## Introduction

In the definition of agent’s properties it is mandatory to precise the number of the model to be used e.g.:

```
<agents operational_model_id="n">
```

The definition of any model parameter is composed of two different sections:

**model_parameters**: Model specific parameter. See below in the different model sections.**agent_parameters**: These parameter are mainly specific for the shape of pedestrians or other pedestrian properties like desired speed, reaction time etc.

## Model parameters (in general)

`<solver>euler</solver>`

- The solver for the ODE. Only
*Euler*. No other options.

- The solver for the ODE. Only
`<stepsize>0.001</stepsize>`

:- The time step for the solver. This should be choosed with care. For force-based model it is recommended to take a value between and s. For first-order models, a value of 0.05 s should be OK. A larger time step leads to faster simulations, however it is too risky and can lead to numerical instabilities, collisions and overlapping among pedestrians.
- Unit: s

`<exit_crossing_strategy>3</exit_crossing_strategy>`

- Positive values in . See Direction strategies for the definition of the strategies.

`<linkedcells enabled="true" cell_size="2"/>`

- Defines the size of the cells. This is important to get the neighbors of a pedestrians, which are all pedestrians within the eight neighboring cells. Larger cells, lead to slower simulations, since more pedestrian-pedestrian interactions need to be calculated.
- Unit: m

## Agent’s parameter (in general)

The *agent parameters* are mostly identical for all models. Exceptions will be mentioned explicitly.

The parameters that can be specified in this section are Gauss distributed (default value are given).

### Desired speed

`<v0 mu="1.2" sigma="0.0" />`

- Desired speed
- Unit: m/s

`<v0_upstairs mu="0.6" sigma="0.167" />`

- Desired speed upstairs
- Unit: m/s

`<v0_downstairs mu="0.6" sigma="0.188" />`

- Desired speed downstairs
- Unit: m/s

`<v0_idle_escalator_upstairs mu="0.6" sigma="0.0" />`

- Speed of idle escalators upstairs
- Unit: m/s

`<v0_idle_escalator_downstairs mu="0.6" sigma="0.0" />`

- Speed of idle escalators downstairs
- Unit: m/s

**Important:**The desired speed changes

*smoothly*from one plane to another. See this documentation for more details.

The reduced speed on stairs (up) is according to Tab 1 in Burghardt2014.

Handbook | Speed Stair Up |
---|---|

PM | 0.63 m/s |

WM | 0.61 m/s |

NM | 0.8 m/s |

FM | 0.55 m/s |

### Shape of pedestrians

Pedestrians are modeled as ellipses with two semi-axes: and , where

and

is the speed of a pedestrian.

`<bmax mu="0.15" sigma="0.0" />`

- Maximal length of the shoulder semi-axis
- Unit: m

`<bmin mu="0.15" sigma="0.0" />`

- Minimal length of the shoulder semi-axis
- Unit: m

`<amin mu="0.15" sigma="0.0" />`

- Minimal length of the movement semi-axis. This is the case when .
- Unit: m

`<atau mu="0." sigma="0.0" />`

- (Linear) speed-dependency of the movement semi-axis
- Unit: s

## Generalized Centrifugal Force Model

Generalized Centrifugal Force Model (preprint) is a force-based model.

Usage:

```
<model operational_model_id="1" description="gcfm">
```

## Collision-free Speed Model

Collision-free speed model is a velocity-based model. See also this talk for more details about the model.

Usage:

```
<model operational_model_id="3" description="Tordeux2015">
```

### Model parameters (Tordeux2015)

Besides the options defined in Model parameters the following options are necessary for this model:

`<force_ped a="5" D="0.2"/>`

- The influence of other pedestrians is triggered by and where is the strength of the interaction and gives its range. The naming may be misleading, since the model is
**not**force-based, but velocity-based. - Unit: m

- The influence of other pedestrians is triggered by and where is the strength of the interaction and gives its range. The naming may be misleading, since the model is
`<force_wall a="5" D="0.02"/>`

:- The influence of walls is triggered by and where is the strength of the interaction and gives its range. A larger value of may lead to blockades, especially when passing narrow bottlenecks.
- Unit: m

The names of the aforementioned parameters might be misleading, since the model is *not* force-based. The naming will be changed in the future.

### Agent parameters (Tordeux2015)

Actually, this model assumes circular pedestrian’s shape, therefore the parameter for the semi-axes should be chosen, such that circles with constant radius can be obtained. For example:

```
<bmax mu="0.15" sigma="0.0" />
<bmin mu="0.15" sigma="0.0" />
<amin mu="0.15" sigma="0.0" />
<atau mu="0." sigma="0.0" />
```

This defines circles with radius 15 cm.

Other parameters in this section are:

`<tau mu="0.5" sigma="0.0" />`

- Reaction time. This constant is used in the driving force of the force-based forces. Small instantaneous acceleration.
- Unit: s

`<T mu="1" sigma="0.0" />`

- Specific parameter for model 3 (Tordeux2015). Defines the slope of the speed function.

In summary the relevant section for this model could look like:

```
<model operational_model_id="3" description="Tordeux2015">
<model_parameters>
<solver>euler</solver>
<stepsize>0.05</stepsize>
<exit_crossing_strategy>3</exit_crossing_strategy>
<linkedcells enabled="true" cell_size="2"/>
<force_ped a="5" D="0.2"/>
<force_wall a="5" D="0.02"/>
</model_parameters>
<agent_parameters agent_parameter_id="1">
<v0 mu="1.34" sigma="0.0" />
<v0_upstairs mu="0.668" sigma="0.167" />
<v0_downstairs mu="0.750" sigma="0.188" />
<v0_idle_escalator_upstairs mu="0.5" sigma="0.0" />
<v0_idle_escalator_downstairs mu="0.5" sigma="0.0" />
<bmax mu="0.15" sigma="0.0" />
<bmin mu="0.15" sigma="0.0" />
<amin mu="0.15" sigma="0.0" />
<atau mu="0." sigma="0.0" />
<tau mu="0.5" sigma="0.0" />
<T mu="1" sigma="0.0" />
</agent_parameters>
</model>
```

**Note:**The recommended values are by no means universal, and may/should be calibrated to fit your scenario.