Mobile robots: the fundamentals
Safety in layers
Safety comes from four layers of obstacle protection, each backing up the one before, plus one more outside the vehicle: site management.
Layer
Means
What it does
Vision anticipation
3D camera
Identifies the type and distance of obstacles ahead (a person, materials or debris that can be passed) and adjusts driving in advance
Laser slowdown
Front and rear lidar, 360° coverage
Slows as soon as an obstacle enters the warning zone
Laser stop
Front and rear lidar
Stops gently or brakes hard when an obstacle enters the stop zone
Contact protection
Safety bumpers, emergency stops
Stops immediately on contact; emergency stops within reach of one hand
Site management
Aisle management, training
Aisles kept clear, people moving as trained
The obstacle zones change with speed: wider at high speed, narrower when turning slowly. Site management is the layer most often neglected: stock left in aisles, untrained people in the work area and the habit of cutting in front of a robot are all covered in the training at delivery.