Development of computational algorithm for prediction of photosensor signals in daylight conditions

This study aims to develop and validate an annual photosensor performance simulation method (APPSM) to compute the photosensor signals for a lighting control system under various daylight conditions. A series of computer simulations using PSENS, which is a simulation program within Radiance software were conducted and field measurements were performed under various daylight conditions in order to validate the simulation results of APPSM.Results indicate that the photosensor signals predicted by PSENS and APPSM showed a strong linear correlation. Prediction results by APPSM generally consisted with the results field measurements, although slight differences between them existed under particular daylight conditions. The differences in photosensor signals between the prediction by APPSM and measurement effectively decreased as shielding conditions were applied to photosensors.A strong linear relationship existed between the photosensor signals obtained from prediction by APPSM and the field measurements. The prediction models for the photosensor shielding conditions were acceptable with a significance level of 0.01. The majority of percent differences between the measured and simulated photosensor signals were within 10% under clear and partly cloudy sky conditions.