Planner result
State
RFQ-ready
Leg screen
268 N.m
Groups
5
Empty state: adjust any input to tailor the result, or use the defaults as a first RFQ baseline.
Tool-first hybrid guide
Identify actuator roles in humanoid robots, estimate architecture risk, then review the evidence, tradeoffs, safety limits, and supplier questions behind the recommendation. This canonical page covers the alias phrase actuators in humanoid robots without creating a separate competing URL.
Canonical alias: actuators in humanoid robots resolves to this humanoid actuator planner.
Route mode
Hybrid
Primary task
Actuator role + RFQ screen
Evidence date
2026-06-09
Defaults model a mid-size humanoid before detailed CAD and thermal data are available.
Live result
RFQ-ready: 268 N.m leg screen, 5 actuator groups
State
RFQ-ready
Leg screen
268 N.m
Groups
5
Empty state: adjust any input to tailor the result, or use the defaults as a first RFQ baseline.
This screen estimates actuator-family pressure, not final joint sizing. It intentionally separates body axes, leg peak events, upper-body payload work, and validation risk.
Upper-body screen: 73 N.m
Use this for shoulder/elbow/wrist routing only after payload and reach envelope are known.
Total moving mass: 62 kg
Mass includes payload because handling and recovery events alter leg and waist actuator load.
Contact: [email protected]
Alias coverage: actuators in humanoid robots is answered here as the same humanoid actuator selection problem.
Report summary
Use these numbers as public benchmark anchors. They establish a decision frame for humanoid actuators, including actuators in humanoid robots as an alias intent, but final choice still needs supplier evidence for duty cycle, cooling, brakes, and lifecycle.
20-40+ axes
Public humanoids commonly disclose body DOF in this band before optional hands; actuator architecture must be planned by joint role, not by one motor family.
90-360 N.m
Unitree public data lists G1 knee torque at 90/120 N.m and H1/H2-class leg torque up to 360 N.m; continuous ratings still require supplier evidence.
2-7 kg arm load
Public G1/H2 data puts rated or typical arm payload in single-digit kilograms; dexterous hands add force-control and fingertip validation rather than leg-scale torque.
2025 + 2023
ISO 10218-2:2025 covers robot-cell integration, while ISO/PAS 5672:2023 addresses force and pressure measurements for human-robot contact.
Selected path: Quasi-direct drive. The chart shows screening tendencies, not a guaranteed supplier capability.
A robust RFQ turns public benchmarks into a supplier evidence package, then into pilot validation. Skip one layer and the result becomes procurement theater rather than engineering evidence.
| Step | Input | Output | Common failure |
|---|---|---|---|
| Map joint roles | Leg, waist, arm, wrist, and hand axis count | Actuator family split instead of one generic BOM line | Buying one torque class for every axis |
| Estimate peak envelope | Robot mass, payload, dynamic factor, lever-arm class | Screening torque for leg and upper-body actuator groups | Comparing only catalog stall or peak torque |
| Derate for continuous duty | Gait cycle, hold time, cooling path, enclosure temperature | Thermal evidence request for RFQ | Assuming peak torque density equals continuous capability |
| Select control topology | Backdrive need, impact tolerance, force-control bandwidth | QDD, geared, SEA, or custom branch | Choosing architecture before contact and impact tests |
| Close safety evidence | Contact scenario, brakes, stops, sensing, force measurement | Robot and cell-level validation plan | Treating actuator compliance as a safety certificate |
| Source | Signal used | Date / scope | Link |
|---|---|---|---|
| Unitree G1 product page | 23-43 degrees of freedom; single leg 6 DOF; knee torque 90 N.m / 120 N.m depending version; arm load about 2 kg / 3 kg. | Reviewed 2026-06-09 | Review |
| Unitree H1 / H1-2 product page | H1-2 lists 27 DOF, maximum arm joint torque 120 N.m, maximum leg joint torque 360 N.m, and 189 N.m/kg peak torque density. | Reviewed 2026-06-09 | Review |
| Unitree H2 Plus product page | Maximum arm torque 120 N.m, maximum leg torque 360 N.m, 7 kg rated arm payload, 15 kg peak arm payload, and 75 total body-and-hand DOF. | Reviewed 2026-06-09 | Review |
| ISO 10218-2:2025 | Robot applications and robot cells require integration, commissioning, operation, maintenance, and decommissioning safety controls. | Published 2025-02; reviewed 2026-06-09 | Review |
| ISO/PAS 5672:2023 | Specifies test methods for measuring and analyzing forces and pressures in physical human-robot contacts. | Published 2023-11; reviewed 2026-06-09 | Review |
Unknowns: most public humanoid pages do not disclose winding temperature, continuous torque, drive current limits, gearbox lifecycle, lubrication, or exact control-loop bandwidth. These must be requested before final design lock.
| Option | Best fit | Strengths | Limits |
|---|---|---|---|
| Quasi-direct-drive rotary joint | Hip, knee, ankle, shoulder programs needing torque transparency | Backdrive behavior, impact tolerance, force-control headroom | Large motor diameter, current demand, thermal path, brake strategy |
| Compact high-ratio geared actuator | Holding axes, compact elbows, wrists, and waist modules | High torque in smaller package and easier static hold | Reflected inertia, lower transparency, shock and backlash evidence |
| Series elastic actuator | Human interaction, compliant legs, collision-tolerant research | Embedded compliance and measurable spring deflection | Bandwidth, resonance, spring fatigue, larger package length |
| Linear actuator or tendon branch | Hands, knees with linkage geometry, or remote mass placement | Packaging freedom and force-path customization | Linkage nonlinearity, friction, cable stretch, maintenance burden |
| Dexterous hand micro-actuator stack | Fingers, thumb opposition, force-touch manipulation | High DOF density near contact tasks | Low torque scale, fragile geartrain, tactile calibration effort |
The tool is strongest during concept, RFQ, and supplier screening. It is not a replacement for detailed multibody dynamics, thermal modeling, or safety validation.
Probability: High | Impact: High
Ask for RMS current, winding temperature, cooling boundary, and repeated-cycle test data.
Probability: Medium | Impact: Medium
Split the actuator stack by joint role, duty cycle, and contact sensitivity.
Probability: Medium | Impact: High
Request no-power backdrive torque, reflected inertia, friction, and impact recovery tests.
Probability: Medium | Impact: High
Define hold torque, release logic, fault state, and manual recovery before sample build.
Probability: Medium | Impact: High
Run application-level risk assessment and contact force/pressure measurement where people can be contacted.
Stack: QDD knees/hips, compact wrist, optional dexterous hand
Gate: 90-120 N.m knee screening plus thermal walk-cycle evidence
Next: Start with G1-class public benchmark, then request continuous-duty data.
Stack: High-torque shoulder/elbow, geared wrist, brake-backed waist
Gate: Arm payload trace, brake fallback, fixture contact forces
Next: Treat H2 Plus arm payload as a public reference point, not a final spec.
Stack: Leg-dominant torque stack with impact and backdrive validation
Gate: Up to 360 N.m class leg screening plus shock and cooling tests
Next: Separate peak event, RMS gait, and hard-stop tests in the RFQ.
Stack: Arm actuator plus hand micro-actuator and tactile stack
Gate: Finger force, backlash, fingertip contact pressure, calibration drift
Next: Do not size the hand from body DOF alone; use object and contact cases.
Yes for this site architecture. The phrase actuators in humanoid robots asks which actuator roles, architectures, and validation evidence matter inside a humanoid. That is the same decision cluster as humanoid actuator, so it is answered on this canonical page instead of a separate near-duplicate URL.
Most modern humanoids combine rotary joint actuators for legs, waist, arms, and wrists with smaller hand actuators or tendon drives for fingers. The exact mix depends on torque density, backdrivability, brake strategy, cooling, and available package space.
Usually no. Legs, arms, wrists, and hands face different torque, speed, impact, and contact requirements. A single-family choice can simplify sourcing but often creates mass, thermal, or force-control compromises.
There is no universal range. Public references show smaller knee axes around 90-120 N.m and full-size leg-class peak torque up to about 360 N.m. Continuous duty, speed, and cooling must be validated separately.
This page is an actuator-stack planner for humanoid robots: it routes body axes into actuator groups, estimates RFQ risk, and compares architectures. A generic humanoid actuator page can cover definitions and product classes more broadly.
Choose it when torque transparency, impact tolerance, and force-control behavior are more important than the smallest possible package. It still needs thermal and brake validation.
It is often better for compact holding axes, wrists, elbows, and waist modules where static torque and package size dominate. The tradeoff is lower transparency and higher need for shock/backlash evidence.
Not always. Series elasticity helps with compliance, shock absorption, and force sensing, but it adds package length, resonance management, and spring fatigue validation.
No. Public specs are useful benchmarks, but they rarely disclose continuous torque, thermal boundary, lifecycle test setup, or exact safety case. Use them to frame RFQ questions, then require supplier evidence.
Include robot mass, payload, joint axes, duty cycle, target torque/speed, package envelope, cooling assumptions, brake behavior, control interface, validation tests, quantity, destination, and timeline.
Treat safety as robot and application-level work. Actuator selection must support braking, stops, force limiting, and contact measurement, but standards and risk assessment apply to the integrated machine and task.
Send the computed inputs with your CAD envelope and intended motion cases. The minimum next path is a dual-track RFQ: one catalog-like joint route and one custom architecture route with explicit validation gaps.
Yes. The fastest path is to share joint-by-joint torque/speed targets, duty cycles, package constraints, and expected prototype quantity so feasibility feedback can be specific.
Send the tool summary plus joint CAD envelope, duty cycle, target quantities, and destination. We will route the request into actuator-family feasibility, sample path, and validation evidence.