| Chassis and casters | What it does. A low steel body about 0.9 m long and 0.6 m wide holds the battery, the computers, and the drive units, and carries the roller top on its deck. Four swivel casters at the corners carry the weight the drive wheels do not. | Why it is hard. The two drive wheels have to stay pressed to the floor over bumps, joints, and dock plates while the casters carry the rest. A body this low clears little, so a lip in the floor or a dropped strap can stop it. The casters swing round when the robot turns, and a caster that sticks pulls it off its path. | Catalogue exampleswheel diameter 8 in · wheel width 2 in · load capacity 272 kg The Colson caster listed is an 8 inch wheel that stands about 0.24 m tall and carries 272 kg. A robot this low uses a smaller caster of the same kind; the catalogue has only this one. |
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| Differential drive unitsWorking at 03 drive, 04 avoid | What it does. Two drive units, one each side, each a brushless motor, gearbox, brake, and wheel in one assembly. The robot steers by turning its two wheels at different speeds, and turns on the spot by turning them in opposite directions. | Why it is hard. Every change of speed is a change of torque at the wheels, and a loaded robot that brakes hard slides its tote or skids its wheels. When a wheel slips, the robot has moved a different distance from the one its wheels counted. The brakes have to hold the robot on a slope when power is lost. | Catalogue exampleswheel diameter 200 mm · load capacity 800 kg · speed rated 107 rpm The Nidec unit is rated for 800 kg, more than a tote robot carries. It is listed because it is the catalogue's integrated wheel drive for automated vehicles, with the encoder and brake a unit like this carries. |
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| Roller top and toteWorking at 05 hand off | What it does. A module on the deck with driven rollers carries a 600 by 400 mm tote at conveyor height and rolls it off onto a conveyor, or takes one on, without a person lifting it. Side guides keep the tote from sliding off while the robot moves. | Why it is hard. The robot has to stop within a few centimetres of the conveyor's end, lined up with it, or the tote catches on the edge. A full tote shifts when the robot brakes or turns, and the rollers must hold it still until the handoff starts. | Catalogue examples The catalogue has no roller conveyor module or tote row. |
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| Safety laser scanners, front and rearWorking at 01 localise, 04 avoid | What it does. A 2D laser scanner at each end sweeps a flat plane a little above the floor, many times a second. The same scans do two jobs: the navigation software matches them to its map, and the scanners check their own configured safety fields for anything inside them. | Why it is hard. A laser at ankle height sees legs, pallets, and rack uprights. It misses a fork tip or a load hanging above its plane, and dark or shiny surfaces return little light. The safety fields have to be set for each speed and each turn the robot makes, and a field that is too long stops the robot for nothing all day. | Catalogue examples The catalogue has no safety-rated 2D laser scanner row. Its lidars, the Ouster OS1-64 and the Livox Mid-360, are 3D sensors that carry no safety rating. |
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| Depth camera | What it does. A depth camera over the front scanner, tipped down, sees what the flat laser plane misses: a load hanging above it, a tote on the floor, a low obstacle. The navigation software adds what it sees to its map of obstacles around the robot. | Why it is hard. A depth camera sees a shorter distance than a laser, and bright light, dark floors, and shiny wrap confuse it. Its view is only useful when the software knows exactly where on the robot it is mounted and how it is tipped; a bumped bracket puts obstacles in the wrong place. | Catalogue examples The catalogue has no depth camera row. The Basler camera it lists is a colour machine-vision camera without depth. |
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| IMU and wheel encodersWorking at 01 localise | What it does. An encoder on each drive unit counts how far its wheel turns. An inertial measurement unit (IMU) measures how fast the robot turns. Together they give the navigation software a smooth estimate of how the robot has moved between laser scans. | Why it is hard. This estimate drifts: a slipping wheel, a worn tyre, or a heavier load changes how far a turn of the wheel really moves the robot, and small errors in heading grow into large errors in position down a long aisle. The scans have to correct it, and in an aisle where every bay looks the same the scans have little to correct it with. | Catalogue examplesresolution 14 bit · resolution 0.0219 ° · fov 360 ° accel range max 24 g · gyro range max 2,000 °/s · supply voltage 2.4 to 3.6 V The AS5048A is a magnetic angle sensor of the kind used as a wheel encoder; the Nidec drive unit listed carries its own encoder. The BMI088 is an IMU built for drones and robots. |
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| Onboard computer running ROS 2Working at 01 localise, 02 plan, 03 drive, 05 hand off, 06 log, 07 return, 09 ship | What it does. A fanless industrial computer runs the customer's ROS 2 stack: the drivers for the scanners, camera, and wheels, localisation against the warehouse map, the path planner, and the controller that follows the path. It also runs the fleet software that gives it jobs. | Why it is hard. The stack is many programs passing messages, and a program that stops publishing leaves the rest working on old data. It is the customer's software, tuned over months for this warehouse, and the team running the fleet is not going to replace it. Anything that manages the fleet has to work around it. | Catalogue exampleslength 242 mm · width 240 mm · height 82 mm The Karbon 700-SE takes 9 to 48 V directly, so it can run from the robot's battery without a separate supply. |
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| Safety controller, emergency stops, and status lightsWorking at 04 avoid | What it does. A safety controller reads the scanners' field outputs, the emergency stop buttons, and each wheel's speed from its own encoder input. It picks the scanners' field set for the speed the robot is going and, when the protective field is entered or a button is pressed, brakes the drives to a stop and removes their power. Light strips at each end show whether the robot is moving, waiting, or stopped. | Why it is hard. The stop has to work whatever the navigation software is doing, even when it has crashed, so it runs on separate hardware wired to the scanners and the drives. That separation is what a safety assessment checks, and it means the ROS 2 stack can slow the robot but cannot switch the stop off. | Catalogue examples The catalogue has no safety controller, emergency stop, or light row. |
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| Battery and charging contactsWorking at 03 drive, 07 return | What it does. A pack of lithium iron phosphate cells powers the drives and everything else. Two contacts low on the rear wall meet the plates of a charging dock when the robot backs onto it, so it charges between jobs without a person plugging it in. | Why it is hard. The robot has to go and charge before it runs low, which takes it out of service while jobs wait. Many short charges through the day suit these cells, but the fleet software has to spread them so that not every robot is on a dock at once. Contacts that wear or collect dust stop charging quietly. | Catalogue examplescapacity 105 Ah · nominal voltage 3.2 V · charge voltage max 3.65 V The EVE LF105 is a 105 Ah lithium iron phosphate cell. A pack of eight in series gives about 25.6 V; many robots of this class carry a smaller pack. |
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| Wi-Fi clientWorking at 02 plan, 07 return, 09 ship | What it does. A Wi-Fi client with two antennas on the deck links the robot to the fleet software that gives it jobs, and to the servers that collect its reports and send it changes. | Why it is hard. A robot moving down an aisle passes from one access point to the next many times an hour, and racking full of metal and stock blocks and reflects the signal. Each handover can drop the link for a moment, so the robot has to keep driving safely on the job it has, with no link at all. | Catalogue examples The catalogue's only Wi-Fi row is a 2.4 GHz module for small embedded devices, which its maker marks as not recommended for new designs, so none is listed. |
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