Sky Light Intersection System

Sky Light Intersection System is the solution to regulate red and green light timing length based on real time traffic conditions.

Wireless sensors are installed in the road surface and collect data continuously, then send them to the traffic regulator via radio, without any wiring work. This system is an efficient wireless replacement to inductive loops.

Thanks to its optical detection technology, Sky Light Sensor is more precise than inductive loops and magnetic sensors, especially in heavy traffic conditions when vehicles are very close to one another and there is a stop and go situation.

A controller adapts traffic light phases according to the real-time traffic situation to relieve traffic congestion and improve the flow of vehicles.

Sky Light Sensor is able to detect vehicles. The sensors send data to a board called Sky Light Hub in real time. In order to replicate the operation of inductive loop systems, a board has been specifically designed. It is called Sky Light Interface Card and it is placed inside the traffic light controller cabinet. Sky Light Hub is integrated directly on this board and it transfers traffic data through a UART serial port. Using opto-isolated dry contacts, data are transferred to the traffic light controller directly.

Besides data transmission to the traffic light regulator, this system can be adapted for different uses.

Configuring the system in presence mode, it is possible to signal to the traffic regulator that a vehicle is at the stop line waiting for the signal to turn green. This operation is similar to pedestrian call buttons.

Another application is to use the system for queue length measurement. Placing the sensors at different distances from the intersection it is possible to measure the length of the queue formed by vehicles waiting for green light.

COMPONENTS

SKY LIGHT SENSOR

It’s a solid, accurate wireless sensor. It is designed to resist the stress of heavy traffic on the roads and of weather conditions.
Sky Light Sensor works with a combination of three detection technologies, coming from a patented ambient light sensor, an infrared sensor and a magnetic sensor. A strong algorithm guarantees extreme accuracy and eliminates possible errors.
Wireless communication offers a great flexibility in choice of location and layout.
Maintenance and installation operations will be quick and easy, using common construction tools. Interrupting the traffic flow completely is not necessary. This is thanks to an additional external case where the sensor is placed.
Sky Light Sensor is powered by a long life battery. If it starts to run out after several years of intense use, Nabla Quadro offers a battery replacement service to guarantee the longest product life.

SKY LIGHT HUB

Sky Light Hub is a radio receiver and coordinator to acquire data from the sensors.
It is a very small component (39mm x 29mm) and it is able to handle up to 16 sensors.
Information about traffic, such as start and end timestamp, is available through a UART serial port.
In the configuration proposed, Sky Light Hub is integrated inside the Access Point, so to send traffic data to a server directly. But, it is possible to use different devices to acquire data from the hub. This enables the creation of a very flexible system where integrators and users can decide to use their preferred devices.
Integrating our system with components from other providers is extremely simple, thanks to transmission and decryption protocols available to users.

SKY LIGHT INTERFACE CARD

Sky Light Interface Card is a 16-channel dry contact board that has a specific slot for the integration of Sky Light Hub.
The events coming from the sensors are inputs to open/close opto-isolated contacts, exactly like inductive loop systems.
Channels are independent from one another and are marked with numbers from 1 to 16. All the events detected by one sensor generate a transition on the corresponding contact. The action associated to an event is set through the configuration software included in the system.
A group of sensors can be associated to an auxiliary output that reacts to a combination of events. For example, you can set a logical OR of two or more sensors to create a wider virtual inductive loop)
The Interface Card has two contacts for diagnosis purposes, in order to communicate possible faults of the sensors and possible interruption of power supply.
The system can be powered by any kind of continuous power supply with a voltage between 10 V and 26 V, thanks to its DC-to-DC converter.
The total electrical absorption is around 60 mA (hub included).

WHAT YOU CAN DO

Managing phases of the traffic signal controller according to real-time traffic conditions, both for single signals or to coordinate more traffic lights

Creating a system to actuate a traffic light when there are vehicles waiting at the stop line

Measurement of the length of the queue in each arm of the intersection

Using data to plan road works, new infrastructures or an alternative mobility management

PROJECTS

Smart City Trento
Smart City Trento

Trento has been one of the first cities to test Sky Light technology …

Smart Cities Test Plant Bologna
Smart Cities Test Plant

In Bologna one of the biggest test plant has been installed …

Smart City tests at National Research Council in Bologna
Smart City tests at CNR BO

The Smart Services Cooperation Lab in Bologna …

Traffic light control in Rome Flaminio
Traffic lights in Rome

The system has been installed by Citelum, one of the most …

Traffic light control for trams in Padova
Tram at a junction in Padova

A test to detect trains approaching a traffic light

Traffic light control for trams in Rome Aldrovandi
Tram detection in Rome

In November 2014 Nabla Quadro and Roma Servizi per la Mobilità started…

Traffic light control for trains in Rome Casilina
Train priority in Rome

This installation has been completed in June 2015 with Roma Servizi per la Mobilità srl…

Traffic light control in Rome Nomentana
Smart traffic lights in Rome

Sky Light Intersection System has been installed in via Nomentana

Traffic light control in Genova
Sensors vs loops in Genova

A comparison between two technologies for traffic light control

Truck monitoring in Este
Truck monitoring in Este

Urban access regulation needs traffic data to …

Traffic monitoring in L’Aquila
Traffic monitoring in L'Aquila

A big project on traffic monitoring on the …

Traffic monitoring at Tosano shopping mall
Traffic at the shopping mall

Traffic data are useful to understand how many visitors…

Traffic monitoring in Castel Romano
Traffic in Castel Romano

The first test plant for traffic monitoring in…