Structure
Load paths, joints, range, service access, and the geometry that defines where a body can work.
PICI / Physical intelligence / Technical brief 01
§H01 System boundary
Humanoid hardware is a systems problem.
The useful question is not whether a robot resembles a person. It is whether its body can sense, move, recover, and operate within defined requirements in environments designed around people and existing processes.
About this brief
PICI is currently focused on compact robotic systems for defined industrial work. This brief explores a broader humanoid systems architecture and should be read as an engineering perspective rather than a statement of present product availability.
01
A compact platform is a chain of coupled choices: load path, energy, control, and operator trust.
§H02 Taxonomy
DOC / PICI-HW-001 REV / 01
System map
Start with the constraints.
Humanoid hardware is legible when the body is read as three linked layers, not as a single machine.
Actuation
Motors, transmissions, brakes, and compliance convert energy into controlled contact.
Intelligence
Sensors and control software turn uncertain surroundings into bounded, recoverable action.
§H03 Mobility
LENS / LOCOMOTION REF / 02
Mechanism plate A
The leg is a force-routing problem.
A leg has to carry the body, absorb error, and place the foot without asking the environment to become perfectly known.
READOUT
Fixed geometry → controlled contact
The mechanism earns useful mobility by managing force at the foot, not by adding degrees of freedom alone.
- Primary load
- Body mass + external contact
- Control surface
- Foot placement and torque
- Failure mode
- Slip, saturation, or recovery loss
§H04 Manipulation
LENS / CONTACT REF / 03
Mechanism plate B
The hand is a sensing surface.
Useful manipulation depends on knowing when an object has been found, loaded, and released. Force is part of the signal.
READOUT
Position → contact state
A reliable grasp is a closed loop between geometry, friction, force, and the next task state.
- Primary signal
- Contact onset + force
- Control surface
- Grip, slip, and release
- Failure mode
- Misalignment or object loss
§H05 Decision matrix
LENS / TRADE-OFFS REF / 04
Spec lens
Every capability spends a resource.
Hardware choices become credible when their costs stay visible alongside their intended benefit.
| Decision | Adds | Costs | PICI lens |
|---|---|---|---|
| More degrees of freedom | Reach + task coverage | Mass + control burden | Use only where contact requires it |
| Higher peak torque | Acceleration + recovery margin | Energy + thermal load | Size for the task envelope |
| Softer compliance | Contact tolerance | Position precision | Pair with measured force |
| More onboard compute | Local response + resilience | Power + heat | Keep the control loop close |
§H06 Principles
FIELD / INDUSTRIAL BASE / TOKYO
Build for the work that remains when the demo ends.
01 Make the environment legible.
02 Keep failure modes recoverable.
03 Treat operator trust as a system requirement.
§H07 Next discussion
A hardware brief is a starting point.
For technical questions about this engineering perspective, contact PICI.
info@pici.co