LED Lighting Fixture with Human Detection Sensor for Power Modulation
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Solution Overview
Problem
Conventional street lighting fixtures with metal halide lamps lack light modulation control, resulting in high power consumption even when no one is present, as they can only operate at 100% lighting output.
Innovation Solution
A lighting fixture equipped with an LED light source, a human detecting sensor, and a controller that adjusts the light modulation level based on the sensor's detection, setting it to a lower level when no one is detected and increasing it when a person is present, thereby reducing power consumption during periods of low occupancy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If metal halide lamp with EE switch is used, then ON/OFF control is achieved, but light modulation control cannot be performed resulting in high power consumption
Solution Approach 1:
The patent changes the operating parameter of the light source from fixed 100% output to variable light modulation levels (e.g., 100%, 70%, 50%). By controlling the LED driver to adjust the light output level based on detection results, the system achieves both energy savings and adaptability. This resolves the contradiction by enabling parameter variation while maintaining control capability.
Solution Approach 2:
The patent introduces dynamic light modulation control where the light output level is not fixed but varies in real-time based on detection results. The system transitions from static 100% lighting to dynamic adjustment (full light when person detected, reduced light when not detected), achieving both energy efficiency and adaptability through temporal variation of operating parameters.
2Loss of energy
If light modulation control is implemented, then power consumption is reduced, but device complexity increases
Solution Approach 1:
The patent makes the detection device serve multiple functions: it not only detects the presence of persons but also triggers light modulation control. The same detection mechanism is used for both occupancy detection and light level adjustment decisions, reducing the need for separate control systems and minimizing overall device complexity while achieving energy savings.
Solution Approach 2:
The patent implements a feedback control system where detection results are fed back to the LED driver to adjust light output levels. This simple feedback loop (detection → control decision → light modulation → energy savings) provides effective power consumption reduction without requiring complex control algorithms or multiple sensors, thus minimizing the increase in device complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively reduces power consumption by modulating the light output according to the presence of individuals, maintaining adequate illumination during peak periods while minimizing energy use during less busy times, thus optimizing energy efficiency.
Implementation Method 1
an LED
Implementation Method 2
a human detecting sensor configured to detect a person
Data Source
AI summary
A controller of a lighting fixture is configured to set a light modulation level of an LED to a first light modulation level in a period from a beginning of a night time slot until when a predetermined first time period elapses, regardless of a detection result of a human detecting sensor, and set the light modulation level of the LED to a second light modulation level that is lower than the first light modulation level when the first time period elapses. The controller is configured to set, when the human detecting sensor detects a person in a state where the light modulation level of the LED is set to the second light modulation level, the light modulation level of the LED to the first light modulation level for a predetermined time period.