Operations at grade
Automated Transit Networks often feature elevated guideways. In the case of short headways elevation is often required in order to be able to intersect other traffic flows. However, when the intensity of traffic is lower at grade operations and intersections are possible. 2getthere is the only company in the industry applying advanced Obstacle Detection Sensors (ODS), a vital safety component for any automated system. The Rivium application features three at grade intersections with cars and five with pedestrians.
The obstacle detection system scans the base hull (vehicle swept path) and extended hull. The extended hull incorporates space adjacent to the path. The vehicle will slow down and ultimately stop for obstacles present in the base hull, while it would only slow down to pass at a lower speed for objects in the extended hull. The lower speed for objects in the extended hull ensures that the vehicles are still able to stop in time should the object move into the base hull.
The software for the interpretation of the sensor raw scans is developed by 2getthere. Both hulls are divided into detection cells, each scanned several times per second to determine a probability factor of an object being present. Based on probability the reaction is computed, which is translated to an adapted speed profile. It should be noted that the obstacle detection system is fail-safe by assuming the space is full of objects and needs to be scanned empty.
The Obstacle Detection Sensor features a wide aperture and four layer scans to detect any obstacles in or right adjacent to the driving path. Additionally the vehicles feature ultrasonic sensors to detect obstacles closer to the vehicle. The ultrasonic sensors are used for reversing, for instance from angled berths or when maneuvering in the maintenance area. The vehicle design also incorporates a safety bumper, which upon contact initiates an emergency stop, alongside emergency stop buttons both on the exterior (on every corner of the vehicle) and interior.