Lighting Controller Auto-Calibration via Presence Transitions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current daylight harvesting systems require time-consuming and expensive manual calibration to achieve desired light levels, which can be disruptive to users and complex to implement, especially when involving central coordination.
Innovation Solution
A controller with presence detection logic and calibration logic that performs auto-calibration by changing the lighting device's output between a lower and higher level during transitions from no-presence to operative levels, masking the calibration effects from users and allowing self-calibration of luminaires without central coordination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual calibration is performed by a commissioning engineer using another light sensor, then calibration accuracy can be achieved, but the process becomes time consuming and expensive
Solution Approach 1:
The lighting device performs self-calibration by using its own light sensor to measure light levels at different output levels. The controller automatically determines the relationship between light output and sensor readings without requiring external calibration equipment or personnel, thereby eliminating time-consuming manual calibration while maintaining accuracy.
Solution Approach 2:
The system calibrates by changing the light output parameter between different levels (e.g., minimum and maximum) and measuring the corresponding sensor readings. This parameter variation approach allows automatic determination of the calibration curve or lookup table without manual intervention.
2Extent of automation
If automatic calibration is performed by cycling through power levels as in Papamichael's system, then calibration can be automated, but unexpected luminaire behavior occurs from the end-user perspective
Solution Approach 1:
The system performs calibration during the transition period when presence is detected but before the lighting settles at the operative level. This preliminary action during an already-expected transition masks the calibration effects from users, maintaining automation while preserving user experience.
Solution Approach 2:
The patent converts the potentially harmful effect of visible calibration cycling into a benefit by performing calibration during normal presence-triggered transitions. What could be disruptive (lighting changes during calibration) is transformed into an acceptable event by aligning it with expected user-triggered lighting changes.
3Extent of automation
If calibration is performed by cycling through power levels, then automatic calibration is achieved, but system complexity increases requiring central coordination between luminaires
Solution Approach 1:
The calibration function is segmented and distributed to individual luminaire controllers. Each luminaire performs its own self-calibration independently using its own light sensor, eliminating the need for central coordination or inter-luminaire communication during calibration. This segmentation reduces system complexity while maintaining automation.
Solution Approach 2:
Each luminaire is self-sufficient for calibration, using its own light sensor and controller to perform calibration without external assistance or coordination. This self-service approach simplifies the overall system architecture by removing the central coordination requirement.
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
This approach reduces complexity, eliminates the need for central coordination, and performs calibration seamlessly during user-presence transitions, enhancing user experience and reducing implementation costs by integrating calibration into normal lighting operations.
Implementation Method 1
a light sensor measures an overall light level
Data Source
Figure 1~2
Figure 2a~3
Figure 4(a)~4(c)
AI summary
A controller comprising: presence detection logic, calibration logic, and an input for receiving a reading from a light sensor representing a sensed light level. The presence detection logic is for detecting presence events based on a presence sensor, and is configured to indicate a set-point to operate at least one lighting device in dependence on a positive detection of presence. The calibration logic is for performing a calibration operation, which is performed by causing a light output of the lighting device to change between a first, lower level and a second, higher level, and by and calibrating the set-point based on the reading from thelight sensor under influence of the first and second levels. The calibration logic is configured to trigger this calibration operation in response to the positive detection of presence.