Wireless Sensor and Actuator Networks for Lighting Energy ...

Other than optimizing the energy consumption, the algorithm can potentially be
modified with different objective functions and constraints for other lighting
applications, such as stage lighting, mood lighting, and so on.
10.1.5 Human Subject Testing
Two topics related to the research system were studied on human subjects:
sensor placement and a comparison of the research system with a representative
commercial product. Both the research and the commercial lighting regulation systems
were implemented in the same small private office. Ten individuals were recruited to
participate in the test.
The sensor placement test studied the impact on the pertinence of the values
fused by the sensor validation and fusion algorithm if the sensor locations are
customized by the occupants. It also identified common patterns of sensor location
choices made by occupants. It was found that the fused sensor readings could deviate
from the task illuminance depending on how the sensors were placed. The lighting
might not be evenly distributed on the entire worksurface, and hence the readings from
each sensor could be inconsistent to some degree. Therefore, it is recommended that
occupants’ preferred lighting is expressed with respect to the fused sensor values for
lighting control purposes instead of referring to the pre-measured illuminance at the task
area.
No obvious pattern of sensor placement was observed from the test. However,
the fact that at least one sensor was pushed to the corner of the desk in almost all testing
cases implies that users move the sensors as far out as possible to maximize their
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