌裝流水線的工作原理灌裝流水線的運作是通過電機和灌裝設(shè)備來控制的。通過電動機的運轉(zhuǎn)，帶動流水線的工作。而灌裝設(shè)備的開通則直接控制飲料流通。通過輸入PLC軟件程序，直接控制電機及流水線的運作.。流水線由傳感器實時監(jiān)控，由PLC控制，控制準(zhǔn)確。當(dāng)PLC運行時，CPU根據(jù)用戶按控制要求編寫好并存于用戶存儲器中的程序，按序號作周期性的程序循環(huán)掃描，程序從第一條指令開始，逐條順序執(zhí)行用戶的程序直到程序結(jié)束。然后重新返回第一條指令，再開始下一次掃描；如此周而復(fù)始。實際上，PLC掃描工作除了執(zhí)行用戶程序

9、外，還要完成其他工作，整個工作過程分為自診斷、通訊服務(wù)、輸入處理、輸出處理、程序執(zhí)行五個階段。如圖2-1所示：圖2-1 PLC循環(huán)掃描工作圖第三章 硬件控制設(shè)計3.1 PLC的選擇（1）PLC的結(jié)構(gòu)與特點：PLC的構(gòu)成從結(jié)構(gòu)上分，PLC分為固定式和組合式（模塊式）兩種。固定式PLC包括CPU板、I/O板、顯示面板、內(nèi)存塊、電源等，這些元素組合成一個不可拆卸的整體。模塊式PLC包括CPU模塊、I/O模塊、內(nèi)存、電源模塊、底板或機架，這些模塊可以按照一定規(guī)則組合配置。PLC編程簡介體積小，重量輕，耗電少，接線編程簡單，可靠性高，反應(yīng)快，可靠性高，抗干擾能力強。PLC一經(jīng)出現(xiàn)，由于它的自動化程度高、

10、可靠性好，設(shè)計周期短、使用和維護簡便等獨特優(yōu)點，備受國內(nèi)外工程技術(shù)人員和工商業(yè)界廠商的極大關(guān)注，生產(chǎn)PLC的廠商孕起。隨著大規(guī)模集成電路和微處理器在PLC中應(yīng)用，是PLC的功能不斷得到增強，產(chǎn)品得到飛速發(fā)展。目前，PLC在國內(nèi)外已廣泛應(yīng)用于鋼鐵、石油、化工、電力、建材、機械制造、汽車、輕紡、交通運輸、環(huán)保及文化娛樂等各個行業(yè)。PLC常用程序設(shè)計語言簡介方源 可編程控制器程序設(shè)計語言。在可編程控制器中有多種程序設(shè)計語言，它們是梯形圖語言、布爾助記符語言、功能表圖語言、功能模塊圖語言及結(jié)構(gòu)化語句描述語言等。其中梯形圖程序設(shè)計語言是用梯形圖的圖形符號來描述程序的一種程序設(shè)計語言。是最廣泛，最受歡迎的

11、一種編程語言。它采用梯形圖程序設(shè)計語言，程序采用梯形圖的形式描述。這種程序設(shè)計語言采用因果關(guān)系來描述事件發(fā)生的條件和結(jié)果。每個梯級是一個因果關(guān)系。在梯級中，描述事件發(fā)生的條件表示在左面，事件發(fā)生的結(jié)果表示在后面。梯形圖程序設(shè)計語言是最常用的一種程序設(shè)計語言。它來源于繼電器邏輯控制系統(tǒng)的描述。在工業(yè)過程控制領(lǐng)域，電氣技術(shù)人員對繼電器邏輯控制技術(shù)較為熟悉，因此，由這種邏輯控制技術(shù)發(fā)展而來的梯形圖受到了歡迎，并得到了廣泛的應(yīng)用。（2）選擇PLC：三菱公司是日本生產(chǎn)PLC的主要廠家之一。該公司生產(chǎn)的FX2N系列機型屬于高性能疊裝式機型，是三菱公司上網(wǎng)典型產(chǎn)品，F(xiàn)X2N系列PLC具有數(shù)十種編程元件。FX

12、2N系列PLC編程元件的編號分為兩部分：第一部分是代表功能的字母。如輸入繼電器勇“X”表示、輸出繼電器用“Y”表示。第二部分為數(shù)字。數(shù)字為該器件的序號。根據(jù)所需的用戶輸入輸出設(shè)備及I/O點數(shù)，選擇FX2N系列型的PLC就可以滿足控制系統(tǒng)的要求。3.2傳感器的選擇傳感器是一種能把物理量或化學(xué)量轉(zhuǎn)變成便于利用的電信號器件，它獲得的信息正確與否，直接關(guān)系到整個系統(tǒng)的精度。通過對各個傳感器的工作環(huán)境和用途的分析確定各個傳感器的型號分別是（1）灌裝監(jiān)測傳感器選型為：光電傳感器（熱型紅外線傳感器）（2）稱重監(jiān)測傳感器的選型為：壓力傳感器（壓阻式）采用紅外線傳感器來監(jiān)測空瓶子的到來后動作，起到接通開關(guān)的作用

13、。它是利用被測物體熱輻射引起敏感元件溫度的變化進行測量。常溫下工作且價格更便宜，不受可見光的影響。壓電電阻型半導(dǎo)體壓力傳感器，靈敏度高，輸出信號大，響應(yīng)速度快，性能穩(wěn)定且電阻值可在較寬的范圍內(nèi)調(diào)整以適應(yīng)不同需要。3.3硬件電路的設(shè)計電氣控制原理圖如圖3-1所示：圖3-1 電氣控制原理圖圖3.1中斷路器QF1、 QF2、 QF3、 QF4、 QF5將三相電源引入，同時QF1、 QF2、 QF3、 QF4、 QF5為電路提供短路保護。電動機的過載保護分別由三個繼電器提供。第四章 軟件控制設(shè)計4.1系統(tǒng)流程圖設(shè)計的灌裝過程是：自動操作模式，開關(guān)啟動，傳送帶運送瓶子經(jīng)過傳感器檢測，若檢測到瓶子，當(dāng)瓶子

14、定位在罐裝設(shè)備下時，停頓1秒，罐裝設(shè)備開始工作，罐裝過程為5秒鐘，罐裝過程應(yīng)有報警顯示，5秒后停止并不再顯示報警。上述工作完成后壓力傳感器開始檢測次品和正品。依次有相應(yīng)的傳送帶傳送進行加工，這樣就完成了整個灌裝工作的一個工作循環(huán)過程。系統(tǒng)設(shè)計流程圖如圖4-1所示。圖4-1飲料罐裝流水線系統(tǒng)設(shè)計流程圖4.2 I/O分配表根據(jù)對生產(chǎn)流水線控制系統(tǒng)的控制要求分析,其輸入信號有系統(tǒng)的開啟、 停止按鈕信號和手動清零按鈕信號;輸出信號有傳送帶驅(qū)動信號、警示燈信號，在進行I/O地址分配時，要特別注意不要產(chǎn)生地址沖突的錯誤。設(shè)計本控制系統(tǒng)共使用了6個輸入點，6個輸出點，I/O分配如表4-2所示。類別元件PLC

15、元件作用輸入（I）SB0XO啟動按鈕SB1X1停止按鈕SB2X2光電傳感器SB3X3壓力傳感器1SB4X4壓力傳感器2SB5X5手動清零輸出（O）KM1Y1啟動傳送帶驅(qū)動電機KM2Y2驅(qū)動灌裝設(shè)備KM3Y3啟動正品傳送帶KM4Y4啟動次品傳送帶HRY5報警顯示HAY6蜂鳴器響表4-2 I/O分配表4.3 I/O接線圖根據(jù)I/O分配表得到I/O接線圖圖4-3 I/O接線圖4.4 梯形圖當(dāng)按下啟動開關(guān)時，系統(tǒng)開始工作其實現(xiàn)過程如下：圖4-4 梯形圖4.5指令表相應(yīng)指令表如下：LD X0 LD T2 OUT T4OR M0 ANI T1 K10OUT M0 OUT Y5 OUT M3LD M0 LD

16、 M2 LD C1OR Y1 AND X3 RST C1ANI X1 OR Y3 LD C2OUT M2 ANI X4 OR M4ANI M1 OUT Y3 ANI T5OUT Y1 LD X3 OUT T5LD X2 OUT C1 K20OR M1 K24 OUT M4ANI T1 LD M2 LD C2OUT M1 AND X4 RST C2LD M1 OR Y4 LD X5OUT T0 ANI X3 ZRST T0 K10 OUT Y4 T5LD T0 LD X4 ZRST C1OUT Y2 OUT C2 C2OUT T1 K24 ENDK50 LD M3LD T0 ANI T4ANI

17、T3 LD M4OUT T2 ANI T5 K3 OUT Y6LD T2 LD C1OUT T3 OR M3 K3 ANI T4第五章 調(diào)試說明（1）在電腦上安裝GX-Developer軟件，程序編號后，將程序輸入GX-Developer軟件中，在電腦上進行初步仿真調(diào)試。（2）先將PLC程序傳入程序控制器中。（3）對各個輸入I/O口給信號處理，看各個輸出口是否有相應(yīng)的輸出，如果沒有按照設(shè)計要求輸出，對程序進行更改，直到各輸出口有相應(yīng)的輸出。（4）如果條件允許的話，用編程軟件將程序輸入PLC中，在確認PLC的電源、外部接線和程序輸入無誤的情況下，接通電源，按照流程圖的順序進行調(diào)試，最終使整個系統(tǒng)

18、能準(zhǔn)確、可靠的工作。第六章 總結(jié)通過飲料罐裝機控制系統(tǒng)的課程設(shè)計，我從中掌握了什么是設(shè)計程序，設(shè)計程序工作的基本過程及各階段的基本任務(wù)，熟悉了設(shè)計程序總流程圖，加深了對PLC的理解，課本上的知識是機械的表面。通過努力把課本上的知識變得更為簡單，對實驗原理也有了更深的理解。通過這次課程設(shè)計，使我更為全面系統(tǒng)的了解PLC的構(gòu)造原理和基本實現(xiàn)方法。把課本的知識變得生動有趣，激發(fā)了我們的學(xué)習(xí)積極性，把學(xué)過的原理加以強化，把課堂學(xué)過的知識通過自己的設(shè)計程序表示出來，加深了對理論知識的理解?，F(xiàn)在通過自己的動對手做實驗，理論聯(lián)系實際，對PLC的原理認識更加深刻。在調(diào)試時應(yīng)該很仔細，一步一步調(diào)試下來，做到準(zhǔn)確

19、無誤。這次課程使我意識到只有理論知識是遠遠不夠的，只有把所學(xué)的理論知識與實踐相結(jié)合起來，才是正確的，才能提高自己動手能力和獨立思索的能力。同時對于PLC發(fā)展歷史、強大功能、應(yīng)用領(lǐng)域以及系列知識得到了大概的系統(tǒng)認識，也初步了解了一個完整的系統(tǒng)開發(fā)的過程，本次課設(shè)，對于創(chuàng)造思維的培養(yǎng)和開發(fā)能力的鍛煉有很大的幫助。在編程過程中，領(lǐng)略到了熟能生巧的含義。編程不僅要求有良好的基礎(chǔ)，而且要求對各種程序有深刻的了解，同時深切感受到團隊合作的重要性，尤其是在查資料的過程中，人多力量大，大家一起努力，查找資料的效率就提高了許多，大家在一起探討，相互學(xué)習(xí)，分工細化，互相提高，解決問題的速度就快多了。老師知識的幫助

20、，經(jīng)驗的傳授，也是本次課設(shè)的一道美麗的風(fēng)景線，真正起到了拋磚引玉的目的。這次課設(shè)讓我的動手能力得到了大大的鍛煉，解決實際問題的能力得到了大大的提高，為以后學(xué)習(xí)和工作奠定了一定的基礎(chǔ)。致 謝通過這一階段的努力，我的畢業(yè)論文飲料灌裝機控制系統(tǒng)設(shè)計終于完成了，這意味著大學(xué)生活即將結(jié)束。在大學(xué)階段，我在學(xué)習(xí)上和思想上都受益非淺，這除了自身的努力外，與各位老師、同學(xué)和朋友的關(guān)心、支持和鼓勵是分不開的。在本論文的寫作過程中，指導(dǎo)老師，從選題到開題報告，從寫作提綱，到一遍又一遍地指出每稿中的具體問題，嚴(yán)格把關(guān)，循循善誘，在此我表示衷心感謝。同時我還要感謝在我這次畢業(yè)設(shè)計過程中給我極大關(guān)懷和支持的各位老師以及

21、關(guān)心我的同學(xué)和朋友。參考文獻1廖常初.FX系列PLC編程及應(yīng)用M.北京：機械工業(yè)出版社，2005.2謝克明.可編程控制器原理與程序設(shè)計M.北京：電子工業(yè)出版社，2002.3戴一平.可編程控制器技術(shù)及應(yīng)用M.北京：機械工業(yè)出版社，2004.4阮友德.電氣控制與PLC實訓(xùn)教程M.北京：人民郵電出版社，20015李道霖.電氣控制與PLC原理及應(yīng)用M北京:電子工業(yè)出版社，20046張萬忠.可編程控制器應(yīng)用技術(shù)M北京: 化學(xué)工業(yè)出版社，20017王延才.電子技術(shù)M.北京：高等教育出版社，20018臺方.可編程序控制器應(yīng)用教程. 北京：中國水利水電出版社，2001.9李穎.譚立新 基于pc和plc精確定量

22、灌裝控制系統(tǒng)【期刊論文】-制造業(yè)自動化200910范永勝.電氣控制與PLC應(yīng)用.北京：中國電力出版社，2007.請刪除以下內(nèi)容，O(_)O謝謝！ The term "autism" refers to a cluster of conditions appearing early in childhood. All involve severe impairments in social interaction, communication, imaginative abilities, and rigid, repetitive behaviors. To be cons

23、idered an autistic disorder, some of these impairments must be manifest before the age of three. The reference book used by mental health professionals to diagnose mental disorders is the Diagnostic and Statistical Manual of Mental Disorders , also known as the DSM. The 2000 edition of this referenc

24、e book (the Fourth Edition Text Revision known as DSM-IV-TR ) places autism in a category called pervasive developmental disorders . All of these disorders are characterized by ongoing problems with mutual social interaction and communication, or the presence of strange, repetitive behaviors,interes

25、ts, and activities. People diagnosed with these disorders are affected in many ways for their entire lives. Description Each child diagnosed with an autistic disorder differs from every other, and so general descriptions of autistic behavior and characteristics do not apply equally to every child. S

26、till, the common impairments in social interaction, communication and imagination, and rigid, repetitive behaviors make it possible to recognize children with these disorders, as they differ markedly from healthy children in many ways. Many parents of autistic children sense that something is not qu

27、ite right even when their children are infants. The infants may have feeding problems, dislike being changed or bathed, or fuss over any change in routine. They may hold their bodies rigid, making it difficult for parents to cuddle them. Or, they may fail to anticipate being lifted, lying passively

28、while the parent reaches for them, rather than holding their arms up in return. Most parents of autistic children become aware of the strangeness of these and other behaviors only gradually. Impairments in social interaction are usually among the earliest symptoms to develop. The most common social

29、impairment is a kind of indifference to other people, or aloofness, even towards parents and close care-givers. The baby may fail to respond to his or her name being called and may show very little facial expression unless extremely angry, upset, or happy. Babies with autism may resist being touched

30、, and appear to be lost in their own world, far from human interaction. Between seven and 10 months of age, most infants often resist being separated from a parent or well-known caregiver, but these infants may show no disturbance when picked up by a stranger. Other children with autism may be very

31、passive, although less resistant to efforts by others to interact. However, they do not initiate social interaction themselves. Still others may attempt to engage with adults and peers, but in ways that strike others as inappropriate, or odd. In adolescence and adulthood, some of the higher-function

32、ing individuals with autistic disorders may appear overly formal and polite. They may react with little spontaneity, as if social interaction doesn't come naturally or easily to them, and so they are trying to follow a pre-determined set of rules. Some individuals with autism have normal intelli

33、gence, and many have special talents in areas such as music or memory. However, individuals with autism may have other mental or emotional problems that co-exist with their autism. Some of these other disorders may include impulse control disorders, obsessive-compulsive disorder , mood and anxiety d

34、isorders, and mental retardation . PSYCHOLOGICAL AND FAMILY FACTORS. Although Henry Maudsley, in the late 1800s, was the first psychiatrist to focus on very young children with mental disorders, it was the psychiatrist Leo Kanner who coined the phrase "early infantile autism" in 1943. Kann

35、er believed that the parents of children with autistic behaviors were emotionally cold and intellectually distant. He coined the term "refrigerator parents" to describe them. His belief that parental personality and behavior played a powerful role in the development of autistic behaviors l

36、eft a devastating legacy of guilt and self-blame among parents of autistic children that continues to this day. Recent studies are unequivocal, however, in demonstrating that parents of autistic children are no different from parents of healthy children in their personalities or parenting behaviors.

37、 In fact, many families with an autistic child also have one or more perfectly healthy children. Because autistic children can be extremely sensitive to change, any change within the family situation can be potentially traumatic to the autistic child. A move, divorce, birth of a sibling or other str

38、essors that occur in the lives of most families may evoke a more extreme reaction from an autistic child. While there is no single neurological abnormality found in children with autistic disorders, some research using non-invasive brain imaging techniques such as magnetic resonance imaging (MRI) su

39、ggests that certain areas of the brain may be involved. Several of the brain areas being researched are known to control emotion and the expression of emotion. These areas include the temporal lobe (large lobe of each side of the brain that contains a sensory area associated with hearing), the limbi

40、c system, the cerebellum, the frontal lobe, the amygdala, and the brain stem, which regulates homeostasis (body temperature and heart rate). Recent research has focused particularly on the temporal lobe because of the finding that previously healthy people who sustain temporal lobe damage may develo

41、p autistic-like symptoms. In animal research, when the temporal lobe is damaged, social behavior declines, and restless, repetitive motor behaviors are common. When measured by MRI, total brain volume appears to be greater for those with autistic disorders. Other neurological factors include lesions

42、 to the brain, congenital rubella, undiagnosed and untreated phenylketonuria (PKU), tuberous sclerosis, and Rett's disorder (a related condition in which the baby develops in an apparently normal manner through age five months, and then begins to lose communicative and social interaction skills)

43、. There is also evidence of a higher proportion of perinatal complications (complications arising around the time of giving birth) among children with autistic symptoms. These complications include maternal bleeding after the first trimester and meconium in the amniotic fluid. (Meconium is a substan

44、ce that accumulates in the bowel of the developing fetus and is discharged shortly after birth.) Some evidence suggests that the use of medications during pregnancy may be related to the development of autistic symptoms. As newborns, children with autistic behaviors show a higher rate of respiratory

45、 illness and anemia than healthy children. ALLERGIES, INFECTIONS, AND IMMUNIZATIONS. Some professionals believe that autistic disorders may be caused by allergies to particular fungi, viral infections, and various foods. No controlled studies have supported these beliefs, but some parents and profes

46、sionals report improvement when allergens and/or certain foods are eliminated from the diet. Viral infections of the mother, such as rubella, or of the young child, such as encephalitis, mumps, and measles, occasionally appear to cause autistic disorders. The common childhood immunization series kno

47、wn as MMR (measles, mumps, rubella) has recently come under scrutiny as a possible cause of some autistic conditions.Basketball can make a true claim to being the only major sport that is an American invention. From high school to the professional level, basketball attracts a large following for liv

48、e games as well as television coverage of events like the National Collegiate Athletic Association (NCAA) annual tournament and the National Basketball Association (NBA) and Women's National Basketball Association (WNBA) playoffs. And it has also made American heroes out of its player and coach

49、legends like Michael Jordan, Larry Bird, Earvin "Magic" Johnson, Sheryl Swoopes, and other great players. At the heart of the game is the playing space and the equipment. The space is a rectangular, indoor court. The principal pieces of equipment are the two elevated baskets, one at each e

50、nd (in the long direction) of the court, and the basketball itself. The ball is spherical in shape and is inflated. Basket-balls range in size from 28.5-30 in (72-76 cm) in circumference, and in weight from 18-22 oz (510-624 g). For players below the high school level, a smaller ball is used, but th

51、e ball in men's games measures 29.5-30 in (75-76 cm) in circumference, and a women's ball is 28.5-29 in (72-74 cm) in circumference. The covering of the ball is leather, rubber, composition, or synthetic, although leather covers only are dictated by rules for college play, unless the teams a

52、gree otherwise. Orange is the regulation color. At all levels of play, the home team provides the ball. Inflation of the ball is based on the height of the ball's bounce. Inside the covering or casing, a rubber bladder holds air. The ball must be inflated to a pressure sufficient to make it rebo

53、und to a height (measured to the top of the ball) of 49-54 in (1.2-1.4 m) when it is dropped on a solid wooden floor from a starting height of 6 ft (1.80 m) measured from the bottom of the ball. The factory must test the balls, and the air pressure that makes the ball legal in keeping with the bounc

54、e test is stamped on the ball. During the intensity of high school and college tourneys and the professional playoffs, this inflated sphere commands considerable attention. Basketball is one of few sports with a known date of birth. On December 1, 1891, in Springfield, Massachusetts, James Naismith hung two half-bushel peach baskets at the opposite ends of a gymnasium and out-lined 13 rules based on five principles to his students at the Internatio