Philips Zhang Yuning: The best use method and experiment analysis of office natural light

In the field of intelligent lighting, the rational use of natural light and the cooperation of natural light, shading system and artificial light are interesting topics. This article is Zhang Yuning of Philips (China) Investment Co., Ltd. to describe some of our attempts and methods.

1. Balance natural light and artificial light

Balanced natural and artificial light with advanced technology to maximize energy savings and improve indoor comfort.

The picture below shows a successful example of a successful installation of an intelligent lighting control system and an electric shading system in Europe, which reduces the energy consumption of the building during its completion and subsequent use. Moreover, the application of advanced lighting solutions has also reduced the building's carbon dioxide emissions, which is also in line with the project owner's environmental strategy and its environmental protection system.

The system is easy to understand and easy to operate. While adjusting the lighting to meet the needs of users, it not only provides comfortable lighting effects for employees' office space, but also helps users save energy.


Figure 1 Apator's smart office building

Similar products and solutions are not uncommon in China. The basic principle is simple, even simple: use natural light as much as possible. When the natural light is too strong or insufficient, it is adjusted with the shading device and the artificial light source, and the specific illumination of the target area has been reached.

This article explores a specific problem from a technical perspective: control accuracy. That is, the method used can improve the accuracy of illumination control as high as possible.

In general, as the most important basis for illuminance control, the illuminance sensor is mounted on the ceiling. The area we are interested in is the office area of ​​the person, the office desk. According to the general design requirements, the desktop illumination should reach 500 lux in the office environment.

This is the goal of the design: dynamic adjustment of natural light, shading equipment (curtains) and artificial light sources to maintain a specific desktop illumination of 500 lux.

The picture below is the environment we built experimentally.

Among them, two illuminance sensors are respectively used to collect the illuminance of the target area of ​​the outdoor illuminance, and are used as input parameters of the closed loop control. The illuminometer placed on the table is used as a calibration device to evaluate the accuracy of the system and is not a device in the system. There are also control systems for lighting and shading equipment as well as computers for testing.


Figure 2 Experimental construction

The control algorithm is shown in Figure 3: the input conditions for the judgment are the solar illuminance, the desktop illuminance, the brightness level of the light, and the position of the curtain. The output is the new light level and curtain position. The goal of the algorithm is to keep the desktop illumination constant (500 lux).


Figure 3 Constant illumination control algorithm

Ceiling Lamp

Hallway Ceiling Lights,Rustic Ceiling Lights,Brass Ceiling Lights,Glass Ceiling Lights

GUANGDONG LAVIUS LIGHTING CO., LTD. , https://www.laviuslighting.com