14 · The mind
One second inside a robot
Follow one spoken request from the microphone to the fingertip and back to the fleet cloud, and watch every earlier chapter do its job at its own speed.
You say "put the cup in the sink" and a humanoid does it in a few seconds. Inside those seconds, magnets push on coils 40,000 times a second, a learned policy writes joint targets 200 times a second, a language model re-reads the scene a few times a second, and the whole episode, including the part where it drops the cup, ends up in a training set weeks later. The robot works because each layer runs 5 to 50 times faster than the layer above it and trusts the layer below. It breaks where one layer is late, blind or out of its depth.
One request, seventeen steps
The walk-through below follows a humanoid built like a Figure 03 or an Optimus-class robot: a VLA brain split into a slow reasoning model and a fast policy, a learned balance layer, an EtherCAT line to every joint, and joint modules with a motor, a harmonic drive and two encoders each. Real robots differ in detail; the order of events and the time scales hold across the field. Press play or step through. The top half shows the robot; the bottom half lights the layer that is working, on a time axis where each tick is ten times the one before.
- Hear · about 1 to 2 s of speech
Microphones in the head pick up the sentence and a speech model turns it into text for the reasoning model. Nothing moves yet. See the main computer that runs it.
- Think · 100 ms to 1 s per look
The slow model, System 2, reads the head camera images and the instruction and writes a plan: find the cup, grasp it, carry it, release it over the basin. Figure's version is a 7B vision-language model at 7 to 9 Hz verified. Chinese engineers call this layer the big brain. Dual systems.
- Act · 5 to 20 ms per step
The fast policy, System 1, turns pixels, joint states and the plan into joint targets. Figure's S1 has 80M parameters and runs at 200 Hz; π0 writes 50-step action chunks, one second of motion at 50 Hz verified. What a VLA is.
- Balance · 1 to 2 ms per tick
Reaching forward moves mass ahead of the feet, so the whole-body layer, System 0, shifts the hips back to keep the centre of mass over the support polygon. On Helix 02 this is a 10M-parameter network at 1 kHz trained only in simulation verified. Balance, whole-body control.
- Broadcast · one frame per millisecond
The real-time controller packs every joint's target into one EtherCAT frame. The frame streams through each joint in turn; each joint reads its command and writes back its state on the fly. At 100 Mb/s one line refreshes 30 or more joints at 1 kHz with clocks synchronised to under a microsecond verified. Buses.
- Drive the coils · 25 to 100 µs per loop
Inside each joint, the motor driver runs field-oriented control: it measures the three phase currents, works out where the rotor is, and switches its transistors so the magnetic field stays 90 electrical degrees ahead of the rotor. This current loop runs at 10 to 40 kHz verified. The driver and FOC.
- Magnets make torque · within the same loop
Current in the stator coils pulls on the rotor's NdFeB magnets. Torque is the motor's torque constant times the current, so the driver controls torque by controlling amps. The magnets hold the rare earths whose export China has licensed since April 2025 verified.
- Trade speed for force · continuous
The motor spins fast and weakly. The reducer, here a harmonic drive at 50:1 to 160:1, turns that into a slow, strong joint. The same gear makes the motor feel ratio-squared heavier to anything pushing on the arm, which is why a stiff joint needs a torque sensor to feel contact. Harmonic drive, properties.
- The arm moves, the encoders report · every tick
Shoulder, elbow and wrist turn together along the kinematic chain. An encoder on the motor and another on the output measure the angles every cycle and ride back on the next EtherCAT frame. The reach itself takes a few tenths of a second. Kinematics.
- See the handle up close · a frame every few tens of ms
The head camera loses the cup behind the hand, so the policy leans on the palm camera for the last few centimetres. Figure 03 carries a camera in each palm verified. A smeared palm lens is the kind of fault a service visit finds in a minute and a lab never sees. Cameras.
- Touch · 1 to 5 ms
The fingers close. Tactile sensors in the fingertips register contact; Figure quotes 3 g sensitivity on Figure 03 verified. Contact switches the policy from reaching to holding. Tactile sensing.
- Catch the slip · a few policy steps
The cup is wet. As the arm lifts, the fingertip pressure pattern creeps downward: the cup is sliding. The fast policy raises grip force within a few of its 5 ms steps estimate. Too little and the cup falls; too much and a paper cup crushes, which is why force and touch data are the scarcest data in robotics. The data pyramid.
- Pay in watts and heat · minutes
Every joint turns battery current into torque and waste heat. Figure 03's 2.3 kWh pack lasting 5 hours implies an average draw of about 460 W derived, most of it ending as heat in the joints. If a shoulder runs hot for minutes, the driver cuts its current limit, the temperature rise stops and so does the arm's strength. Heat and derating.
- Fail · one bad release
The policy opens the hand a few centimetres short of the basin. The cup clips the rim and tips onto the counter. Nothing was broken, yet the task failed. In unseen homes, Figure's best published model still fails 44% of attempts verified. What works.
- Take over · seconds to minutes
The robot flags that it is stuck. A remote operator in a VR headset takes the arm, picks up the cup and places it in the sink. 1X sells this openly as Expert Mode on NEO, and every takeover becomes training data verified. This is teleoperation as a safety net. Teleoperation.
- Log · minutes to hours
The robot writes the episode: synchronised camera frames, joint states, actions, tactile readings, the failed release and the operator's correction. It uploads to the maker's fleet cloud over Wi-Fi. Whoever controls that upload owns the most valuable record of the day. A log record, telemetry.
- Learn · days to weeks
The lab retrains on failures and interventions. Physical Intelligence's RECAP method, which trains on human corrections, roughly halved failure rates and doubled throughput on its hardest tasks verified. The new policy ships to the fleet as an OTA update, and the next cup goes in first time. The data flywheel.
Twelve orders of magnitude
The single most useful picture of a robot is the time axis in FIG 14.1. Read it from the left. At 1 µs, EtherCAT's distributed clocks keep every joint in step. At 25 to 100 µs, each motor driver closes its current loop. At 1 ms, the whole-body layer balances the robot and the bus delivers a fresh set of targets. At 5 to 20 ms, the learned policy writes the next targets. At 100 ms to 1 s, the reasoning model looks again. Past a second, humans and clouds take over: the operator in seconds to minutes, the log upload in hours, the retrain in days or weeks.
Real
Each control loop runs 5 to 50 times faster than the loop that commands it: current loops at 10 to 40 kHz, joint loops near 1 kHz, whole-body control at 500 Hz to 1 kHz, a visuomotor policy at 50 to 200 Hz and a reasoning model at 1 to 10 Hz verified. The separation lets each layer treat the one below as instantaneous and the one above as constant. The inner loop has settled before the outer loop's next command arrives.
ELI5
You decide to pour tea once. Your arm adjusts the angle many times a second. Your muscles twitch far faster than you can notice. You never think about the twitches, and your muscles never think about tea. A robot copies that split, with a computer for each speed.
The same axis tells you where money and failure sit. The left half, microseconds to milliseconds, lives in firmware on chips inside each joint. It is mature, cheap to run and made in China: a Unitree G1's entire compute subsystem costs about CNY 1,415 (US$200) estimate. The middle, 5 ms to 1 s, is where the frontier labs fight: Figure has committed US$3.5 billion of compute to Helix verified. The right half, seconds to weeks, is people, logistics and data, and it is the part a company in Southeast Asia can own without a chip team.
Latency hurts in proportion to a loop's rate. A loop that responds at 10 Hz and picks up 20 ms of extra delay loses about 72 degrees of its stability margin verified. The same 20 ms inside a 1 kHz joint loop would be twenty missed cycles. That is why the bottom layers never wait on Wi-Fi, a cloud call or a busy GPU: each layer gets a time scale and a latency budget, and a robot fails gracefully only if every layer can hold its last good command when the layer above goes quiet.
Figure's Helix 02 shows the boundary moving. Its S0 layer replaced 109,504 lines of hand-written C++ balance and whole-body code with a 10M-parameter network running at 1 kHz, trained across more than 200,000 parallel simulated environments verified. Learning has eaten down to the millisecond layer. The current loop and the bus below it stay classical, because physics at 40 kHz has no data problem to solve. See where learning replaces classical control.
The whole machine on one sheet
FIG 14.2 is the wiring diagram behind the walk-through. Every sensor ends at one of two computers. Every motor hangs off one EtherCAT line. One battery feeds everything, and one hardwired safety chain can cut motor power without asking any software.
- 1Orange: the EtherCAT line to every joint 总线
- 2Blue: data links (camera, Ethernet, CAN, Wi-Fi)
- 3Thick black: DC power; dashed: hardwired safety
Walk the diagram in the order a fault travels:
- Cameras to the main computer. Head and palm cameras stream images to a Jetson Thor-class computer drawing up to 130 W verified. NVIDIA raised the Thor T5000 module price from US$2,999 to US$4,999 at 1,000 units on 22 Jul 2026 verified, so compute is now one of the few humanoid parts getting dearer. Three brains and a cloud.
- Main computer to real-time controller. Joint targets go down over Ethernet at 50 to 200 Hz; robot state comes back up. The real-time controller runs PREEMPT_RT Linux or an RTOS, where a late answer counts as a wrong one. Real time.
- The EtherCAT line. One cable threads through every joint group and back. A cut or chafed cable in a moving arm takes out everything downstream of it, and Figure named the forearm, with its moving cables feeding the wrist motors, as Figure 02's top hardware failure point at BMW verified. Wiring and cable fatigue.
- Inside one joint. Driver, motor, reducer, two encoders, torque sensor, brake and bearing. In a rotary joint the reducer is about 36% of the cost, the torque sensor about 30% and the motor about 13.5% estimate. The bill of materials.
- Power and safety. A G1's 13-cell pack sits near 47 V nominal verified. The BMS reports charge and temperature on CAN. The emergency stop opens a contactor on the power bus. On a wheeled robot that is a safe state. On a legged one it means a fall, which is the unsolved problem in humanoid safety.
- Up to the cloud. Logs, maps and updates move over Wi-Fi or 5G to the maker's fleet cloud, which is also where a remote operator's takeover session comes in. That link is the main attack surface found in Unitree's robots. Cybersecurity.
From fleet to magnet
FIG 14.3 zooms in six times. Each panel is roughly ten to a hundred times faster and smaller than the one before, and each has its own specialists, its own suppliers and its own way to fail.
Each zoom level maps to a different kind of company. Magnets come from a supply chain China dominates and has licensed for export since April 2025, with a broader October 2025 expansion suspended until 10 Nov 2026 verified. Motors and drivers are a Chinese price war: Leadshine plans 2 million frameless motors in 2026 after delivering 120,000 in 2025 estimate. Joints are where Unitree makes its margin, since it builds its own joints, drivers and BMS verified. Arms and whole robots are the makers. Fleets are the customers, the distributors and the service firms.
Where the second goes wrong
Every step in FIG 14.1 has a characteristic failure, and each one shows up at a different distance from the robot. The list below runs from the magnet outward, which is also the order of how hard the fault is to fix in the field.
| Layer | Time scale | Typical fault | Who sees it first |
|---|---|---|---|
| Motor and driver | 25 to 100 µs | Overheating, a failed transistor, an encoder fault | The robot's own fault code |
| Reducer and bearing | continuous | Backlash growth, grease loss, flexspline fatigue | A technician listening to the joint |
| EtherCAT and harness | 1 ms | Chafed cable in a moving limb, dropped frames | Intermittent errors nobody can reproduce |
| Balance layer | 1 to 2 ms | A fall after a push, a slip or a controller change | Whoever is standing nearby |
| Policy | 5 to 20 ms | Wrong grasp, slip, early release | The customer, then the remote operator |
| Sensors | 1 to 50 ms | Smeared lens, knocked camera, glass and mirrors | A field visit |
| Reasoning model | 0.1 to 1 s | A wrong plan in a room it has never seen | The customer |
| Cloud and OTA | hours to weeks | A bad update, a lapsed licence, a hijacked link | Everyone, at once |
Real
Published success rates describe the middle rows only. Helix 2.5 reached 56% zero-shot success in 30 unseen homes against 9% for a model trained from scratch verified Sep 2026; DYNA-1 folded 850+ napkins in 24 hours at 99.4% success with zero interventions, at about 60% of human speed verified. Neither figure tells you how often a harness chafes, a lens smears or a joint overheats over a year of shifts. Nobody publishes that.
ELI5
A robot's report card grades its brain on tests the school picked. It says nothing about how often its shoelaces snap or its glasses get smudged. Those are the things that actually stop it working on a Tuesday.
Treating a demo video as one second repeated. A four-minute uncut run, such as Helix 02's dishwasher unload and reload with 61 actions and no resets verified, proves the stack can work end to end once. It says nothing about the 44% of attempts that fail in new rooms, or about how many operators sat behind the fleet that week. The evidence that matters is the intervention log and the uncut attempts. Real autonomy or a person with a headset.
The failed attempt is the valuable part
Steps 14 to 17 are where the robotics industry's money is moving in 2026. The cup that tipped over, the operator who finished the job, and the synchronised record of both, are exactly the data every frontier lab now trains on. Physical Intelligence's π*0.6 learns from teleoperator interventions during autonomous runs, and π0.7 trains on "potentially suboptimal" autonomous data including failures, labelled with how well each attempt went verified. 1X guides NEO's launch autonomy at 60 to 70%, with a remote operator covering the rest verified.
Real
An intervention record pairs the state where the policy went wrong with the action a human took instead, with every camera frame, joint state and tactile reading time-aligned. That pairing is the training signal for correction-based fine-tuning such as RECAP. A repair ticket that says "gripper fault, replaced" carries none of it.
ELI5
A driving instructor grabbing the wheel is the most useful moment of a lesson, because it shows exactly where you went wrong and what right looked like. The recording of that grab is what the labs want.
Who captures that record decides who owns it. The robot writes it; the maker's fleet cloud receives it; the lab that trains the policy uses it. A third party sees it only if its contract gives it the logins and the logs, or if it operates the robots and the takeover desk itself. See why failures are the most valuable data and who holds the keys.
Terms in this chapter
| English | 中文 + pinyin | ELI5 | Real definition |
|---|---|---|---|
| Control loop | Look, compare with what you wanted, nudge, and do it again, over and over. Your hand does this when you carry a full glass. | A repeating cycle that reads a sensor, compares the reading with a setpoint and sends a correction to an actuator. A humanoid nests several: a current loop at 10 to 40 kHz inside each joint, joint position loops near 1 kHz, a whole-body loop at 500 Hz to 1 kHz, a learned policy at 50 to 200 Hz and a planner at 1 to 10 Hz. | |
| Latency | 延迟yánchí | The delay between something happening and the robot reacting to it. Like the lag on a video call, except a lagging robot drops the cup. | The time from a sensor event to the matching actuator response, summed across sensing, transport, computation and actuation. Latency eats stability margin: 20 ms of extra delay costs a 10 Hz loop about 72 degrees of phase margin, so each layer of the control stack gets a latency budget sized to its rate. |
| Time scale | How long one step of a job takes. A magnet's push lasts millionths of a second; retraining the robot's brain takes weeks. | The characteristic period of a process, such as one current-loop cycle (25 to 100 µs), one policy step (5 to 20 ms) or one retrain and OTA cycle (days to weeks). A robot spans about twelve orders of magnitude of time scales, which is why its software is layered and why the layers are drawn on a logarithmic axis. |
Sources for this chapter
- Research dossier (25 Sep 2026): control rates table, VLA master table, headline results, techniques, fleet and real-time notes.
- Figure, Helix 02 (27 Jan 2026): https://www.figure.ai/news/helix-02
- Figure, Helix 2.5 zero-shot home generalisation (17 Sep 2026): https://www.figure.ai/news/helix-2-5-zero-shot-30-home-generalization
- Figure 03 battery: https://www.figure.ai/news/f-03-battery-development
- Physical Intelligence, π0 (Oct 2024): https://arxiv.org/abs/2410.24164 · openpi: https://github.com/Physical-Intelligence/openpi
- Physical Intelligence, π*0.6 and RECAP (Nov 2025): https://arxiv.org/abs/2511.14759
- Physical Intelligence, π0.7 (Apr 2026): https://arxiv.org/abs/2604.15483
- Dyna Robotics, DYNA-1: https://www.dyna.co/research/dyna-1
- Research dossier: joint cost split (aiptesting.com and honpine.com 2025), G1 compute cost (China Post Securities teardown), Jetson price rise (CNX Software, 22 Jul 2026), Leadshine capacity, rare earth licensing timeline.
- Industry report, 28 Jun 2026: Helix S1 and S2 rates, 1X Expert Mode and autonomy guidance, Jetson Thor power.
- Earlier chapters of this primer for EtherCAT, battery voltage, latency and phase margin, and field failure points: Compute, wiring and power, Control, Failure and repair.