Sensor-Actuator System

To design an ambient information system for the representation of human behavior and arousal, we developed a Sensor-Actuator System. Using the software MaxMSP, we set up a technical environment that allowed the acquired data streams to be mapped to physical parameters in real time and the signals to be recorded for later analysis. Behavior and arousal were captured by sensor measurements of:

  • position tracking (camera-based color tracking of red hat: x, y coordinates),
  • head movement (3-axis accelerometer fixed to red hat: sum of delta values),
  • wrist movement (3-axis accelerometer sensor in E4 Empatica wristband: sum of delta values),
  • heart rate (pulse sensor in E4 Empatica wristband: beats per minute (bpm).

Some sensors were wired, others transmitted data via xBee or bluetooth wireless protocols. The measured data was processed and different actuator parameters were controlled according to a rule-based system:

  • light by different types of lamps (brightness, hue, saturation, interval),
  • sound by speakers (source, volume, audio effects),
  • vibration by contact speakers (source, intensity, interval),
  • and airflow by a ventilator (strength, interval).

Ambient Information System (AIS)

For the technical implementation of the AIS, we developed a rule-based system that triggers the ambient events. It was based on conditions, thresholds, and value ranges that were defined or scaled based on preliminary tests we conducted with subjects. For example: If the participant is in the work area and the heart rate is above 85 bpm, start to increase the intensity of the contact speaker according to the bpm (85+).

We developed a mapping choreography to interpret measured data as behaviors and respond with physical feedback as signifiers: PDF.