Lighting Control 3D Simulator — Daylight Harvesting & Occupancy Sensing Interactive

Interactive 3D two-zone office lighting simulator with occupancy on/off, three control modes (automatic occupancy + daylight, manual-on/automatic-off vacancy, and manual switching/dimming), adjustable daylight, blind position, illuminance target, vacancy timeout, minimum dimming level, daylight sensor bias, occupancy sensor fault injection, an open dimming-wire fault, illuminance and power charts, a 20-check verification bench and a knowledge-check quiz.

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About the Lighting Control 3D Simulator

This simulator models a generic two-zone office — a window-side perimeter and an interior core — served by dimmable LED luminaires, a ceiling occupancy sensor and a daylight sensor, so you can compare automatic occupancy/daylight control, manual-on vacancy control and plain manual dimming under different daylight, occupancy and fault conditions.

What the simulator shows

• A real-time 3D cutaway of the window and adjustable blind, the ceiling PIR occupancy sensor, the daylight sensor/photodiode, separate perimeter and core LED luminaire/driver assemblies, a wall station/room controller, the desks and workplane, and a selectable room-occupant visual cue, with toggleable enclosure, auto-rotate, expand and selectable numbered components with callouts. • A control-mode selector: automatic occupancy + daylight, manual-on/automatic-off vacancy, or manual switching and dimming. • Eleven fixture controls: room occupied, unshaded perimeter daylight (lux), window blind openness, workplane illuminance target, vacancy off delay, minimum enabled dimming, daylight sensor bias (lux, to simulate miscalibration), an occupancy-sensor-fault selector (healthy / fails to detect / stuck occupied), an open-dimming-pair fault (driver fails to full output), and manual dimming level. • Direct actions: start/stop trial, Manual ON and Manual OFF (for vacancy/manual modes). • A Curves & measurements tab with an illuminance chart (perimeter, core and target) and a driver-output chart (perimeter, core), the underlying model equations, and live readouts of workplane lux, driver output percentages, input power, accumulated energy and vacancy-hold time remaining. • A Test & diagnose Experiments tab with four guided experiments (daylight harvesting, manual-on vacancy, biased daylight sensor, open dimming pair) plus a Verification bench of automated model checks and a timestamped event log with report export. • A Learn & assess tab with four guided lessons, a two-question knowledge-check quiz, and a written model-scope statement with an ASHRAE/Lutron reference link.

How daylight harvesting and dimming are modeled

Perimeter daylight is the unshaded exterior daylight multiplied by blind openness; the core zone always receives one quarter of whatever daylight reaches the perimeter, which is why the interior typically needs more electric light to reach the same target. The controller estimates daylight as max(0, actual daylight + sensor bias) — a positive bias makes the controller think there's more daylight than there really is, so it under-delivers electric light relative to the actual target.

From that estimate, the requested electric-light fraction is clamp((target − measured daylight)/600, minimum enabled dimming, 1), and each driver fades toward its commanded output at 50 percentage points per second rather than switching instantly. Actual workplane illuminance combines the real (unbiased) daylight with the electric-light contribution: daylight + 600 × output fraction. Driver power is 4 + 76 × output fraction watts when lit and 0 W when off, and accumulated energy integrates total watts over time (Wh = ∫P dt / 3600).

Reading the charts and what the model leaves out

The illuminance chart lets you compare the perimeter and core workplane lux against the target line directly, which is the fastest way to see whether a sensor bias or fault is causing under- or over-lighting. The driver-output chart shows each zone's dimming percentage — for example, the open-dimming-pair fault drives both enabled drivers to full output regardless of daylight, which shows up immediately as both traces pinning at 100%.

Per the model's scope statement, this is a two-zone calibrated illuminance and energy fixture, not a photometric design or code-compliance tool. It excludes ray tracing, glare analysis, spectral response and real PIR detection physics; the open-dimming-pair failure behavior is specific to this configured driver type, not universal; dimming can only reduce artificial light output and cannot cancel excess daylight; and Manual ON/OFF actions only apply in manual or vacancy control mode.

Frequently asked questions

Why does the core zone need more electric light than the perimeter?

The core always receives only one quarter of the daylight reaching the perimeter (Dcore = 0.25 × Dperimeter), since it is farther from the window. With less daylight contribution, the core driver has to make up a larger share of the illuminance target electrically.

What is the difference between the three control modes?

Automatic occupancy + daylight turns lights on with presence and trims output using the daylight sensor. Manual-on/automatic-off vacancy control requires a manual ON request to turn lights on, then automatically turns them off after the vacancy timeout once the room is unoccupied. Manual mode obeys direct ON/OFF requests and a fixed manual dimming level with no automatic daylight trim.

What does a biased daylight sensor actually change?

The sensor bias only changes the controller's estimate of daylight (measured = actual + bias), not the real daylight on the workplane. A positive bias makes the controller think there is more daylight than there is, so it delivers less electric light than needed to hit the actual target — you can see the gap directly on the illuminance chart.

What does this lighting model not include?

It is a calibrated two-zone illuminance and energy fixture, not a photometric design or code-compliance analysis. It excludes ray tracing, glare, spectral response and real occupancy-detection physics, and the open-dimming-pair failure behavior it models is specific to one driver configuration, not a universal standard.

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