In the article has analyzed the elevator loadcharacteristics, elaborated uses the trapezoid acceleration curve theelevator ideal velocity curve, unifies the frequency changer and thePLC performance, elaborated the elevator control system constitutionand the operational factor. Elaborated the elevator speed curveproduces the method, has induced the characteristic which designs byPLC constitution control system software.Key word: Load characteristics ideal velocity curve control systemsoftware design1. OutlineAlong with the urban construction unceasing development, thehigh-rise construction unceasingly increases, the elevator has thewidespread application in the national economy and the life. Theelevator took in the high-rise construction the vertical movementtransportation vehicle already and people's daily life is inseparable.In fact the elevator is according to exterior movement and so oncalling signal as well as own control rule, but calls is stochastic,the elevator is a person machine interactive control system in fact,purely is cannot satisfy the control request with the sequentialcontrol or the logical control, Therefore, the elevator control system uses the stochastic logical waycontrol. At present the elevator control generally has selected twomethods, one is uses the microcomputer to take the signal controlunit, completes the elevator signal gathering, the running status andthe function hypothesis, realizes the elevator automatic dispatch andthe collection chooses the movement function, drives the control tocomplete by the frequency changer; The second control mode (PLC)substitutes for the microcomputer realization signal collection withthe programmable controller to choose the control. Said from the control mode and the performance, these two methodscertainly not too big difference. The domestic factory mostly choosesthe second way, its reason lies in the production scale slightly, owndesign and the manufacture microcomputer control device cost ishigher; But PLC reliability high, programming convenience nimble, theantijamming ability strong, the movement stable is reliable and so onthe characteristic, therefore the present elevator control systemwidely uses the programmable controller to realize.2. Elevator ideal performance diagramIndicated according to the massive research and the experiment, theperson may accept the maximum acceleration is am <= 1.5m/s2,acceleration rate of change rho m <= the 3m/s3, elevator idealperformance diagram may divide according to the acceleration is thetriangle, the trapezoid and the sine profile, As a result of sine profile acceleration curve realization moredifficult, but the triangle curve maximum acceleration and is startingand applies the brake the section turning point acceleration rate ofchange to be bigger than the trapezoidal curve, namely + rho m jumpsto - rho m or jumps from - rho m to + rho the m acceleration rate ofchange, therefore very little uses, because the trapezoidal curve iseasy to realize and has the good acceleration rate of change frequenttarget, therefore is widely used, uses the trapezoidal accelerationcurve elevator ideal performance diagram like chart 1 to show: The intelligent frequency changer is for the elevator special-purposefrequency changer request and so on elevator nimble velocitymodulation, control and high accuracy even level which but speciallydesigns, may use for parts the general three-phase asynchronous motor,and has function and so on intellectualized software, standardconnection, menu prompt, input elevator curve and other essentialparameter. It has the debugging convenience quickly, moreover can automaticallyrealize the single multilayered function, and has the automaticoptimization deceleration curve the function, is composed the velocitymodulation system crawling time by it few, the even level distance isshort, no matter is the double winding electric motor, or electric motor suitable, its highest design speed may reach 4m/s, itsunique computer monitoring software, may choose the serial interfacerealization input/output signal the non- electronic contact control. The frequency changer constitutes elevator system, when the frequencychanger receives the controller to send out shouts the ladderdirection signal, the frequency changer basis hypothesis speed and theacceleration value, the starting motor, after achieved the maximumspeed, the uniform speed moves, when arrives the goal leveldecelerates, the controller sends out shuts off the high velocitysignal, reduces the speed which the frequency changer establishes themaximum speed to reduce to the crawling speed, In decelerates in the movement process, the frequency changer can theautomatic computation decelerate to the even level spot betweendistance, and calculates the optimized curve, thus canaccording tothe optimized curve movement, cause the low speed crawling time toreduce to 0.3s, the frequency changer through adjusts leveling thespeed in the elevator even level process or applies the brake thepitch to adjust leveling the precision. Namely when the elevator stops too early, the frequency changerincreases the low speed value or the reduction applies the brake thepitch value, otherwise reduces the low speed value or increasesapplies the brake the pitch value, when the elevator to leaves evenlevel position 4 - 10cm, has the even level switch automaticseparation low speed signal, the system according to the optimizedcurve realization high accuracy even level, thus achieved the evenlevel accurate is reliable.3. Elevator speed curveElevator movement comfortableness is decided in its movementprocess acceleration a and the acceleration rate of change p size, theoversized acceleration or the acceleration rate of change can createpassenger's ill feeling. At the same time, for guaranteed the elevatorthe operating efficiency, a, the p value not suitable excessively issmall. Can guarantee a, the p best value elevator performance diagramis called the elevator the ideal performance diagram. The elevatormovement ideal curve should be the parabola - straight linecomprehensive velocity curve, namely elevator Canada, reduces theprocess constitutes by the parabola and the straight line. Theelevator assigns the curve is whether ideal, direct influence actualperformance diagram.3.1 velocity curves have the methodUses FX2-64MR PLC, and a consideration input output requestincreased FX-8EYT, FX-16EYR, the FX-8EYR three expansions modules andthe FX2-40AW twisted pair line correspondence adapter, FX2-40AW usesin the system serial communication. Using PLC the expansion functionmodule D/A module realization speed ideal curve output, whenbeforehand the digitized ideal velocity curve stores the PLC register,the procedure movement, through looks up the table way to read in D/A,transforms the simulation quantity after D/A the speed ideal curveoutput.3.2 Acceleration assign the curve the production8 D/A outputs 0 ~ 5V/0 ~ 10V, the corresponding numerical valueis 16 enters system several 00 ~ FF, altogether 255 levels. Ifelevator rise time between 2.5 ~ 3seconds. According to theconservative value computation, in the elevator acceleration processeach time Zha Biao time-gap not suitably surpasses 10ms.As a result of elevator logic control section procedure biggest, butthe PLC movement uses the cyclical scanning mechanism, thus usuallyuses looks up the table method, Zha Biao instruction time-gapexcessively is each time long, cannot satisfiedly assign the curve theprecision request. In the PLC movement process, its CPU with variousequipment between exchange of information, user program execution,signal gathering, control quantity operation and so on output all isdefers to the fixed order to circulate the scanning way to carry on,each circulation all must carry on the inquiry, the judgement and theoperation to all functions. This kind of order and the form capableperson are not the change. The usual scanning cycle, is basic mustcomplete six steps the work, including movement surveillance, andprogramming exchange information, and digital processor exchangeinformation, and communication processor exchange information,execution user program and input output connection service and so on.In a cycle, CPU only carries out to the entire user program. This kindof mechanism has its convenient one side, but timeliness is bad. Theexcessively long scanning time, directly affects the system to thesignal response effect, in under the guarantee control functionpremise, maximum limit reduces CPU the cyclical scanning time is avery complex question. Generally only can short adopt the method fromthe user program execution time. The elevator logic control sectionprocedure scanning time has surpassed 10ms, although has adopted somereduced procedure scanning time means, but still will be unable toscan the time to fall to 10ms below. At the same time, applies thebrake the section curve to use according to is away from theprinciple, each section of distances arrive the response time notsuitably surpasses 10ms. In order to satisfy the system the timelyrequest, in the velocity curve production way, uses the severancemethod, thus effectively has overcome the PLC scanning mechanismlimit.The starting acceleration movement by decides the cycle interruptservice isr to complete. This kind of severance cannot carry on theswitch by the procedure, once establishes, continuously presses thehypothesis time-gap circulation severance,therefore, the startingmovement condition must put in the interrupt service isr, when doesnot satisfy the movement condition, the severance namely returns.3.2 Decelerates applies the brake the curve productionIn order to guarantee applies the brake process completing,must carry on in the master routine applies the brake the condition tojudge and to decelerate a determination. In decelerates before adetermination, the elevator continuously is in the acceleration or thesteady fast movement process. The acceleration process completes bythe fixed cyclical severance, accelerates after the correspondingpattern maximum value, the acceleration procedure movement conditionno longer satisfies, after each time severs, no longer carries out theacceleration procedure, directly returns from the severance. Theelevator corresponds the pattern the maximum value movement,decelerates in this pattern to after, has the high-speed countingseverance, the execution decelerates the service routine. Revises thecounter in this interrupt service isr to suppose the definite valuethe condition, guaranteed the next time will sever the execution. In the PLC internal register, deceleration curve table value from big to small , each time severs all carries out time "theindicator needle to add 1" the operation, then the next severance willlook up the table number is smaller than this severance to look up the table numbers. Thegate area peaceful level area judgement produces by exterior signal,guarantees the moderating process the reliability.4. Elevator control system4.1 Elevators control system characteristicIs relates the elevator movement comfortable feeling target in theelevator performance diagram start section the key link, but thecomfortable feeling with the acceleration direct correlation,according to controls the theory, must cause some quantity accordingto prearrange the rule change to have to carry on the positivegoverning to it, said regarding the elevator control system, mustcause the acceleration to have to use the acceleration feedbackaccording to the ideal curve change, according to electric motormoment of force equation: M - MZ= Delta M=J (dn/dt), obviously theacceleration rate of change had reflected the system dynamic extensionis apart from the change, the control acceleration is apart from DeltaM=M - MZ on the control system dynamic extension. Therefore uses theacceleration in thissection the timing control principle, when thestart ascent portion speed achieved when stable state value 90%,systematically will cut the speed control from the accelerationcontrol, because in the steady fast section, the speed will besmaller for the permanent value control undulation, the accelerationchange will not be big, also will use the speed closed-loop controlto be allowed to cause the stable state speed hold certain precision,will be applies the brake the section precise even level to create thecondition. Uses the PI regulator control in the system speed ascentportion and steady fast Duan Suidu, but two section of PI parameter isdifferent, enhances the system the dynamic response target.Applies the brake the section in the system, namely must to reduce thespeed to carry on the essential control, guarantees the comfortablefeeling, also must strictly controls according to the elevatormovement speed and the distance relations, guarantees the even levelthe precision. In system’s rotational speed reduces to 120r/min in front of, in orderto enable two to obtain the proper attention to both, adopts by theacceleration to the timing control primarily, simultaneously actsaccording to on each as soon as the stopping distance the actualrotational speed and the theory rotational speed deviation revises theacceleration to assign the curve the method. For example in is awayfrom the even level spot some as soon as to be away from L place, thespeed should reduce to Vm/s, but the actual rotational speed is highis V ' m/s, then explained adds the system turns is apart frominsufficiently, after therefore calculates the here to assign reducesspeed value -ag, causes it to add on a negative deviation againepsilon, even if the here reduces the speed given value to revise for- (ag+ epsilon) causes to assign reduces the speed and the true speednegative deviation enlarges, thus enlarged the system to turn thedistance, caused the speed very quickly to fall to the standard value,when electric motor’s rotational speed reduces to 120r/min after, this time thetheater box above the level only had several centimeters, The elevatorrunning rate is very low, for did not prevent phenomenon appearancewhich stops to the even level area, enables the elevator comparativelyquickly to enter the even level area, uses the proportional control inthis section, and uses the time optimization control, guaranteed theelevator accurately promptly enters the even level area, achieves theaccurate reliable even level.4.2 elevators controls constitutionBecause the elevator movement is according to the floor and the theater box calling signal, the travelling schedule signalcarries on the control, but the floor and the theater box call isstochastic, therefore, the systems control uses the stochastic logicalcontrol. Namely in realizes in the elevator basic control requestfoundation by the smooth logic control, according to stochastic inputsignal, as well as elevator corresponding condition at the rightmoment control elevator movement. Moreover, the theater boxposition is determined by the pulse encoder pulse number that, anddelivers PLC the counter to carry on the control. At the same time,each building establishes to approach the switch to use in to examinethe system the floor signal. In order to be advantageous for the observation, is at the floor tothe elevator movement direction as well as the elevator to carry onthe demonstration, uses LED and the photo tube demonstrated, but tothe floor and the theater box calling signal to the indicating lampdemonstrated (on switch has indicating lamp).In order to enhance the elevator the operating efficiency peacefullevel precision, the system requests PLC to be able to theater boxCanada, to decelerate as well as to apply the brake to carry on theeffective control. Realizes according to the theater box physicallocation as well as the exchange velocity modulation system controlalgorithm. For the elevator movement security, the system shouldestablish the reliable fail safe and the corresponding es the PLC realization the elevator control system to constitute byfollowing several main parts.4.2.1 PLC control circuit; PLC receives shouts the ladder from thepanel board and each level to summon the signal, the theater boxand the gate system function signal as well as the well and thefrequency changer condition signal, realizes the elevator collectionafter the procedure judgement and the operation to choose the control.PLC during the output demonstration and supervisory signal, sends outthe movement direction, the start, Canada to the frequencychanger/decelerates moves and applies the brake to stop the ladderequisignal.4.2.2 electric currents, speed double closed loops electric circuit;Frequency changer itself is equipped with the electric currentdetector set, from this constitution electric current closed loop;Through revolves the encoder with the electricalmachinery coaxialjoint, produces a, the b two pulses enters the frequency changer,during confirmation direction, counts the constitution speed closedloop using the pulse.4.2.3 displacements control circuit; The elevator took one kindcarries the person tool, reigns under the potential state of loading,besides request safe reliable, but also requests the movement to besteady, rides comfortably, anchors accurately. Uses the frequencyconversion to modulate velocity Shuanghuan to control may basicallyanswer the purpose, the use existing revolves the encoder toconstitute the speed ring at the same time, moves the proportionthrough the frequency changer PG card output and the electricalmachinery speed and the elevator the pulse number, introduces it PLChigh-speed counting to input the port, through the accumulation pulsenumber, (1) calculates the pulse equivalent after the type, from thisdefinite elevator position. Elevator displacement H=SI In the formula I - accumulation pulse number; S - pulse equivalent; S = plD/(pr) (1) L – Proportion of decelerates ; D - tows the wheel diameter; P - revolves the encoder every time to transfer corresponding thepulse number; R - PG card frequency division ratio.4.2.4 ends stations protection; When in elevator direction detectionline, on the good directional relay, the express train assistancecontact device, the express train movement contact device, the doorlock relay, on the good contact device electricity attracts gathers, mechanical floodgate opens, on elevator line. When the theater box bumps intoforces speed changeing the switch, the PLC internal lock saves the relay toresult in the electricity to attract gathers, timer Tim10, Tim11 startfixed time, it fixed time time length visible end station leveldistance with ladder fast hypothesis. After on forces speed changing theswitch movement, the elevator transfers the slow train movement by theexpress train movement, in the normal condition, the previous line ofeven strata time elevator should stop. If the theater box has notstopped continues the line, when Tim10 supposes the definite value toreduce the zero hour, it the separation, the slow traincontact device and on the good contact device loses the electricity,the elevator stops moving. Bumps into after the arrogant theater boxon forces speed changing the switch, because certain reason elevators have notbeen able to transfer the slow train movement, and the express trainmovement contactdevice has not been able to release, when Tim11supposes the definite value to reduce the zero hour, it N.C. contactthe separation, the express train movement contact device and on thegood contact device loses the electricity, the elevator stops moving.Therefore, no matter is the slow train movement or the express trainmovement, so long as on forces speed changing the switch to send out thesignal, no matter the end stands other protection switches whetheract, can cause the elevator with the aid of Tim10 and Tim11 to stopmoving, thus causes the elevator end station protection to be morereliable.Under when the elevator needs the line, so long as had has chosen theladder instruction, got down the good directional relay to result inelectricity its Chang Kaidian closed, the lock saved the relay toreposition, Tim10 and Tim11 lost the electricity, it N.C. contactclosed for the elevator normal under line has prepared for. The lowerextremity stands the protection principle and the upper extremestation protection similar no longer duplicates.4.2.5 floors count; The floor counts uses relatively counts the way.Before the movement through from the study way, determines thecorresponding floor highly pulse number, corresponds 17 elevatorsseparately to store 16 memories units DM06 ~ DM21. The floor counter(CNT46) is a bidirectional counter, when arrives each level the floorcounts, according to moves the direction to carry on adds 1 or reduces1 to count. In the movement, the high speed counter tiredly estimates the valuereal-time counts the point correspondence pulse number with the floorto carry on the comparison, is equal when sends out the floor to countthe signal, the previous line of Canada 1, the next line reduces 1. Inorder to prevent the counter in counts the pulse high level periodrepetition to count, uses the floor to count on the signal along totrigger the floor counter.4.2.6 is fast speed changing; When the high speed counter value and the fastspeed changing point correspondence pulse number is equal, if the elevator isin the quick operating also this level has chooses the level signal,sends the fast speed changing signal. If the elevator medium speed movement oralthough the quick operating but this not chooses the level signal,then does not send speed changing the signal.4.2.7 areas signals; When high speed counter CNT47 value correspondsin the pulse number scope when the gate area, sends the gate areasignal.4.2.8 pulses signals failure detection; Pulse signal accurategathering and the transmission appears in the system especiallyimportantly, revolves the encoder for the examination and the pulsetransmission circuit breakdown, whether there is has designed thepulse signal and the errors and omissions pulse examination electriccircuit, guarantees the system normal operation through the real-timeexamination. In order to eliminate the pulse to count the accumulativeerror, in base station the establishment reset switch, turns on PLC highspeed counter CNT47 the replacement end.5. Software design characteristic5.1 uses the priority formationPosition and movement direction locates which according to theelevator, in the programming, has used four priorities formations,namely on good priority formation, on line of inferior priorityformation, under good priority formation, next line of inferiorpriority formation. When among them, on good priority formation forelevator upward movement, locates the upward movement calling signalin the elevator which above the position the floor sends out, thearray which should call which the signal cabin correspondence thefloor to have the pulse number depositing register constitutes. Whenprevious line of inferior priority formation for elevator upwardmovement, locates the upward movement calling signal in the elevatorwhich below the position the floor sends out, the formation whichshould call which the signal cabin correspondence the floor to havethe pulse number depositing register constitutes. Control system inelevator movement real-time arrangement four priorities exhibition,has provided the foundation for the realization stochastic logiccontrol.5.2 uses advanced first leaves the formationAccording to elevator movement direction, with to the priorityformation's in non-vanishing unit (has when call this unit is 70units, does not have when call then this unit for zero) (advancedsends in the register formation first to leave formation FIFO), theuse advanced first leaves the read-out instruction SFRDP instruction,sends in the FIFO first unit in data compares the register.5.3 uses the stochastic logical controlWhen the elevator approaches by some movement direction somefloor decelerates the position, distinguished whether this floor doeshave with to the calling signal (on a line of call symbolizedregister, next line of call symbolized when register, has callrequest, corresponding register is l, otherwise is 0), if has, thecorresponding register pulse number and the comparison register willcarry on the comparison, if will be same, then will decelerate in thisfloor stops: If is not same, then sends in this register data comparesthe register, and the original comparison register data preservation,carries out this floor to decelerate stops. After this movementfinished, the data which will preserve reis sent in compares theregister, will realize the stochastic logical control.5.4 uses the software demonstration The system use travelling schedule judgement floor, andtransforms the BCD code output, through hardware connection electriccircuit by LED demonstration.5.5 pair of frequency changers control PLC acts according to the stochastic logical control therequest, may send out to the frequency changer to the movement, thereverse movement, is decelerating as well as applies the brake thesignal, again controls the electrical machinery by the frequencychanger basis certain control rule and the control algorithm. At thesame time, when the system appears the breakdown, PLC to the frequencychanger sends out the signal.6. Concluding remark Uses elevator control system which the MIC340 elevatorspecial-purpose frequency changer constitutes, may realize theintellectualization which the elevator controls, but because theperiod of five days ladder and the elevator in person arrives eachlevel the population is the intelligent elevator is unable todetermine, even if uses the AITP artificial intelligence system, thetransmission transportation passenger flow information also is fuzzy,for solves the elevator this vertical transportation control systemtwo to be big cannot know the factor, will need us to go to theunceasing research and the exploration in the next work.译文:文中分析了电梯的负载特性，阐述了采用梯形加速曲线的电梯理想速度曲线，结合变频器和PLC的性能，论述了电梯控制系统的构成和工作特性。
