In 1996, the first traffic signal controllers in Munich were supplied directly with the TRENDS kernel. The TRENDS kernel is a reliable, transparent, rule based system for intersection control with a free logic language, in devices continuity and already implemented within various signal controllers of different manufacturers. Through the traffic engineering workstation CROSSIG, the control can be directly supplied since the early 1990s. The TRENDS kernel is used by cities like Munich, Dortmund, Ingolstadt, Gdansk, Cracow, Beograd and many others.
Direct supply of traffic signal control
The direct supply of traffic signal controllers can be distinguished into semi-automatic and fully automatic direct supply:
- Semi-automatic direct supply: The traffic engineer’s supply is translated to the controller specific computer language by a compiler. An advantage is that controller specific functions can be used. The disadvantage, however, is that the planning has to be specific to a certain traffic signal controller. Unfortunately, it is often not known which traffic signal controller finally will be used in the field when the traffic planning is done, as this tender is usually placed after the planning. For that reason, the traffic engineer’s planning remains unfinished and has to be completed manually by the traffic controller manufacturer, which is expensive. New controller specific functions cannot be considered within the planning process, as long as the traffic engineering workstation and the compiler are not updated.
- Fully automatic direct supply: The supply from the traffic engineering workstation can be used directly to supply the traffic signal controller. The planning is therefore completely independent from the controller in the field. The translation of the commands to the controller specific computer language has only to be done once when implementing the interface between the TRENDS kernel and the controller runtime environment by the controller manufacturer. The translation of the commands used by the traffic engineer and the public administration for the traffic engineering and the supply of the traffic signal controller do not cause any additional effort and costs anymore.
Traffic engineer planning with the engineering workstation CROSSIG
Traffic signal controllers from SIEMENS can be planned and semi-automatically supplied with CROSSIG.
Traffic signal controllers from various manufacturers support the TRENDS kernel. These controllers can be planned, tested and fully automatically supplied directly with CROSSIG.
Traffic signal controller direct supply with CROSSIG
New TRENDS Kernel 5.2
As of 2014 the TRENDS kernel is available as Version 5.2 with extended functionality.
The TRENDS kernel 5.2 extends the previous TRENDS-Kern kernel 4.2 by the following functionalities:
- Higher number of signal groups, detectors, reporting points, as well as logical conditions and constants.
- Verification of network control commands (e.g., PTV BALANCE) by the TRENDS kernel (not as before by the control unit).
- Support for current OCIT-O and OTS interface requirements.
- Complete support of R09.xx telegrams, for example to take account of the timetable for flexible public transport prioritization.
- Integration of traffic situation detectors, e.g. to use travel times from TOMTOM within the vehicle actuated control logic.
- Connection of the model-based node control system PTV EPICS via the TRENDS core. The combination of TRENDS and EPICS thus uniquely combines the advantages of control- and model-based control.
The implementation of the TRENDS kernel is free of licensing fees and can be ordered via GEVAS software.