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methodology of elevator systems
Recent studies have revealed that the dominant traffic pattern of a modern high-rise building is much more complicated than the conventional up-peak model, i.e. incoming traffic only, upon which the popular formula of round trip time... more
Recent studies have revealed that the dominant traffic pattern of a modern high-rise building is much more complicated than the conventional up-peak model, i.e. incoming traffic only, upon which the popular formula of round trip time (RTT) calculation is based. RTT calculation is still recommended by ISO 8100:32:2020 and CIBSE Guide D: 2020 to precede any computer simulation. Nowadays, the concern is more on the lunch peak with a mixture of incoming, outgoing and interfloor traffic patterns. Moreover, the independent one-passenger arrival model should be replaced by the more practical batch arrival model, in particular during lunch-time peak. This article first summarizes what were previously published on the universal RTT evaluation for mixed traffic conditions, highlights the main arguments, updates and supplements some previously introduced formulae such as that related to coincidental stops, uses more symmetrical and easily manipulated graphics, and, second in particular, brings...
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Abstract. A methodology has been developed for the simulation and experimental verification of the axial force exerted by an electromagnet on a concentric permanent magnet. This comprises four stages. The first involves the modeling of... more
Abstract. A methodology has been developed for the simulation and experimental verification of the axial force exerted by an electromagnet on a concentric permanent magnet. This comprises four stages. The first involves the modeling of the permanent magnet as a current sheet ...
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the upper performance limit of destination elevator group control using idealised optimal benchmarks
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The effect of design geometry on the output voltage, linearity and sensitivity of linear variable differential transformers (LVDTs) is presented. The effect of varying six geometric design parameters, including primary coil length,... more
The effect of design geometry on the output voltage, linearity and sensitivity of linear variable differential transformers (LVDTs) is presented. The effect of varying six geometric design parameters, including primary coil length, secondary coil length, inner and outer coil radii, and the length and radius of the core, on the transfer characteristics of LVDT is investigated using Finite element simulations. Output voltage vs. core displacement figures are used to determine the effect of the parameters investigated on the stroke and sensitivity. Copyright © 2013 IFSA.
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An apparatus for managing power outages in an elevator system in a building having a plurality of plants, the apparatus comprising: one or more elevators; a calculator connected power with elevators and able to determine a total energy of... more
An apparatus for managing power outages in an elevator system in a building having a plurality of plants, the apparatus comprising: one or more elevators; a calculator connected power with elevators and able to determine a total energy of the elevator system, a total energy required to operate a cutting power supply, characterized by further be the energy calculator capable of determining a plan to prepare for cutting power supply, and a plan to manage the cutting power supply, in which the plan to prepare for cuts power supply comprises changing one or more selected from a position and a velocity of one or more elevators during normal operation in an attempt to provide sufficient power in the elevator system to at least meet the total energy required to manage the power outage; and further comprise the apparatus comprising a motion controller connected to the elevator or elevators and the energy calculator, wherein the motion controller receives the plan to prepare for cutting powe...
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A major focus of mechatronic engineering education is on the design and analysis of integrated engineering systems. Therefore, it is importance to develop a well-structured mechatronic system design course for undergraduate engineering... more
A major focus of mechatronic engineering education is on the design and analysis of integrated engineering systems. Therefore, it is importance to develop a well-structured mechatronic system design course for undergraduate engineering students. This course can be considered as a capstone course that integrates vast amount of knowledge and skills acquired by students throughout their education. This paper presents an overview of a mechatronic design course contents. It also provides the appropriate method of delivering the needed material through case studies and examples.
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The passenger arrival rate is a fundamental term in quantifying the demand in elevator traffic system. The peak value of the arrival rate is the basis for determining the number and the specification of the required elevators. The ability... more
The passenger arrival rate is a fundamental term in quantifying the demand in elevator traffic system. The peak value of the arrival rate is the basis for determining the number and the specification of the required elevators. The ability to estimate the elevator passenger arrival rate in real time enhances the controller's decisions such as selecting the suitable number of sectors and switching between algorithms suitable for different traffic modes (e.g., incoming, outgoing, inter-floor). This paper discusses the use of exponentially weighted moving average to estimate the arrival rate of passengers in real time. It also studies the optimum value for the smoothing constant that minimizes the sum of the square of the deviations of the estimated arrival rate from the actual arrival rate. It is shown that the exponentially weighted moving average (EWMA) provides a better estimate of the arrival rate than the simple moving average (SMA). The arrival rate estimation using EWMA was ...
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Elevator group control is critical to the optimal operation of elevator traffic systems under general traffic conditions. In the last 20 years, new elevator group control algorithms have become available for use under up-peak traffic... more
Elevator group control is critical to the optimal operation of elevator traffic systems under general traffic conditions. In the last 20 years, new elevator group control algorithms have become available for use under up-peak traffic conditions. These up-peak algorithms can be generally classified into three categories: static sectoring, dynamic sectoring and destination group control. It is customary to use simulation to assess the effectiveness of group control algorithms. This paper offers a new approach, which is built around numerical methods. Numerical methods can be used to objectively assess the effectiveness of an up-peak group control algorithm by subjecting the group controller to a large number of random scenarios. Each random scenario comprises a set of randomly generated passenger destinations. The performance of each scenario is recorded and the average performance of all the scenarios is used as an indicator of the effectiveness of the algorithm. The conditions under...
An experimental investigation has been carried out into the factors that affect the energy consumption of an escalator. The type of energy consumed by the escalator is classified into fixed losses and variable losses. The two main factors... more
An experimental investigation has been carried out into the factors that affect the energy consumption of an escalator. The type of energy consumed by the escalator is classified into fixed losses and variable losses. The two main factors that affect the energy consumption have been identified as the mechanical design of the escalator (that affects the fixed losses) and the number of passengers using the escalator (that affects the variable losses). Experimental and survey work have been carried out on a large number of heavy duty escalators to find the relationship between the mechanical design aspects, the number of passengers using the escalator and the energy it consumes. The generic mechanical and electrical design features of the escalators were extracted to allow a grouping of the escalator in order to find general rules. Surveys were also carried out on the total daily number of passengers using an escalator and the corresponding daily total energy consumed. The relation bet...
The origin-destination matrix is a two-dimensional matrix that describes the probability of a passenger travelling from one floor in the building to another. It is a two-dimensional square matrix. The row index denotes the origin floor... more
The origin-destination matrix is a two-dimensional matrix that describes the probability of a passenger travelling from one floor in the building to another. It is a two-dimensional square matrix. The row index denotes the origin floor and the row index denotes the destination floor for the passenger journey. A previous chapter described the methodology for constructing the origin-destination matrix (OD matrix) from the user requirements. However, that chapter placed the restriction that any floor must either be assigned as an entrance floor or an occupant floor, but not both. This chapter relaxes this restriction and shows a method for developing the origin-destination matrix that allows any floor to either be an entrance floor; an occupant floor; or both. The origin destination matrix can be compiled using three sets of parameters: the mix of traffic (incoming traffic, outgoing traffic, inter-floor traffic; and inter-entrance traffic); the floor populations; and the entrance perce...
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Sectoring is a group control algorithm that is used in elevator traffic control systems by grouping passengers that have common destinations or common origins into elevator cars that serve these floors. The building is split into sectors... more
Sectoring is a group control algorithm that is used in elevator traffic control systems by grouping passengers that have common destinations or common origins into elevator cars that serve these floors. The building is split into sectors usually comprising contiguous floors. Two different alternative algorithms for sectoring are discussed in this paper. The first approach is based on dynamic allocation with equal sector allocation. The second approach is based on static allocation with unequal sector sizes. Under static allocation, the same elevator car is allocated to the same sector in every round trip. Under dynamic allocation, each elevator car is allocated to a different sector in each round trip. Under the dynamic allocation scheme suggested in this paper, the elevator cars are sequenced to the various sectors in the buildings in a round-robin fashion. It is important to note that under both schemes, the provided (relative) handling capacity of different sectors is equalised. ...
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Arrival rate is the number of passengers arriving for elevator service in a certain period of time. Arrival rate is fundamental in expressing the heaviness of the traffic. Hence, it is vital for determining the required number of... more
Arrival rate is the number of passengers arriving for elevator service in a certain period of time. Arrival rate is fundamental in expressing the heaviness of the traffic. Hence, it is vital for determining the required number of elevators and the specifications of each elevator such as the speed, capacity, and sector sizes. The passenger arrival process is a random process that is full of noise, and a processing step is required to extract the arrival rate from recorded arrival times of passengers. This work develops a real-time estimator and a benchmark for estimating the arrival rate. There are three contributions in this work; the first is suggesting a benchmark for estimating arrival rate; singular spectrum analysis extracts the arrival rate from noisy data. Hence, singular spectrum analysis is suggested as a benchmark for evaluating the performance of other algorithms. Even though singular spectrum analysis is powerful in extracting the arrival rate, it is not convenient for u...
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For a long time, there was no action that a group controller could take during incoming traffic conditions other than returning the elevators back to the main entrance and opening their doors. Passengers would arrive in the main entrance... more
For a long time, there was no action that a group controller could take during incoming traffic conditions other than returning the elevators back to the main entrance and opening their doors. Passengers would arrive in the main entrance and board the first available elevator car. However, in the early 1990s, sectoring was introduced during incoming traffic conditions. Sectoring is the soft division of the building into groups of (usually but not necessarily contiguous) floors, usually of equal populations. One or more elevators are assigned to a sector. The allocation of the elevator(s) to a sector can either be fixed (static sectoring) or variable (dynamic sectoring) within consecutive round trips. In addition, the size and composition of the different sectors can be static or dynamic. Sectoring is thus a powerful tool in dealing with peaks of incoming traffic demand. However, most of the analysis carried out to understand the effects of sectoring on the performance of the elevato...
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Double-deck elevators are a very efficient mode of transport, especially in high rise buildings. This is due to the fact that they reduce the number of stops in a round trip (leading to a smaller value of the round trip time hence a... more
Double-deck elevators are a very efficient mode of transport, especially in high rise buildings. This is due to the fact that they reduce the number of stops in a round trip (leading to a smaller value of the round trip time hence a higher handling capacity) and take up less space of the core of the building leading to high space usage efficiency. This paper provides a comprehensive treatment of the double-deck elevator traffic calculations. It derives an exact set of equations to find the value of the round trip time under incoming traffic conditions, for the cases of equal and unequal floor populations. Moreover, equations have also been derived for two performance coefficients. The first coefficient is called the passenger transfer efficiency coefficient and is representative of the time taken by passenger to alight from the double-deck elevator. The second coefficient is called the coincidental stopping coefficient and is representative of the stopping efficiency. All the result...
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The boost in the handling capacity of destination elevator group control systems has been previously calculated under idealised conditions, assuming simultaneously minimum values of the highest reversal floor and of the average number of... more
The boost in the handling capacity of destination elevator group control systems has been previously calculated under idealised conditions, assuming simultaneously minimum values of the highest reversal floor and of the average number of stops in a round trip. The boost has also been calculated under conditions of allocating the landing calls with full advanced knowledge of the passenger destinations (offline allocation). This paper re-calculates the boost in handling capacity under real time allocation conditions of the landing calls as they are registered. The landing calls are revealed to the controller one at a time, and the controller has to make an irrevocable allocation of the landing call to an elevator. The efficiency drops under real time allocation conditions compared to the other two conditions as expected. However, it still reveals a significant boost in handling capacity that increases with the number of elevators in the group.
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Elevator traffic system design has been traditionally based on rules of thumb and the designer’s judgement and expertise. This is especially true for high-rise buildings. This paper attempts to develop a systematic methodology for the... more
Elevator traffic system design has been traditionally based on rules of thumb and the designer’s judgement and expertise. This is especially true for high-rise buildings. This paper attempts to develop a systematic methodology for the design of high-rise buildings, by the use of rational rules. In order to ensure clarity and consistency, it defines the terms sector, zone and stack. A sector is a group of floors that are served by one or more elevators in a journey and are not necessarily fixed and are not necessarily contiguous. A zone is a group of contiguous floors that are served by a group of elevators and are fixed in hardware. When a number of zones are grouped together they form a stack, which is effectively a building within a larger building that is served by a main lobby or by a sky lobby. The systematic methodology is built around the use of rational rules. Rational rules differ from rules of thumbs in a number of ways, and these are discussed in the paper. Six rational r...
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This paper attempts to understand the reasons for the difference in the value of the round trip time between calculation and simulation. It is posited the main reason for the difference is the combination of two factors: the restricted... more
This paper attempts to understand the reasons for the difference in the value of the round trip time between calculation and simulation. It is posited the main reason for the difference is the combination of two factors: the restricted car capacity and the randomness in the behavior of the elevator traffic system, thus leading to a reduced effective car loading (effectively based on a smaller number of passengers in the car). There are three sources of randomness in the behavior of the system: the randomness of the passenger destinations (thus making the value of the round trip time a random variable), the randomness of the passenger arrival (driven by a Poisson passenger arrival model), and the effect of elevator bunching (thus making the value of the interval a random variable). Using a MATLAB-based simulator, the value of the round trip time is plotted against the system loading level for the case of a single entrance and incoming traffic only. Different conditions are simulated,...