14.6 Signal Controllers

A signal controller applies a signal cycle to a signal group. The mapping of dynamic signals to a signal group is done in <controller>. The ID of the referenced signal is stored in the <control> element within the <controller> element. Unlike signal dependency, signal controllers are high-level elements that do not depend on other signals.

Dynamic content like the signal cycle itself is specified outside of this standard, for example, in ASAM OpenSCENARIO. For detailed definitions of terms specific to dynamic signals see Annex C, Terms for dynamic signals (normative).

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Figure 131. Example of a junction with 20 traffic lights mapped into six signal groups (IDs 42-47)

Figure 131 shows an example of an X-Junction with six traffic signals for vehicles, six traffic signals for trams, and eight traffic signals for pedestrians. These are grouped into six signal groups that are controlled by controller with ID 42 to 47.

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Figure 132. Example of a signal program that defines the signal cycles for the signal groups

Figure 132 shows an example of an appropriate signal program for signals controlled by controller with ID 42 and 44.

Elements in UML model

<controller> element

In ASAM OpenDRIVE, controllers are represented by the <controller> element within the <OpenDRIVE> element.

UML class: t_controller
XML tag:   <controller> (Multiplicity: 0..*)

Controllers provide a signal program for a traffic signal or a signal group. The mapping of traffic signals to a signal group is done in t_controller. Dynamic content like the signal program itself is specified outside of this standard (i.e. in OpenSCENARIO).

Table 126. Attributes of the <controller> element
Name Type Use Description

id

string

required

Unique ID within database

name

string

optional

Name of the controller. May be chosen freely.

sequence

nonNegativeInteger

optional

Sequence number (priority) of this controller with respect to other controllers of same logical level
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Figure 133. UML class diagram of the Controller class

Figure 133 shows the UML class diagram of the ASAM OpenDRIVE Controller class.

<control> element

In ASAM OpenDRIVE, controlled signals are represented by the <control> element within the <controller> element.

UML class: t_controller_control
XML tag:   <control> (Multiplicity: 1..*)

Provides information about a single signal within a signal group controlled by the corresponding controller.

Table 127. Attributes of the <control> element
Name Type Use Description

signalId

string

required

ID of the controlled signal

type

string

optional

Type of control.
Free Text, depends on the application.

XML example

Rules

The following rules apply to controllers:

  • Controllers shall be valid for one or more signals.

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