Non-Intrusive Luminance Mapping via High Dynamic Range Imaging and 3-D Reconstruction

Continuous luminance monitoring is challenging because high-dynamic-range cameras are expensive, they need programming, and are intrusive when placed near the occupants’ field-of-view. A new semi-automated and non-intrusive framework is presented for monitoring occupant-perceived luminance using a low-cost camera sensor and Structure-from- Motion (SfM)-Multiview Stereo (MVS) photogrammetry pipeline. Using a short video and a few photos from the occupant position, the 3D space geometry is automatically reconstructed. Retrieved 3D context enables the back-projection of the camera-captured luminance distribution into 3D spaces that are in turn re-projected to occupant-FOVs. The framework was tested and validated in a testbed office. The re-projected luminance field showed with good agreement with luminance measured at the occupant position. The new method can be used for non-intrusive luminance monitoring integrated with daylighting control applications.

Standardisation issues related to lighting and daylighting control systems

Even though there are existing codes and standards regarding daylighting and electric lighting controls, they have to be constantly reviewed and updated, as the technology is growing rapidly - and so do the users’ expectations. That is, in both efficiency of buildings in terms of sustainability and energy usage (utilizing advanced sensor-based systems), and also in the need for high quality of lighting at the workplaces.

Review of lighting and daylighting control systems

There is a large number of control systems proposed either by lighting manufacturers or motor manufacturers for shading systems. In addition there are many other solutions proposed by specific manufacturers of Building Management Systems (BMS) or manufacturers of components to be installed in luminaires and switches, as well as in the electric lighting architecture (transformers, gateways to the internet, sensors, etc.). For many consumers -i.e.-the installer, the facility manager, or the final user (building occupant) – this forms a complex and dynamic market environment with high frequent changes, every year or even every month or day. In this report we aim to provide some basic strategic information, showing the status of the supply at the time this report was written (2019-2021). Although the market develops very fast, there are principles of controls which are rather independent of the progress of technology.