580 mm is the robot. The aisle is what you measure.
A minimum aisle figure is taken in a test bay, between clean surfaces. A building adds rack protectors, pallet overhang, door frames, a charge bay and people. This page is about that difference.
- P300 minimum aisle
- 580 mm — vehicle passage
- P300 turning diameter
- 988 mm — turn in place
- P1500 minimum aisle
- 990 mm — full stringer pallet
- P1500 right-angle stacking
- 1,800 mm — into racking
What each number actually measures.
Four figures appear on every AMR datasheet. They answer two different questions — can it pass, and can it turn — and confusing them is the most common source of a bad quote.
P300 — 580 mm minimum aisle
The clear width the vehicle needs to pass between two surfaces, measured at the widest point of the chassis. It is a passage figure, not a working figure.
P300 — 988 mm turning diameter
The space needed to turn around in place. A 90-degree turn at the end of an aisle sweeps wider than the aisle itself, so the cross aisle has to be measured too.
P1500 — 990 mm minimum aisle
The same passage measurement for the pallet carrier, which is wider because the load it carries is.
P1500 — 1,800 mm right-angle stacking
The working envelope for turning into racking at a right angle, including the swing of a full pallet. This is the number that decides whether a bay can be served at all.
Figures for P300 and P1500 as supplied by SEER Robotics. They describe the vehicle, not the building.
What the figure leaves out.
An aisle is not two clean walls. Five things in a real building change the number before a robot ever arrives.
Rack uprights and their protectors
Measure between the protectors, not between the steel. The protector is the surface the vehicle sees, and it is the one that was added after the racking went in.
Pallet overhang
A pallet wider than the truck it sits on overhangs. The width that has to fit is the vehicle plus the load, not the vehicle alone.
Door frames and fire shutters
The clear opening is narrower than the frame, and a shutter that drops needs an interface before the vehicle can pass underneath it.
The charge bay
A charger is a parking space with a swing. It is the measurement most often left out of a survey, and it cannot be improvised later.
People in the same aisle
The vehicle slows or stops for a person, so it still fits — but throughput drops. A separate walking route is a layout decision, not a robot setting.
Measure the narrowest point, not the average.
Five measurements cover almost every aisle question. They are cheap to take and they decide which vehicle can be quoted.
Width at load height
Aisle width at floor level is rarely the constraint. The constraint is at the height of the load, where pipework, cable trays and column bases sit.
Width between what the robot sees
Protectors, conduit, a fire hose reel. Anything that protrudes is part of the wall as far as the scanner is concerned.
The turn, at both ends
Walk the route with a tape where the vehicle turns. A route that measures well in the straight is often lost in the last two metres.
The floor along the route
Laser SLAM needs no tape or magnets. It still needs a floor it can cross: expansion joints, drain covers, ramps and level changes all belong in the notes.
A photo of the tape
One photo of a tape against the obstruction settles more questions than a drawing, and it is what the engineer will ask for anyway.
Send the narrowest measurement, the load unit dimensions and one photo. That is enough to say which vehicle can be quoted and which cannot.
One site, three answers.
A warehouse asks whether a P300 can serve a line. It sends three measurements. Each one answers a different part of the question.
Aisle: 640 mm between protectors
Against a 580 mm requirement that leaves 60 mm total. It passes, with nothing to spare for a pallet overhanging the load.
Cross aisle: 1,100 mm
The vehicle turns in 988 mm, so the turn fits with 112 mm spare — provided the turn is made in the wide part and not at the rack end.
Charge bay: 900 mm with the door swing
This is the one that fails. The bay has to be re-planned before the vehicle is ordered, which is the cheapest possible moment to find out.
Same robot, three measurements, one layout change. A datasheet would have answered all three with a single number.
Three surveys that look right.
The empty aisle
Tape taken with the bay empty and pallets pulled out. The same aisle with a full bay and a pallet overhanging is a different number.
The drawing
Nominal bay width from a CAD file ignores the protector added in 2019 and the conduit run added in 2023. Drawings describe intent; tape describes the building.
The last metre
The straight measures fine, and then the turn into the cell does not fit. The narrowest point is usually a corner, not a corridor.
What buyers ask about aisle width.
Short answers to the questions that decide whether a site can take an AMR at all. Every case is confirmed by measurement, not by a datasheet.
01Can a P300 work in a 600 mm aisle?
The 580 mm figure is the clear passage the vehicle needs between two surfaces, which leaves 20 mm in a 600 mm aisle — with nothing allowed for rack protectors, load overhang or a person. Measured on site, most nominal 600 mm aisles are narrower at the protectors. This is a survey question, not a catalogue question.
02Does the 580 mm include the load?
The figure describes vehicle passage. Once a load overhangs the chassis, the combined width is what has to fit, so the aisle has to grow with the load.
03What is the 988 mm turning diameter for?
Turning in place. A 90-degree turn into a cross aisle needs the vehicle to sweep, so the cross aisle must be wider than the aisle it came from.
04Do we have to widen the aisle?
Sometimes, but it is rarely the first answer. Choosing the narrower vehicle, moving a charger or rerouting one leg is usually cheaper than moving racking.
05Does the floor have to be level?
Laser SLAM builds its own map and needs no tape or magnets. It still needs a floor it can cross, so expansion joints, drain covers, ramps and level changes are checked in the survey.
06Can you tell us without a site visit?
Often, yes. Send the narrowest aisle measurement, the load unit dimensions and a photo of the obstruction. That is enough to say which vehicle can be quoted.