Variable Lighting Control via Occupancy and Ambient Sensors
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Solution Overview
Problem
Conventional occupancy-based lighting systems using PIR, ultrasonic, and dual-technology sensors are limited in flexibility and energy efficiency, as they primarily operate in full-on or full-off states, lacking the ability to adjust lighting levels based on occupancy and ambient light conditions, and are constrained by specific installation requirements and sensitivity issues.
Innovation Solution
The development of LED-based lighting systems equipped with occupancy and ambient light sensors, state machine controllers, and communication interfaces, allowing for programmable dimming and variable lighting levels based on occupancy, ambient light, and time, enabling sophisticated control of illumination to reduce energy consumption and enhance user comfort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional occupancy sensors (PIR, ultrasonic, dual-technology) are used for lighting control, then motion detection capability is provided, but lighting flexibility is limited to full-on/full-off states only
Solution Approach 1:
The patent implements dynamic lighting control by transitioning from static full-on/full-off states to variable dimming levels. The lighting system continuously adjusts illumination intensity based on real-time occupancy detection and ambient light sensor readings, enabling smooth transitions across multiple brightness states rather than binary on/off control.
Solution Approach 2:
The patent changes the control parameter from binary (on/off) to continuous variable output (dimming levels). By incorporating ambient light sensors and occupancy sensors that provide analog or multi-level digital signals, the system adjusts lighting intensity as a continuous parameter rather than discrete states, achieving greater adaptability.
2Loss of energy
If conventional occupancy-based lighting systems operate in full-on/full-off states, then energy saving is achieved through simple switching, but energy efficiency is limited due to inability to adjust lighting levels
Solution Approach 1:
The patent implements feedback control by continuously monitoring ambient light levels through photodiode sensors and occupancy status through motion detectors. The system uses this feedback information to dynamically adjust lighting output, reducing illumination when ambient light is sufficient or occupancy is low, thereby optimizing energy consumption based on real-time conditions.
Solution Approach 2:
The system transitions from static switching to dynamic dimming control, continuously adjusting lighting intensity based on environmental conditions and occupancy patterns. This dynamic adjustment enables progressive energy reduction rather than abrupt on/off transitions, improving overall energy efficiency.
3Measurement precision
If PIR sensors are used for occupancy detection, then motion sensing is provided, but sensitivity to minor movement at distances greater than 15 feet is limited
Solution Approach 1:
The patent combines multiple sensing technologies including PIR sensors, ultrasonic sensors, and ambient light photodiodes into an integrated occupancy detection system. This multi-sensor approach compensates for the limitations of individual sensors by cross-validating detection signals and extending effective detection range while maintaining sensitivity.
Solution Approach 2:
The lighting system incorporates multiple sensor types that serve multiple functions: PIR sensors detect thermal motion patterns, ultrasonic sensors detect acoustic wave reflections from moving objects, and photodiodes monitor ambient light levels. This multi-functional sensing approach enables accurate occupancy detection across various distances and movement types.
4Length of stationary object
If ultrasonic sensors are used for occupancy detection, then detection range is extended beyond line-of-sight requirements, but sensitivity to high levels of vibration and air flow increases causing nuisance switching
Solution Approach 1:
The patent uses the ultrasonic sensor as an intermediary detection layer that works in conjunction with PIR and ambient light sensors. The ultrasonic sensor provides additional detection capability for obscured or distant occupancy, while the system integrates multiple sensor inputs to verify occupancy signals, reducing false activations from vibration or air flow interference.
5Adaptability or versatility
If LED-based lighting systems with multiple sensors and state machine controllers are implemented, then lighting control flexibility and energy efficiency are improved, but device complexity increases
Solution Approach 1:
The patent segments the lighting control system into modular functional blocks: occupancy sensing module, ambient light sensing module, state machine control module, and LED driver module. Each module performs a specific function and can be independently configured or replaced, managing complexity through functional decomposition while maintaining system flexibility.
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 LED-based lighting systems provide customizable and energy-efficient illumination by dynamically adjusting lighting levels based on occupancy and ambient conditions, optimizing energy use and user comfort, while accommodating various environmental settings.
Implementation Method 1
A sensor module including a photodiode for detecting an intensity of ambient light
Implementation Method 2
PIR sensors sense the difference in heat emitted by humans in motion from that of the background space
Data Source
AI summary
A presence or an absence of an occupant is detected, and an occupancy sensor signal is generated representative of an active state in which the presence of the occupant is detected, and an inactive state in which the absence of the occupant is detected. An ambient light sensor detects the ambient light level and generates an ambient light sensor signal representative of the ambient light level. Dimmable illumination is generated at a first dimming level, based on the ambient light level, corresponding to the active state and a second dimming level corresponding to the inactive state. A transition delay time between an onset of the inactive state and a transition between the first dimming level and the second dimming level may be controlled. The first dimming level, the second dimming level, and/or the transition delay time may be variably set or controlled locally or via a remote device.