A mechanical and functional safety deep-dive into achieving certified safety integrity levels (SIL 2 / PL d) in healthcare mobile robots.
A 150 kg mobile robot carrying heavy payloads through corridors shared with frail geriatric patients and small children must possess certified safety hardware that guarantees it cannot collide with a human under any software failure condition.
Complying with ISO 3691-4 requires dual safety LiDARs that configure dynamic protective fields based on current vehicle speed and steering angle, guaranteeing safe emergency stopping distances at all times.
Safety sensors interface directly with hardware safety relays that physically cut power to the drive motor brakes, bypassing the main ROS operating system entirely during an emergency stop condition.