Safety First!
Put bumpers on the robot/bed so it doesn't run over patient's in the hallway.
Use indirect and contact sensors to stop the bed.
(check out industrial robots)
http://motioncontrolsrobotics.com/ro...ded-carts-agc/
https://www.bastiansolutions.com/sol...-robotics/lynx
http://www.mmh.com/article/agvs_carts_and_robots
http://www.aethon.com/industrialtug/
Is the robot going to tow or push the bed? (beds would need their own wheels)
If riding an elevator is needed; can the robot fit under the bed to save space?
Dave