Release

September 2021


Innovations:


  • vs | plus on-demand control

On-demand systems are traffic light systems that are only switched on when required. Two types are known in Germany:

  • All dark: all signal groups are switched to dark.
  • Half dark: some signal groups remain on, e.g. pedestrian remains on red

vs | plus is now able to control the switching on and off of such a system completely by itself.

Whether and when a system is active as a demand system or not is defined via a signal programme that contains a vs | plus demand control. For example, systems can be used as demand systems in a city by parameterising one of their vs | plus programmes with the vs | plus demand control. The other programmes without vs | plus demand control work as the usual vs | plus controls.

Switching the system off in demand mode is evaluated in vs | plus via the idle stage. This means that as soon as the idle stage configured in the vs | plus parameterisation is reached, e.g. main direction green or all red, the system is switched off and set to demand mode via a preconfigured switch-off sequence. As only one idle stage is defined for a signal programme, only one switch-off sequence can be configured per programme for demand control.

During demand mode, vs | plus continues to run internally and monitors whether requests are registered at the intersection. If a specific, predefined request is observed, the system is switched on. Up to three switch-on sequences can be parameterised per signal program in order to correspond to the different types of request (pedestrian, public transport, etc.).


vs | plus mode

Traffic situation

Idle stage



Full operation

Calls and extensions

inactive


 

Full operation

No traffic

active

             

           

On-demand mode - Switch-off sequence

No traffic

on-demand

             

             

On-demand mode

No traffic

on-demand

             

                

On-demand mode

Request

on-demand

             


   

On-demand mode - Switch-on sequence

Request

on-demand

             

             

Full operation

Calls and extensions

inactive


 



  • vs | plus Remaining time display

The forecast and display of the remaining red time of a signal group available for vs | plus 8.0.0 as open vs | plus programming is now anchored in the vs | plus core of version 9.0.0.

The remaining time display allows road users to see how long it will take for a connected signal group to turn green (vs | plus currently only supports remaining red displays).

Remaining time displays are easy to implement with fixed-time control, as it is known from the outset how long it will take until the next status change of a signal group. In contrast, in a traffic-dependent control system such as vs | plus, the current situation must be analysed in each calculation cycle (e.g. extensions due to increased traffic volume, prioritised interventions by PT, etc.). This constant reassessment means that the remaining time can also be constantly extended or shortened.

The algorithm for calculating the remaining time in vs | plus smoothes this dynamic and can be parameterised with additional fuses to ensure a continuous and smooth display of the remaining time.

The remaining time display requires a compatible control unit and an appropriately constructed display element (as an additional signal group), which can be operated via the newly created interface function from vs | plus. 

You can see an example of a compatible display element in remaining time display. 

The remaining time is visualised by an LED ring whose individual LEDs are switched off in a clockwise direction the shorter the remaining time. If the remaining time is longer, the switch-off is slowed down accordingly. However, this delay is hardly noticeable for the road user. After the stage transition has been switched (a stable situation), the display changes to a constantly counting down end sequence.


Figure 93: Remaining time display


More information