Luminaire Daylight Sensor Adaptive Control for Aging Compensation
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Solution Overview
Problem
Existing luminaire control systems fail to accurately switch on and off over extended periods due to aging of daylight sensors and degradation of materials, leading to premature activation and deactivation.
Innovation Solution
A control method and system that registers and adjusts switching criteria over time, accounting for sensor degradation by averaging values over periods like years, and adjusting thresholds based on measured light levels and angles to maintain accurate operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a fixed switching criterion is used for the luminaire control system, then the initial switching accuracy is good, but the measurement precision deteriorates over time due to sensor aging and material degradation
Solution Approach 1:
The switching criterion is transformed from a fixed static value to a dynamic adaptive value that automatically adjusts over time. The control system continuously monitors the relationship between measured light levels and actual solar positions, and updates the switching criterion to compensate for sensor aging and material degradation, thereby maintaining accurate switching performance throughout the operational lifetime
Solution Approach 2:
The system implements a feedback mechanism where the measured light level from the daylight sensor is continuously compared with the expected light level calculated from the actual solar position. The difference between measured and expected values is used to automatically adjust the switching criterion, creating a closed-loop control system that self-corrects for sensor degradation without manual intervention
2Reliability
If no adjustment mechanism is implemented, then the device complexity remains low, but the reliability deteriorates over time due to uncorrected measurement errors
Solution Approach 1:
The control system performs self-calibration automatically using readily available data (measured light levels and calculated solar positions) without requiring external intervention, specialized calibration equipment, or manual adjustment. The system serves itself by detecting its own measurement errors and correcting the switching criterion accordingly, thereby improving reliability while adding minimal complexity
Solution Approach 2:
The system changes the parameter of the switching criterion dynamically based on observed measurement deviations. By monitoring how the relationship between light level and solar position changes over time, the system adjusts the switching threshold parameter to maintain accuracy, transforming a static control parameter into an adaptive one that evolves with the system's aging characteristics
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
Ensures accurate and prolonged precise control of luminaire switching by compensating for measurement errors caused by aging, maintaining optimal activation and deactivation times.
Implementation Method 1
a daylight sensor, such as a photodiode, for measuring a light level of daylight
Data Source
AI summary
A control method for a luminaire with a daylight sensor, comprising: obtaining a first value (α) representative for the angle of the sun with respect to the horizon; if the obtained first value is within a first predetermined range corresponding with a dusk or dawn range, performing the following steps: obtaining a second value (Ev) representative for a light level using the daylight sensor of the luminaire; and controlling the switching on or off of the luminaire when the obtained second value (Ev) fulfils a first predetermined criterion; registering over time, for at least one determined obtained second value, at least one corresponding obtained first value (α); and/or, for at least one determined first value, at least one corresponding obtained second value (Ev); adjusting the first predetermined criterion based on the registrations over time.