DETERMINING THE NUMBER OF SIMULATIONS REQUIRED FOR STATISTICALLY VALID RESULTS
Maria Abbi, Richard Peters
Peters Research Ltd, UK
Lift simulations use a random number generator to create a list of passengers based on anticipated passenger demand. Depending on the random number seed, different lists of passengers and resulting lift journeys will occur. Each random number seed scenario yields a different simulation run with different results. An infinite number of runs would yield results including a mean average waiting time and standard deviation which would be fully representative of the data. But only a finite number of runs can be completed as there are practical limitations on time and processing resources. How many runs need to be completed until the mean average waiting time can be said to be statistically valid? Different approaches to assessing the number of runs required for statistically valid results are proposed and discussed. The preferred approach allows the user to specify the required confidence level and acceptable margin of error. The method can be applied to both dispatcher based and Monte Carlo simulation.
USING THE MONTE CARLO SIMULATION TO EVALUATE THE ROUND-TRIP TIME UNDER DESTINATION CONTROL
Lutfi Al-Sharif1, Richard Peters2
1The University of Jordan, Jordan. 2Peters Research Ltd, UK.
Lift traffic calculations for planning purposes typically use formulae, or simulation software which applies a traffic control system to dispatch lifts. Formulae methods rely on simplifying the modelling exercise so that the operation of the lifts can be described in mathematical equations. These equations are transparent and repeatable. Simulation is more sophisticated but relies on many advanced dispatching and other complex decisions which are hidden from the user. This can be controversial when results from different simulation software are compared. In this paper the authors demonstrate how Monte Carlo Simulation can be used to evaluate destination control (also known as hall call allocation) for any traffic mix (incoming, outgoing, interfloor). The technique requires less simplifications than formulae-based methods. It does not require a dispatcher, making it a supplier independent way to evaluate the application of this form of traffic control.
ESCALATOR WEIGHTLESS WEIGHT TESTING: A CASE STUDY FROM A UK METRO
The University of Jordan, Jordan.
The escalator braking system is the most critical safety component. It is thus necessary to ensure that brakes are tested at regular interval to ensure passenger safety. Carrying out this test using weights is a very complex, risky and expensive procedure, and thus cannot be carried out regularly. For this reason, a model for weightless weight testing has been develop. This paper describes the work carried out by the author in setting up a weightless weight testing at the Tyne & Wear Metro in the United Kingdom.
The first step was to gather escalator type test data on the four models of escalator that the Metro had.
In the second step, the data from the weight tests was used to build a theoretical mathematical model in MS Excel for the different types of escalators. The model allowed the operator to understand the range of acceptable deceleration values that indicate operational brakes.
In the third step, all the remaining 28 escalators (out of the full fleet of 32 escalators) were tested and adjusted without the use of weights. They were adjusted in accordance with the outputs of the theoretical model. In the fourth and last test, a training manual was developed for the testing and adjusting the braking systems. On-site training was carried out for the maintenance staff.
THE HISTORY OF THE HUMAN LIFT TRAFFIC DESIGN EXPERT
Gina Barney1, Richard Peters2
1Gina Barney Associates, UK. 2Peters Research Ltd, UK.
The (human) lift traffic expert solves a number of equations (a mathematical model) to select a suitable lift installation to meet certain design criteria. The expert often then has to adjudicate between several possible designs. This requires a great deal of experience and perspicacity. Many lay people (architects, developers, facility managers, general M&E consultants) and also some lift industry personnel (sales engineers, support staff) desire a simple and quick method of selection.
Over the years there have been many attempts to provide look up tables and charts for a quick selection. This paper describes these early attempts from the 1960s onwards to the present time. The mathematical models are explained, and the design process is described. A demonstration of the design process using a simple spreadsheet will be presented illustrating the expert decision-making process.
EXPERT SYSTEMS FOR LIFT TRAFFIC DESIGN
Gina Barney1, Richard Peters2 and Sam Dean2
1Gina Barney Associates, UK. 2Peters Research Ltd, UK.
An expert system is software that emulates the decision-making ability of a human expert.
Although software tools are available that automatically select a likely lift system, these designs should always be checked by an expert.
This paper thus poses the question "What is required in order to develop a truly expert system for lift traffic design that encapsulates a sufficient expertise for a well thought out and robust design?" The paper explores the synthesizing of the sufficient expertise of a lift traffic analysis expert and the implementation of this expertise into software.
The knowledge base required, the design processes followed, and the subtleties applied when the human expert considers borderline cases are explored. The resulting "expert engine" can used to produce software tools, or quick selection graphs and tables, based on the embodied expertise of the human expert, in order to answer specific traffic design questions within specified boundaries.
TRAFFIC ANALYSIS – A DIFFERENT PERSPECTIVE
John Bentley, LECS
Are averages the best way to represent traffic studies – some people only have two friends and one of them is under average!
People will have spent 10 minutes in a well-known coffee house waiting for an under average flat white yet will ping their building manager an e mail when they had to wait 35 seconds for a lift to arrive.
The industry now designs lift systems in buildings around what would happen if one or more of the lifts in a group were out of service. Is reliability not the key rather than acceptance that a new lift might break down?
Is waiting just a part of life?
LIFT REMOTE CONNECTIVITY
Canary Wharf Contractors Ltd, UK.
This paper addresses the key elements that are required to enable a phone or data user to have continuous uninterrupted service when using the building lifts. There are a number of challenges which need to be considered and overcome to achieve this goal. Technologies considered include the application of (a) a leaky feeder; (b) a trailing flex with suitable characteristics. Consideration of equipment location needs to take into account maintenance requirements. The application of lift codes and possible requirements for Notified Body approval are discussed. A trial project involving double deck lifts will be reviewed, showing solutions to each of the challenges, and assessing if success criteria have been achieved. Successful application of these technologies enabling continuous service for lift users has global potential and could be considered an important next step in services being provided by the lift industry.
HOW MANY BREAKDOWNS ARE ACCEPTABLE?
LECS UK Ltd, University of Northampton, UK.
The number of acceptable breakdowns that a lift may experience is an emotive subject.
There appears to be only one published record that says that four breakdowns per annum are acceptable before an interest should be taken into the reasons why.
The owner of the lift may also have a different view of the acceptable number of breakdowns compared to the contactor.
There are a number of variables that have an input into the number of breakdowns that actually occur – age of equipment, external influences (power cuts etc.), type of equipment compared to environment, type of occupant, skills level of maintenance operative, type of maintenance contract, number of landing doors being a few.
The question is…. can an acceptable number of breakdowns be agreed upon subject to the equipment being the right type for the right environment?
LIFTING ELEVATORS INTO THE CLOUD – PERMANENT DETECTION OF WEAR USING INTELLIGENT SENSORS
Henning GmbH & Co. KG, Germany.
Condition Monitoring Systems for elevators going beyond a mere display of stored faults or counter readings are hard to find on the lift market. Yet, only a few sensors already allow the monitoring of significant components of a lift system to ensure that wear is detected at an early stage and appropriate servicing recommendations are automatically generated. As such, a predictive maintenance of elevators is possible, which saves a lot of resources and time and nevertheless warrants a high availability of the lift system. Especially for retrofitting of existing elevators an intelligent device is needed, which doesn't need communication to the lift controller. Within the context of a field trial, several lift systems worldwide have been equipped with an IoT-device (Internet of Things) which evaluates every single elevator ride using intelligent algorithms permitting the wear of individual component groups to be detected. The collected data, resulting messages and alerts are transmitted automatically via the internet by a standard protocol into a cloud, where extended big data analysis is done. The concept and also the experience with such a device shall be presented in this paper.
OPTIMIZATION OF A LEARNING AND TRAINING PORTFOLIO AT A MULTI-NATIONAL LIFT MANUFACTURER
Thomas Ehrl1, Stefan Kaczmarczyk2, Jonathan Adams2
1thyssenKrupp Elevator AG, Germany. 2University of Northampton, UK.
Learning is a lifelong process. The seed campus, a learning organization with hubs and satellites in each region of the business, is the sole learning provider at the multinational Lift Manufacturer for business-specific and business-adopted training globally. However, due to different histories of each core hub (Asia Pacific, Europe and North America), the learning offerings differ from region to region. On the other hand, the Education Technology is evolving with a dramatic pace, which requires an agile design approach for training programs and courses. The paper looks into the current state of the lift engineering training portfolio and investigates, whether
• the seed campus portfolio (e.g. GETpro) meets the latest engineering/technology/manufacturing/installation standards,
• the portfolio structure and individual programs meet latest adult education principles, and
• portfolio components (course design and teaching methodology) meet the standards of Adult Education.
The paper examines the fundamental pedagogic design principles as well as the latest lift engineering requirements and technology trends to develop relevant and up-to-date Adult Learning strategies. The paper concludes with recommendation to improve the seed campus portfolio catalogue to ensure that the current expectations from the internal user group and the business are met.
NEW WAYS TO APPROACH EMC IN LIFT INDUSTRY. CASE OF ITER PROJECT
MAC PUAR S.A. (MP Lifts), Spain.
Over the years, designs have been developed considering the requirements of Electromagnetic Compatibility (EMC) for lifts, following the EN 12015 & EN 12016 standards, to achieve and increase quality and reliability. To achieve this, EMC requirements are considered from the first steps of the design, other requirements are established when testing in a laboratory and then collaborations have been carried out with partners to achieve the EMC compliance of the complete electrical installation.
A new challenge in EMC currently being worked on is designing lifts for a singular installation: the ITER project. This facility requires special actions to meet such unique requirements as the project is, especially in terms of magnetic fields. The project involves not only a challenge for designing, but also for the companies who cooperate in tests and simulations as they must manufacture ad hoc instrumentation, thus innovating in the process to perform the tests.
INVESTIGATIONS ON SAFETY MEASURES FOR LIFTS AND ESCALATORS; OUTCOMES FROM THE RESEARCHES FUNDED BY THE BUILDING STANDARD DEVELOPMENT PROMOTION PROGRAM
Satoshi Fujita1, Motoo Shimoaki2
1Tokyo Denki University, Japan. 2Japan Elevator Association, Japan
The devastating earthquake of Mw9.0 hit the Tohoku district, northeast part of Japan on March 11, 2011. About 16,000 people died and 3,000 people declared missing because of the strong motion and tsunami. The economic damage was estimated about 16.9 trillion yen excluding the influence of the Fukushima Daiichi Nuclear Power Plant nuclear accident. In addition to the main shock, many strong aftershocks occurred in the long term until June in 2011. The industrial facilities, power plants, and research facilities were damaged in these earthquakes, and various kinds of mechanical equipment set in these facilities were damaged.
During this earthquake, four fall-off accidents of escalators used in three steel framed shopping mall buildings, occurred. One of the main causes of escalators falling is due to the lack of sliding margin of the non-fixed joints between the escalator-truss and the supporting beam mounted on the building horizontal frame due to the unexpected excessive storey-deflexion of the building structures caused by the earthquake. The other causes are thought to be the escalator-truss structures colliding with the supporting beam, as described above, in the non-fixed end and the compression force induced during collision maybe giving elasto-plastic deformation and residual displacement to the escalator as a result. In this case, the escalator might not only lose the vertical load supporting ability but also the shortening of the length of the truss might cause a reduction in the sliding margin.
For the existing escalators, the fall-off phenomenon on the side where the support interval widens during earthquake can be dealt with by lengthening the supporting margins. However, because the problem on the compression side is difficult to deal with, experimental and analytical studies were carried out to clarify the elasto-plastic restoring force characteristics of the escalator-truss structures and to refine and improve the seismic design guidelines and the Japanese building standard law, and its enforcement order. A series of experimental tests were carried out by using the actuator/jack-testing apparatus of Tokyo Denki University. And this project was supported by the building standard development promotion program conducted by the Japanese Ministry of Land, Infrastructure and Transport (MLIT) in order to improve and maintain the Japanese building standard law, and its enforcement order by applying non-government organizations such as research institutes, private enterprises and universities.
STUDY ON THE PROPER PERFORMANCE OF LIFT BUFFERS IN REVISED JIS A 4306 USING NON-LINEAR DAMPING CHARACTERISTIC
Osamu Furuya, Ryoto Matsuzaki, Satoshi Fujita
Tokyo Denki University, Japan.
Further improvement in the safety of lifts has been expected because of the occurrence of various accidents. Safety devices such as an emergency stop device, a deceleration switch and an emergency stop switch have already been installed to ensure the safety of the user even in the case of trouble in a lift. Especially, in the event of a falling down accident, a buffer in the bottom of the lift hoistway is a key element in preventing the progress of a serious accident.
A buffer plays a role to minimize the injury to a passenger by absorbing the shock of the falling down accident of the lift car. However, little research has been done from engineering viewpoints. In the research, it is considered that the following viewpoints are important factors for the way of thinking of the safety design to avoid severe accidents: “Defense in Depth”, “Safety Margin and Fail-Safe System” and “Redundancy, Diversity and Independence”. The first is an important fundamental idea for the design of lift to prevent the progress of a serious accident in each safety function. The others are also important key points to aid the safety of the passengers. Although the performance requirements of a buffer have been determined in the Ministry of construction notification No.1423, an issue has occurred in an examination item, a standard for judgment, a performance requirement of the buffer and so on, in Japan. Therefore, as for the performance of buffer, the standard has been revised as necessary with a governor. In Japan, the performance regulation for an emergency stop device was revised in JIS A 4306 in 2016.
In this study, the way of a buffer design satisfying a safety requirement of revised Japanese Industrial Standards is analytically examined. In a former paper, the fundamental parameters to satisfy the revised performance regulation were as in JIS. As the next step of the study, design parameters for buffer of lift is examined in a non-linear response analysis from a practical viewpoint. Moreover, the analysis is conducted to investigate an actual condition by considering the effect of gravity in a car and a buffer.
TRAFFIC ANALYSIS FOR A MULTI CAR LIFT SYSTEM USED AS LOCAL GROUP
thyssenkrupp Elevator, Germany. The University of Northampton, UK.
In a circulating multi car lift system multiple lift cars are sharing shafts. Shafts are used as one way tracks and cars are changing between shafts horizontally. Handling capacity depends on the time between two subsequent cars (multi car cycle time). If these transportation systems are used in buildings as local groups, people’s individual destinations lead to different stops of cars. That affects the average multi car cycle time.
This paper/research explores the average multi car cycle time in a pure incoming traffic situation of a multi car lift systems used as local group considering quality of service constraints. The traffic analysis is established by applying Monte Carlo simulation that calculates an additional multi car cycle time avoiding “traffic jams”. Based on a simplified calculation model handling capacity results are presented for different numbers of served floors and different numbers of passengers per car. Results are affected by floor to floor distances and required distances between cars.
TRANSVERSE AND LONGITUDINAL COUPLING VIBRATION BEHAVIOUR OF HOISTING SYSTEMS WITH VARIABLE LENGTH AND MULTI ROPES
Cao Guohua, Zhang Ning, Wang Lei
China University of Mining and Technology, China.
The parallel rope lifting system is widely used in high-speed elevator lifting, super deep well hoisting, multiple cranes parallel hoisting and so on. When high-speed elevators and other lifting systems operate with multiple ropes, because of the circumferential error and axial oscillation caused by non-uniform wear and manufacturing errors of rope grooves, displacement deviation between parallel hoisting ropes during winding process will be triggered, which will result in the axial and transverse vibration phenomena. In order to reduce the movement deviation between different ropes and improve the safety of the hoisting system, the rope length compensation device is designed. According to the coupling geometry and mechanics boundary of the parallel ropes, the transverse and longitudinal coupling vibration model of the variable length lifting system under the action of the compensator is constructed. The coupling dynamic behaviour under different guidance methods is explored. The unsteady evolution law in the lifting process is revealed, which will provide the reference for the stability design of the long-distance and high-speed lifting system.
GOODS LIFTS. WHO NEEDS THEM?
Canary Wharf Contractors, UK.
Much has been written about the importance of passenger lifts, their performance and passenger traffic analysis in office and residential buildings over many years. The same cannot be said of goods lifts, even though they play a vital role in the efficient running of buildings. The movement of goods, plant, furniture, and the needs of the emergency services, especially in residential buildings, all need to be considered when assessing the services necessary to ensure the smooth back of house operations that contribute to well managed buildings and satisfied tenants.
The move to higher population densities in office buildings combined with introduction of magnet attractions such as roof top restaurants and retail outlets brings to light the need to reassess both the role of the goods lift and how goods lift provision is assessed. Goods lifts are a key part of building logistics and failure to meet the needs of tenants and owners can be both expensive and frustrating. The humble goods lift provides a wide range of services from everyday deliveries and the movement of back of house personnel to enabling fit out and refurbishment works to be undertaken whilst minimising the impact on passenger lift usage.
Recent years has seen the growth in public access to major landmark buildings with restaurants, retail outlets and viewing areas being located within and at the tops of tall buildings. This together with higher office density levels brings new meaning to planning building logistics and the need for correlation between loading bay and delivery capacities and the ability to distribute goods and materials efficiently and quickly up the building. In addition, the removal of waste is a key use of goods lift time and the ability to manage this aspect of building operations should form a key part of the design associated with goods lift use and building logistics.
The management and operation of goods lifts is something largely overlooked in building design and yet the poor provision of such services has a significant impact on both building operations and tenant satisfaction.
This paper looks at the changing operational needs of office buildings and also seeks to examine the requirements for goods movement provision within residential buildings. The current guidance provided and the key points of reference are examined and assessed against todays demanding requirements for efficient management of modern buildings.
STUDY ON SEISMIC RESPONSE OF ESCALATOR IN CONSIDERATION OF INTERACTION WITH BUILDING DURING LARGE EARTHQUAKES
Kimiaki Kono, Satoshi Fujita, Asami Ishii
Tokyo Denki University, Japan.
In the Great East Japan Earthquake of 2011, fall accidents of escalators occurred. In the fall accidents, the escalators connected the third floor and the second floor and were in commercial facilities of steel frame buildings. In general, escalators are set on the beam of buildings without fixation. The cause of the fall accidents was that the escalators were moved off from the beams of the buildings by the great earthquake more than expected. After the escalator accidents, the quake resistance standard was revised in Japan. According to this standard, the layer displacement of buildings to be expected during earthquake is greater than before. However, it is considered that a non-fixed part of an escalator collides with a beam of a building by an earthquake. In addition, the collision may give compression and residual displacement to the escalator. Therefore, the purpose of this study is to grasp the dynamic behaviour of an escalator at earthquake which considers impact with the beam. In this paper, the dynamic behaviour of an escalator during large earthquakes is investigated by seismic response analysis which considers interaction with the building.
A RETROFIT SOLUTION FOR REMOTE LIFT MONITORING
Ben Langham1, Vergil Yotov2
1London Underground, UK. 2Amey Consulting, UK.
A trial has been undertaken on the lifts at Covent Garden station to extract data from the controllers and explore its value for maintenance and asset management. The programmable logic controllers (PLCs) monitor a large amount of information, from discrete signals such as the status of relays, buttons and switches to analog data for lift car speed and position.
A retrofit monitoring system was designed and installed to facilitate extraction of all available data from the PLCs in real time using a modern lightweight messaging protocol. An original approach to the visual representation of the historical data was developed to enable insights to be gained.
The findings demonstrated that there is value in extracting PLC data for root cause analysis, improved fault response time and a better understanding of asset operation and condition. This will support a more proactive approach to maintenance and inform whole life asset management.
THE SPACE ELEVATOR CONCEPT AND DYNAMICS
The International Space Elevator Consortium, USA.
The Space Elevator is a radical technology for accessing space and the ultimate Earth bound slender structure. The concept was first published in 1960 and was subsequently popularized in science fiction stories. After the discovery of carbon nanotubes in 1991 and subsequent calculations and measurements of their strength, the Space Elevator concept moved from the realm of science fiction to science possibility.
In this presentation the basic outline of Space Elevator design and proposed technology will be presented. This outline includes the economic motivation, major components, deployment scenario and technological challenges of the Space Elevator. Next the focus will shift to the details of carbon nanotube technology, the material usually identified as Space Elevator. Finally, the challenges of understanding the dynamics of the Space Elevator, the ultimate Earth-bound slender structure, will be presented.
STUDY ON COMPRESSIVE DEFORMATION OF ESCALATOR TRUSS DURING EARTHQUAKES CONSIDERING LARGE DEFORMATION
Ryoto Matsuzaki, Satoshi Fujita, Asami Ishii
Tokyo Denki University, Japan.
Escalators are generally installed by attaching L-shaped steel, known as support angle irons, at both ends and hooking it on a building beam. The escalators have truss-structure where one end is fixed and the other end is unfixed to prevent breakage, when a building is deformed by an earthquake. However, four fall accidents of escalators occurred in three shopping centres during Greatest East Japan Earthquake in 2011. The reason is that the non-fixed parts detached due to large inter-story deflection.
Based on the fall accidents, the quake-resistance standard of the escalator was reviewed in Japan. In the new quake-resistance standard, inter-story deflection assumed during earthquakes was set larger than before. Therefore, it is possible to prevent fall accidents, but on the other hand it is conceivable that an existing escalator receives compressive load from a building. However, it is difficult to secure a sufficient clearance between the building beam and the escalator, and when the large inter-story deflection occurs, the escalator truss may be greatly deformed by compression load and may cause troubles in safety. Also, since the structure of the escalator truss has no fixed provision, it differs according to each company. Therefore, it is necessary to investigate how the escalator truss behaves due to compressive load. From the above background, this study builds a finite element analysis model of the escalator truss that is subjected to compressive load based on results of a compression experiment of the escalator trusses of actual machine size. In this study, a simple analysis model is created - welds are made as one body and material properties are uniformly decided. The validity of the analysis model is investigated by comparing it with the compressive experiment of the escalator truss of the actual size.
LIFT ENGINEERING DESIGN CHALLENGES FROM THE POSTGRADUATE PROGRAMME PERSPECTIVE
Nick Mellor, Stefan Kaczmarczyk, Rory Smith
Faculty of Arts, Science and Technology, The University of Northampton, UK
This paper describes the background and concept of a postgraduate lift engineering programme, comprising MSc in Lift Engineering and PhD/ MPhil, aimed at those involved in lift engineering and related fields. The MSc in Lift Engineering integrates a systems engineering approach with other modules such as a study of global codes and standards, contract management, elective modules and a dissertation. Solutions to a design challenge arising from the results of safety gear drop tests are drawn from the systems engineering approach of the learning materials and in the context of an earlier MSc dissertation. Data from the drop tests is analysed to provide information on the variation of safety gear friction with rubbing speed and this is compared with the results from earlier dissertation research work and published sources.
REPORT ON SEISMIC DAMAGES OF LIFTS AND ESCALATORS BY LARGE EARTHQUAKES IN JAPAN
Keisuke Minagawa1, Satoshi Fujita2, Motoo Shimoaki3
1Saitama Institute of Technology, Japan. 2Tokyo Denki University, Japan.
3Japan Elevator Association, Japan
The devastating earthquake of Mw9.0, so-called the Great East Japan earthquake, hit the Tohoku district, north east part of Japan on March 11, 2011. About 16,000 people died and 3,000 people were declared missing due to the strong motion and tsunami, and the economic damage was estimated about 16.9 trillion yen excluding the influence of the nuclear accident of Fukushima Daiichi Nuclear Power Plant. In addition to the main shock, many strong aftershocks occurred in the long term. After that, a strong near-field earthquake called Kumamoto earthquake occurred in 2016 in Kyushu district of Japan. The buildings, houses and industrial facilities were damaged in these earthquakes, and various kinds of mechanical equipment set up in these structures were also damaged. The Japan Society of Mechanical Engineers (JSME) have set up the investigation committee and investigated the seismic damage of mechanical equipment of these industrial facilities for the purpose to understand the situation and cause of the damages in such facilities and contribute to the improvement of preparedness for a forthcoming earthquake. Additionally, an investigation regarding lifts and escalators was mainly carried out by the Japan Elevator Association. This paper provides a summary of the investigation regarding the lift systems and escalator systems to contribute to improving the seismic design for forthcoming destructive earthquakes. Typical damages of the lift systems and escalator systems utilized in buildings are also shown in this paper. Although many of the buildings were hit by unexpected massive earthquake, the system damages were reduced to a certain level especially for the systems designed after the newly issued 2009 Seismic Design Guideline.
TRANSIENT DYNAMIC COMPUTATION FOR MEGA-HIGH RISE LIFTS
Gabriela Roivainen, Jaakko Kalliomaki, Mirko Ruokokoski, Jarkko Saloranta, Vishnu Sreenath
KONE Corporation, Finland.
The megatrend of urbanization brings new challenges for the lift industry, overlapping the need for shorter travel time with the demand for safety and comfortable ride. In case of mega-high buildings, the performance of lift system can be substantially affected by the behaviour of the building to various excitations as strong wind or earthquakes.
This presentation is focused on the computation of in-car vibrations for various running parameters, lift configurations, installation accuracy and building sway, using a chain of multi-physic computation. The core of the computation is finite element method where solutions were developed to accommodate both installation accuracy – guide rails misalignment of range of millimetres – and lift travel of range of 500m-1000m. Aerodynamic loads were considered by using a transient fluid dynamic computation where the clearance of the car-shafts played a significant role. Behaviour of ropes during the running with different building sway parameters and speed profiles were computed using a finite differential method. The correlation of the computational results was validated in no-sway conditions and the results used for predicting in car behaviour also for sway conditions. Finally, the results were analysed against the probability of various excitations to assess the long term implication to the elevator system performance.
The advantage of this approach is that the dynamics of the entire structure can be analysed for every lift component: car, sling, roller, roller’s stopper; for the entire travel and for different running parameters. This provides the opportunity of optimizing -for example - the lift speed, based on the targeted ride comfort class and elevator system performance in various sway conditions.
ZONING A BUILDING IN LIFT TRAFFIC DESIGN
KONE Corporation, Finland.
In the design phase of a building, the number of lifts, their capacities and nominal speeds are selected. In high-rise buildings, it is a common practice to divide the building into contiguous floor segments, called zones. Typically, each zone is served by a group of lifts, and zones do not have common floors except the entrance floor. As a result, the lifts of the upper zones make express runs between the entrance floor and the lowest floor of the zone. Such a zoning improves lift service and saves core space. The zoning should be designed so that service among all zones is as equal as possible and each lift group satisfies the traditional design criteria related to handling capacity, interval, and nominal travel time. This paper formulates the zoning problem under an up-peak traffic condition as an optimization problem. The solution to the optimization problem divides the floors of the building into stacked zones and, for each zone, specifies the number of lifts as well as their speeds and capacities. Two objective functions are considered: up-peak filling time and core space occupied by all lifts. A large set of hypothetical buildings is formed by varying the number of upper floors above the entrance floor and floor populations. The zoning is solved for each building by the presented optimization algorithm to get an overall understanding of when the zoning should be applied, how many zones are needed, how much zoning in general decreases core space, and what is the impact of different objective functions on zoning arrangements.
THE EFFECTIVENESS OF REMOTE LIFT MONITORING WITH REGARDS TO IMPROVING LIFT RELIABILITY
ACE Lifts, UK.
A study was carried out to understand more about whether the lift industry can benefit from the internet of things (IoT); specifically, to understand whether connecting lifts electronically to the internet and then remotely monitoring various elements of the lift can reduce breakdowns, by enabling the service company to identify a maintenance programme that ensures better reliability.
Ten lifts were selected that were alike in type, usage and condition to compare similar lifts and rule out any anomalies associated with this. Further, the lifts selected had been refurbished to a similar level within the last three years and they all had the same control panel, levelling and signalling equipment, that is an encoder-based system. The selected lifts were then fitted with a remote monitoring device (RMD) that connected directly to the lift control panel. Functions such as movement up and down, the doors opening and closing, and the number of journeys undertaken were passed from the controller to the RMD.
Failure mode, effects and criticality analysis (FMECA) was the method used to quantify numerically the effects of lift breakdowns. The lifts were retrospectively analysed 160 days before a remote monitoring system was fitted and 160 days after. With the remote monitoring device fitted, supervisory engineers could influence engineer’s decisions, and to interact with the client. The results were averaged over the 3 sets of data to give an average score.
Overall there was a 63% reduction in the number of calls. The data showed that remote monitoring can offer many advantages to managing a lift system in terms of maintenance and reliability, specifically task-based maintenance.
The conclusions would suggest that IoT technology has now developed in terms of cost, availability and along with this, customer expectations; in the subsequent 12 months the system was fully integrated into a CRM system synchronising the maintenance and FMECA functions.
ROBOTS, NON-HUMAN PASSENGERS
University of Northampton, USA
Lifts are increasingly being called upon to transport non-humans (robots) between floors in multi-story buildings. The robots that are presently available place special demands on lifts and those demands affect traffic handling. The special demands, that include the interaction between humans and non-humans, are explained and the impact of those demands on waiting time and transit time are reviewed using simulation.
LIFT TRAFFIC ANALYSIS FOR A PROPOSED INNER-CITY DEVELOPMENT
Abbacas Consulting Ltd, UK.
There are many generic lift control systems on the market, several more with a specific proprietary bias. HCA - Hall Call Allocation, ETA - Estimated Time of Arrival or NCA - Next Car Available. Which is the most beneficial? Is there a best system? What are the limitations?
The report commences with the original enquiry regarding a proposed mixed development in Nottingham and the results presented to the client. The initial enquiry indicated the conditions encountered during heavy mixed lunch time traffic to be, in this instance, the most onerous for all the control systems. It was surprising to note the newest and most complex system, HCA, failed to satisfy the clients’ and the BCO requirements. This exercise set out to examine the differences and why one of the control systems favoured certain conditions to the others. Alongside academic research, the process followed traditional mathematical calculations and simulations to explore and test the differences. The paper outlines and examines the common generic control systems and explores the basic concepts and differences of each system considered for this project. As part of the journey, it also briefly reviews calculation vs simulation or the need for calculation and simulation!
BOOSTING TRAFFIC CAPACITY IN THE ADAM TOWER
Deerns Nederland B.V., Netherlands.
This paper discusses the technical design and traffic handling simulations for the lift system in the transformation of the multifunctional ADAM tower in Amsterdam. This former Shell office for 500 employees was refurbished in 2014-2017 for 3,000-5,000 daily users in a dense mix of different (public) functions. It has become an international hotspot for the music & dance industry since. The lift configuration in the tower has been radically redesigned to accommodate this huge increase of traffic (6-10x) through a combination of drastic measures:
- multifunctional lift sharing (combining passengers from different user groups in lift cars);
- increasing lift capacity through destination controls and higher loads/speeds;
- adding an extra lift within the existing core;
- adding local lifts in the podium and crown;
- reducing the number of stops during intense traffic peaks;
- time sharing of dedicated lifts for goods and observation deck shuttles in specific time windows;
- flow separation through different entrances/lobbies.
For all user groups an individual traffic profile was built up and composed into an over-all day profile. This profile reflects the 24/7 nature of the building. It was analysed for different usage scenarios using simulation, to check for sufficient capacity and acceptable waiting times over the course of a typical busy day. After phased commissioning in 2017 several practical measures were taken to optimise traffic handling even further, based on the size and characteristics of the actual traffic and the waiting times that were experienced in practice. The paper will include the results of a recent traffic measurement and the unique origin-destination matrix that was measured from the actual destination control system.