Proximity Detection
The capability to detect when tracked objects are near each other or near specific locations. Enables applications including collision avoidance, interaction tracking, contact tracing, and proximity-based access control. Detection typically based on signal strength, ranging measurements, or geofence overlap.
Technology and techniques for determining when objects are physically near each other, foundational capability for proximity alerts and collision avoidance. Limitations: accuracy limited by positioning accuracy, requires absolute position calculation for all objects. (2) Direct ranging - tags measuring distances to nearby tags using peer-to-peer radio ranging without infrastructure involvement.
Advantages: simple implementation, low computational requirements. Primarily used for coarse proximity. (4) Hybrid approaches - combining methods for optimal performance. Proximity detection performance requirements: (1) Range accuracy - detecting proximity within 10-30 cm accuracy for collision avoidance, 50-200 cm sufficient for general awareness. (2) Update rate - 5-10 Hz minimum for fast-moving vehicles. (3) Detection reliability - >95% detection rate for safety applications. (4) False alarm rate - <5% spurious proximity detections. (5) Latency - end-to-end delay <500ms. (6) Range - detecting proximity out to 3-10 meters providing adequate warning time. Proximity detection technologies: UWB enables both accurate positioning (10-30 cm) and precise peer-to-peer ranging, making it preferred for collision avoidance; BLE supports position-based proximity (1-5 meter accuracy) and basic peer-to-peer ranging; Wi-Fi provides position-based proximity only (3-15 meter accuracy); RFID supports only coarse zone-level proximity.
Proximity detection testing and validation: critical for safety applications requiring thorough testing: (1) Range testing - verifying detection at specified distances. (2) Reliability testing - ensuring >95% detection rate. (3) False alarm testing - measuring spurious detections, tuning to achieve <5% false positive rate. (4) Latency testing - confirming <500ms. (5) Edge case testing - verifying behavior with obstacles, vertical separation, signal interference.