| Tracks and slew ring | What it does. Two steel crawler tracks carry the machine over soft and broken ground. A slew ring on top of the track frame carries the upper structure, so the house, the cab, and the arm turn all the way round while the tracks stay put. | Why it is hard. Everything that turns with the house has to cross the slew ring: oil through a rotary joint, wiring through a slip ring. Next to the trench it is digging, the ground under the near track can give way, so the machine has to know where the edge is and keep its tracks back from it. | Catalogue examplesthrough bore 0.5 in · circuit 24 · current per circuit 5 A The slip ring listed is an example of how wiring crosses a joint that turns without limit; the one on a machine this size is larger and sealed. The catalogue has no crawler track or slew bearing of this size. |
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| Upper house, engine, and cab | What it does. The upper structure carries the diesel engine, the counterweight that balances a full bucket at reach, the fuel and hydraulic oil tanks, and the cab. The cab stays, so a person can still drive the machine from the seat. | Why it is hard. The engine sets how much hydraulic power there is, and it runs near full load for a whole shift in dust and heat. After the refit the machine has two drivers, a person in the seat and the computer, and it has to be clear at every moment which one is in control. | Catalogue examples The catalogue has no diesel engine, counterweight, or cab row. |
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| Boom, stick, and bucketWorking at 03 dig, 05 dump | What it does. The boom lifts, the stick reaches in and out, and the bucket curls, each on a steel pin. Together they reach several metres below the tracks and high enough to clear the side of a truck. | Why it is hard. Soil is unknown until the bucket is in it. Clay, wet sand, roots, and buried rock each push back differently, and a motion that fills the bucket in one pass stalls it in the next. The pins wear, so the teeth end up centimetres from where the joint angles say they are. | Catalogue examples The catalogue has no boom, stick, or bucket row. They are welded steel, built by the machine's maker. |
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| Hydraulic pump, valves, and cylindersWorking at 03 dig, 04 swing, 05 dump | What it does. An engine-driven pump feeds a block of valves, and each valve sends oil to a cylinder or a motor: two cylinders lift the boom, one moves the stick, one curls the bucket, a motor turns the house, and two more drive the tracks. | Why it is hard. Hydraulics are slow and nonlinear. A valve does nothing until its spool passes a dead band, flow changes with oil temperature and with how many motions share the pump, and a raised, loaded arm creeps down while its valve is closed, as oil leaks past the spool. A controller tuned on a cold morning overshoots by the afternoon. | Catalogue examplesmax operating pressure 350 bar · coil voltage 24 V The valve listed is a small on-off directional valve, an example of the valve family. An excavator's main control valve is a larger block of proportional spools, usually moved by pilot pressure rather than directly by a solenoid. |
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| Perception mastWorking at 01 see, 04 swing | What it does. A lidar on a mast over the cab, tilted down toward the digging, measures the pit and the ground around the machine in 3D, a second lidar watches behind it, and cameras beside the first see what a lidar cannot, such as a person in a high-visibility vest or a paint mark on the ground. | Why it is hard. The arm crosses the lidar's view on every cycle, dust rises from every bucket, and the ground changes shape each pass, so the map of the pit goes out of date almost as soon as it is made. The mast shakes with the engine and with every swing. | Catalogue examplesrange 80pct 170 m · range 10pct 90 m · range min 0.5 m fov horizontal 360 ° · fov vertical 59 ° · range min 0.1 m resolution 1,920 × 1,200 · frame rate 40 Hz · sensor size 1/1.2 in |
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| Joint angle and pressure sensorsWorking at 03 dig, 07 log | What it does. An angle sensor on each pin, tilt sensors on the boom and the stick, and pressure sensors on the cylinder lines tell the computer where the bucket is and how hard it is pushing. | Why it is hard. The sensors sit where the digging is: on pins that flex, in mud, under blows from rock. Pressure is the only way the machine feels the soil, and it mixes the soil's resistance with the weight of the arm and of the load. | 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 angle and motion chips listed are examples of what sits inside such sensors; on a machine they come in sealed, rugged housings. The catalogue has no hydraulic pressure sensor row. |
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| Compute and CAN busWorking at 02 plan, 06 take over, 07 log, 09 ship | What it does. A sealed computer behind the cab turns the lidar map into a plan for each bucket and sends valve commands over a CAN bus to the machine's own controller, which still drives the valves. | Why it is hard. The machine's own controller was built for a person's joysticks, and it may accept outside commands only through the maker's interface, or not at all. A plan has to leave margin for hydraulics that answer late, and the computer has to stop the machine if it falls behind. | Catalogue exampleslength 242 mm · width 240 mm · height 82 mm AI throughput 275 trillion operations/s · memory 64 GB · memory bandwidth 204.8 GB/s supply voltage 1.7 to 3.6 V · data rate max 8 Mbit/s · bus fault voltage 58 V The two computers are examples of a rugged vehicle computer and an embedded module for perception. The CAN transceiver is the chip that connects a computer to the bus. |
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| Radio link for take-over and videoWorking at 06 take over | What it does. A cellular modem and antennas on the hood connect the machine to the people who run it and to a remote operator, carrying live video out and joint commands in. | Why it is hard. Coverage in a pit or behind a spoil heap comes and goes as the site changes. Video that stalls for half a second is long enough to hit something, so the operator has to see how old the picture is, and the machine has to stop on its own when the link drops. | Catalogue examplesdownlink rate max 300 Mbit/s · uplink rate max 50 Mbit/s · transmit power 23 dBm length 52 mm · width 30 mm · height 2.3 mm |
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| Stops and swing zoneWorking at 04 swing, 06 take over | What it does. Emergency stop buttons on the machine and a radio stop that a person on the site carries cut hydraulic power, and a warning beacon warns anyone nearby. The lidar watches the circle the house and the arm swing through. | Why it is hard. A person inside the swing circle can be crushed between the counterweight and whatever stands behind it. Every stop has to cut hydraulic power in hardware without waiting on the computer, and a stopped machine has to hold the bucket where it is rather than let it drop. | Catalogue examples The catalogue has no safety-rated part. A real remote stop is a certified radio system wired to a safety relay that removes the pilot pressure the valves need to move. |
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