How does guarding by location differ from guarding by distance?

• A. Guarding by location uses sensors to maintain a safe distance; guarding by distance uses physical barriers
• B. Guarding by location uses physical barriers at the cell boundary; guarding by distance uses sensors to maintain a safe distance
• C. They are the same concept in practice
• D. Guarding by distance is only used outdoors

Answer: (B)

Guarding by location focuses on enclosing the robot’s workspace with fixed physical boundaries, creating a defined cell. These barriers physically prevent access to the robot’s moving parts, and crossing the boundary typically triggers a stop or lockout.

Guarding by distance, on the other hand, uses sensors to monitor how close a person or object gets to the robot or its danger zones. When a preset safe clearance is breached, the control system stops or slows the robot to prevent contact, even if there isn’t a hard barrier.

So, the best description is that location-based guarding uses physical barriers at the cell boundary, while distance-based guarding relies on sensors to maintain a safe distance.