4 Fix Train Models

4.1 Explanations valid for all kind of Fix Train Models

For trains that usually operate in a foreseeable train configuration with known brake characteristic (like EMUs or DMUs), the brake model parameters can be determined in the development phase and stored in the ERTMS/ETCS on-board. Those trains are called fix trains or gamma trains. The values AD(V ) are calculated and/or measured in the design phase of the train, whereupon the limits V 1, …, V m can be selected in such way, that the actual deceleration curve a(v) is suitably approximated. The brake model defined like this does not yet consider

1.
deviations due to component tolerances,
2.
losses of brake capacity due to failures of the brake components (either already existing but not yet detected failures or failures arising in the moment of the emergency brake request),
3.
extensions of the distance due to bad adhesion conditions.

The effects of point 1 and 2 are modelled in correction factors Kdry_rst, that need to be defined for each speed range and ten Emergency Brake Confidence Levels, EBCL 0 to EBCL 9, leading to Kdry_rst(V,EBCL). Thus there is in fact not only one brake model but ten for the same physical train configuration. The brake model for EBCL=0 is the nominal brake model, the brake models for EBCL>0 are called Safe Brake Models. Which of the ten models is to be used is determined by the track-side, sending the required confidence level in variable M_NVEBCL.

In [Subset 026-3] no correction factor is defined for the brake build-up time Tbu, nevertheless some parts of the brake system (namely the ep-brake system) only effect the build-up time. Therefore it makes sense to correct also this parameter by a factor KT_rst(EBCL).

To make things even more complicated, the brake model can change while running not only due to a change of the EBCL, but also because some special brakes can be inhibited and re-enabled by track-side command. Therefore multiple brake models need to be defined for the different configurations of the train brake system, out of them exactly one needs to be selected by the vehicle control (or brake control) while running according to the status of the special brakes. Each of these sets of brake models (consisting of 10 models each, one for each EBCL) gets a number, which is named Brake Model Index (BMI) in ETCS Brake Model Tool.

The BMI needs to reflect the status of the special brakes (as required in [Subset 026-3]), but obviously it can also encode additional information such as unavailable parts of the brake system that are already known (e. g. as the result of the start-up brake test), or the train configuration (one consist, two consists coupled etc.).

The three lower bits of the brake model index have a fixed meaning, since they shall always code the status of the special brakes as defined in [Subset 034]. Therefore their name, sequence and size (1 bit) cannot be changed in ETCS Brake Model Tool.

To get complete here, it shall be mentioned, that also the effects of point 3 are considered in the calculation of braking distance, therefore correction factors Kwet_rst(V) are defined for each speed range. In contrary to the Kdry_rst(V, EBCL) they do not depend on the EBCL and thus Kwet_rst(V) is identical for each nominal brake model and the related 9 safe brake models.

Thus finally the deceleration used in the calculation of the braking distance is given according to [Subset 026-3], paragraph 3.13.6.2.1.4 as

A_brake_safe(V, d) = A_brake_emergency(V, d) Kdry_rst(V, M_NVEBCL)
(Kwet_rst(V) + M_NVAVADH (1 - Kwet_rst(V)))

The national values M_NVEBCL and M_NVAVADH don’t change within the braking distance d, whereas the model may change due to a change of track conditions, indicated by the ”d”.

Each brake model of a fix train model consists of

Fix brake models are created by Edit – Validate Brake Models (in case of a fix train model (direct input)), or Edit – Calculate Brake Models (in case of a fix train model by combinatorial logic or fix train model by Monte Carlo simulation). In case of fix train model by combinatorial logic and fix train model by Monte Carlo simulation, the parameters of the fix brake models are shown in a separate tab ’Brake models’. This table displays all values of all brake models either as absolute values or as correction factors, see 2.5.

Summary

All values used for the calculation of the braking distance except of the so called ’national values’ M_NVEBCL and M_NVAVADH need to be calculated in the engineering process.

Each ETCS emergency brake model in fact consists of 10 brake models:

The brake model index (BMI) is the same for EBCL=0…9.

The brake model can change while running due to change of EBCL or BMI. The BMI can change while running for different reasons, e. g. due to inhibition/re-enabling of special brakes or brake failures. ERTMS/ETCS on-board should not stop the train if the BMI changes, except if there is no brake model available for the new BMI (should not happen), or the new brake model cannot ensure sufficient deceleration for the given EBCL and the track profile. If someone sees a need to stop the train for the driver to do something, this is outside the scope of ETCS, thus the brake system or vehicle control must stop the train if necessary.

The three options how to determine or define fix train model are described in the following three subsections.

4.2 Direct Input of the Parameters of a Fix Train Model

If you already have the parameters of the fix train model(s), you can create a fix train model by File – Create New Member and selecting ”Fix Train Model (direct input)”. All properties of the fix train model (direct input) are stored in the train model file with extension .fiximm. The input screen consists of three sections as shown in figure 6.


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Figure 6: Immediate input of fix train model parameters


4.2.1 General Train Model Data

This data is necessary for both fix and flexible train models. It is described in section 3.1.1.

4.2.2 Brake Model General Parameters

Here you have to enter the brake build up times and the upper speed limits of each section. The last section has no upper limit, i. e. if you want to define two speed sections, you only have to enter one value.

4.2.3 Parameter Table

The third section is the table containing all brake models with all parameters necessary for a fix brake model according to [Subset 026-3].

A new brake model is created by Edit – Create Brake Model. After entering the BMI of the new brake model, a new line will be shown. The last three bits of the BMI define whether the brake model includes eddy current brakes and/or magnetic track brakes and/or regenerative brakes. E. g. BMI 13 is binary (1)101b, i. e. it considers eddy current brakes and regenerative brakes according to the definitions in ETCS Brake Model Tool. Maybe your particular ERTMS/ETCS on-board has other definitions, in that case the index might have to be adjusted when transferring the values to the actual ERTMS/ETCS on-board.

In each line, you have to enter the nominal decelerations for each speed section, the correction factors or decelerations for each EBCL, the EB build up times, the correction factors for wet rails and the service brake model.

4.2.4 Validation

The brake models are validated by selecting Calculate – Validate brake models. After that, the brake distances as function of initial speed and EBCL can be displayed (see section 4.5) and scenarios can be calculated (see section 8).

4.3 Calculation of Correction Factors by combinatorial Logic

Note: This method of determination of fix brake models is not recommended for new projects anymore, since it is not completely conform to [prEN 17997-1].

ETCS Brake Model Tool is able to calculate all nominal brake models, all safe brake models (the Kdry_rst values for each EBCL) and the Kwet_rst values based on the master nominal brake model and some information related to brake failures, given by brake failure models, see section 4.3.3.

The panel for entering all necessary data is shown in figure 7.


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Figure 7: The parameters necessary to determine the fix brake models by combinatorial logic


4.3.1 General Train Model Data

The general train model data is the same as for the flexible train model, see section 3.1.1

4.3.2 Master Brake Model

The master nominal brake model defines the speed dependent decelerations and build-up time for EBCL=0 when all components of the brake system are available. It also defines standard deviations for these values in order to model statistical deviations of the physical parameters of the components. It has no specific meaning outside the engineering process, thus it is not noticeable in the set of brake models or the brake model index. In the set of brake models created by ETCS Brake Model Tool, it will be the one with the highest BMI.

Data entry mode

The nominal braking capacity and the differences caused by brake failures can be entered in two ways: as deceleration values or as brakes forces. If ”deceleration” is selected, the braking capacity is entered in terms of decelerations. If ”brake forces” is selected, the braking capacity is entered in terms of brake forces. Since finally always decelerations are needed, also the train mass and the equivalent train rotating mass must be given in case ”brake forces” is selected in order to convert the input to decelerations. If the train mass or the train rotating mass is changed, the deceleration values will be recalculated accordingly. Thus don’t change the train masses after you entered the correct decelerations.

Train model prefix

The train model prefix is used to distinguish the brake models created by multiple independent fix train models by combinatorial logic. It is part of the brake model index of each created brake model, located in the bits above the sections needed for the coding of the brake status.

Nominal values

In the first line the nominal parameters are entered — either decelerations or brake forces. All values are positive values. The deceleration is limited to 2.55 ms2. The nominal brake build up time has to be stated as well.


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Figure 8: The master brake model parameters table


Standard deviations

Both decelerations and brake build up time depend on a lot of actual physical parameters of a lot of components. Due to the central limit theorem, the overall distribution function will be close to the standard distribution therefore. The related standard deviations are entered in the second line.

Speed limits

The upper speed limits of the seven speed sections. The last speed section has no upper speed limit. If you need less than seven sections, type ’i’ into the speed limit text field(s) that you want to set to ”infinity” (see figure 7).

In addition to this data, the deceleration effect of each component or group of components needs to be stated.

4.3.3 Brake Failure Models

A brake failure model contains all data related to the unavailability of a certain part of the train brake system, that is necessary to consider its effect to the braking capacity of the train:

Since the effect to braking distance is identical, independent from if the unavailability is known before or not, this data is also necessary (except of the probability) and sufficient to calculate all nominal brake models. Thus a brake failure model does not exclusively describe the functional safety parameters but also the operational effects. Therefore the inhibition of a special brake is also modelled by a brake failure model. If the inhibition and re-enabling would be perfectly safe, the probability of this failure would be zero. But in fact it can never be excluded that the command or status signal fails, so there is always a probability, that the special brake will not work as assumed by the ERTMS/ETCS on-board.

An unavailability that is known early enough (e. g. due to a brake test at start of mission or due to a track-side inhibition) doesn’t contribute to this probability. So if the complete system is tested at start-up and the test has a good fault detection and is sufficiently reliable, only those failures have to be considered, that occur within some few hours. Thus this probability is highly depending on the specific train.

All brake failure models related to a fix train model by combinatorial logic are presented in the brake components table in the middle of the graphics panel.


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Figure 9: The brake component models table and properties panel


This table displays all values of the brake failure models. If a brake failure model is selected in this table, its properties can be changed in the properties panel on the left.

4.3.4 The Brake Failure Models Properties Panel

General Properties

Name A user defined name of the brake failure model. The name must be unique within the train model.

Description A user defined description of the brake failure model.

Unavailability

Describes the probability of a failure on demand, given by the unavailability Q.

Effect

The effect if this component is not available. Most unavailabilities will affect the deceleration (equivalent to the brake forces). Some components will only or in addition affect the brake build-up time. Since deceleration will always decrease, only negative values are allowed for the changes of deceleration or brake forces. The unavailability of some components might also lead to a decrease of the resulting overall mean brake build-up time , therefore positive and negative values are possible.

Combinations

Number of elements The number of physical or logical elements in the train, that can fail by this failure mode.

Complete independence is assumed between these elements. For global failures, e. g. common cause failures, failures of the overall control system, failures of command or status signals etc., set this value to 1.

Distinguished states Distinguished numbers of available elements. In order to decrease the number of brake models it makes sometimes sense not to assign a separate brake model to each and every possible brake system state, but to group some states. For example if the train has 20 bogies whose pneumatic brakes can fail independently, it makes sense not to have a separate brake model for: no (known) unavailable bogies, for 1, for 2 etc. up to maybe 10, but only one for 0 or 1 unavailable bogies (19 avail.), one for 2 to 4 unavailable bogies (16 avail.), and one for 4 to 10 unavailable bogies (10 avail.). Thus only the states ”at least 10 bogies available”, ”at least 16 bogies available” and ”at least 19 bogies available” are distinguished.

In order to add or remove a single number, press the ”Ctrl” key while clicking the number you want to add or remove.

Inclusions Tell the algorithm that some other failure (or known unavailability) will have no additional effect if this failure (or known unavailability) occurs.

Only elements existing once per train can include other failures. If the failures of only some elements related to another failure are superseded by this failure, e. g. if a failure of this component affects only 5 out of 10 local elements, create two separate brake failure models of this type (with number of elements per train = 1 for each), and two seperate local element components (with number of elements per train = 5 for each).

Adhesion

Activate the checkbox if the brake force created by this component doesn’t depend on wheel-rail adhesion.

If the checkbox is deactivated, the decrease of deceleration (corresponding to the increase of braking distance according to EN 15595, see [Subset 040]) shall be entered as well.

Service brake

Activate the checkbox if the component is used also for service brake.

4.3.5 Brake Model Index Sections

The brake model index (BMI) is a 16 bit value. This 16 bit value is divided up into sections representing the status (availability) of certain parts (components) of the train brake system, including non-friction brakes such as regenerative brakes.

Each section typically corresponds to one brake failure model. The only exception is, if the effect of a brake failure model is included in another brake failure model, see the example below. The length of each section is determined by the number of distinguished states to be encoded in this section. The sequence of sections is identical to the sequence of brake failure models in the fix train model by combinatorial logic.

For example a failure of the (global) command signal for the magnetic shoes brakes (Mg brakes) will result in all Mg brakes not applied on demand. Thus the brake failure model for the command signal includes (supersedes) the brake failure model for local failures of the Mg brakes. Let’s further assume that there are 5 Mg brakes installed. The global command failure will result in all Mg brakes failing. The probability of this failure is usually much higher than the independent sporadic failure of 2 (or more) local Mg brakes. Thus it usually makes sense to define the standard case (all elements available) as one state, a sometimes needed partial defect state as a second state, and the complete loss as a third state.

state 1: 0 Mg brakes available (or 1 or 2)
state 2: 3 Mg brakes available (or 4)
state 3: 5 Mg brakes available

By this the number of brake models can be drastically reduced compared to coding each possible number of available Mg brakes (0-5) as a separate state. Since state 1 is already included in the global failure, if the global failure is described in the third brake failure model of the fix train model by combinatorial logic and the local failure in the sixth, the brake model index will be composed like this (assumed the fourth and fifth brake failure model is encoded in one bit):

xxxx xxxx xxLx xGxx

with G being the bit for the global failure, L the bit for the local failure.

The resulting encoding is shown in table 2, ”d” means ”don’t care”.


Table 2: Brake model index sections, example 1



No of avail. elem. L G



0, 1, 2 d 0



3, 4 0 1



5 1 1




If 3 and 4 available Mg brakes shall be encoded separately, the encoding will be like this:

xxxx  xxxx xLLx xGxx

with states listed in table 3.


Table 3: Brake model index sections, example 2



No of avail. elem. L L G



0, 1, 2 d d 0



3 0 0 1



4 0 1 1



5 1 0 1




The tab ’Brake model index sections’ shown in figure 10 provides information about the bits in the brake model index, so that the vehicle side train control software can be developed correctly.


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Figure 10: The brake model index sections table


In order to facilitate and ensure correct creation of the brake model index by a train control software, ETCS Brake Model Tool can create a C-code template, that will correctly reflect the content of the brake model index, see section 4.6.

4.3.6 Brake Models Table

Brake models are created when the Edit – Calculate Brake Models command is executed. After that the tab ’Brake models’ can be selected. All brake models related to the train model will be presented in a table in the graphics panel, see figure 11. This table displays all values of all brake models either as absolute values or as correction factors,


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Figure 11: The brake models table


4.4 Calculation of Correction Factors for Fix Brake Models by Monte-Carlo Simulation

If all statistical parameters of a train’s braking behaviour shall be modeled, it is not possible to calculate the correction factors by combinatorial logic anymore. In that case, a Monte-Carlo simulation is necessary. ETCS Brake Model Tool fully supports all requirements of [prEN 17997-1] plus some enhancements. A new model for Monte-Carlo simulation is created by File – Create New Member and selecting ”Fix Train Model by Monte Carlo Simulation”. All properties of the fix train model by Monte Carlo simulation are stored in the train model file with extension .fixmc. The simulation results and the final models will be stored in this file as well.

The input screen consists of three sections as shown in figure 12.


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Figure 12: The editor to define the architecture of the brake system


Before starting to define any parameters, define a nominal train state with respect to

This nominal state is not universally defined, you can (and have to) define it by yourself. Typically, the nominal train state assumes minimal mass (empty train) and maximum wheel diameter (new wheels). This definition has to be considered when you want to define a parameter later on in order to model the deviation from this nominal state.

4.4.1 General Train Model Data

This data is necessary for both fix and flexible train models. It is described in section 3.1.1.

4.4.2 Brake Model General Parameters

Here you have to enter the brake build up times and the upper speed limits of each section. The last section has no upper limit, i. e. if you want to define two speed sections, you only have to enter one value.

4.4.3 Architecture Editor

The third section is the architecture editor. Here the logical structure of the brake system is defined in terms of a block diagram.

There are two basic kinds of brake components: controls and actors. Both controls and actors may be characterized by an unavailabily (i. e. the probability of failing when the next emergency brake is required by the ETCS on-board) and statistical deviations, see section 4.4.5. An actor in addition is defined by its brake force for each speed section and some additional parameters, see section 4.4.8. A control can control other controls and/or actors, whereas an actor cannot control anything.

Components are added by Edit – Create Control or Edit – Create Actor. Both an actor or a control can be added on top level or below a selected control. Thus, the lowest level in the architecture contains only actors. The solid lines between components are to be read as ”controls” (from top to bottom) or as ”is controlled by” (from bottom to top).

4.4.4 Redundancies in Brake Systems

Typically, there are two kinds of redundancies in train brake systems:

With fix train model by Monte Carlo simulation of ETCS Brake Model Tool you can model ”redundancies by intention” as well – even if the replacement has different parameters compared to the nominal component.

A replacement is visualized by a background in orange colour. The replacement is controlled by the higher level control. I. e. the dotted line between the replacement and the nominal component is to be read as ”replaces” (from right to left) or as ”is replaced by” (from left to right). The replacement is always of same type (control or actor) as the nominal component, and the number of replacements is always identic to the number of nominal components.

If a control is simulated as ’failed’, the components of the branch below this control are ignored, i. e. the forces of all actors directly or indirectly controlled by this control will not be considered. If there is a replacement defined, the replacement branch will be considered instead. A replacing control may control the identic components as the nominal control (this is quite typical), but the replacement branch might as well look totally different.

4.4.5 Parameters of a Control

The parameters of a control are entered in the properties panel, see figure 13.


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Figure 13: Parameters of a control block


General Properties

Name Each control needs a name. Blocks with identic names denote the identic component in the system, except of their manifold (see below).

Description An optional description of the component.

Number of components per control The brake system of a train typically consists of many similar components, e. g. two clamps per wheelset, two cylinders per bogie, two bogies per car, one WSP per car controlling 4 valves each. It would be annoying and error prone if someone would need to define each of these components separately. Thus you can define for each component, how many of these components are controlled by the same control. In the diagram this number is shown in square brackes beside the name of the component.

By View – Expand Brake System Architecture each component of the overall brake system is shown with a separate box, and its particular number (e. g. ”[3/5]” means the third out of five identic components). The first component of each type is shown in the normal (dark) background, all similar components with lighter background.

Unavailability

The probability that the component will not perform its intended function when an emergency brake is commanded.

4.4.6 Random Variables

One of the benefits of fix train model by Monte Carlo simulation over fix train model by combinatorial logic is, that you can model the random characteristics of each component quite precisely. Each component may be characterised by multiple statistic parameters. By Create Local you define a random variable for each particular component of this kind. A dialog will open where you can select the distribution function and enter the relevant parameters, see figure 14.


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Figure 14: Statistical deviations parameters


Library values: Often the same value is used for many components. In order to simplify changing this value in all components, you can define a parameter holding the particular value. E. g. the value of the parameter ”Pad_s” in figure 14 is defined in the library for easy adaptation.

Random parameters independent of brake components: In practise, there are random parameters that aren’t induced by a technical characteristic of a brake system component. For example the wheel diameter is not related to any of the components of the brake system, but it affects the brake effort. Given that the two wheelsets of a bogie are supposed to always have the same diameter, but there is no relationship to the diameters of other wheelsets (re-profiling is performed bogie-wise), you can define a random variable on bogie level. If there is no control on bogie level, you can introduce a ”virtual” control on this level, i. e. a ”component” with no unavailability, just describing the wheel diameter with a random variable. Another (more difficult) option would be the use of global variables, see section 4.4.7.

Reciprocal of a random value: In case of a uniform distribution, you can select to use the reciprocal (see figure 15, i. e. to divide the brake force by the random value instead of multiplying.


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Figure 15: Parameters of a uniform distribution


This is in particular useful if you defined the nominal train status as train without load and maximum wheel diameter: In that case it is more intuitive to define the actual mass as a uniform distribution with min = 1.0 and max = mmax∕mmin and using the reciprocal instead of setting max = 1.0 and min = mmin∕mmax. Similar for the wheel diameter: It is more catchy to define a uniform distribution with min = dmin∕dmax and max = 1.0 and using the reciprocal instead of setting min = 1.0 and max = dmax∕dmin. 1

4.4.7 Global Random Variables

It is possible to define random variables outside components. These random variables are called global random variable. A global random variable can be created in any component by Create Global. A global random variable can be used by any component by selecting Add Global. A dialog will occur showing all existing global random variables, see figure 16.


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Figure 16: Global distribution selection


Assume for example a train consisting of three EMUs (of same or different type) coupled. Assume that all wheelsets of one EMU are typically re-profiled at the same time, thus the diameter of the wheelsets is a random variable on EMU level. The three EMUs within the train can be assumed to have different wheel diameters. Thus you can define a global variable ”dw_1” for EMU 1, ”dw_2” for EMU 2 and ”dw_3” for EMU 3 and use these variables in the relevant actors of the three EMUs.

4.4.8 Parameters of an Actor

The parameters of an actor are entered in the properties panel, see figure 17.


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Figure 17: Parameters of an actor


An actor has all parameters of a control (see section 4.4.5), plus the following in addition:

Nominal Forces per Element: The deceleration forces for each speed section for the nominal train state (positive values).

In the rare case that you want to consider a failure of the traction system (applying positive traction effort by fault), you can select the ”Traction” checkbox and enter the traction forces (positive values as well).

Adhesion: Select if the component is adhesion independent (e. g. magnetic track brakes or Eddy current brakes) or the decrease of deceleration in low adhesion conditions. See [prEN 17997-1] for more information.

Other parameters: Select the type of the actor and whether the actor shall be considered in the service brake model or not.

4.4.9 Performing the Simulation

In order to actually create ETCS brake models for commercial purpose, you’ll need to buy a license for ETCS Brake Model Tool.

Simulations are performed on a GPU due to computational effort. In ETCS Brake Model Tool version 2.2 only GPUs by NVIDIA are supported.

When you select Calculate – Calculate Brake Models and any previously determined simulation results are still valid (e. g. if you only change some general train model values), you’ll be asked whether you want to reuse the existing simulation results.

If there are no valid results or if you want to perform a simulation with more runs, the dialog shown in figure 18 will open.


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Figure 18: Simulation parameters


Simulation without GPU: If you have no NVIDIA GPU or no license for ETCS Brake Model Tool, you can nevertheless define a fix train model by Monte Carlo simulation and perform a Monte-Carlo simulation with 1 million simulation runs on the main CPU. 2

In that case a variant of the (free) GNU Compiler Collection (gcc) must exist on your computer (no installation required). For Microsoft Windows see e. g. www.mingw-w64.org. The path to the C-Compiler has to be stated here.

Simulation with Alternatives: If you select Simulate with Alternative ETCS Brake Model Tool will perform the standard simulation plus an additional simulation for each alternative parameter stated in the library, see section 2.4. The overall simulation time will extend accordingly. Thus it is typically useful and sufficient to reduce the number of simulations to e. g. 1 billion instead of 10 billion. The results are presented in the k_dry or A_dry chart, see section 4.4.10.

Progress Monitor: The progress of the simulation will be shown by a progress monitor, see figure 19. You can abort the simulation at any time. In that case any previous or intermediate results are lost.


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Figure 19: The progress monitor


Simulation results: In general, maximum eight brake models are required for a given trainset and brake system status – one for each combination of the three special brakes that can be de-activated by trackside. Since the simulation for de-activated special brakes only slightly increases the overall computational effort, these simulations will be performed as well.

Based on the simulation results the correction factors k_dry are determined considered a statistical confidence of 95% in accordance to [prEN 17997-1]. The ETCS brake models are presented in the Brake Models tab, see figure 20. Depending on the actually existing special brakes, two, four or even all eight brake models will be identic.


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Figure 20: The brake models table


4.4.10 k_dry and A_dry Chart

The simulation results can be presented graphically, see figure 21. The statistical confidence of 95% defined in [prEN 17997-1] is applied herefore as well.


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Figure 21: The chart presenting the dependency of the probability not to achieve the modeled deceleration as function of k_dry (or A_dry)


You can select which of the eight brake models (i. e. combination of special brakes) shall be shown, and whether the correction factors k_dry or the resulting safe deceleration a_dry shall be shown.

If the latest simulation has included alternative parameters (see section 4.4.9), you can select the curves for alternative parameters as well.

The graphics can be exported as .png or .svg file.

In the text field below the graphics, you can specify a probability and you’ll get the exact correction factors and decelerations for this probability.

4.5 The Emergency Brake Decelerations Chart Window

After having calculated the brake model parameters, you can calculate brake distances as a function of the initial speed by Calculate – Show Distances by EBCL Chart. A separate window will open, see figure 22.


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Figure 22: The emergency brake decelerations chart window


The brake distances for each brake model (BMI) and each EBCL can be visualized. The brake model for which the distances shall be shown is selected by its brake model index. The distances for different EBCL will be marked by different color.

Here, no track profiles or other data are considered. For calculating the brake curves according to [Subset 026-3] see section 8.

All axis can be scaled and zoomed.

The presented graphics can be exported to a vector graphic (.svg) or a bitmap (.png) file, select File – Export ... in the menu of the chart. Note that in vector graphics format, the graph data is exported with original resolution, so a later printout will have a very high quality (if not reduced by the later processing).

4.6 Exports

By Export – Export Brake Models all brake models of the fix train model will be saved in an CSV file with extension .csv. Depending on the result mode either absolute values are written for all EBCL’s, or for EBCL > 0 the correction factors will be written.

The file has the same name as the train model file, it is located in a subdirectory named ’export’.