Attributes of detectors

The Detectors window opens automatically when you insert a network object and have selected to automatically open the Edit dialog after object creation (Right-click behavior and action after creating an object). By default, only the Detectors list is opened.

Into the window, you enter attribute values for the network object. For network objects which have already been defined, you can call the window using the following functions:

  • ►  In the list of network objects of the network object type, double-click the row with the desired network object.
  • ►  In the Network editor, select the network object of your choice. Then, on its shortcut menu, click Edit.

The network object may have additional attributes. In the network objects list of the network object type, you can show all attributes and attribute values. You can open the list via the following functions:

In the network objects list of the network object type, you can edit attributes and attribute values of a network object (Selecting cells in lists), (Using lists).

The objects of this object type may have relations to other objects. This is why the attributes list is shown as part of a coupled list (on the left). On the Lists toolbar, in the Relations box, you can show and edit the coupled list with the attributes of the desired relation on the right (see below Showing and editing dependent objects as relation) and (Using coupled lists).

Note: In lists, you can use the  Attribute selection icon to show and hide attribute values (Selecting attributes and subattributes for columns of a list).

The basic attributes of the network element are shown in the upper area of the window and in the list of network objects for the particular network object type.

Element Description

Port no.

Physical Port number (PortNo) of the detector, which identifies the detector in the control procedures. If multiple detectors of a signal controller are available via the same number, they behave as if they are connected in parallel to one entry port of the control device (logical OR-operation).

Name

 Designation

Length

 Length of the detection range of a detector. The value 0.000 is e.g. permissible and useful for modeling trolley wire contacts and pedestrian sensors. These are represented in the network as thin horizontal lines.

SC

 Signal controller to which detector is assigned. If in the Type box, > PT Calling Pt. is selected, the SC box is deactivated. PT calling points do not belong to a specific signal controller.

Type

Type: Select detector type (Modeling PT lines):

  • Standard: Standard detectors detect vehicles, including PT vehicles.
  • Pulse: Impulse detectors do not send information regarding occupancy to the control procedures.
  • Presence: does not send information regarding the impulse via the front end or back end of the vehicle to the control procedures.
  • PT calling pt (PT calling point): only records PT vehicles that send PT telegrams.

Location tab

The list in the tab contains, amongst others, the following attributes:

Element Description
Link Link, in which the detector is located
Lane Ln: Number of lane on which the detector is installed.
At Position (Pos) Distance from start of the link or connector
Before stop Distance in front of stop line (DistStopLine): Distance of the front edge of the detector to the next signal head of its signal controller on its lane, if a signal head exists

Activation tab for vehicles

The list in the tab contains, amongst others, the following attributes:

Element Description
Vehicle Classes VehClasses: Vehicle classes detected by detector
Restriction to PT Lines:

PTLines: One or multiple PT lines, for which the detector shall be relevant. Thus vehicles of these PT lines are only detected if their vehicle class is selected.

Departure Signal

If this option is selected, the detector triggers an impulse for closing the doors of the PT vehicle under the following conditions:

  • If a PT vehicle is located on a detector and stops at the stop specified in the PT stop box, plus the boarding and alighting is completed in the first time step after the time defined in the s before departure box or before then.
  • When a PT vehicle is located on a detector that has already decided to omit the PT stop selected in the PT stop box. The impulse is then triggered upon reaching the detector.

The time the door is closed can thus be determined via the detector.

Activation tab for pedestrians

A detector defined for a link with the attribute Is pedestrian area is used to model pedestrians pressing a crosswalk button. Here pedestrian classes are displayed.

1.  Make the desired changes:

Element Description
Pedestrian Classes Pedestrian classes detected by detector. A pedestrian is recognized by the detector only if the pedestrian type belongs to a selected pedestrian class.
Maximum speed

If the pedestrian falls below this speed, a registration is transferred. The pedestrian requests a green light. If the pedestrian then exceeds this speed before the signal controller switches to green, a deregistration is transferred.

The maximum speed applies only to links used as pedestrian areas. The default value of 1.0 km/h prevents slow-moving pedestrians coming from the other side of the pedestrian crossing, for example, from triggering a call again.

Others tab

2.  Make the desired changes:

Element Description

Smoothing Factors

SmthFactDecr, SmthFactIncr: Factors for the exponential smoothing of occupancy values, which is conducted for individual control procedures (Exponential smoothing of detector occupancy rates).

  • Smoothing factor decrease: Factor used whien the detector is not occupied (attribute Presence = Passive).
  • Smoothing factor increase: Factor used when the detector is occupied (attribute Presence = Active).
Label

 If the option is not selected, the label for the detector is not displayed, even if the label for all detectors is selected.
Sound file (Sound)

SoundFile: Wavetable sound file *.wav, which is played each time a vehicle is detected by the detector. This file is saved in the same directory as the network file *.inpx. A sound card or suitable Microsoft Windows driver must be installed.

3.  Confirm with OK.

The network object has additional attributes that you can show in the Attributes list. Among them are the following for example:

Element Description

Presence

Presence state:

  • Active: A vehicle is located on the detector and is detected. This also applies for pedestrians.
  • Always Passive for detectors of the type Impulse and PT Calling Pt..

A vehicle is located on a detector, if the following conditions apply:

  • The vehicle is located on the same link as the detector.
  • The front edge of the vehicle has passed the start section of the detector: The Position (Pos) attribute of the vehicle is greater than the Position (Pos) attribute of the detector.
  • The rear edge of the vehicle has not yet passed the end section of the detector: The Position (Pos) attribute of the vehicle, minus the length of the vehicle (rear edge), is smaller than the Position (POS) attribute of the detector, plus the length of the detector (end position).

A pedestrian is considered on a detector, if the center of the pedestrian is located within the rectangle that defines the length of the detector and the width of the lane on which the detector is located.

Ensure that the detector is at least as long as the distance a pedestrian can walk within a simulation time step back. In addition, account for the maximum possible speed of the pedestrian at this position. If the detector dimensions are too short, meaning that in one time step, the center of the pedestrian will be in front of the detector and in the the next time step, the pedestrian will be behind it (having already passed it), the detector will not be able to detect the pedestrian. In front of and behind refer to the visually assessed walking direction on the pedestrian link. As pedestrians have no link coordinate, Vissim cannot determine whether the walking direction is towards or away from the detector.
Detection

Detection state:

  • Active for detectors of the types Standard and Occupancy, as long as the Presence attribute is active.
  • Active for detectors of the types Standard and Impulse after a vehicle or pedestrian occupies or leaves a detector, until the signal controller resets the detection state to Passive.
  • A fixed time control resets the value of the Detection attribute after each signal controller time step.
  • Always Passive for detectors of the type PT Calling Pt.

Impulse

Impulse state:

  • Active, as soon as a vehicle or pedestrian reaches a detector that is not occupied. The impulse state remains Active until the signal controller resets the impulse state back to Passive.
  • A fixed time control resets the value of the Impulse attribute after each signal controller time step.
  • Always Passive for detectors of the type Occupancy and PT Calling Pt..
Gap time

Time: Period [s] after the attribute Presence (Presence state) had the value Active. 0 = Presence attribute is Active.
Occupancy

Occ: Period [s] that has passed since occupancy of the detector. 0 = The detector is not occupied (Presence attribute = Passive). Always 0 for detectors of the type PT Calling Pt.
Occupancy rate

OccupRate: Proportion of time the detector was occupied during the last simulation second. The occupancy rate is exponentially smoothed based on each simulation second. Value range 0 to 100 %
Showing and editing dependent objects as relation

The attribute and attribute values of this network object type are shown in the list on the left, which consists of two coupled lists.

1.  In the list on the left, click the desired entry.

The list on the right contains attributes and attribute values of network objects, and/or base data allocated to the network object selected in the list on the left (Using coupled lists):

The attributes are described further above.

2.  On the list toolbar, in the Relations list, click the desired entry.

3.  Enter the desired data.

The data is allocated.

Superordinate topic:

Using detectors

Information on editing:

Defining detectors