Forklift proximity sensors detect pedestrians in one of three ways. Tag-based systems use radio tags worn by workers, such as ultra-wideband or RFID, and measure the distance between the tag and a reader on the truck. Object sensors, such as radar, ultrasonic or LiDAR, sense anything inside a zone and most cannot tell a person from a pallet or a post. Camera systems with vision models recognise the human form without any tag. Each type then warns the operator, some also alert the pedestrian through a vibrating tag, and on compatible forklifts the system can slow the truck.
The full guide is forklift proximity detection technologies compared. Tags can detect a person around a corner or behind racking without line of sight, although dense metal can reduce accuracy; they miss anyone without a tag. Object sensors need no wearables but alert on racking and pallets, which feeds alarm fatigue in tight aisles. Cameras cover untagged people, but only within line of sight and with enough light.
Many sites combine a tag system with a camera to cover both gaps. Forklift sensors explains each sensor type in more detail.