Office intelligent lighting system based on the natural lighting and the ZigBee wireless network

Area of Science:

• Building Science
• Illumination Engineering
• Control Systems

Background:

• Discomforting lighting environments reduce comfort, work efficiency, and cause visual fatigue.
• Optimizing artificial lighting with natural light is crucial for energy efficiency and user well-being.
• Existing systems may not dynamically adapt to real-time occupancy and natural light variations.

Purpose of the Study:

• To develop an intelligent lighting system for offices that enhances comfort and work efficiency.
• To dynamically adjust artificial lighting based on natural light availability and workspace occupancy.
• To achieve significant energy savings through intelligent illumination control.

Main Methods:

• A control algorithm was developed to establish a linear function between illuminance, natural lighting, occupancy, adjacent luminaire illuminance, and dimming factor (K).
• The simplex method was employed to determine the optimal dimming factor (K) for each luminaire.
• A ZigBee tree network structure was used for transmitting dimming factors to luminaires.
• Network simulation (Opnet) and lighting simulation (DIAlux) were used for system verification.

Main Results:

• Network transmission delay was 0.011 s, with load and throughput exceeding 3.0×10⁴ bits/s.
• Simulated illuminance reached 500 lx on occupied surfaces and 300 lx on unoccupied surfaces.
• Illuminance uniformity was maintained above 0.7, with improvements noted in day mode compared to uncontrolled systems.
• Energy savings of 34% during the day and 25% at night were achieved.

Conclusions:

• The proposed intelligent lighting system effectively manages office illumination for comfort and efficiency.
• The system demonstrates significant energy savings through dynamic adaptation to environmental conditions.
• The ZigBee network ensures reliable and efficient transmission of control signals for real-time lighting adjustments.