About the Radars/Sensors for Automatic Sliding Door

Here's an overview of frequently-used radars /sensors in automatic sliding doors, swing doors including Microwave Radar, Infrared Radar, Ultrasonic Radar, Light Detected Radar .

1. Microwave Radar Sensors

Principle: Detects motion based on the Doppler effect (frequency shift of reflected waves).

Characteristics:

Wide detection range (typically 3–10 meters).

Works well in various weather conditions (rain, fog, dust).

Detects movement only (not suitable for stationary objects).

May have false triggers from moving objects outside the intended area.

Best for High-traffic areas like shopping malls, airports.

2. Infrared (PIR) Sensors (Passive Infrared, not radar but commonly used alongside)

Principle: Detects body heat (infrared radiation).

Characteristics:

Energy-efficient (consumes less power than radar).

Works best for human detection (not affected by wind or moving objects like curtains).

Limited range (usually 1–5 meters).

Affected by temperature changes (may fail in extreme heat/cold).

Best for Indoor automatic doors (offices, hospitals).

3. Ultrasonic Sensors (Not radar, but another proximity option)

Principle: Uses sound waves to detect objects.

Characteristics:

Detects both moving and stationary objects.

Short to medium range (0.5–5 meters).

Slower response time compared to radar.

Affected by air turbulence and noise.

Best for Sliding doors where object presence (not just motion) matters.

4. LiDAR (Light Detection and Ranging) (Emerging technology)

Principle: Uses laser pulses for precise distance measurement.

Characteristics:

High accuracy (millimeter-level precision).

3D mapping capability (useful for smart door systems).

Expensive compared to microwave/PIR sensors.

Limited performance in direct sunlight or fog.

Best for Advanced automatic doors in smart buildings.

Brief Comparison for the 4 types of radars above .

Key Considerations for Choosing a Sensor.

Indoor vs. Outdoor Use (Microwave for outdoor; PIR for indoor).

Traffic Density (Radar for high traffic; PIR for controlled access).

Energy Efficiency (PIR consumes less power).

False Trigger Prevention (Microwave may need tuning to avoid interference).