毕业论文外文翻译-电梯安全系统模拟器的设计和评价电梯安全系统.doc

本科毕业设计（论文）外文参考文献译文及原文 学 院 机械工程学院 专 业 机械设计制造及其自动化 年级班别 学 号 学生姓名 指导教师 2014 年 5月 1 日 目 录外文参考文献原文1.INTRODUCTION32.OUTLINE OF SAFETY SYSTEM33.SIMULATION MODEL44.EXPERIMENTS65.CONCLUSION6电梯安全系统模拟器的设计和评价电梯安全系统71.引言72.外形安全系统83.仿真模型94.实验125.仿真模型13 A Simulator for the Design and Evaluation of Elevator Safety SystemsABSTRACT We developed a simulator to evaluate the safety of elevator. This simulator includes a dynamic model with a normal state and some abnormal states and a safety logic model. These models are described with a state transition model. This report outlines this simulator, and we show its effectiveness by comparing the simulator's results with experimental results.KEY WORDS Safety System, Elevator, Simulator, State Transition Model1. INTRODUCTION We developed a simulator to evaluate safety of an elevator. There are some simulators whichsimulate the dynamics of an elevator 1 2. These have a model that shows when the elevator is normal or has a specific error. There are no simulators which can simulate the state transition of an elevator. A transition of the dynamic characteristics of an elevator according to the operation of the safety logic has a high level of influence in terms of elevator safety. To accurately evaluate safety of an elevator, we need a simulator that can continuously and precisely simulate the state transitions of a running elevator. Therefore, we developed asimulator that combines a safety logic simulation model and a dynamic simulation model, whichexpresses the consecutive transitions of states of the elevator. Using this simulator allowed us toprecisely express the continuous transitions of an elevator This simulator is composed by the following state transition models.(1) Dynamic simulatessimulation model: this precisely the continuous transitions of a running elevator's state.(2) Safety logic simulation model: this simulates safety logic operations according to the continuous transitions of an elevator's state. By the integration of the dynamic simulation model(1) and the safety logic simulationmodel(2), we achieved the evaluation of the elevator's safety. In this paper, we explain this new simulator and show its effectiveness by comparing its results with those of experiments.2. OUTLINE OF SAFETY SYSTEMEVALUATION SIMULATOR Figure 3 shows the outline of an elevator system. An elevator is composed of a motor, asafety gear, a brake, a sheave, traction ropes, a car, a counter-weight, and so on. A motor generates the torque to drive. A safety gear is a braking device which stops a car in the emergency, and a brake is a braking device which stops a motor in the emergency. A sheave transmits the torque of a motor to traction ropes. Traction ropes connect a car and a counter- weight. Passengers get on a car. A counter- weight is a weight to take balance with a car. An elevator operates according to the combination of these components. Safety of an elevator is secured by the movement of the braking devices in theemergency. The state transition of braking devices influences safety of an elevator. It is necessary to structure a simulator that can evaluate the influence of a state transition of a certain component on the whole system. Figure 1 shows the outline of this new simulator. The simulator is composed of a dynamic simulation model and a safety logic simulation model. The state transitions in the dynamic simulation model and the safety logic simulation model are described as state transition models. A state transition model is a simulation model that uses a state transition diagram. Figure 2 shows an outline of a state transition diagram. In a state transition diagram, there are state models that show different states, and conditions that change states are described in each state model. In ' the simulator, the components which show normal states and abnormal states of an elevator are described by using state transition models. For an example, a normal state of a brake is a state of standing by, and an abnormal state is a state of being operated. By coupling each state transition of a component, the influence that a continuous transition in each component gives to a whole system is appreciable. In Figure I, components A, B, and C, are components of an elevator. They are a traction machine, a car, ropes, sheaves, a governor, and so on. Equations of an elevator's motion are formed by coupling of the each component's motion. We modeled the dynamic characteristics for each component which show normal state and some abnormal state, and they form the conditions for the state transitions. The state of each component is changed when the state transition conditions are met. In the safety logic simulation model, we described safety devices as state transition models, too. We modeled each safety device which shows the state of watching an abnormal state and the operating state after an abnormal state is detected. The models of safety devices form the conditions for the state transitions. The transition conditions are set to correspond to the operation condition of each safety device. The models of safety devices output instructions to operate the braking devices, when the state of the safety devices changes. The next paragraph details the modeling of a dynamic simulation model and a safety logic simulation model for the elevator shown in Figure 3. An elevator is composed of a mechanical system and an electrical system. The dynamic simulation model of the mechanical system is composed of the dynamic characteristics of the ropes, and so on. The dynamic simulation model of the electrical system consists of the motor characteristics, and so on. Safety logic simulation model is composed of some safety algorisms.3. SIMULATION MODELA. Dynamic simulation model(1) Modeling of the mechanical system Figure 4 shows the dynamic model of an elevator's mechanical system in the normal state. Equations of the motions of each component, which show the normal state and abnormal states, can be changed according to the state transitions of each component. As a result, we can precisely simulate the continuous transitions of the mechanical system's dynamic characteristics. As a first example, we explain the modeling of the state transition of traction between the traction rope and the sheave. The structure shown in Figure 4 changes when slipping occurs between the traction rope and the sheave. The condition in which the rope doesn't slip can be expressed by equation (1): where Fs is frictional force between the sheave and the rope, is a coefficient of friction, B is the angle of the rope's wrap, T, and几are in the portion ofthe rope situated at the sheave, and I'is the either limit forces side of of the traction's ability. 3 When equation (1) doesn't hold, slipping occurs between the sheave and the rope. In turn, FS, which is shown in the next equation, occurs. FS influences the behavior of the car, so thedynamic characteristics of the rope are modeled to accurately evaluate the tension. In the simulator, slipping is observed by using equation (2), in which tension is derived by the expansion 1 en多h of the rope situated at either side of thesheave. When rope slipping does not occur, the model assumes that the rope moves in unison with the sheave. When rope slipping occurs, the model shows the rope and the sheave as separated, andthe frictional force mutually shown in equation(2) is put into effect. The slipping state's continuous transition is modeled by assuming the condition of the rope and the sheave immediately before rope slipping occurs, as with each initial condition of the rope and the sheave in the slipping model. The second example shows the modeling of the state transition when the traction rope is broken. The rope is modeled by connecting the spring characteristics and certain masses, as shown in Figure 5. Also, the broken rope is modeled using the lack of spring characteristics that connect the two masses. As an example, at the time the rope breaks, which is shown in Figure 5, the tack of these spring characteristics is embodied by switching the following equations of motions of m ; and m ,_,. Before the rope breaks In this simulator, the dynamical characteristics of braking devices, such as a safety gear and abrake, are also modeled. This means we can understand the influence of braking devicedelays and changes in the ability of braking devices according to time.(2) Modeling of the electrical system The drive circuit of the motor and the control circuit of the controller are illustrated on thesimulator in the circuit block chart. One safety device blocks current supply to the motor whenthe emergency stopping circuit is broken and the control of the motor stops as well. In this case,the state change is expressed in the simulator using block separation. Moreover, the abnormalstates of the motor and the controller are modeled in the simulation to be continuously switched. In the simulator, component of the electrical system is the state transition mechanical modeled by system of each and the using a state transition chart. Figure 6 shows an outline of this. B. Safety logic simulation model In this section, we explain the safety logic model of the "Smooth Emergency Terminal Slowdown (SETS)" system as an example. The SETS system is an electronic safety device applied for elevators. Applying electronic technology to the safety device for an elevator has become possible with the development of this technology in recent years. Because the current safety devices of elevators are built with mechanical devices, they are not able to unify a complex safety algorithm. However, such a complex safety algorithm can be achieved by applying electronic technology to the safety device of an elevator. As a result, various advantages can be gained in elevator design. However, the complexity of safety algorithm makes the evaluation of its validity difficult. We developed the SETS system to achieve space-saving in low-speed elevator. The SETS system, which detects the position and the speed of the car by using a sensor, and which uses aCPU to detect whether the over designated speed detection level has been exceeded, is a brandnew electronic safety device. Figure 7 shows three over- speed detection levels of an elevator equipped with the SETS system. A past, a conventional low-speed elevator which doesn't have the SETS system detectover-speed with a mechanical governor. A mechanical governor has' only two over-speeddetection levels which are Tripping Speed Level (Vtr) and Over-Speed Detection Level (Vos) asshown in Figure 7. These two over-speed detection levels are constant independently of the position of the car. Therefore, the speed of a car that runs into a buffer due to some abnormalities is not able to be reduced, and it is necessary to set up the buffer with a long stroke. However, the SETS system has an over-speed detection level that lowers as it approaches the terminals as shown in Figure 7. Therefore, the speed of a car with the SETS system that runs into the buffer due to some abnormalities is lower than the speed of a car without the SETS system. As a result, because we can set up a buffer with a short stroke, we can save the space of the elevator shaft. The position and the speed of a car are detected by using an encoder installed in agovernor. When over-speed is detected, the SETS system refuses the current input to themotor and stops the car by operating the brake. The modeling of the safety logic for the SETS system is illustrated in Figure 8. This is also described as a state transition model. In this model, the following steps are described.Step 1:Calculation of the speed and position of the car with the input from the encoder installed in the governor.Step 2: Calculation of the over-speed detection level using the position of the car.Step 3: Comparison between the speed of the car and the over-speed detection level. The state is B (usual continuous observation) if the over-speed detection level is higher than the car speed. However, the state changes to A (brake operation instruction) if the car speed is higher than the over-speed detection level.4. EXPERIMENTS We conducted experiment to confirm the validity of this simulator model. The result of the experiment was compared with the simulation result. In Figure 9, the distance is regularized bythe slowing-down length, and the speed is regularized by the rated speed. The simulation results show the values detected by the modeled governor encoder, in toward the bottom which the car accelerates of the shaft due to an abnormality; the SETS system detects the over-speed running, and the brake stops the traction machine. In the experiment, to make acomparison with the simulation, a car that had stopped was accelerated to the bottom floor because it was difficult to accelerate the car while it was running. In Figure 9, the simulation result corresponds quantitatively with the experimental result fromabnormal acceleration to the point of stopping. Thus, the simulator was able to simulate the logic of the SETS system and the state transition of the dynamic characteristics of the elevator according to the operation of the SETS system's logic.5. CONCLUSIONWe developed a simulator to simulate the effects of the safety logic operations. We obtained thefollowing conclusions simulation's result with by comparing the an experiment.(1)We confirmed that the simulator precisely expressed the dynamic characteristics which were translated continuously. Furthermore, we clarified that by the operation of the safety logic, the dynamic characteristics were changed.(2) We confirmed that the simulator was able to model the complex safety logic of an elevator by using the state transition chart.(3) We also confirmed the effectiveness of the simulator for quantitatively evaluating the effect of the safety system by the integration of the dynamic simulation model and the safety logic simulation model.REFERENCESProceedings Papers:1 Takahiro Masuda, Kouji Okada, Takenobu Honda, and Yoshiki Sugiyama, Vibration of Elevator Rope and C