Technics
The Section 1216 playground floor is based on a simple principle. We chose not to use RFID (Remote Frequency IDentification) in a traditional use identification of objects. Instead the concept incorporates the RFID tags into a grid on the floor. Each tag in the grid has its own unique ID and then so does each location on the floor.
The user of the system is equipped with a bracelet around the ankle containing the RFID reader, a Bluetooth module, a small vibrating unit and a piezo speaker. While the user is walking over the floor the reader scans the tags the user walks over and a passes the identification number on to a computer located on the side of the field via the Bluetooth module.
In the computer there is a software program with a digital representation of the RFID grid in the floor. This program receives the identification numbers from tags the user is walking over and by these means can track the whereabouts of the user on the floor. Figure 1 displays a schematic overview of the steps of the communication of the system.
With the received data the software system not only can track the whereabouts of the users it can also calculate the direction and the speed the user is going in that direction. These variables are compared to the variables calculated for the other users and by these means the system can make predictions about possible collisions between users.
If there is significant danger about a collision the system warns the users by sending a signal back to the ankle bracelet over the Bluetooth connection. In the bracelet a vibration motor and a small piezo 
speaker are activated to warn the user about the collision. If the user gets near the edges of the field the system also gives a warning signal.
The audio signaling coming from the piezo in the bracelet also gives other users the possibility to hear where their fellow teammates are walking, so the signaling uses can also be employed as a part of an application on the field.
Next to this interacting system of floor, bracelet and computer software there is also a separate audio setup round the field. With 8 speakers placed all round the side of the field different audio environments can be created. The speakers are also controlled by the computer software but serve a more entertainment value than a practical collision warning value.
