Driver assistance systems
Tram forward collision warning system

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PRODUCT BENEFITS▶ Active support for tram drivers in critical situationsin urban traffic▶ Greater safety for driver and passengers as well asfor all other road users in the immediate vicinity▶ Trams more consistently on time thanks to reductionof accident frequency▶ Reduced costs by avoiding or reducing accidents

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Mid-range radar sensor

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Rail control unit

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Multi purpose camera

Driver assistance systems Tram forward collision warning system

DANGER DETECTED
For tram drivers, tough situations like heavy commuter traffic orpoor visibility quickly become serious challenges. Obstacles on
the rails or road users who approach the rails have to be detected in enough time for the risks to be recognized.
DANGER AVERTEDWhen it comes to its collision warning system for light rail vehicles,
Bosch Engineering relies on proven components from automotive
technology to actively reduce the expensive consequences of accidents or prevent them altogether. If the system detects an impending collision, it warns the tram driver, and if the driver reacts
too late or not at all, the system can initiate automatic braking.
GREEN LIGHT FOR GREATER SAFETY
The collision warning system consists of a multi purpose camera, a radar sensor and a control unit. The multi purpose camera
monitors the track layout ahead, as well as vehicles and people
and transmits this information in real time to the radar sensor.
The object information of the video camera and radar sensor arefused to an overall picture of the environment. Taking the vehicle’s speed into consideration, the system uses the information
to determine the danger of a collision.
In the event of a hazard due to an obstacle, the system calculates whether an optical and / or acoustic warning should be given
to the driver. It determines whether the threat presented by anobstacle warrants a visual and/or acoustic warning to the driver.
It sends a signal via relay output to trigger automatic braking,Detecting critical situations

should the driver respond too late or not at all to the system’swarning. The relay’s switching function can be checked automatically when the system starts up to confirm that it is working
properly. The tram drivers can take action – they can override
the system or stop the initiation of automatic braking via thedriver control function if the dangerous situation has alreadybeen resolved.
The system monitoring function gives the driver an overview ofcomponents’ system status, which can be displayed using LED,for example. How the warning is given, the warning/braking
thresholds, and other system parameters can be individuallycustomized
RECOGNIZING – AND LEVERAGING – STRENGTHS
Combining the data from the multi purpose camera and mid-range
radar sensor improves obstacle detection. The principle of sensor
data fusion, adopted from the field of automation development
for road vehicles, selectively merges the strengths of multiple
sensor principles. In this way, it boosts both the reliability and theavailability of the sensor technology.

Driver assistance systems Tram forward collision warning system

TECHNICAL CHARACTERISTICS
SystemAperture

up to +/− 35° horizontal

Speedmax. 80 km/h

Compatibility

Electromagnetic compatibility (EMC) as per DIN EN50121-3-2

Output interface

8 digital outputs

Warning and braking threshold

can be tailored for customerInput interfaces

up to 4 analog inputs, e. g. speed signal, warning/ braking
acknowledgement, relay monitoring

Certification

EN50155

Tram forward collision warning system

Driver brakes

Driver canintervene
Criticalsituation

Objectdetection

Situation
analysis

Warning to driver(acoust./vis.)

Collision warning system
initiates braking

Braking
initiatedDriver assistance systems Tram forward collision warning system

improvedsafetythrough avoiding collisions by means of early warning or braking system

lowersimple

cost

integration

for the correction of accident consequences, as collisions
can be avoided or significantly reduced

thanks to compact components

highavailabilityof light rail vehicles: fewer accidents means
less vehicle downtime

TASK
The collision warning system for trams supports drivers in criticalsituations. Especially in congested traffic or poor visibility conditions, the system warns the driver about obstacles on the rails inplenty of time. This lets drivers avoid accidents, or at least significantly limit the effects.

FUNCTION
Consisting of a multi purpose camera, a radar sensor, and a control unit, the system monitors the track ahead and any possible
obstacles in front of the vehicle in real time. If it detects a potential collision, it sends a warning to the driver. And should thedriver respond too late or not at all, the collision warning system
can initiate automatic braking.

Bosch Engineering GmbH | Robert-Bosch-Allee 1 | 74232 Abstatt | Germany | BEG.Rail@de.bosch.com | www.bosch-engineering.com
Printed in Germany 292000P1NP-03/2021-BEG © Robert Bosch GmbH 2021. All rights reserved, also regarding any disposal, exploitation, reproduction,editing, distribution, as well as in the event of applications for industrial property rights.