Robotic cleaning fleet
Sizing the number of cleaning robots a plant needs, and deciding gap by gap where a supported bridge will be installed.
🤖 Robotic Module Cleaning sizes the cleaning fleet: how many robots the plant needs to cover every module. It works from the layout you have placed, so the answer reflects the real geometry — where the control rooms landed, where the arresters sit, where obstructions broke the rows — rather than a rule of thumb applied to a capacity figure.
The output is a count you can procure and price against. It reaches the bill of materials, so it is also the point at which a cleaning system stops being an assumption in the loss table and becomes a line item.
Before you size the fleet
The count is measured off the placed layout, so generate the layout first. More than that: settle the equipment that breaks the rows before you start ticking gaps, because that equipment is what creates most of them.
| Decide first | Why it matters here |
|---|---|
| Lightning arresters | On a fixed-tilt plant an arrester footprint sits in the row and produces a gap blocked by equipment. Placing them later changes the gap list |
| Control rooms and unit substations | Every building footprint clears tables around it and interrupts the lines that ran through it |
| Obstructions you draw by hand | Each one breaks the rows it crosses, so each one can add segments |
| Half tables and Maximize placement | Both change how rows are packed, and a staggered plant has a different set of gaps from a gridded one |
If any of those change afterwards, open the window again. The gap list is a measurement of one particular layout, not a property of the site.
How a robot moves
A robot drives along the module frames of one cleaning line. The frames are its track: it travels the continuous run of structure, cleaning the modules it passes, and it can only go where that run continues.
That is why the direction of a cleaning line is not a setting but a consequence of the mounting type.
Lines run west to east. Rows of MMS tables run east to west, so the continuous run of frames along a row is the east–west direction, and a line follows one row of tables across the plant.
In both cases the rule is the same — the line follows the frames — and the two answers differ only because the frames run differently. A robot cannot cross from one line to the next; each line is its own track.
The robot inputs
Four fields, in a Robot group. On a tracker plant the word "table" reads "tracker" throughout the group.
| Field | Default | Range | What it does |
|---|---|---|---|
| Travel per charge | 0 m | 0–100 000 m | How far a robot travels on one charge. 0 means no battery limit |
| To-and-fro run — "Robot must clean out AND return on the same charge" | ticked | — | Requires the robot to finish its run and come back on a single charge, so the distance to be covered is twice the segment length |
| Standard bridge span (table gap) | the gap already configured | 0–50 m | The widest gap a robot crosses unaided, on the plant's own standard bridge |
| Skip robot if line has ≤ | 0 | 0–1000, in steps of 0.5 | Segment size below which a line is too short to warrant its own robot. 0 counts every line |
Travel per charge ships at 0, so out of the box there is no battery constraint at all and every cleaning segment gets one robot. That is the right setting when you are sizing on geometry alone, or when the system you are pricing is continuously powered. Enter a real range and it becomes a second reason for the fleet to grow, on top of broken lines.
To-and-fro run ships ticked, and it halves the effective reach, because the robot travels the segment twice. Leave it ticked unless the cleaning system genuinely supports a charging point or a swap at the far end of a line.
Standard bridge span (table gap) starts from your own geometry rather than a constant, so it is consistent with the layout on first open. It is taken from the Gap between MMS-Tables on a fixed-tilt plant, which ships at 1.0 m — see Table configuration — or from the N–S service gap between units on a tracker plant, which ships at 2.0 m; see Tracker configuration. Where that gap is zero the span falls back to 2.0 m. Any gap at or under the span is crossed as a matter of course; anything wider is a decision, which is the next section.
Skip robot if line has ≤ ships at 0, so nothing is discarded until you raise it. It steps in halves because a half unit counts as 0.5 — the section on short segments below covers what raising it does and does not do.
A wide gap is a decision, not an assumption
This is the part of the window that does the real work, and the reason the tool exists rather than a formula.
Every gap in the plant too wide for a standard bridge is listed individually, with its measured span and its location, in two groups:
| Group | What is in it |
|---|---|
| Gaps blocked by equipment | Gaps interrupted by something physically in the way — a lightning arrester, a control room or other building, an obstruction |
| Gaps in open ground | Gaps that are wider than a standard bridge, with nothing occupying them |
Each listed gap has a tick box, and the tick box is a commitment:
- Ticked means you will install a supported bridge across that gap. The robot drives over it, the line stays continuous, and the fleet count drops.
- Left unticked means the line is broken there. The stretch on the far side becomes its own segment, and that segment keeps its own robot.
Nothing is bridged unless you tick it. The application will not assume a bridge anywhere, at any span, for any reason. A wide gap is a civil and structural commitment with a cost and a design behind it, and assuming it away would produce a fleet count that quietly depends on structures nobody has agreed to build.
The split into two groups is there because the two decisions are not the same kind of decision. A gap in open ground needs a longer span of the same idea — usually straightforward. A gap blocked by equipment needs a bridge that gets a robot over or around something solid, which may be expensive, may be impossible, and may be a reason to move the equipment instead while the layout is still editable.
- What it shows
- A zoomed plot view where a ticked gap is highlighted, showing where a supported bridge would be installed.
- How to get there
- In the robotic cleaning window, tick one wide gap and preview it, then zoom to that location.
- Callouts to add
- Outline the highlighted bridge area.
Every tick is a structure someone has to design, buy and install. Tick the gaps you have decided to bridge, not the gaps that would give you a convenient fleet count.
How the fleet is counted
Sizing starts from the simplest possible answer and grows it for two reasons.
One robot per row to start. Each cleaning line gets one robot. On a plant of unbroken rows with no range limit — which is what the shipped Travel per charge of 0 gives you — that is the whole answer.
Broken lines add robots. Every unticked wide gap splits a line into segments, and each segment needs its own robot, because no robot can cross the gap to reach the rest of the line. A line broken in two places carries three robots where an unbroken one carried a single robot.
Travel per charge adds robots. With a range entered, a robot that cannot finish its segment on one charge needs company — the segment is shared between more than one robot. With To-and-fro run ticked, the distance to be covered is the segment travelled twice, so range binds sooner.
The two causes compound: a long line broken into segments may still exceed the range within each segment. That combination is what makes an eyeballed estimate unreliable on a real plant, and it is why the count is worth deriving.
Segments too short to be worth a robot
A segment can be a stub — two tables cut off in a corner by an obstruction. A dedicated robot for it is not a sensible procurement, so Skip robot if line has ≤ sets a threshold:
A segment whose weighted table count is at or below the threshold is treated as too short to justify a dedicated robot, and is not counted.
- The count is weighted: a half unit counts as 0.5, so two half tables count the same as one full table. That is why the field steps in halves.
- The field ships at 0, which counts every line however short. Raising it discards more short stubs and lowers the fleet count.
- Whatever the threshold discards still has modules on it. Those tables are not covered by the fleet the count describes, so decide how they will be cleaned — by hand, or by a robot moved there — rather than letting the threshold hide them.
Live recalculation, and where the result goes
Everything in the window recalculates live. Tick a gap and the fleet count moves immediately; change Travel per charge or the bridge span and it moves again. Work the two lists top to bottom, watching what each decision is worth, and you can see directly which bridges pay for themselves in robots saved.
Start with everything unticked
Because nothing is bridged unless you tick it, the first count you see is the honest baseline: the fleet required if you build no additional bridges at all. Note it before you change anything — it is the upper bound, and the figure every bridge is measured against.
Set the robot inputs before touching the gap lists
Travel per charge, To-and-fro run and Standard bridge span (table gap) all change which gaps are even listed and how long a segment one robot can serve. Settling them first stops you re-deciding the same gaps twice.
Work the open-ground list
These are the cheaper decisions — a longer span of a bridge you are already buying. Tick the ones you will genuinely install and watch the count fall.
Work the equipment-blocked list last, and sceptically
Each of these needs a bridge that gets a robot past something solid. Some are straightforward, some are not worth building, and some are a reason to move the equipment while the layout is still editable.
Record which gaps you ticked
The fleet count alone does not carry the commitments behind it. The bridges are a materials and civil scope item, so capture the ticked gaps with their spans and locations alongside the count.
The result then reaches two places:
- The summary table's robot count. It sits with the other equipment counts — see Summary columns.
- The bill of materials. The fleet becomes a materials line, alongside the rest of the plant.
The bill of materials never carries a fleet you did not ask for. Robots appear in it only after you have run this sizing, so a materials list from a plant where you never opened this window contains no cleaning fleet at all — not a zero, not an estimate. If a bill of materials has to include the cleaning system, run this first and rebuild the list afterwards. See Bill of materials.
The soiling loss in the performance ratio is a separate input that you set, and it is not derived from the fleet — see Loss breakdown. The two belong together in a report, though: a soiling assumption presumes a cleaning regime, and this is where the regime gets counted.
Where to go next
Sizing from an AC capacity
Work backwards from a contracted AC capacity and a target DC to AC ratio to a layout capped at the capacity you are allowed to build.
Building the single-line diagram
Diagram mode — the A3 drawing sheet, the drawing tools, and how the finished diagram reaches the report, a standalone PDF and a CAD file.