Configuring and running

Fleet groups minimum distance and starting stations under Motion and distances; Orders groups criteria under Advanced dispatch. Battery curves and disturbance Duration and recovery are initially closed. In Vehicles open the fleet card: speeds and pickup and drop-off times are on the card, ramps under Advanced settings and, for the VNA truck, VNA warehouse is a section of its own. Scenario → Warehouse displays run inventory; Edit initial inventory opens Draw. With Plant logic active, periodic flows are inactive and cannot be edited.

In Simulate, the Scenario tab turns the layout into a fleet with work to do. The journey is always the same: check the steps, press Start run, read Results, compare runs.

The Scenario panel

The scenario is organised in seven steps. Each step header shows a status dot and a summary of its values, so you can check the whole setup without opening anything:

One step is open at a time. Until you choose one, the first step that needs attention opens automatically, and problems are shown inside the step they belong to.

Pickup and drop-off

Tick the stations that generate orders under Pickup stations and Drop-off stations; both lists have a search box. Only stations with the corresponding role and not blocked are listed. The summary shows how many usable pairs result, for example 2 → 3 · 6 pairs.

• A pair is usable when an allowed route goes from the pickup to the drop-off. A return route is not required.
• A pickup and a drop-off on the same station are excluded.
• With several fleets, a pair also needs a fleet with at least one AGV that is permitted at both the pickup and the drop-off (see Fleets).
• Excluded combinations are counted, and pickups or drop-offs with no compatible partner are listed.
• When the selection has no valid pair, a Use connected pair button proposes one that works.

When Plant logic is enabled, this step shows From Plant logic: pickups, drop-offs and frequencies are then defined in the blocks.

Fleet

The step lists the fleets with their shape and a field for each fleet's AGV count (0–50 per fleet, 1–50 in total); Edit fleets opens the Vehicles tab, where each fleet's name, count, type, size, speeds, pickup and drop-off times and battery are set (see Fleets).

The step also lists the Starting stations and offers Reset all layout speeds to defaults. Its summary, such as 2/3 AGV · 80 cm/s (the fleet's straight speed) or 4/5 AGV · 2 fleets, shows how many vehicles could actually be placed.

Placement rules. AGVs start only on unblocked Charger or Parking location stations permitted for their fleet, one per station, and only where they are at least the minimum distance apart. The fleet with the fewest permitted stations is placed first, so it keeps the stations reserved to it. With several fleets the message names the fleets that could not be fully placed, for example Forklifts 1/3. No other node is used as a fallback. If fewer vehicles can be placed than requested, a message tells how many stations are usable and how many were skipped: mark more stations as Charger/Parking in Draw, spread them out, or reduce the fleet.

Orders

Dispatch and allocation rules

Assigning work is a two-stage decision. First the mission priority chooses the order:

• Oldest reachable mission: first come, first served, among orders some free AGV can reach.
• Pickup nearest to a free AGV: the order whose pickup is closest, by route distance, to a free vehicle. Ties go to the oldest, then the lowest ID.

Then the AGV selection chooses the vehicle, from its current position:

• Nearest to pickup: the shortest approach distance.
• Fastest delivery: the shortest estimated time for approach, loading, transport and unloading.
• Least busy time: the vehicle that has worked least so far, to balance the fleet.

An order only goes to an AGV of a fleet permitted at both its pickup and its drop-off, even when a vehicle of another fleet is closer. Ties go to the vehicle idle the longest, then the lowest ID. Orders that no vehicle can take stay queued with a reason and never block the others. Estimated durations include accelerations, service times and reversals, but not future traffic waits. An assignment does not require the whole route to be free: the vehicle stops in front of obstacles along the way.

Traffic rules

The Traffic step switches the Traffic and anti-collision rules on or off. They are on by default: vehicles reserve the space they sweep, brake on their scanners and respect exclusive zones, zone conditions on links and transit points, so the results include traffic waits and possible gridlocks.

Switched off, the step reads Capacity only and vehicles drive through each other without waiting. Use it in an early study to estimate what the fleet can move with travel and service times alone. Physical capacity still applies:

• a station serves one AGV at a time; the next one waits in front of it, and the wait is counted for that station;
• a charger or parking place holds one AGV;
• a warehouse aisle admits one mission at a time, a floor-stack or drive-in lane one AGV at a time;
• starting positions stay one vehicle apart, so both modes place the same AGVs, except that a start against a zone no longer holds it.

Without the rules, manual zone reservations have no effect (their settings are kept), scanner fields are not drawn, the Network tab no longer reports two-way lanes at risk and traffic optimization is unavailable. Results, the PDF report and the run comparison state the mode. Capacity-only figures are optimistic: confirm a layout with the rules on before relying on it.

Battery

The battery model is off by default. Tick Simulate charging and discharging to enable it. The thresholds set here apply to everyone; battery type, autonomy and charge time belong to each fleet, in the Vehicles tab. The summary lists the types in use and the step shows the curves of each.

Consumption is relative to unloaded driving: 1 when empty, 1.2 when loaded, 0.6 during loading and unloading, 0.1 while waiting or stopped away from a charger. Below the threshold an AGV finishes the transport it has, then drives to the nearest free, reachable Charger permitted for its fleet (a Parking location does not charge) and takes no orders until it reaches the resume level. If no work arrives it keeps charging up to 100 %. At 0 % it stops where it is, still occupying its space.

The charge level is shown under each AGV, in the Movements tables and in the results. Pause also pauses charging and discharging; Reset restores the initial charge.

Disturbances

Real plants are not perfectly smooth. The Disturbances step adds random stops that come from outside the model, so you can see how much throughput survives when things go wrong. Every disturbance is optional and off by default. Once switched on it shows a volume slider with five levels, Low, Moderate, Medium, High and Extreme, and the range of seconds the AGV stays stopped (the duration of each event is drawn at random inside the range).

Parked, charging and traffic-waiting AGVs are not struck by obstacles or faults. Default durations are 5–30 s for obstacles, 120–600 s for faults and 30–120 s for empty pickups and full drops; the range accepts 1–86 400 s.

Backup. For empty pickups and full drops you choose whether to enable an automatic backup. With it, the AGV needs 5 s to detect the problem, then goes to the nearest other station of the same order set (another pickup, or another drop-off) that its fleet may serve and that it can reach, and the order continues from there. A station already tried by the same order is not tried again. Without a backup, or when no alternative exists, the AGV waits for the operator for the duration drawn from the range and then completes the operation at the same station. The results tell how many failures the backup solved and how many needed the operator.

Manual reservation of traffic zones. Below the four disturbances, every traffic zone of the layout has its own switch, so you decide zone by zone. An enabled zone gets the same volume slider and a range of seconds: every now and then an operator reserves the zone for a manual transport and later frees it. While it is reserved no AGV may enter; they stop at the zone's protective edge and wait. An operator cannot reserve a zone that already has an AGV inside: that attempt fails, is counted separately and the operator tries again later. Each zone is reserved on its own, even when it touches or overlaps another: an AGV that has to cross both waits until both are free. Waiting for a reserved zone is counted as traffic waiting but never as a possible gridlock, and it is shown separately per zone in the results.

You choose only the volume, never a cadence: events strike at irregular moments, sometimes in clusters, sometimes with long gaps. The scenario seed makes those choices repeatable; use different seeds to study variability. Editing a disturbance restarts the simulation, like any scenario change. Stopped AGVs keep their space, so others queue behind them; a longer stop can also expose a gridlock that a smooth run never reached.

Costs and ROI

The Costs and ROI step estimates the return on investment of the AGVs against the truck operators they replace. Switch on Calculate the return on investment and enter your own costs: the app suggests no prices, and an item left at zero counts as zero.

The step stays Needs review while the price of a staffed fleet, the working hours or the operators and hourly cost of the manual alternative are missing, and says which inputs are missing; it never blocks the simulation. Once ready, its header shows the investment. Costs are saved in the project but are not part of the run: editing them updates the ROI results without restarting the run.

Repeat a run with the same seed

Open Randomness below Disturbances in Scenario. Seed is a whole number from 0 to 4294967295, initially 1. Enter a value to reuse it or choose Generate a new seed. The seed controls random missions, disturbances and manual zone reservations together. Starting a new run keeps the chosen seed; changing it resets the simulation and is saved in the project, including exported .sim files.

With the same layout, scenario, seed and engine version, runs reproduce the same results at the same simulated duration. Playback speed and pauses do not change the random sequence. To measure variability, keep the scenario and duration fixed and try several seeds. When comparing alternatives, use the same set of seeds for each one. Changing the model can change the order of random draws, so the same seed does not promise faults at identical times in different scenarios.

Results → Technical data records the seed used by the run. An archived run offers Reuse this seed to apply it to the current scenario; it does not restore that run's other settings or layout.

Sizing the fleet

Optimize → Fleet finds the smallest number of AGVs that meets the targets you choose, by trying fleets of different sizes in simulation on the current project. The targets are Serve all demand (at the end of a trial, at most the orders the fleet can take at once are still queued, the same rule as the ROI), Missions per hour as a minimum, Average lead time and AGV utilisation as a maximum. With several fleets you choose which to size; the others stay as they are.

The search starts from the current number of AGVs: if it is enough, it reduces it; if not, it doubles it until the targets are met and then narrows the range down to the smallest number. With several fleets it adds one AGV at a time to the fleet that improves the result most, then removes the ones not needed. Each configuration is tried over the duration in the map toolbar (with an ∞ duration you set it in Settings, initially 8 hours). With Show the trials on the map, on at first, each configuration is a visible run on the map, one after another, with the scenario’s seed: the first starts at full speed, then the speed chosen in the toolbar stays, and every finished trial joins the Run comparison as Sizing · N AGV. Without the map the trials run in the background with up to three seeds, or only once when the trial uses no randomness. A configuration meets the targets only if it meets them in every trial, with every AGV placed and no possible gridlock at the end.

The table lists the configurations tried with missions per hour, average lead time and utilisation; values that miss a target are highlighted. When AGVs are not enough the search stops and says why: there are no more starting positions, the scenario generates fewer orders than the target, more AGVs no longer improve the result (traffic or stations are the limit), or the maximum number of AGVs was reached. Apply sets the recommended number as an ordinary edit, undone with Ctrl+Z, and restarts the run. Compare opens the Run comparison with the trials played on the map; in the background it adds the recommended configuration, the one just below and the one just above. Costs and ROI show when you have entered them.

Trials run on copies and never change the project. On the map the current trial replaces the ordinary run: pausing it or starting another run stops sizing, and at the end the map returns to the project with its speed and duration. In the background the ordinary run is paused. Editing the project while sizing stops it, and a result computed before an edit asks you to size again. The count of the sized fleets does not count as an edit: you can change it and come back to the result. Fleet sizing and Optimize traffic never run at once. The search assumes more AGVs do not make the result worse: this holds in most plants, but with very dense traffic also check the neighbouring configurations in the comparison.

Automatic traffic

The experimental Automatic traffic panel in Scenario starts a separate search for zones and transit points to address blocks that do not resolve themselves. Local explores families of changes and refines promising ones; with AI entitlement, AI assisted analyses incidents, proposes its own changes and uses local trials and diagnostic images to decide how to proceed. Each improvement is presented as soon as it passes full verification: Ask before changing requires acceptance, while Full access accepts it automatically.

The ordinary run stays paused and project editing is suspended during the session. Trials use isolated copies over your chosen finite duration: five seeds, or one execution when the engine verifies that this configuration uses no randomness throughout that duration. The panel shows alternatives and estimated real time remaining in the current round; you can read the candidate's operations and view a read-only map preview. You can stop and keep only the best verified and accepted result, or discard the session. Read Optimize traffic for the complete workflow, transit points and recovery.

Running a simulation

One command for the run

Choose Run duration in the toolbar above the map: 1, 4, 8 or 24 h (initially 8 h), or ∞. Start run begins at zero at the selected playback speed; Pause stops the clock; Resume continues without resetting; New run starts from zero after completion. The panel and toolbar buttons perform the same action, and in Simulate the Space bar does too when you are not typing in a field. When the command is disabled, its tooltip says what to fix, for example the fields marked in red. Choose Max for fast calculation. A new run opens Results. On completion it joins Run comparison and the Run archive.

A run stops by itself, before its duration, when its work is over, so missions per hour and fleet utilisation are measured over the working time rather than idle hours. This happens only with a finite demand from the plant logic, for example a Start with a quantity of missions: no mission in progress or queued, and nothing that time can still bring. Gaps between orders do not stop it: a Periodic timer, a Production profile with a baseline or a peak still ahead, a Start not yet fired, a Wait or a Time window in progress, Cyclic missions, deliveries from outside on their way or a replenishment still due keep it running. The periodic order generator and periodic storage flows never end. Results shows Work done with the time the last mission was delivered. If missions stay queued that no AGV can carry out, or sequences wait for conditions that can no longer change, with every AGV idle for 60 simulated seconds, the run stops as Work blocked and says so. In the Run comparison the duration of such runs carries a mark, and they stay comparable with the others.

Run controls in the canvas toolbar

For interactive work, the toolbar above the canvas controls the same simulation:

When the duration is reached, the command becomes New run. To continue the current run, choose a longer duration and press Resume. Switching to Draw pauses the simulation.

On narrower windows the toolbar hides secondary controls first: the screen scale and Origin, the − / + buttons (in 3D already on mid-size windows), then the image button, +1 s and the light button. With the AI button, the − / + buttons and the 3D image button go on mid-size windows and Labels on the narrowest. Mouse, trackpad and keyboard gestures keep working, and expanding the view or folding the side panel brings the controls back.

Record a video

The Record video button after the run controls records the map as you see it, in 2D or in 3D, into a video file. Press it to start: the button turns red and a timer at the top of the map shows the elapsed time. Press it again to stop: the file is downloaded at once, named after the project with the date and time of the take, for example Warehouse_2026-10-26_15-04-09.mp4. Recording is independent of the run: start it before Start run to film the plant still, pause and resume while it records, change the speed or the heatmap.

The video is MP4 (H.264), which plays on phones, in presentations and in mail previews; a browser that cannot write MP4 records WebM instead. It has the sharpness of the map on your screen, up to 1080p worth of pixels, at about 30 frames per second, and a minute usually takes a few megabytes. Every frame carries a small made with www.agvsimulationstudio.com mark in the lower-left corner; the timer, the panels and the pointer are not recorded.

While recording you can switch between 2D and 3D, hide or show the labels, or change the theme or the language: the video follows the view. Leaving Simulate or opening another project ends the take and downloads it, and a take stops by itself after 60 minutes. The video is as smooth as the map on screen: in a hidden tab or a minimized window the picture holds until you come back. Recording never changes the project, the run or its results.

Runs in the background

The simulation engine runs in a dedicated Web Worker on your computer, separately from the interface. The 2D and 3D views receive periodic updates; Pause and +1 s show the exact state reached. Computation is local: closing or reloading the page ends the run. If execution fails, the message offers Reset to start again.

The simulation keeps running when the tab is not visible or the window is covered: a background worker advances the model without redrawing the map. The tab title shows the progress, ▶ hh:mm:ss while running and ✓ hh:mm:ss when finished. Simulated time never jumps: after the computer sleeps, the run continues where it was. Browser energy savers can still freeze a tab that stays hidden for a long time; for very long runs, exclude the studio's address from them.

Reading the canvas

Vehicles

Vehicles keep a body front separate from the direction of travel: when the new direction turns more than 90° from the front, the vehicle drives in reverse rather than turning around. On curves the heading changes progressively.

Stations

Stations keep their role symbol and change colour with activity: the pickup of an assigned mission is green until loading is complete, the drop-off magenta until unloading is complete, and both ends of queued orders are orange with a dashed outline. Assigned activity takes precedence over queued orders; two colours mean simultaneous pickup and drop-off.

3D view

The cube button in the view toolbar switches the Simulate map to 3D and back to 2D. The CAD floor plan and the paths become the base of the floor. Stations are flat coins with the shape and colour of their symbol, and they change colour with activity as in 2D; a station can also take a 3D model. AGVs are detailed models of their fleet's shape and size: a light shell on a dark bumper for platform and conveyor AGVs, industrial yellow for forklifts, VNA trucks and tuggers, with wheels, safety scanners, emergency stops, headlights and tail lights. The colour of the state lights their LED bands, the light ring on top and the beacon, as on real vehicles; pin and arrow markers keep their whole token in that colour. The load is visible from pickup to the end of unloading; at stations with a 3D model the load hand-over is animated. Walls, floors and objects from the 3D library stand around the network; solid walls at least 1.5 m tall turn see-through while they stand between the camera and the point it looks at. Objects, walls, stations and vehicles cast soft shadows on the floor, and metal, glass and glossy floors reflect a studio light. Traffic zones, heatmaps and scanner fields remain visible, and so do station numbers and AGV labels with battery while Labels is on.

The sun button beside the cube sets the light of the 3D view. Directional is a sun with crisp shadows: drag it round the dial to choose the side it comes from (the top of the dial is the top of the 2D plan; arrow keys move it by 5°, with Shift by 15°) and set its Height above the floor, from a low 10° with long shadows to 90° straight overhead. Diffuse is an overcast sky: even light from every side and soft shadows under objects and vehicles; the button then shows a cloud. The choice is kept in the browser for both 3D views (Draw and Simulate); it never changes the project or the run.

Ctrl/⌘ + Shift + wheel cuts the view: walls, scene objects, station models and racks nearer to the camera than the cut are cut away, so you can look inside machines, offices and aisles; vehicles, floors and the network are never cut. The cut is measured from the asset nearest to the camera, so it keeps its place while you zoom and follows the view when it turns. A label at the top right shows its depth and × removes it.

Fit returns to the overview and Origin centres the point 0, 0. Panning and zooming keep the view over the floor, so the plant never drifts out of sight. The screen scale appears only in 2D, because in perspective it changes with distance. The image button downloads the 3D view as a PNG, with the labels shown on screen and the heatmap legend. Close up, coins have a real size tied to the narrowest vehicle; from far away they never shrink below a readable size. AGVs always stay at real scale.

The 2D or 3D choice stays in the browser: it does not change the project and never restarts or resets the simulation. Draw also offers a 3D view with model selection and rotation. The 3D view needs a browser with WebGL 2.

Routing options

Scenario → Orders → Advanced routing holds the avoid stations as pass-through points options, which steer routes away from stations of the chosen kind unless there is no other way. They are part of the scenario: changing them restarts the simulation.

3D station models

In Draw›Properties, a station has a 3D appearance list that replaces its coin in the 3D views of Draw and Simulate, with the same assets and rotation in the 2D views of Draw and Simulate too. In Simulate 2D loads follow orders and transfers; during pickup they stay on the station until service ends, when they pass to the AGV. Role and activity symbols remain visible. The 2D symbol, the routes, the run and the results do not change, and choosing a model never restarts the simulation. The choice is saved in the project. The models are: Coin (the default), Roller conveyor (with a generic load, with empty pallets or with loaded pallets), Belt conveyor and Belt conveyor with boxes (boxes), Empty pallet, Loaded pallet, Pallet rack (loaded pallets), Machine (boxes on a shelf under the hatch), Battery charger, Parking area and, for stainless powder bins, Bin bay (on the floor), Bin filling (under a filling head) and Bin discharge (on a stand 900 mm above the machine it feeds).

Models are drawn at real size: EUR pallets are 1200 × 800 mm and conveyor rollers stand at about the height of an AGV deck. The vehicle stops on the station point and the model stands past the vehicle towards the direction set by the model’s Rotation relative to path, whichever way the vehicle arrives: point it at the equipment, for example towards the end of a dead end. For mixed fleets, the model is laid out for the forklifts or VNA trucks allowed at the station; otherwise it uses the fleet with the most AGVs. Bins are moved by forklifts only: their models can be chosen where a forklift fleet is allowed, and are laid out for it. It is sized by the largest allowed vehicle: for platform AGVs, conveyors, pallets and racks become a stand that the AGV drives under from the pallet's short side: its rails hold the pallet's outer runners just outside the lifting plate and above the body, and its posts stand beyond the vehicle's width; a forklift AGV travels chassis first with forks and load behind and reaches the station with its forks towards the model, that is in reverse; the model stands past the vehicle and the pallet overhanging its forks, so the forklift pulls clear of the station before lowering them (on a conveyor the pallet waits at the end stop, on the vehicle's side); if it arrives with its chassis towards the model the forks cannot reach it, and the load changes hands halfway through the service without moving; a VNA truck works the same way at stations, and stations laid out for VNA trucks hold the warehouse pallet, sized as the fleet's pallet; otherwise, and always for belt conveyors and machines with platform AGVs, the model stands just past the vehicle's outline. The battery charger keeps a floor plate under the vehicle and its cabinet to the right of the model’s orientation, beyond the widest vehicle, leaving the longitudinal lane clear. The parking area draws corner marks around the vehicle. The colour of the station's role and activity is shown on one detail of the model (rail strips, strapping, beacon, status light or floor marks); the ring at the station point still marks activity.

In Simulate a model shows its load only when there is one: at a pickup station while a queued or active order still has to pick it up there, at a drop station for five simulated seconds after unloading, or until another AGV picks it up. A station an AGV is bringing a load to is empty when it arrives. Loading and unloading follow the simulated service time, so pause and reset keep the exact pose. A platform AGV raises its plate, lifts the load off the stand and travels with the plate raised; a conveyor AGV rolls the load from the model onto its deck; a forklift AGV brings its forks to pocket height, backs up until they are inside the pallet, lifts it, pulls out and lowers the forks, then travels with the pallet just off the floor (its simulated position stays on the station: the movement is in the view only, within the loading time); a tugger takes the load on its deck over the cab. Unloading runs the same movements in reverse. The load keeps its look from pickup to drop. An empty pickup leaves the station bare, a full drop finds it occupied. Pin, arrow and VNA trucks show the load only at the end of the service.

Movements dock

Active lists missions and returns in progress: AGV, activity, from → to, phase or assignment, waiting reason and time, including current speed and, with batteries, charge level. Pending lists queued orders and why they are waiting, for example Compatible AGVs busy or No AGV can reach the pickup. Long lists are paged with Previous / Next.

Idle vehicles and returns

After unloading, an AGV takes the next available order first. Otherwise it returns to the nearest free, reachable charger or parking permitted for its fleet, by route distance, not necessarily the one it started from. The station is reserved at departure, so two vehicles never head for the same place. Returns appear in the Movements table but never count as transport missions.

Orders take priority even during a return: an AGV heading to a charger can accept a waiting mission, cancel its return and drive to the pickup from where it is. The reserved station is released only once the new plan is accepted. Transports already assigned are never interrupted.

Fleets

A fleet is a group of identical AGVs, with its own speeds and pickup and drop-off times. The Vehicles tab shows one card per fleet, with a preview of the vehicle in its proportions; Add fleet creates a new one (up to 8) and the bin deletes one (at least one always remains).

AGVs are numbered in fleet order. Name and type only change the drawing, except the VNA truck, which carries warehouse handling, the AGV forklift, which carries its lift, and the Tugger, which carries trailers; dimensions, clearance, scanners, speeds, ramps, service times, count and battery restart the simulation. Traffic protects the oriented rectangular body, with its actual dimensions and clearance on every side; Minimum distance remains a lower bound on both protected dimensions. Reservations compare the swept bodies, including intermediate positions during rotation: vehicles alongside with clear space do not block each other merely because they share a search cell. Exclusive zones and reserved braking space still apply.

Open Advanced settings in the fleet card. Safety clearance adds 0–10000 mm on every side. Front scanner and Rear scanner set the stop range (100–50000 mm, default 1000), measured from the body’s leading edge. Only the field in the direction of travel is active: front in forward travel, rear in reverse. An AGV in that field causes braking and a wait until the field clears. A vehicle only alongside does not trigger the scanner, while the body's swept area stays protected on curves too. Range extends when speed and braking require more stopping space. Movements shows the scanner reason.

Under Advanced settings, Acceleration and Deceleration (1–1000 cm/s², default 40 and 60) also belong to the fleet. Projects saved when speeds, ramps and pickup and drop-off times belonged to the scenario open with those values copied into every fleet that had none of its own, so their results do not change. Ramps also apply to returns, disturbances, scanner braking and estimated durations. AGVs brake to zero before pickup, drop and parking: at 80 cm/s with 60 cm/s², braking takes 1.33 s and covers about 533 mm, so it may look brief at high simulation speeds. ZIP, JSON, PDF and run comparisons include these settings.

Tugger trains

Choosing Tugger as the type adds a Trailers section to the fleet card. A train is the tractor plus identical trailers, and every trip takes all of them from one pickup to one drop-off.

A line below the fields gives the length of the whole train and the loads per trip. Service at a station takes the fleet's fixed pickup or drop-off time plus the time of each trailer; a station with custom times replaces only the fixed part. For example, 12 s plus three trailers at 15 s gives 57 s. The defaults are only a starting point: enter the times of the real train and stations.

The tractor's centre stops on the station point, as for every AGV, and the trailers stay behind it on the path. They follow the path of the tractor's hitch ideally: every coupling stays on that path and every drawbar and trailer keeps its exact straight length, so on a curve a trailer cuts it by its chord. At a sharp corner between two straight paths the tractor turns on the spot and the hitch swings around it, so draw curves where the real train turns. Off-tracking dynamics and jackknifing are not simulated. Trailers are drawn with their drawbars in 2D and 3D; in 3D the loads appear on the trailers one after the other during loading and leave them the same way.

The results count one load per trailer. With a train fleet, Loads (delivered and per hour) appears below the headline KPIs, the run comparison adds Loads/h, and the exports add the loads per mission and per AGV and the trailer settings. A mission of an AGV without trailers counts as one load. A tugger saved before trailers existed works as a lone tractor until you edit its trailers.

Forward only. A train with trailers never reverses. Its route may turn by up to 90° at a time, never back on itself, and both legs of a trip are planned together, so it reaches the pickup facing a forward way to the drop-off; after the drop-off it must be able to drive on to a station its fleet uses. A station at the end of a spur can therefore be reached but not left: trains do not deliver or park there. An order a train could serve only by reversing stays queued with the reason The train cannot reverse: no forward route, and the Network tab lists the trips trains cannot make and the stations that are dead ends for them. A train finishes a return to its charger or parking before it takes a new order. Read Tugger trains in traffic for how the trailers occupy space.

Stations reserved to a fleet

With at least two fleets, the properties of a station with a role (Pickup, Drop, Charger or Parking location) show Permitted fleets, in Draw›Properties. By default every fleet may use every station. Untick a fleet to stop it picking up, dropping off, charging, parking or starting at that station; it may still drive through. At least one fleet always stays permitted. Deleting a fleet also removes it from the stations.

An order that no placed fleet can serve stays queued with the reason No placed AGV belongs to a fleet permitted at both the pickup and the drop-off.

Warehouse flows and vertical service

The VNA truck type serves every rack; AGV forklifts serve floor stacks, drive-in racks and racks with a wide enough aisle (see below). Choosing it loads an editable preset: 3000 × 1100 mm, 100 cm/s on straights and 30 on curves, ramps of 30 and 50 cm/s², 25 s to pick up and 25 to drop off, maximum height 8000 mm, lift 30 and lowering 40 cm/s and the pallet already used by other VNA fleets; choosing another type removes warehouse handling. Projects where a fleet of another type had warehouse handling open with that fleet converted to a VNA truck. In Vehicles → VNA warehouse, enter maximum height (mm), lift speed and lowering speed (cm/s), pallet length and width (default 1200 × 800 mm) and Aisle side: Short side (default) or Long side, the pallet side facing the aisle in the cells, which the forks enter through. With a EUR pallet by its short side, 800 mm run along the aisle and 1200 mm into the rack. All VNA fleets use the same pallet and entry. If the pallet carried with the forks in travel exceeds the fleet length, the card shows the overhang and the minimum length, because traffic protects only the fleet footprint; Network warns when the pallet does not fit the cells. A fleet cannot serve cells above its maximum height. In Scenario → Warehouse, add Storage/Retrieval flows with exchange station, aisles and interval. Storage takes a pallet at the exchange and deposits it; Retrieval delivers a stored pallet to the exchange. One unresolved request per periodic flow waits for stock/capacity rather than accumulating missed periods.

Cell priority uses nominal exchange-to-cell time for storage, cell-to-exchange time for retrieval, plus raising, the fleet's pickup or drop-off time and lowering (for an AGV forklift also its turns and manoeuvres in front of the cell). It takes the minimum across compatible fleets with vehicles, excluding future traffic waits and AGV approach. Equal times use stable cell identity. Vehicle allocation and mission dispatch remain separate.

A cell is reserved when the order enters the mission queue. Full/empty or inaccessible stock remains pending with a reason. One warehouse mission per aisle is admitted at a time, including approach and exit, so other vehicles stay outside. Traffic also protects complete body exit and vehicles driving through. Ensure external stops have room beyond the aisle's protected envelope; a dead end must allow a legal return.

The sequence is arrival, raising, loading/unloading, lowering, then driving with forks down. A deposit includes an external escape before becoming idle. Pickup/drop faults retain the same cell and stock until successful service; operator recovery resumes the attempt even when station backup is enabled. Pause and run completion never finish pending work. Reset restores initial stock.

The elevation shows empty, occupied, reserved and blocked cells, with the cell in service highlighted and named in its tooltip. Simulate 3D outlines each assigned mission's cell from approach onwards, showing its code and AGV. Queued reservations have a distinct outline; only occupied cells show a pallet. When a cell is deeper than its pallet, the 3D view adds support bars between the front and rear beams beneath the outer runners, keeping the contact surface at the configured level. With VNA handling the forklift asset becomes a full-size turret truck: a triplex mast fixed to the chassis, a telescopic side traverse and a swivel head. Like every AGV forklift it travels chassis first, with mast, head and pallet behind. At the column stop the truck first moves forwards or backwards until its head, not its body centre, faces the column (at most 50 cm/s with the fleet's ramps, in 2D and 3D), then raises the carriage. The head turns towards the served side keeping the pallet on the aisle centre line, the traverse carries it into the cell, sets it down on the beams (storage) or lifts it out of the pockets (retrieval), retracts and returns to travel before lowering; the truck then returns to the stop. Turning, insertion, transfer and return use the configured loading/unloading time, including ground-level cells; positioning, lifting and lowering take their own time. Animation follows simulation time: Pause holds the height and Reset lowers the forks. Selection, side, search and 2D/3D navigation do not reset the run or change the project. Initial stock is editable before running or after Reset. All pallets are equivalent, one per cell, at single depth.

AGV forklifts in racking

An AGV forklift serves a rack when its aisle is wide enough to turn in with the pallet on its forks. The forklift turns in place on the aisle centre line, so the distance from the path to the rack face must be at least its turning radius with the pallet plus the fleet's safety margin plus 50 mm. A 1600 × 900 mm AGV forklift carrying a EUR pallet by its long side turns within 1175 mm: it needs 1225 mm on each side, a 2450 mm aisle. It serves the cells up to its maximum height; higher ones are left to the VNA trucks that reach them. An aisle no AGV forklift can turn in is a VNA aisle, and only then is the rack's type VNA racking, measured against the scenario's staffed AGV forklifts (or, without any, a standard AGV forklift). With both types each cell goes to the fleet that serves it sooner.

At the column stop the AGV turns with its forks towards the cell's side, moves towards the rack, lifts the pallet before the rack face, backs in until the pallet is centred in the cell, sets it down or picks it up, comes out, lowers and turns towards its next route; after a store it leaves the aisle like a VNA truck. The warehouse rules apply: one mission per aisle, the cell reserved at admission and stock that changes only at the transfer. The turning circle in front of the cell stays with the AGV from its arrival until it leaves. In 2D and 3D its body, forks and mast follow simulated time. The Network tab reports an aisle too narrow to turn in (with radius and widths), cells above the reach of every fleet that serves the aisle, and an AGV forklift carrying a different pallet from the VNA trucks'.

Floor stack and drive-in service

Floor stacks and drive-in racks are served by AGV forklift fleets. In Vehicles → Lift, set the forks' maximum height, the lift and lowering speeds, the pallet and the Entry side: the pallet face towards the lane mouth. The defaults are 4500 mm, 25 and 35 cm/s and a EUR pallet taken by its long side, so a 900 mm wide AGV fits between stacks and between rails; all forklift fleets use the same pallet. In 3D the mast has three stages and grows with the maximum height. Flows and the Store and Retrieve blocks choose floor stacks and drive-ins like any warehouse.

For each order the simulator chooses the cheapest free lane: a store takes the lane's next position, a retrieval its last stored pallet. In a floor stack with Fill from or Empty from set, the order takes the lane whose turn it is from that side instead (see Floor stacks and drive-in racks). One forklift at a time works a lane. When the stop is reached only by one-way paths (besides the drive-in's own path), several orders for the same lane start together: each AGV picks up its pallet and waits before the entrance, where it would take the turning circle or an exclusive zone the circle reaches, with the reason Lane busy with AGV n: waiting before the entrance; the first to go in takes the place whose turn it is, so the lane stays LIFO whatever the arrival order. An order takes a free lane nearby when waiting would cost more than the longer route, and stores and retrievals for the same lane do not queue together. With a two-way access the lane keeps one mission at a time. Two nearby lanes are worked together when the forklift inside one does not take the space the other needs (its turning circle or its lane): two drive-ins side by side, even with overlapping turning circles, work at once and only their turns at the stops take turns. Otherwise, as for adjacent lanes of a floor stack, the order waits with the reason Nearby lane busy: waiting for the whole mission under way. An exclusive zone covering both stops is the exception: the zone already lets one forklift in at a time, so both missions start and the second forklift waits at the zone edge. On a two-way access, two forklifts bound for different lanes can meet head on, as on any two-way path: make the main paths one-way and put exclusive zones on dead-end lanes and on junctions where routes reverse (see Traffic).

At the stop the AGV turns in place with its forks towards the lane, backs in, lifts the pallet, brings it over the position, sets it down, pulls the forks out, lowers, drives out and turns again. In a drive-in the pallet is lifted before the mouth, above the rails; in a floor stack one position in front of the stack. Body, turn and forks move in simulated time, in 2D and 3D: in a lane the AGV drives at most at its curve speed and turns at 30°/s. The fleet's pickup or drop-off time covers setting down or picking up; disturbances on that step keep the same position until it succeeds. Each phase reserves the space it takes, pallet included. The turning circle in front of the lane belongs to the AGV from its arrival, reserved from one radius before the stop, during its turns and in every phase where the forklift, pallet included, reaches the paths other vehicles drive on. Deeper in, the AGV holds its own lane only: vehicles passing on the path drive across the mouth, and another forklift can work the next drive-in. To come out, the AGV takes the circle back from inside the lane and keeps it until it drives off, so a vehicle passing or following it never takes the room it needs to get in or out. The drive-in's own path, and paths that lead only to its stop, do not count as other vehicles' paths; a drive-in whose path also serves stations or other paths keeps the circle for the whole service. Exclusive zones follow the same rule: deeper in, the AGV holds only those its lane touches, so a zone drawn over the path in front of the mouth stays open to passing vehicles, and to come out the AGV waits inside the lane until the zone is free. An order waiting for a nearby lane does not hold an idle AGV on the path: the free AGV meanwhile goes to park.

Transfers between warehouses. A periodic flow with the Transfer operation, or the Transfer block in plant logic, takes a pallet from one of the From warehouses and stores it in one of the To warehouses in the same trip, with no exchange station. The source pallet and the destination place are reserved together, keeping lanes LIFO, for a fleet that serves both: VNA trucks between racks, AGV forklifts between floor stacks, drive-ins and racks with a wide aisle. If no fleet can serve both, the run reports it at start.

The Network tab reports fleets that cannot reach the top level, are too wide for the lane or have no room to turn in front of the mouth, stops the exchange station cannot reach, and pallets that do not fit the positions.