【正文】
....................................................... 30 附件 中英文翻譯 ................................................. 31 致 謝 ............................................................ 42 天津工業(yè)學(xué) 2021 屆本科畢業(yè)生畢業(yè)設(shè)計(jì) 1 第一章 緒論 前言 在 1949 年至 1979 年的 30年中,我國總共生產(chǎn)安裝電梯約 1 萬臺(tái)。曳引機(jī)由電動(dòng)機(jī)、聯(lián)軸器、制動(dòng)器、減 速箱、機(jī)座、曳引輪等組成,它是電梯的動(dòng)力源。自由度,使轎廂和對(duì)重只能沿著導(dǎo)軌作升降運(yùn)動(dòng)。它是由轎廂架和轎廂體組成。 ( 6) 電力拖動(dòng)系統(tǒng) 電力拖動(dòng)系統(tǒng)由曳引電機(jī)、供電系統(tǒng)、速度反饋裝置、調(diào)速裝置等組成,對(duì)電梯實(shí)行速度控制??刂破涟惭b在機(jī)房中,由各類電氣控制元件組成,是天津工業(yè)學(xué) 2021 屆本科畢業(yè)生畢業(yè)設(shè)計(jì) 4 電梯實(shí)行電氣控制的集中組件。 交流拖動(dòng)電梯更是得到迅速的發(fā)展,己由以前的變級(jí)調(diào)速 (ACVP)發(fā)展成為調(diào)壓調(diào)速 (ACVV)及調(diào)頻調(diào)壓調(diào)速 (ACVVVF),使得電梯的速度、加速度、加加速度控制更加符合人們的生理要求,電梯的舒適感大為改善。 天津工業(yè)學(xué) 2021 屆本科畢業(yè)生畢業(yè)設(shè)計(jì) 5 ( 2) 電梯群控系統(tǒng)將更加智能化 電梯智能群控系統(tǒng)將基于強(qiáng)大的計(jì)算機(jī)軟硬件資源,如基于專家系統(tǒng)的群控、基于模糊邏輯的群控、基于計(jì)算機(jī)圖像監(jiān)控的群控、基于神經(jīng)網(wǎng)絡(luò)控制的群控、基于遺傳基因法則的群控等。這種技術(shù)將減少電梯的安裝周期和費(fèi)用,提高電梯的可靠性和控制精度,更好地解決電 氣設(shè)備的兼容性,有利于把電梯歸納到大樓管理系統(tǒng)或智能化管理小區(qū)系統(tǒng)中。補(bǔ)償裝置用來補(bǔ)償曳引繩運(yùn)動(dòng)中的張力和重量變化,使曳引電動(dòng)機(jī)負(fù)載穩(wěn)定,轎廂得以準(zhǔn)確停靠。鋼絲繩懸吊在 曳引 輪上,一端懸掛轎廂,另一端懸吊對(duì)重裝置,由鋼絲繩和曳引輪槽之間的摩擦力產(chǎn)生曳引力驅(qū)動(dòng)轎廂做上下運(yùn)動(dòng)。的繞繩方式稱為單繞,或稱半繞;曳引繩繞曳引輪和導(dǎo)向輪一周后才被引向轎廂 和對(duì)重的繞繩方式稱為復(fù)繞,或稱全繞。摩擦系數(shù) ? 取 ,則當(dāng)量摩擦系數(shù) : 2 1 6 in1 8 095) in1( ????????? ??f (36) ?? ?? ?? ee f (37) 所以, fveccT T ??? 212 1,曳引能力足夠。 減速器的 選擇 目前速度不大于 ,其主要優(yōu)點(diǎn)是: ( 1) 傳動(dòng)平穩(wěn),運(yùn)行噪聲低: ( 2) 結(jié)構(gòu)緊湊,外形尺寸小; ( 3) 傳動(dòng)零件少,因而減少了維修和更換零件的次數(shù); ( 4) 具有較好的抗沖擊載荷特性。 天津工業(yè)學(xué) 2021 屆本科畢業(yè)生畢業(yè)設(shè)計(jì) 14 如圖 35 為 直流 電磁制動(dòng)器的機(jī)械原理 圖 圖 34為電磁制動(dòng)器原理圖 電磁鐵 閘瓦片 制動(dòng)彈簧 制動(dòng)力矩的計(jì)算 制動(dòng)力矩由兩部分組成:靜力矩和動(dòng)力矩。 假設(shè)摩擦制動(dòng)器的制動(dòng)力是恒定的,因而可以把制動(dòng)期間的運(yùn)動(dòng)看成是勻減速的,則角速度可由下式計(jì)算: bttn???30?? (327) 式中: tn 電動(dòng)機(jī)在制動(dòng)開始瞬間的轉(zhuǎn)速 (r/min)。 電梯鋼絲繩一般是圓形股狀結(jié)構(gòu),主要由鋼絲、繩股和繩芯組成。12?Sf 對(duì)于二繩的曳引驅(qū)動(dòng): 。 鋼絲繩端接裝置的形式有:金屬或樹脂填充的繩套、自鎖緊楔形繩套、繩夾、手工編織捻接接頭等。 圖 41為通用電梯結(jié)構(gòu) 示意圖 各類電梯的轎廂基本結(jié)構(gòu)相同,由于用途不同,在具體結(jié)構(gòu)及外形上有一定差異 客梯的轎廂一般寬大于深,這樣設(shè)計(jì)的目的是為了方便人員的出入,有利于提高運(yùn)行效率 貨梯的轎廂一般深大于寬或?qū)捝钕嗤?,這主要是考慮裝卸貨物的方便。 如圖 42 轎廂架的基本結(jié)構(gòu): 圖 42 轎廂架的基本構(gòu)件 1— 上梁; 2— 立柱; 3— 拉條; 4— 底梁 (2) 轎廂體 轎廂體 形態(tài)像一個(gè)大箱子,由 轎頂 、轎壁、 轎底 及轎門等組成,轎底框架采用規(guī)定型號(hào)及尺寸的槽鋼和角鋼焊成,并在上面鋪設(shè)一層鋼板或木板。 (3)轎廂頂?shù)臉?gòu)造和強(qiáng)度要求 由于在安裝、檢修和營救的需要,轎廂頂有時(shí)需要站人,我國有關(guān)技術(shù)標(biāo)準(zhǔn)規(guī)定,轎頂要能承受三個(gè)攜帶工具的檢修人員 (每人以 100kg 計(jì) )時(shí),其彎曲撓度應(yīng)不大于跨度的 1/1000。為了增大轎壁阻尼,減小振動(dòng),通常在壁板后面粘貼夾層材料或涂上減振粘子。 為了防止由于轎廂內(nèi)人員過多引起超載,轎廂的有效面積應(yīng)予以限制。 (1)對(duì)重裝置的種類及其結(jié)構(gòu) 對(duì)重裝置,一般分為無對(duì)重輪式 (曳引比為 1: 1的電梯 )和有對(duì)重輪 (反繩輪 )式 (曳引比為 2:1的電梯 )兩種。 平衡系數(shù)選值原則是:盡量使電梯接近最佳工作狀態(tài)。尤其當(dāng)電梯的提升高度超過30m 時(shí),這二側(cè)的平衡變化就更大 ,因而必須增設(shè)平衡補(bǔ)償裝置來減弱其變化。 天津工業(yè)學(xué) 2021 屆本科畢業(yè)生畢業(yè)設(shè)計(jì) 24 導(dǎo)軌 的設(shè)計(jì) 導(dǎo)軌 功能是限制轎廂和對(duì)重的活動(dòng)自由度,使轎廂和對(duì)重只沿著各自的導(dǎo)軌作升降運(yùn)動(dòng),使兩者在運(yùn)行中平穩(wěn),不會(huì)偏擺 , 有了 導(dǎo)軌 ,轎廂只能沿著左右兩側(cè)的豎直方向的導(dǎo)軌上下運(yùn)行。 T型導(dǎo)軌的主要規(guī)格參數(shù),是底寬 b、高度 h和工作面厚度 k。一般的電梯,都裝有自動(dòng)開啟,由轎門帶動(dòng)的,層門上裝有電氣、機(jī)械聯(lián)鎖裝置的門鎖。 根據(jù)客戶的功能要求,以及設(shè)計(jì)要求, 我們選擇門的形式為中分式。目前乘客電梯多采用變頻門機(jī)機(jī)構(gòu)。同時(shí)設(shè)置一種保護(hù)裝置,當(dāng)乘客在門的關(guān)閉過程中被門撞擊或可能會(huì)被撞擊時(shí), 保護(hù)裝置將停止關(guān)門動(dòng)作使門重新自動(dòng)開啟。 當(dāng)電梯額定速度很低時(shí) (如小于 ),轎廂和對(duì)重底下的緩沖器也可以天津工業(yè)學(xué) 2021 屆本科畢業(yè)生畢業(yè)設(shè)計(jì) 27 使用實(shí)體式緩沖塊來代替,其材料可用橡膠、木材或其它具有適當(dāng)彈性的材料制成。對(duì)重安全鉗若速度大于 ,也應(yīng)用漸進(jìn)式安全鉗。擺錘 式限速器一般用于速度較低的電梯。Scientific American。 Tsitsiklis, 1996) applies naturally to the case of autonomous agents, which receive sensations as inputs and take actions that affect their environments in order to achieve their own goals. RL is based on the idea that the tendency to produce an action should be strengthened (reinforced) if it produces favorable results, and weak end if it produces favorable framework appealing from a biological point of view, since an animal has builtin preferences but does not always have a teacher to tell it exactly what action it should take in every situation. If the members of a group of agents each employ an RL algorithm, the resulting collective algorithm allows control policies to be learned in a decentralized way. Even in situations where centralized information is available, it may be advantageous to develop control polisci in a decentralized way in order to simplify the search through policy space. Although it may be possible to synthesize a system whose goals can be achieved by agents with conic objectives, this paper focuses on teams of agents that share identical objectives corresponding directly to the goals of the system as a whole. To demonstrate the power of multiagent RL, we focus on the difference problem of elevator group supervisory control. Elevator systems operate in highdimensional continuous state spaces and in continuous time as discrete event dynamic systems. Their states are not fully observable, and they are nonstationary due to changing 天津工業(yè)學(xué) 2021 屆本科畢業(yè)生畢業(yè)設(shè)計(jì) 32 passenger arrival rates. We use a team of RL agents, each of which is responsible for controlling one elevator car. Each agent uses article neural works to store its actionvalue estimates. We pare a parallel architecture, in which the agents share the same works, with a decentralized architecture, in which the agents have their own independent works. In either case, the team receives a global reward signal that is noisy from the perspective of each agent due in part to the effects of the actions of the other agents. Despite these difficulties, our system outperforms all of the heuristic elevator control algorithms known to us. We also analyze the policies learned by the agents, and show that learning is relatively robust even in the face of increasingly inplete state information. These results suggest that approaches to decentralized control using multiagent RL have considerable promise. In the following sections, we give some additional background on RL, introduce the elevator domain, describe in more detail the multiagent RL algorithm and work architecture we used, present and discuss our results, and finally draw some conclusions. 2. Reinforcement Learning Machine learning researchers have focused primarily on supervised learning, where a “ teacher” provides the learning system with a set of training exa