基于可编程序控制器(PLC)设计和实践的电梯控制系统--外文文献翻译-中英对照

1、 译文基于可编程序控制器PLC设计和实践的电梯控制系统 摘要- 本文阐述了nine-storey电梯控制系统的开展。控制系统采用PLC为控制器,并采用并联调度规那么基于“最小等待时间来跑两电梯并联模式。本文介绍了根本结构、控制原理和实现方法的PLC控制系统进行了详细的介绍。给出了梯形图的关键方面的系统。该系统具有外围电路简单,运行结果说明,系统的可靠性和性能的提高电简介 随着建筑技术的开展,楼房一座比一座高,电梯自然成了高楼大厦垂直运输的重要工具,承载着来往大厦里居住、办公、参观的人们可以舒适而又快捷到达目的地的责任。电梯控制系统在每一部电梯的通顺平安的运行中必不可少的,它决定电梯什么时候停层

2、、开关门,以及处理紧急平安问题。 传统的电梯控制系统是继电器控制系统,它存在着诸如电路复杂、故障率高和可靠性差的缺点,很大程度上影响了电梯运行质量。因此,通过企业的委托,我们用PLC改良了一座住宅楼继电器控制电梯的电气控制系统。结果说明,改良后的系统运行更可靠,维修更方便了。 这篇论文详细的介绍了电梯PLC控制系统的根本结构、控制原理和实现的方法。系统结构 电梯控制系统的目的在于控制电梯的运动以便符合用户的需求。它主要包括两局部:电力驱动系统 电力驱动系统包括电梯轿厢、牵引电机、门电机、制动器和开关电路。我们在这采用新型的LC系列AC接触器代换旧接触器,用PLC软接触器代换大量中间继电器,保存

3、牵引电机的电路。这样一来,就有效的克服了原先控制柜响声大、噪音大等缺点。信号控制系统 电梯的控制信号几乎都来自与PLC。输入信号有:运行模式、运行的控制信号、轿外呼叫、平安/保护信号、门开/关信号以及平层信号等。像轿内外呼叫的记录、显示、消除,轿厢位置的判断,电梯的选层和上下行选择等所有电梯系统的控制功能都是由PLC系统实现。电梯的PLC信号控制系统框图如右图2.1所示。 图2.1 PLC信号控制系统框图 一般来说,电梯运行情况有如下:(1)、一部电梯运行 电梯一般有三种工作状态:正常模式、防火模式和维护模式。维护模式有最高优先级,只有在维护模式撤销时候,其他模式才开始实行;其次是防火模式,当

4、火警开关翻开时,电梯必须马上返回底层或者基站,当火警开关复位时返回正常模式运行;在正常模式下控制系统的根本任务就是命令电梯上下行、停层或启动、开门或者关门。不过有一定的约束:每一电梯有对应每层楼的一组九个按钮布置在轿厢控制面板上,当被按下要电梯来到该层时按钮就会变亮,当电梯来到该层时按钮灯灭。每一层(除了顶层和底层)有两个按钮布置在层控制面板上,一个呼叫上行另外一个呼叫下行,按钮被按下时变亮,电梯运行到该层时熄灭,之后向呼叫方向运行。分布在轿厢和层控制面板上的按钮用来控制电梯的运动。电梯不能跳过乘客要离开的楼层,不可以停在无人呼叫的楼层,在运送轿厢内需要当前方向的乘客时候电梯不能改变方向,也不

5、相应外呼直到送完,如果电梯没有被呼叫,就关门停靠在当前的楼层。(2)、两部电梯并联运行 这种情况下两部电梯同时效劳该大楼,每天分别在上午7点到9点和下午5点到7点运行。电梯每到一层都会检测是否需要停下,当检测到停层的需要时就会停靠该层。与此同时为了平衡停层的次数,两部电梯的运行会遵循一定的调度原那么。当有一电梯停在或正要停在某一楼层时候,另一电梯就不会停靠那层。电梯的正常运行通过电力驱动系统和逻辑控制系统来共同实现的。 最小的等待时间算法 在电梯系统的调度中,通常有两种控制任务。其一是电梯上下行、起停、开关门的根本控制功能。其二是多部电梯并行的控制,组合电梯效劳厅门和轿厢呼叫的主要要求是效劳到

6、建筑的每一层楼,减少乘客呼叫等待时间,减少乘客上下楼层的时间,相同时间内能为更过的乘客效劳。电梯的群控有许多调度算法。如电梯总是相应最近需求的最近邻域算法,分析对于不相等楼层数量需要电梯系统的调度来调遣电梯的分区算法,一部电梯效劳奇数楼层另一部效劳偶数楼层的奇偶规那么。 最近邻域算法使得电梯空载移动到下一个呼叫路程最小,通常有着非常小的平均轮侯时间,可是各人轮侯时间变得很大。分区算法一般应用在像办公大楼午餐时间这样交通频繁的情形下。相对于办公大楼、商场,住宅楼和楼层的流量较小。 其次人们认为电梯只是纯粹的功能性物体,而且对于大多数人来说,乘坐电梯的经验就是等待。此外,当试图满足所有需求时存在大

7、量的问题。鉴于上述原因,我们采用“最小轮侯时间算法来实现两部电梯的并行运行。 图6 floor-stopping评估函数 “最小轮侯时间算法的目标就是在所有呼叫中预测每一电梯的响应时间,并选择有最短响应时间电梯来效劳。当有呼叫的时候,系统根据(1)(2)评估函数计算出每一电梯的函数值:J*MinJ1,J2,Jn (1) JiTri+KTdi+KToi i1,2,n (2)Ji是电梯的评价指标;Tr(i)指出电梯从当前位置直接移动到相应最近呼叫的地方的时间;To(i)指出电梯停层时加速和减速的时间;Td(i)是乘客登上电梯或者走出电梯的时间;K表示厅门呼叫和轿内呼叫的总和。最小轮侯时间的计算 在

8、公式(2)中K为定值,To和Td可以通过统计方法获得。TrT*L,T是电梯通过一层楼的时间,L是呼叫楼层和当前楼层的相隔层数。为了计算L值,我们定义两部电梯分别为A和B;YA,YB分别表示电梯当前楼层;H是厅门呼叫按钮按下时相应的键值,即H等于呼叫层数。为PLC的的实现定义4个表:上行厅门呼叫记录表,下行厅门呼叫记录表,电梯A的轿内呼叫记录表,电梯B的轿内呼叫记录表。当呼叫按钮被按下时,对应楼层数就会记录在相应的表中。 我们以电梯A为例。首先定义变量MA,MB和MW;MA和MB分别表示A或者B同方向上轿内呼叫的最值。当电梯A上行时,置MA等于轿内呼叫记录表A中的最大值;当电梯A下行时,置MA等

9、于叫内呼叫记录表A中最小值。MW为同方向A运行中,厅门呼叫的最值。当电梯A上行并且上行呼叫值YA时,置MW0;否那么,置MW等于上行厅门记录表A中的最小值。当电梯A下行并且下行厅门呼叫值YA时,置MA0;否那么,置MW等于下行厅门呼叫记录表A中最大值。这样我们就可以根据YA,H,MA和MW来判断L值。分如下三种情况:厅门呼叫方向和电梯A当前运行方向相反; L|YA-MA|+|MA-H|(3)厅门呼叫和运行方向相同并且在电梯前方; L|YA-H|(4)厅门呼叫和运行方向相同但在电梯前方; L|YA-MA |+|MA-MW|+|H-MW| (5)第i层的最小轮侯时间可以由(6)计算出:TimeiT

10、Li+KTdi+KToi,i1,2,n 6当呼叫在运行的时候变化时,系统自动计算出每一部电梯的最小轮侯时间,然后分配当前呼叫给有较小值的电梯。当最小;轮侯时间相等时,电梯A对于当前呼叫有优先权。当其中一部电梯故障或者不能运行时,系统自动退出调度算法,返回单部电梯运行模式。算法的实现 相对于单电梯运行模式,并行电梯运行模式主要是在厅门呼叫处理方法上的不同。前者采用集选控制方法,后者采用调度原那么结合集选控制的方法。这里系统用来控制一栋9层的大楼,我们选择两个西门子S7-200 PLCsCPU226和它的扩展模块分别控制单部电梯,同时使用PPI协议来实现两个PLC的通信。PPI协议采用主从通信模式

11、,所以我们定义电梯A为主,电梯B为从。两个PLC通过通信协议来传递诸如当前位置、厅门或者轿内呼叫和运行方向等信息。然后用“最小轮侯时间算法来使系统实现两部电梯的调度运行。图4.1是电梯A轿内呼叫最值计算的梯形图。图中VB121VB130是电梯A轿内呼叫对应每层楼的存放地址,Q3.1是电梯A的上行灯,轿内呼叫的最值保存在VB120中。 图4.1 电梯最值算法梯形图参考文献1 Ricardo Gudwin,Fernando Gomide,Marcio 1998. “A Fuzzy Elevator Group Controller With Linear Context Adaptation. I

12、EEE World Congress on Computational Intelligence. Vol. 12, No. 5, pp.481-486.2 Philipp Friese, Jorg Rambau 2006. “Online-optimization of multi-elevator transport systems with reoptimization algorithms based on set-partitioning models. Discrete Applied Mathematics .No. 154, pp.1908-1931.3 Zheng Yanju

13、n, Zhang Huiqiao, Ye Qingtai, Zhu Changming. 2001. “The Research on Elevator Dynamic Zoning Algorithm and It's Genetic Evolution. Computer Engineering and Applications, No. 22, pp.58-61.4 Xiaodong Zhu, Qingshan Zeng 2006. “A Elevator Group Control Algorithm for Minimum Waiting Time Based On PLC.

14、 Journal of Hoisting and Conveying Machiner, No. 6,pp.38-40. 原 文Design and Practice of an Elevator Control System Based on PLCXiaoling Yang1, 2, Qunxiong Zhu1, Hong XuCollege of Information Science &Technology,Beijing University of Chemical Technology, Beijing 100029, ChinaAutomation College of

15、Beijing Union University,Beijing,100101, Chinayxl_lmy sina, zhuqx/0>.AbstractThis paper describes the development of 2 nine-storey elevators control system for a residential building. The control system adopts PLC as controller, and uses a parallel connection dispatching rule based on "minim

16、um waiting time" to run 2 elevators in parallel mode. The paper gives the basic structure, control principle and realization method of the PLC control system in detail. It also presents the ladder diagram of the key aspects of the system. The system has simple peripheral circuit and the operati

17、on result showed that it enhanced the reliability and performance of the elevatorsIntroductionWith the development of architecture technology, the building is taller and taller and elevators become important vertical transportation vehicles in high-rise buildings. They are responsible to transport p

18、assengers, living, working or visiting in the building, comfortable and efficiently to their destinations. So the elevator control system is essential in the smooth and safe operation of each elevator. It tells the elevator in what order to stop at floors, when to open or close the door and if there

19、 is a safety-critical issueThe traditional electrical control system of elevators is a relay-controlled system. It has the disadvantages such as complicated circuits, high fault ratio and poor dependability; and greatly affects the elevators running quality. Therefore, entrusted by an enterprise, we

20、 have improved electrical control system of a relay-controlled elevator in a residential building by using PLC. The result showed that the reformed system is reliable in operation and easy for maintenanceThis paper introduces the basic structure, control principle and realization method of the eleva

21、tor PLC control system in detail.System structureThe purpose of the elevator control system is to manage movement of an elevator in response to users requests. It is mainly composed of 2 parts:Electric power driving systemThe electric power driving system includes: the elevator car, the traction mot

22、or, door motor, brake mechanism and relevant switch circuitsHere we adopted a new type of LC series AC contactors to replace the old ones, and used PLCs contacts to substitute the plenty of intermediate relays. The circuits of traction motor are reserved. Thus the original control cabinets disadvant

23、ages, such as big volume and high noise are overcome efficiently.Signal control systemThe elevators control signals are mostly realized by PLC. The input signals are: operation modes, operation control signals, car-calls, hall-calls, safety/protect signals, door open/close signal and leveling signal

24、, etc. All control functions of the elevator system are realized by PLC program, such as registration, display and elimination of hall-calls or car-calls, position judgment of elevator car, choose layer and direction selection of the elevator, etc. The PLC signal control system diagram of elevator i

25、s showed in Figure 1.Figure 1Informally, the elevators behavior is defined as follows.1 Running with a single elevatorGenerally, an elevator has three operation states:normal mode, fire-protection mode and maintenance mode. The maintenance mode has the highest priority. Only the maintenance mode is

26、canceled can the other operation modes be implemented. The next is fire-protection mode, the elevator must return to the bottom floor or base station immediately when the fire switch acts. The elevator should turn to normal operation mode when the fire switch is reset. Under normal operation mode, t

27、he control systems basic task is to command each elevator to move up or down, to stop or start and to open and close the door. But is has some constraints as follows: Each elevator has a set of 9 buttons on the car control panel, one for each floor. These buttons illuminate when they are pressed and

28、 cause the elevator to visit the corresponding floor. The illumination is canceled when the corresponding floor is visited by the elevator. Each floor, except the first and the top floor, has two buttons on the floor control panel, one to request an upelevator, one to request a down-elevator. These

29、buttons illuminate when they are pressed. The illumination is canceled when an elevator visits the floor, then moves in the desired direction. The buttons on the car control panel or the floor control panel are used to control the elevators motion. The elevator cannot pass a floor if a passenger wan

30、ts to get off there. The elevator cannot stop at a floor unless someone wants to get off there. The elevator cannot change direction until it has served all onboard passengers traveling in the current direction, and a hall call cannot be served by a car going in the reverse direction. If an elevator

31、 has no requests, it remains at its current floor with its doors closed.2 Parallel running with two elevatorsIn this situation, there are two elevators to serve the building simultaneously. It runs at 7am to 9am and 5pm to 7pm every day.When an elevator reaches a level, it will test if the stop is r

32、equired or not. It will stop at this level when the stop is required. At the same time, to balance the number of stops, the operation of two elevators will follow a certaindispatching principle. An elevator doesnt stop at a floor if another car is already stopping, or has been stopped there. The nor

33、mal operation of elevators is implemented by cooperation of its electric power driving system and logic control system.Minimum waiting time algorithmIn traffic of elevator systems, there are two types of control task usually. The one is the basic control function to command each elevator to move up

34、or down, to stop or start and to open and close the door. The other is the control of a group of elevators. The main requirements of a group control system in serving both, car and hall calls, should be: to provide even service to every floor in a building; to minimize the time spent by passengers w

35、aiting for service; to minimize the time spent by passengers to move from one floor to another; to serve as many passengers as possible in a given time1.Figure 6 The elevators floor-stoppingThere are many dispatching algorithms for elevators group control. Such as Nearest-neighbor Algorithm2, which

36、the elevator always serve the closet request next; Zoning Algorithm3 which by analyzing the traffic of elevator system with unequal floor and population demand to dispatch the elevator; and Odd-even rule, which an elevator only serves the odd floor and the other only serves the even floor. The Neare

37、st-neighbor Algorithm minimizes the length of the elevators empty move to the next request. It usually has very small average waiting times, but individual waiting times can become quite large2. The Zoning Algorithm usually used in buildings which has heavy traffic situations, such as the office bui

38、lding at lunch time.Compared to the office building and shopping mall, the traffic flow of residential buildings is relatively low and even in every floor. Secondly, people usually think of elevators as purely functional objects and the experience of riding an elevator is time waited for most of the

39、m.Furthermore, there exist immense problems when attempting to satisfy all requirements.Considering all of the reasons above, we adopted the “minimum waiting time algorithm to realize the 2 elevators parallel running4 Evaluation functionThe goal of the “minimum waiting time algorithm is to predict t

40、he each elevators response time according to all calls, and select the elevator which has the shortest response time to serve. When there is a call, the system calculates out the function values of each elevator according the evaluation function showed in 1 and 2:J*MinJ1,J2,Jn 1JiTri+KTdi+KToi i1,2,

41、n 2Ji is the evaluation index of each elevator; Tridenotes the time of the elevator directly moving to the destination corresponding the latest call from its current floor; Toi denotes the additional acceleration and deceleration time of a floor-stop of the elevator; Tdi denotes the average time of

42、the passenger boarding and alighting the elevator; and K is the sum of hall-calls and car-calls. But when a hall-call and a car call corresponds the same floor, the K is only calculated one time Calculation of minimum waiting timeIn equation 2, K is a certain value, To and Td can be obtained by mean

43、s of statistics. Tr T*L, where T denotes the average time of the elevator passing by one floor; L denotes the desired floors of the elevator from current floor to the hall-call floor. In order to calculate the L value, we defined the 2 elevators are A and B respectively; YA,YB denotes thecurrent flo

44、or of elevator A and B respectively. H is the corresponding key value when a hall-call button is pressed, and Hfloor number of the hall-call. We defined 4 tables for the PLC realization: up hall-call registration table, down hall-call registration table, car-call registration table of A and car-call

45、 registration table of B. When a certain call button is pressed, its floor value is recorded in corresponding table. Here we take elevator A as an example. First, define the variable MA, MB and MW. Where MA, MB denotes the extreme value of car-calls with same direction of A or Bs movement respective

46、ly. When elevator A is up-moving, set MA is equal to the imum value in car-call registration table A; when elevator A is down-moving, set MA is equal to the minimum value in car-call registration table A.MW denotes the extreme value of hall-calls with same direction of As movement. When elevator A i

47、s up-moving and up-hall-call valueYA, set MW0; otherwise, set MW is equal to the minimum value in up-hall-call registration table A. When elevator A is down-moving and up-hall-call valueYA, set MW0; otherwise, set MW is equal to the imum value in down-hall-call registration table AThus, we can deter

48、mine the L value according to YA, H, MA and MW. There are 3 situations:1 When the hall-calls direction is opposite to elevator As movement:L|YA-MA|+|MA-H| 32 When the hall-calls direction is same as elevator As movement and it is in the front of elevator A:L|YA-H| 43 When the hall-calls direction is

49、 same as the elevator As movement and it is in the back of elevator A:L|YA-MA |+|MA-MW|+|H-MW| 5So the i-th floors minimum waiting time can be calculated by 6 as follows:TimeiTLi+KTdi+KToi i1,2,n 6When the calls change during the operation of elevators, the system calculates the minimum waiting time

50、 of each elevator. Then it allocates the current call to the elevator which has small value. When the each elevator has the same value, then the current call is prior to elevator A. When an elevator is wrong or not in service, the system can exit the dispatching algorithm and turns to a single eleva

51、tor running mode Algorithm realizationCompared with single elevator running mode, the parallel running mode is mainly different at the processing method about hall-calls. The former uses collective selective control method, and the latter uses dispatch rule combined with collective selective control method. Here the system is to co