Mobile robots: the fundamentals
Five ways to navigate
Method
How it works
Strength
Limitation
Magnetic tape
Follows tape laid on the floor
Cheap and stable
Fixed route; changes mean new installation; tape wears
QR code
Reads codes on the floor
Accurate, affordable
Codes cover the whole floor and need upkeep
Reflectors
Laser triangulates from reflectors
Accurate and stable
Requires installation; blocked reflectors break it
Laser SLAM
Scans the environment and matches a map
No site work, highly flexible
Degrades where features are sparse or change constantly
Visual SLAM
Camera features matched to a map
Rich information, allows semantics
Sensitive to lighting
Real projects rarely use just one. Jiangsong robots travel by laser SLAM, accurate to ±10 mm, and read QR codes at the points that need precise docking, such as under racks, in front of chargers and at machine docking ports, bringing accuracy to ±5 mm.