28 May 2017

Interactive Light Street

Research

During my minor course on Intelligent Environments at Technical Informatics at the HvA, I worked in a project to help increase the quality of residence in public spaces. In this particular case, the experiment was to increase the feeling and perception of safety on the ArenA Boulevard in the Amsterdam Bijlmer district. This research challenge was commissioned by research group CO-ReUs (Co-Creating Responsive Urban Spaces) in combination with the municipality of Amsterdam.

In a joint effort I worked on the design and development of the prototype of an an interactive light street that could then be used for our scientific research on this topic. The design process resulted in an embedded system consisting of battery powered LED-rails and a series of wireless cubes with ultrasone-sensors. The prototype allowed pedestrians on the boulevard to create dynamic environmental illumination with the aim to increase the perception of safety.

Perceived Safety in Public Spaces

Light plays an important role when it comes to the pedestrian’s perception of safety, by providing sufficient street lighting the collective sense of safety and security can be improved. Once this sense of safety and security due to sufficient street lighting has been reached, more pedestrians can be found after dark in public spaces. As soon as the sun sets, street lighting plays a major role in the quality of public spaces.

Light Contrasts

Traditional lighting, such as street lanterns, offers the pedestrians a visible field of sight, but also casts shadows and therefore increases the contrast between highlighted and shaded areas. Traditional lanterns also cast light downwards from a tall pole. A peripheral positioned light casts a bigger radius with a contrast that is lower than that of an overhead lighting, and therefore increase sight in the highlighted area.

Demo of the light street’s ultrasone modules: the LED strip illuminates the location of the pedestrian
Demo of the light street’s ultrasone modules: the LED strip illuminates the location of the pedestrian

Prototype

The light street consists of four LED strips that are each two meters long. Each LED rail is equipped with a battery and a printable circuit board holding a XBee module and an Arduino. Because every LED rail is powered and can communicate wirelessly, it can be modularly placed. Also, there are four sensor-cubes, all communicating wirelessly with a central Sodaq module.

Embedding the XBee module in the custom PCBs
Embedding the XBee module in the custom PCBs

The ultrasonic sensors measure distances constantly through echo-location. This signal is then used to calculate the position of a pedestrian in the proximity of the light street, triggering the LEDs positioned around the pedestrian. This creates an illuminated area around the individual.