Analysis Data

Introduction

You can access Analysis Data by selecting Edit, Analysis Data, or by pressing the  button on the Toolbar.



Figure 3   Analysis Data dialog

This dialog contains general information about the analysis you want to perform.  The Analysis type selected here determines what data is entered in Building Data, Elevator Data and Passenger Data.


Analysis Type

The Analysis type determines what type of calculation will be performed by Elevate.  Select between:

Simulation

In a simulation Elevate models the whole process of passengers arriving, pressing the hall call buttons, getting into the elevators when they arrive, and then getting out at their destinations.  By monitoring every passenger, Elevate provides an analysis that includes Passenger Waiting Times and Passenger Transit Times.

Up peak

In an up peak calculation it is assumed that all passengers get into the elevators at the lowest, “main terminal” floor.  The destinations of passengers are determined by the population of upper floors, as entered in Building Data.  Elevate uses formulae to calculate the Interval and Handling Capacity of the system.  This analysis method will provide similar results to most other elevator planning software and hand calculations providing consistent input data is used.

Enhanced up peak

This performs the same calculation as the Up peak analysis type, but requires Handling Capacity to be entered.  Capacity Factor is adjusted automatically during the analysis so that the required Handling Capacity is achieved.  This is a much quicker method of finding solutions when designing to a specified Handling Capacity and Interval.

General analysis

This analysis method gives similar results to the Enhanced up peak, but it does not restrict passengers to loading the elevators at the lowest floor in the building.  Passengers can get into the elevators at any or all floors.  This is particularly useful for buildings with multiple entrance floors, car parks and basements. Elevate uses formulae to calculate Interval and Capacity Factor for the system.

Double Deck General analysis

This analysis method is the equivalent of the General analysis, but for double deck elevators.  Passengers can get in at any or all floors. Passengers may only travel from odd to odd or even to even number floors.


For more information about the analysis techniques used by Elevate, please select Elevate on the web from the Help menu.


Measurement System

Choose whether you want to use Metric or U.S. (Imperial) units for this analysis.  Your selection here will determine whether Elevate uses “metres and kilograms” or “feet and pounds” in the other dialog boxes, and for output of results.

Dispatcher

These inputs are only applicable and active when the Analysis type is Simulation.   The dispatcher algorithm determines how the elevators will serve the calls placed on the system by the passengers.

Select either Standard or Custom Algorithms.  Custom algorithms are only available if you have chosen to implement your own algorithms using the Developer interface.

Select the chosen Algorithm, Mode and Advanced Options.  For Standard algorithms, the available options are discussed below.

Group Collective

A control system that allocates hall calls by (i) estimating the expected travel distance between hall calls and each elevator; (ii) allocating the call to the “nearest” elevator.  Allocations are regularly reviewed in case a delay to one elevator means that another could answer the call sooner.  A load bypass feature is included to avoid the elevator stopping to pick up passengers when it is already full.

In Up peak 1 mode,  “idle” cars are returned to the Home Floor with a parking call that does not open the elevator doors on arrival.  This strategy normally improves up peak traffic handling.  Using this algorithm elevators are loaded one at a time.  This encourages people to fill one elevator rather than part fill two or more elevators.

In Up peak 2 mode “idle” cars are returned to the Home Floor with a parking call which opens the elevator doors on arrival.  This strategy improves on Up peak 1 for particularly heavy traffic situations when it is advantageous to load more than one elevator at a time.  If this is not the case, the algorithm is normally less efficient than Up peak 1.

In Down peak mode, the served floors above the Home Floor are divided into sectors, where the number of sectors is equal to the number of elevators.  Elevators are dispatched to the sectors in turn.  When the elevator has served the down calls in its allocated sector, it is allowed to stop for additional hall calls in its path on the trip back to the Home Floor.  This strategy normally improves performance when the predominant traffic flow is in the down direction towards the home floor.

In Auto mode, up and down peak detection is used to turn the Up peak and Down peak modes on and off.  The detection parameters are accessed by clicking on the Advanced settings button.

For, Up peak detection, when a car leaves the Home floor, the dispatcher tests if the load exceeds the Load switch detection level (%).  The Up peak detection counter is incremented by 1 when a car leaves with a load above the Load switch detection level and is decremented if the load is below that level.  When the counter reaches the On level, the up peak program is switched on.  A blocking system ensures that the up peak detection counter does not exceed the On level.  If the up peak program is on, the Clock inhibit timer decrements the Up peak detection counter by 1 at fixed time intervals, as defined by the Clock rate.  When the up peak detection counter reaches the Clock inhibit level, the Clock inhibit timer is switched off.  When the Up peak detection counter reaches the Off level (always set at 1), the up peak program is turned off.

Down peak detection operates as per the up peak detection system, except that the load is measured as the car arrives at the home floor; the down peak as opposed to up peak program is initiated.

Estimated Time of Arrival (ETA)

A control system that allocates halls calls to the elevator with the lowest Estimated Time of Arrival.

In Up peak mode, “idle” cars are returned to the Home Floor with a parking call that does not open the elevator doors on arrival.  This strategy normally improves up peak traffic handling.  Using this algorithm elevators are loaded one at a time.  This encourages people to fill one elevator rather than part fill two or more elevators.

In Heavy up peak mode “idle” cars are returned to the Home Floor with a parking call that opens the elevator doors on arrival.  This strategy improves on Up peak for particularly heavy traffic situations when it is advantageous to load more than one elevator at a time.  If this is not the case, the algorithm is normally less efficient than Up peak.

In Down peak mode, the served floors above the Home Floor are divided into sectors, where the number of sectors is equal to the number of elevators.  Elevators are dispatched to the sectors in turn.  When the elevator has served the down calls in its allocated sector, it is allowed to stop for additional hall calls in its path on the trip back to the Home Floor.  This strategy normally improves performance when the predominant traffic flow is in the down direction towards the home floor.

In Auto mode, up and down peak detection is used to turn the Up peak and Down peak modes on and off.  For up peak detection, each time the car departs from the home floor, the system counts the number of car calls registered.  If this is greater than a calculated trigger number, then the up peak counter is incremented; otherwise the counter is decremented.  To allow for application in different scenarios, the trigger number is a function of the number of floors and number of elevators.  When the up peak counter reaches a threshold, the up peak mode is turned on.  If a second, higher threshold is reached, heavy up peak mode is turned on.  For up peak detection, the system counts the number of down calls in a round trip.  Like up peak detection, there is a trigger number based on which the down peak counter is incremented or decremented.  If the threshold is reached, the down peak mode is turned on.  Both up and down peak counters are incremented faster than they are decremented as it is normally better to have the peak mode selected early than late.  Mode detection modes include hysteresis to avoid the peak mode selection being turned off if there is just a short period of low traffic demand.

Early car announcement can be turned on or off.  When turned on, it is assumed that as soon as a passenger places a hall call, the allocated car is “announced” with a gong and or/light.  This can assist in passenger loading, which can be modelled in Elevate by reducing Passenger Loading Time.  However, when a call is announced it can no longer be re-allocated.  This generally impairs the performance of the dispatcher.

Load bypass can be turned on or off.  Turned on, this feature will prevent hall calls from being allocated to full cars.  The Load bypass threshold determines how full a car is before load bypass comes into operation.

Coincident call bonus reduces the calculated ETA for a hall call if the elevator is already stopping at the same floor for a car call.  This normally reduces the overall number of stops made by the elevator, and consequently improves performance.

Number of cars loading simultaneously during up peak allows you to specify the maximum number of elevators you want to be able to load at the same time, during an up peak, from the Home Floor.  Normally a system would only load one car at a time.  But in heavy traffic situations it can be advantageous to load more.  The based on people counter at home floor option assumes that there is a people counting device at the home floor.  This device decides how many people are waiting, and uses this information to decide how many elevators to load simultaneously.

Destination Control (ACA)

Destination Control or Adaptive Hall Call Allocation (ACA) requires every passenger to enter his or her destination on the landing.  When a call is entered the system makes an allocation, and immediately displays the selected elevator to the passenger.

When a new call is introduced, the system calculates every passenger’s remaining waiting and transit times for each possible allocation.  The allocation is made according the selected Cost Function, which is either Minimum Waiting Time or Minimum Journey Time.

Minimum Journey Time is generally applied during the morning up peak.  Either function may be applied at other times of the day.

Minimum journey time with waiting time constraint is a Minimum Journey Time function.  However, a penalty is applied if the dispatcher anticipates the waiting time will exceed the specified threshold level.

Reduction in number of stops can be applied to increase the chance of people travelling to/from the same floors being allocated to the same elevator.

For a detailed discussion of this algorithm, please refer to the Elevator Traffic Handbook by Dr Gina Barney.

Allow allocations requiring doors to re-open is an option which determines whether or not the dispatcher is allowed to allocate a new destination call at the elevator’s current floor.  Re-opening the doors delays the passengers already in the car, but may reduce the new passenger’s waiting time significantly.

Destination Control can dramatically improve performance during up peak traffic.

Caution!  This improvement is not consistent across all traffic conditions.  If you select less, slower, or smaller elevators because of the performance improvements realized by destination control, it is very important to analyse other peak traffic conditions (e.g. down peak and lunchtime traffic).

Please also see Mixed Control (Enhanced ACA) which is based on ACA, but includes enhancement reflecting the ongoing improvements in this technology achieved by developers in recent years.

Double Deck

A control system for double deck elevators that allocates hall calls to the car with the lowest Estimated Time of Arrival (ETA).  Traffic must be arranged so that passengers only travel (i) from odd numbered floors to other odd numbered floors, and (ii) from even numbered floors to other even numbered floors.

In Up peak mode,  “idle” cars are returned to the Home Floor with a parking call which does not open the elevator doors on arrival.  This strategy normally improves up peak traffic handling.  Using this algorithm elevators are loaded one at a time.  This encourages people to fill one elevator rather than part fill two or more elevators.

In Heavy up peak mode “idle” cars are returned to the Home Floor with a parking call that opens the elevator doors on arrival.  This strategy improves on Up peak for particularly heavy traffic situations when it is advantageous to load more than one elevator at a time.  If this is not the case, the algorithm is normally less efficient than Up peak.

Double Deck Destination Control

A control system for double deck elevators that requires every passenger to enter his or her destination on the landing.  When a call is entered the system makes an allocation, and immediately displays the selected elevator to the passenger.

When a new call is introduced, the system calculates every passenger’s remaining waiting and transit time for each possible allocation.  The allocation is made according to the selected Cost Function, which is either (i) Minimum time to destination, (ii) Minimum waiting time or (iii) Minimum 3x waiting time + transit time, for which waiting time is deemed to be three times as important as transit time when choosing which car to allocate.

Allow allocations requiring doors to re-open is an option which determines whether or not the dispatcher is allowed to allocate a new destination call at the elevator’s current floor.  Re-opening the doors delays the passengers already in the car, but may reduce the new passenger’s waiting time significantly.

Mixed Control (Enhanced ACA)

Mixed Control (Enhanced ACA) is based on Destination Control (ACA), but includes enhancements reflecting the ongoing improvements in this technology achieved by developers in recent years.

The system is “mixed” because it is possible to select which floors have destination call stations, see Elevator Data.  For a full destination system select all floors to have destination call stations.


Interfaces

A number of interfaces have been developed so that Elevate communicate with other software including Elevate Live monitoring.  If you would like to interface with Elevate, please contact technical support.  For more information about Elevate Live, please visit www.peters-research.com.


Time Slice Between Simulation Calculations

This input is only applicable and active when the Analysis type is Simulation.

Elevate runs a time slice simulation.  It calculates the status (position, speed, etc.) of the elevators, increments the time, re-calculates status, increments time, and so on.  The time slice between simulation calculations is the time increment in this loop.


No of Time Slices Between Screen Updates

This input is only applicable and active when the Analysis type is Simulation.

Elevate does not have to update the screen after each time slice.  Increasing the No of time slices between screen updates will speed up the simulation, but the display will be less smooth during the run.  This variable has no effect on the final results calculated by Elevate.

If you want to turn off the simulation display completely, set this variable to 999.


Random number seed for passenger generator

This input is only applicable and active when the Analysis type is Simulation.

When Elevate runs a simulation, it takes the information entered in Building Data and Passenger Data to make a list of people.  For example, if you have a total arrival rate of 10 persons per five minutes, and a simulation running for 5 minutes, then a list of 10 people will be generated.

A random number generator is used to determine at what time these people arrive.  For example, one person may arrive after 10 seconds, another after 23 seconds, another after 1 minute 23 seconds, and so on.

By changing the random number seed, the simulation will have the same number of people generated, but they will arrive at different times.


Number of simulations to run for each configuration

This input is only applicable and active when the Analysis type is Simulation.

There is a chance element in simulation which means that changing a parameter, such as speed or handling capacity, can sometimes lead to performance results getting worse when you expect them to get better (or vice versa).  For example, consider two simulations with exactly the same data, except one had 2.5 m/s elevators and the other 1.6 m/s.  In a single simulation with 2.5 m/s elevators, a group of passengers may miss an elevator by less than a second, where as in the simulation with 1.6 m/s elevators they catch it.  So, sometimes the faster elevators perform worse.  Of course, in the long run, the faster elevators will perform better.  By running multiple simulations for the same data, Elevate is mimicking real life.  It is as if we are simulating Monday, Tuesday, Wednesday, etc.  The results are then averaged for all the simulations, so overall we can see the benefit of the improved performance.


Losses

This input is only applicable and active when the Analysis type is Up peak, Enhanced up peak, General analysis or Double Deck General Analysis.

Some designers add a % to the calculated value of Round Trip Time (RTT) to allow for controller inefficiencies and people holding doors, etc.  To increase RTT in this way, enter a value here.  Alternatively, enter zero.

Energy model

This input is only applicable and active when the Analysis type is Simulation.

Select either energy model off or energy model on. The Energy model options are selected in Elevator Data.