How can individual mobility in urban areas be maintained alongside scooters and cargo bikes if conventional vehicles are foreseeably no longer allowed to enter city centers?And how can urban living be combined with in...How can individual mobility in urban areas be maintained alongside scooters and cargo bikes if conventional vehicles are foreseeably no longer allowed to enter city centers?And how can urban living be combined with individual mobility in a sustainable and socially acceptable way?LiMo-2040 attempts to provide answers to these questions.It follows a holistic approach according to the criteria:As light,as compact and as simple(cost-effective)as possible.Modular e-vehicle concepts(consisting of vehicle cabin and chassis)are known,but have not yet been thought through to their logical conclusion.The LiMo cabin is not only a vehicle cabin,but also a component of a modern high-rise apartment.It therefore requires no parking space and combines urban living and individual mobility sustainably and cost-effectively.If a vehicle is needed,an app can be used to book a chassis that comes along autonomously and waits until the cabin,including its occupants,travels down a sophisticated rail system,docks and autonomously heads for the desired destination.展开更多
With the growing global environmental awareness,the development of renewable and green materials has gained increased worldwide interest to substitute conventional materials and are favorable for sustainable economic ...With the growing global environmental awareness,the development of renewable and green materials has gained increased worldwide interest to substitute conventional materials and are favorable for sustainable economic development.This paper proposed a novel eco-friendly sound absorbing structure(NSAS)liner for noise reduction in elevator shafts.The base layer integrated with the shaft walls is a damping gypsum mortarboard,and a rock wool board and a perforated cement mortarboard are used to compose the NSAS.Based on the acoustic impedance theory of porous materials and perforated panels,the sound absorption theory of the NSAS was proposed;the parameter effects of the rock wool board(flow resistivity,porosity,structure factor)and perforated panel(perforated rates,thickness,density,perforated diameter)on NSAS absorption were discussed theoretically for absorption improvement,and experiments were also conducted.Numerical results showed that the perforation rate,the thickness of the perforated plate,and the porosity,flow resistance,and volume density of the rock wool board played a key issue in the absorption performances of the NSAS.Experiments verified the accuracy of the proposed theoretical model.Wideband sound absorption performance of the NSAS at frequencies between 500–1600 Hz was achieved in both numerical analysis and experiments,and the sound absorption coefficient was improved to 0.72 around 1000 Hz after parameter adjustments.The NSAS proposed in this paper can also be made of other renewable materials with preferable structure strength and still has the potential to broaden the absorption bandwidth.It can provide a reference for controlling the elevator shaft noise.展开更多
In this paper, an improved two-dimensional convolution neural network(2DCNN) is proposed to monitor and analyze elevator health, based on the distribution characteristics of elevator time series data in two-dimensiona...In this paper, an improved two-dimensional convolution neural network(2DCNN) is proposed to monitor and analyze elevator health, based on the distribution characteristics of elevator time series data in two-dimensional images. The current and effective power signals from an elevator traction machine are collected to generate gray-scale binary images. The improved two-dimensional convolution neural network is used to extract deep features from the images for classification, so as to recognize the elevator working conditions. Furthermore, the oscillation criterion is proposed to describe and analyze the active power oscillations. The current and active power are used to synchronously describe the working condition of the elevator, which can explain the co-occurrence state and potential relationship of elevator data. Based on the improved integration of local features of the time series, the recognition accuracy of the proposed 2DCNN is 97.78%, which is better than that of a one-dimensional convolution neural network. This research can improve the real-time monitoring and visual analysis performance of the elevator maintenance personnel, as well as improve their work efficiency.展开更多
Elevators are one of the most important elements of vertical communication used in buildings.Especially in recent times,where high and high rise buildings have become a modern architectural phenomenon and the spread o...Elevators are one of the most important elements of vertical communication used in buildings.Especially in recent times,where high and high rise buildings have become a modern architectural phenomenon and the spread of architecture has become a feature of the age.Hence,the research discusses the technique of installing elevators in buildings.A general introduction to elevators and their types will be discussed,as well as a historical overview of the beginning of the idea of the elevator and the first buildings that were used.The technique of installing the elevator inside the building explained with the images shown components elevator.Also it will mention several speeds of modern elevators used in buildings,the world’s fastest elevator,ultra-rope technology and the reasons for choosing this technique in elevator components in high-rise buildings which may be used in the space elevator that will connect earth and space.As well it shows features of the wire used in the elevators of the Burj-Khalifa,the highest skyscraper in the world.Then it mentions a number of the most recent and newest elevators in the world,then research results and references.展开更多
AIM: To describe the clinical features of congenital double elevator palsy(CDEP) and to evaluate various surgical outcomes between the standard Knapp and augmented Knapp procedures, based on improvements in primary ey...AIM: To describe the clinical features of congenital double elevator palsy(CDEP) and to evaluate various surgical outcomes between the standard Knapp and augmented Knapp procedures, based on improvements in primary eye position and ocular motility.METHODS: Twenty-two patients with CDEP at Shanghai Children's Hospital were enrolled from July 2014 to January 2018. The forced duction test(FDT) was negative in 21 patients, aged 8 mo to 12 y(mean 5.4 y). Patients were divided into two treatment groups: 16 patients underwent the standard Knapp procedure(group A), with or without horizontal squint procedure; and 5 patients underwent the augmented Knapp procedure(Foster procedure; group B). One patient underwent inferior rectus recession in the affected eye and superior rectus recession in the sound eye because of a positive FDT. The pre-and postoperative vertical deviations in the primary position and ocular motility were compared in the two groups.RESULTS: Twenty-one eyes of the 22 patients(95%) were aligned within 10 prism diopters(PD), and all patients(100%) reached ≥25% elevation improvement after surgery. The average corrected vertical deviation in group B was statistically better than that of group A. For group A, the vertical deviation in the primary position decreased from 24.75Δ±8.35Δ to 4.56Δ±8.07Δ after surgery, for an improvement of 23.06Δ±6.51Δ(P<0.05). In group B, the decrease was from 35.00Δ±5.00Δ(range 30Δ-40Δ) to 1.00Δ±2.24Δ, for an improvement of 34.00Δ±4.18Δ(P<0.05). There were significant differences between the pre-and postoperative elevation in each group(group A, P<0.05; group B, P<0.05). The average scale of improved elevation in group B(1.80±0.45) was not significantly better than that of group A(1.69±0.87; Z=-0.732, P=0.548). The average follow-up periods lasted 21 mo in group A and 18 mo in group B.CONCLUSION: For vertical deviations <30Δ, the standard Knapp procedure can be chosen. For deviations greater than 30Δ-40Δ, the Foster procedure should be chosen. Because of our early interference, the inferior rectus(IR) muscle did not show mechanical restriction. Monocular elevation deficiency(MED) should be diagnosed early so that complications will be reduced and the procedure will be easier for the surgeon.展开更多
To make elevator group control system better follow the change of elevator traffic flow (ETF) in order to adjust the control strategy,the prediction method of support vector machine (SVM) in combination with phase spa...To make elevator group control system better follow the change of elevator traffic flow (ETF) in order to adjust the control strategy,the prediction method of support vector machine (SVM) in combination with phase space reconstruction has been proposed for ETF.Firstly,the phase space reconstruction for elevator traffic flow time series (ETFTS) is processed.Secondly,the small data set method is applied to calculate the largest Lyapunov exponent to judge the chaotic property of ETF.Then prediction model of ETFTS based on SVM is founded.Finally,the method is applied to predict the time series for the incoming and outgoing passenger flow respectively using ETF data collected in some building.Meanwhile,it is compared with RBF neural network model.Simulation results show that the trend of factual traffic flow is better followed by predictive traffic flow.SVM algorithm has much better prediction performance.The fitting and prediction of ETF with better effect are realized.展开更多
In order to discover the main causes of elevator group accidents in edge computing environment, a multi-dimensional data model of elevator accident data is established by using data cube technology, proposing and impl...In order to discover the main causes of elevator group accidents in edge computing environment, a multi-dimensional data model of elevator accident data is established by using data cube technology, proposing and implementing a method by combining classical Apriori algorithm with the model, digging out frequent items of elevator accident data to explore the main reasons for the occurrence of elevator accidents. In addition, a collaborative edge model of elevator accidents is set to achieve data sharing, making it possible to check the detail of each cause to confirm the causes of elevator accidents. Lastly the association rules are applied to find the law of elevator Accidents.展开更多
In this research, the vibration of elevator ropes, including the main rope and compensation rope are investigated simultaneously in a high-rise elevator system under earthquake excitation. Moreover, the paper presents...In this research, the vibration of elevator ropes, including the main rope and compensation rope are investigated simultaneously in a high-rise elevator system under earthquake excitation. Moreover, the paper presents a new control method to restrain the sway of both ropes. This study considers varying rope lengths during elevator operation which cause other system parameters such as natural frequency, and damping ratio to be time-variant variables. The dynamics of the ropes are analyzed by solving the governing non-stationary, nonlinear equation numerically. In order to mitigate the vibration of ropes in several motion conditions, particularly upwards movement, downward movement, stopped at the lowest position, and stopped at the highest position, an active equipment is installed at the compensation sheave. The stability of the system using the controller is analyzed at four states: without disturbance and static car, without disturbance and mobile car, including disturbance and static car, and including disturbance and mobile car. The efficiency of the controller used for dampening the vibration of elevator ropes is validated by numerical simulation results.展开更多
In this paper, three different controllers are proposed and simulated for maglev guiding systems to have convenient and smooth elevator motion. The proposed controllers are PID, sliding mode, and PID sliding mode cont...In this paper, three different controllers are proposed and simulated for maglev guiding systems to have convenient and smooth elevator motion. The proposed controllers are PID, sliding mode, and PID sliding mode controllers. The advantages and disadvantages of the proposed controllers are discussed. Although, PID controller is fast, its response affected considerably by external disturbances. Unlike PID, the sliding mode controller is so robust, but its transient is unsuitable based on application conditions. However, an acceptable controller for ropeless elevator guiding system should guaranty the passengers safety and convenient. Consequently, the response of the system should be fast, robust, and without considerable overshoots and oscillations. These required advantages are compromised in the proposed parallel PID sliding mode controller. The affectivity of the introduced controllers for maglev guiding system is investigated through conducted simulations in MATLAB/Simulink environment. The obtained results illustrate that PID sliding mode controller is a so fast and robust controller for a ropeless elevator maglev guiding system.展开更多
In order to get a globally optimized solution for the Elevator Group Control System (EGCS) scheduling problem, an algorithm with an overall optimization function is needed. In this study, Real-time Particle Swarm Opti...In order to get a globally optimized solution for the Elevator Group Control System (EGCS) scheduling problem, an algorithm with an overall optimization function is needed. In this study, Real-time Particle Swarm Optimization (RPSO) is proposed to find an optimal solution to the EGCS scheduling problem. Different traffic patterns and controller mechanisms for EGCS are analyzed. This study focuses on up-peak traffic because of its critical importance to modern office buildings. Simulation results show that EGCS based on Multi-Agent Systems (MAS) using RPSO gives good results for up-peak EGCS scheduling problem. Besides, the elevator real-time scheduling and reallocation functions are realized based on RPSO in case new information is available or the elevator becomes busy because it is unavailable or full. This study contributes a new scheduling algorithm for EGCS, and expands the application of PSO.展开更多
The present work proposes a methodological approach for modeling decisions regarding energy reduction in an elevator. This is achieved with the integration of existing as well as acquired knowledge, in a decision modu...The present work proposes a methodological approach for modeling decisions regarding energy reduction in an elevator. This is achieved with the integration of existing as well as acquired knowledge, in a decision module implemented in the electronics of an elevator. So far, elevators do not exploit information regarding their recent usage. In the developed system decisions are driven based on information arising from monitoring the use of the elevator. Monitoring provides various records of usage which consequently are used to predict elevator’s future usage and to adapt accordingly its functioning. Till now, there are only elevators that encompass in their electronics algorithms with if then rules in order to control elevator’s functioning. However, these if then rules are based only on good practice knowledge of similar elevators installed in similar buildings. Even this knowledge which unavoidably is associated with uncertainty is not encoded in a mathematically consisted way in the algorithms. The design, the implementation and a first pilot evaluation study of an elevator’s intelligent decision module are presented. The study concludes that the presented application sufficiently reduces energy consumption through properly controlled functioning.展开更多
In the thunderstorm process on August 3,2016,among the nine elevators in a housing estate in the middle of Neijiang City,six elevators were damaged by lightning. In this study,the impact of lightning stroke on elevato...In the thunderstorm process on August 3,2016,among the nine elevators in a housing estate in the middle of Neijiang City,six elevators were damaged by lightning. In this study,the impact of lightning stroke on elevators was analyzed firstly,and then measures to protect elevators against lightning were proposed,which provides a practical basis for the improvement of protection of elevators against lightning.展开更多
This project involves modeling a water elevator in order to study its behavior and relate its mechanical advantages to various fluid mechanics properties. The reason that this small scale water elevator was constructe...This project involves modeling a water elevator in order to study its behavior and relate its mechanical advantages to various fluid mechanics properties. The reason that this small scale water elevator was constructed was to get a better understanding of such real world applications. As developing engineers, students have to grasp how to implement the theory they learn in the classroom. The properties of the water elevator were described with the energy equation, conservation of mass, volumetric flow rate, and hydrostatic pressure. After conducting various tests, theoretical and experimental values were compared and an analysis of the data was assembled allowing for the development of a more thorough understanding of fluid mechanics.展开更多
It is difficult to imagine that many of the modern buildings in China adopt elevators produced by the Tianjin Otis Elevator Co., Ltd.——one of the 500 largest foreign-funded enterprises nationwide and ranking 27th am...It is difficult to imagine that many of the modern buildings in China adopt elevators produced by the Tianjin Otis Elevator Co., Ltd.——one of the 500 largest foreign-funded enterprises nationwide and ranking 27th among the 100 largest machinery enterprises. It is also the largest foreign-funded enterprise in Tianjin. Founded in February 1984,展开更多
Generally speaking,there are two reasons for elevator operation resonance to occur.One is because the quality of the hardware facilities is not up to standard,resulting in a mismatch between the operations of the vari...Generally speaking,there are two reasons for elevator operation resonance to occur.One is because the quality of the hardware facilities is not up to standard,resulting in a mismatch between the operations of the various components in the elevator operation;the other is caused by irregular installation,use and maintenance of the elevator.The installation of each component between the elevators should cooperate with each other to perfectly cooperate to complete the operation of the elevator.If not,there will be big problems.While using the elevator to replace the traditional ladder,we must also understand the cause of the elevator operation resonance,and study the corresponding countermeasures to reduce the accident caused by the elevator operation resonance.展开更多
In order to solve the best maintenance interval problem of the elevator hydraulic actuation systems on civil aircraft, a method based on reliability and cost minimum is introduced in this paper. The estimation of syst...In order to solve the best maintenance interval problem of the elevator hydraulic actuation systems on civil aircraft, a method based on reliability and cost minimum is introduced in this paper. The estimation of system reliability is presented by using two-parameter Weibull distributions. The parameters are estimated by using Weibull probability statistical analysis and the practical operational data. Then, the maintenance optimization model isformulated where the objective function is to minimize the expected schedule maintenance cost in a time unit. The results of numerical example show that the proposed model could scheme the optimal maintenance intervals for the considered system when the parameters are given. This research has certain significance in theoryand engineering practice.展开更多
Pressure guide plate plays a certain role in the safe operation of elevator.Based on understanding the respective performance of new and old pressure guide plates,this paper analyses the problems existing in the origi...Pressure guide plate plays a certain role in the safe operation of elevator.Based on understanding the respective performance of new and old pressure guide plates,this paper analyses the problems existing in the original pressure guide plate.It also conducts stress analysis according to the function of pressure guide plate on elevator,and designs a new type of pressure guide plate combined with technological capability and equipment.According to the stress characteristics,a test device is designed and a comparative test is made between the new type of pressure guide plate and the old in order to test the reliability of the new type of pressure guide plate.The test proves that the new pressure guide plate of elevator can meet the requirements of product use and safe operation of elevator products.展开更多
Nowadays, the elevator has become an indispensable means of indoor transportation in people’s life, but in recent years this kind of traffic tools has caused many casualties because of the gate system fault. In order...Nowadays, the elevator has become an indispensable means of indoor transportation in people’s life, but in recent years this kind of traffic tools has caused many casualties because of the gate system fault. In order to ensure the safe and reliable operation of the elevator, the failure of elevator door system was predicted in this paper. Against the fault type of elevator door system: elevator door opened, excessive vibration when elevator door opened or closed, elevator door did not open or closed when reached the specified level. Three fault types were used as the output of the prediction model. There were 8 reasons for the failure, used them as input. A model based on particle swarm optimization (PSO) and BP neural network was established, using MATLAB to emulation;the results showed that: PSO-BP neural network algorithm was feasible in the fault prediction of the elevator door system.展开更多
The metrics of gravitational and cosmological models are brought into canonical form in comoving coordinates. The FWR curvature parameter k is read from this and it is shown that k=0 does not correlate to a flat model...The metrics of gravitational and cosmological models are brought into canonical form in comoving coordinates. The FWR curvature parameter k is read from this and it is shown that k=0 does not correlate to a flat model, but for a spatially positively curved geometry in which reference systems which are in free fall exist. This also corresponds to Einstein’s elevator principle. Moreover, we will show that our subluminal cosmos is associated with the R<sub>h</sub>=ct model of Melia, assuming that k=0 is related to a free-falling system in the sense described above.展开更多
文摘How can individual mobility in urban areas be maintained alongside scooters and cargo bikes if conventional vehicles are foreseeably no longer allowed to enter city centers?And how can urban living be combined with individual mobility in a sustainable and socially acceptable way?LiMo-2040 attempts to provide answers to these questions.It follows a holistic approach according to the criteria:As light,as compact and as simple(cost-effective)as possible.Modular e-vehicle concepts(consisting of vehicle cabin and chassis)are known,but have not yet been thought through to their logical conclusion.The LiMo cabin is not only a vehicle cabin,but also a component of a modern high-rise apartment.It therefore requires no parking space and combines urban living and individual mobility sustainably and cost-effectively.If a vehicle is needed,an app can be used to book a chassis that comes along autonomously and waits until the cabin,including its occupants,travels down a sophisticated rail system,docks and autonomously heads for the desired destination.
基金supported by Opening Foundation of Key Laboratory of New Technology for Construction of Cities in Mountain Area,Ministry of Education,China(LNTCCMA-20210104)This work was also supported by the Natural Science Foundation of China(Grant No.51408113)the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20140632).
文摘With the growing global environmental awareness,the development of renewable and green materials has gained increased worldwide interest to substitute conventional materials and are favorable for sustainable economic development.This paper proposed a novel eco-friendly sound absorbing structure(NSAS)liner for noise reduction in elevator shafts.The base layer integrated with the shaft walls is a damping gypsum mortarboard,and a rock wool board and a perforated cement mortarboard are used to compose the NSAS.Based on the acoustic impedance theory of porous materials and perforated panels,the sound absorption theory of the NSAS was proposed;the parameter effects of the rock wool board(flow resistivity,porosity,structure factor)and perforated panel(perforated rates,thickness,density,perforated diameter)on NSAS absorption were discussed theoretically for absorption improvement,and experiments were also conducted.Numerical results showed that the perforation rate,the thickness of the perforated plate,and the porosity,flow resistance,and volume density of the rock wool board played a key issue in the absorption performances of the NSAS.Experiments verified the accuracy of the proposed theoretical model.Wideband sound absorption performance of the NSAS at frequencies between 500–1600 Hz was achieved in both numerical analysis and experiments,and the sound absorption coefficient was improved to 0.72 around 1000 Hz after parameter adjustments.The NSAS proposed in this paper can also be made of other renewable materials with preferable structure strength and still has the potential to broaden the absorption bandwidth.It can provide a reference for controlling the elevator shaft noise.
基金Sponsored by the National Natural Science Foundation of China (Grant No.61771223)the Key Research and Development Program of Jiangsu Province(Grant No.SBE2018334)。
文摘In this paper, an improved two-dimensional convolution neural network(2DCNN) is proposed to monitor and analyze elevator health, based on the distribution characteristics of elevator time series data in two-dimensional images. The current and effective power signals from an elevator traction machine are collected to generate gray-scale binary images. The improved two-dimensional convolution neural network is used to extract deep features from the images for classification, so as to recognize the elevator working conditions. Furthermore, the oscillation criterion is proposed to describe and analyze the active power oscillations. The current and active power are used to synchronously describe the working condition of the elevator, which can explain the co-occurrence state and potential relationship of elevator data. Based on the improved integration of local features of the time series, the recognition accuracy of the proposed 2DCNN is 97.78%, which is better than that of a one-dimensional convolution neural network. This research can improve the real-time monitoring and visual analysis performance of the elevator maintenance personnel, as well as improve their work efficiency.
文摘Elevators are one of the most important elements of vertical communication used in buildings.Especially in recent times,where high and high rise buildings have become a modern architectural phenomenon and the spread of architecture has become a feature of the age.Hence,the research discusses the technique of installing elevators in buildings.A general introduction to elevators and their types will be discussed,as well as a historical overview of the beginning of the idea of the elevator and the first buildings that were used.The technique of installing the elevator inside the building explained with the images shown components elevator.Also it will mention several speeds of modern elevators used in buildings,the world’s fastest elevator,ultra-rope technology and the reasons for choosing this technique in elevator components in high-rise buildings which may be used in the space elevator that will connect earth and space.As well it shows features of the wire used in the elevators of the Burj-Khalifa,the highest skyscraper in the world.Then it mentions a number of the most recent and newest elevators in the world,then research results and references.
文摘AIM: To describe the clinical features of congenital double elevator palsy(CDEP) and to evaluate various surgical outcomes between the standard Knapp and augmented Knapp procedures, based on improvements in primary eye position and ocular motility.METHODS: Twenty-two patients with CDEP at Shanghai Children's Hospital were enrolled from July 2014 to January 2018. The forced duction test(FDT) was negative in 21 patients, aged 8 mo to 12 y(mean 5.4 y). Patients were divided into two treatment groups: 16 patients underwent the standard Knapp procedure(group A), with or without horizontal squint procedure; and 5 patients underwent the augmented Knapp procedure(Foster procedure; group B). One patient underwent inferior rectus recession in the affected eye and superior rectus recession in the sound eye because of a positive FDT. The pre-and postoperative vertical deviations in the primary position and ocular motility were compared in the two groups.RESULTS: Twenty-one eyes of the 22 patients(95%) were aligned within 10 prism diopters(PD), and all patients(100%) reached ≥25% elevation improvement after surgery. The average corrected vertical deviation in group B was statistically better than that of group A. For group A, the vertical deviation in the primary position decreased from 24.75Δ±8.35Δ to 4.56Δ±8.07Δ after surgery, for an improvement of 23.06Δ±6.51Δ(P<0.05). In group B, the decrease was from 35.00Δ±5.00Δ(range 30Δ-40Δ) to 1.00Δ±2.24Δ, for an improvement of 34.00Δ±4.18Δ(P<0.05). There were significant differences between the pre-and postoperative elevation in each group(group A, P<0.05; group B, P<0.05). The average scale of improved elevation in group B(1.80±0.45) was not significantly better than that of group A(1.69±0.87; Z=-0.732, P=0.548). The average follow-up periods lasted 21 mo in group A and 18 mo in group B.CONCLUSION: For vertical deviations <30Δ, the standard Knapp procedure can be chosen. For deviations greater than 30Δ-40Δ, the Foster procedure should be chosen. Because of our early interference, the inferior rectus(IR) muscle did not show mechanical restriction. Monocular elevation deficiency(MED) should be diagnosed early so that complications will be reduced and the procedure will be easier for the surgeon.
基金Sponsored by the National Eleventh Five year Plan Key Project of Ministry of Science and Technology of China (Grant No. 2006BAJ03A05-05)
文摘To make elevator group control system better follow the change of elevator traffic flow (ETF) in order to adjust the control strategy,the prediction method of support vector machine (SVM) in combination with phase space reconstruction has been proposed for ETF.Firstly,the phase space reconstruction for elevator traffic flow time series (ETFTS) is processed.Secondly,the small data set method is applied to calculate the largest Lyapunov exponent to judge the chaotic property of ETF.Then prediction model of ETFTS based on SVM is founded.Finally,the method is applied to predict the time series for the incoming and outgoing passenger flow respectively using ETF data collected in some building.Meanwhile,it is compared with RBF neural network model.Simulation results show that the trend of factual traffic flow is better followed by predictive traffic flow.SVM algorithm has much better prediction performance.The fitting and prediction of ETF with better effect are realized.
文摘In order to discover the main causes of elevator group accidents in edge computing environment, a multi-dimensional data model of elevator accident data is established by using data cube technology, proposing and implementing a method by combining classical Apriori algorithm with the model, digging out frequent items of elevator accident data to explore the main reasons for the occurrence of elevator accidents. In addition, a collaborative edge model of elevator accidents is set to achieve data sharing, making it possible to check the detail of each cause to confirm the causes of elevator accidents. Lastly the association rules are applied to find the law of elevator Accidents.
文摘In this research, the vibration of elevator ropes, including the main rope and compensation rope are investigated simultaneously in a high-rise elevator system under earthquake excitation. Moreover, the paper presents a new control method to restrain the sway of both ropes. This study considers varying rope lengths during elevator operation which cause other system parameters such as natural frequency, and damping ratio to be time-variant variables. The dynamics of the ropes are analyzed by solving the governing non-stationary, nonlinear equation numerically. In order to mitigate the vibration of ropes in several motion conditions, particularly upwards movement, downward movement, stopped at the lowest position, and stopped at the highest position, an active equipment is installed at the compensation sheave. The stability of the system using the controller is analyzed at four states: without disturbance and static car, without disturbance and mobile car, including disturbance and static car, and including disturbance and mobile car. The efficiency of the controller used for dampening the vibration of elevator ropes is validated by numerical simulation results.
文摘In this paper, three different controllers are proposed and simulated for maglev guiding systems to have convenient and smooth elevator motion. The proposed controllers are PID, sliding mode, and PID sliding mode controllers. The advantages and disadvantages of the proposed controllers are discussed. Although, PID controller is fast, its response affected considerably by external disturbances. Unlike PID, the sliding mode controller is so robust, but its transient is unsuitable based on application conditions. However, an acceptable controller for ropeless elevator guiding system should guaranty the passengers safety and convenient. Consequently, the response of the system should be fast, robust, and without considerable overshoots and oscillations. These required advantages are compromised in the proposed parallel PID sliding mode controller. The affectivity of the introduced controllers for maglev guiding system is investigated through conducted simulations in MATLAB/Simulink environment. The obtained results illustrate that PID sliding mode controller is a so fast and robust controller for a ropeless elevator maglev guiding system.
文摘In order to get a globally optimized solution for the Elevator Group Control System (EGCS) scheduling problem, an algorithm with an overall optimization function is needed. In this study, Real-time Particle Swarm Optimization (RPSO) is proposed to find an optimal solution to the EGCS scheduling problem. Different traffic patterns and controller mechanisms for EGCS are analyzed. This study focuses on up-peak traffic because of its critical importance to modern office buildings. Simulation results show that EGCS based on Multi-Agent Systems (MAS) using RPSO gives good results for up-peak EGCS scheduling problem. Besides, the elevator real-time scheduling and reallocation functions are realized based on RPSO in case new information is available or the elevator becomes busy because it is unavailable or full. This study contributes a new scheduling algorithm for EGCS, and expands the application of PSO.
文摘The present work proposes a methodological approach for modeling decisions regarding energy reduction in an elevator. This is achieved with the integration of existing as well as acquired knowledge, in a decision module implemented in the electronics of an elevator. So far, elevators do not exploit information regarding their recent usage. In the developed system decisions are driven based on information arising from monitoring the use of the elevator. Monitoring provides various records of usage which consequently are used to predict elevator’s future usage and to adapt accordingly its functioning. Till now, there are only elevators that encompass in their electronics algorithms with if then rules in order to control elevator’s functioning. However, these if then rules are based only on good practice knowledge of similar elevators installed in similar buildings. Even this knowledge which unavoidably is associated with uncertainty is not encoded in a mathematically consisted way in the algorithms. The design, the implementation and a first pilot evaluation study of an elevator’s intelligent decision module are presented. The study concludes that the presented application sufficiently reduces energy consumption through properly controlled functioning.
文摘In the thunderstorm process on August 3,2016,among the nine elevators in a housing estate in the middle of Neijiang City,six elevators were damaged by lightning. In this study,the impact of lightning stroke on elevators was analyzed firstly,and then measures to protect elevators against lightning were proposed,which provides a practical basis for the improvement of protection of elevators against lightning.
文摘This project involves modeling a water elevator in order to study its behavior and relate its mechanical advantages to various fluid mechanics properties. The reason that this small scale water elevator was constructed was to get a better understanding of such real world applications. As developing engineers, students have to grasp how to implement the theory they learn in the classroom. The properties of the water elevator were described with the energy equation, conservation of mass, volumetric flow rate, and hydrostatic pressure. After conducting various tests, theoretical and experimental values were compared and an analysis of the data was assembled allowing for the development of a more thorough understanding of fluid mechanics.
文摘It is difficult to imagine that many of the modern buildings in China adopt elevators produced by the Tianjin Otis Elevator Co., Ltd.——one of the 500 largest foreign-funded enterprises nationwide and ranking 27th among the 100 largest machinery enterprises. It is also the largest foreign-funded enterprise in Tianjin. Founded in February 1984,
文摘Generally speaking,there are two reasons for elevator operation resonance to occur.One is because the quality of the hardware facilities is not up to standard,resulting in a mismatch between the operations of the various components in the elevator operation;the other is caused by irregular installation,use and maintenance of the elevator.The installation of each component between the elevators should cooperate with each other to perfectly cooperate to complete the operation of the elevator.If not,there will be big problems.While using the elevator to replace the traditional ladder,we must also understand the cause of the elevator operation resonance,and study the corresponding countermeasures to reduce the accident caused by the elevator operation resonance.
文摘In order to solve the best maintenance interval problem of the elevator hydraulic actuation systems on civil aircraft, a method based on reliability and cost minimum is introduced in this paper. The estimation of system reliability is presented by using two-parameter Weibull distributions. The parameters are estimated by using Weibull probability statistical analysis and the practical operational data. Then, the maintenance optimization model isformulated where the objective function is to minimize the expected schedule maintenance cost in a time unit. The results of numerical example show that the proposed model could scheme the optimal maintenance intervals for the considered system when the parameters are given. This research has certain significance in theoryand engineering practice.
文摘Pressure guide plate plays a certain role in the safe operation of elevator.Based on understanding the respective performance of new and old pressure guide plates,this paper analyses the problems existing in the original pressure guide plate.It also conducts stress analysis according to the function of pressure guide plate on elevator,and designs a new type of pressure guide plate combined with technological capability and equipment.According to the stress characteristics,a test device is designed and a comparative test is made between the new type of pressure guide plate and the old in order to test the reliability of the new type of pressure guide plate.The test proves that the new pressure guide plate of elevator can meet the requirements of product use and safe operation of elevator products.
文摘Nowadays, the elevator has become an indispensable means of indoor transportation in people’s life, but in recent years this kind of traffic tools has caused many casualties because of the gate system fault. In order to ensure the safe and reliable operation of the elevator, the failure of elevator door system was predicted in this paper. Against the fault type of elevator door system: elevator door opened, excessive vibration when elevator door opened or closed, elevator door did not open or closed when reached the specified level. Three fault types were used as the output of the prediction model. There were 8 reasons for the failure, used them as input. A model based on particle swarm optimization (PSO) and BP neural network was established, using MATLAB to emulation;the results showed that: PSO-BP neural network algorithm was feasible in the fault prediction of the elevator door system.
文摘The metrics of gravitational and cosmological models are brought into canonical form in comoving coordinates. The FWR curvature parameter k is read from this and it is shown that k=0 does not correlate to a flat model, but for a spatially positively curved geometry in which reference systems which are in free fall exist. This also corresponds to Einstein’s elevator principle. Moreover, we will show that our subluminal cosmos is associated with the R<sub>h</sub>=ct model of Melia, assuming that k=0 is related to a free-falling system in the sense described above.