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ELF 3

ELF 3 is a medium-sized humanoid robot developed in-house by BXI Robotics, standing 1.45 m tall with motion parameters comparable to a human of similar height. It is designed for high-dynamic movement and open-platform development.

ELF 3 Front View ELF 3 Side View
Front View Side View

Key Highlights

  • High-Dynamic Motion: 31 BXI hollow planetary joint motors across the body, enabling running, jumping, backflips, and parkour
  • Skeletal Lightweight Design: Minimized weight; custom shells can be attached to change appearance and mount additional devices
  • High Reliability: Hollow cable routing greatly reduces the wiring harness; built-in fall-resistant design
  • High-Speed Bus: PCIE-CANFD with full-body control frequency > 1000 Hz
  • Hot-Swap Battery: Replace batteries without powering off, ensuring continuous operation
  • Open Development Interface: CANFD MIT protocol for direct motor control + ROS2 SDK + one-click MuJoCo simulation deployment

Full Specifications

Appearance & Motion Performance

Item Specification
Height 1450 mm
Width 450 mm
Depth 280 mm
Thigh Length 320 mm
Shin Length 320 mm
Upper Arm Length 240 mm
Forearm Length 240 mm
Total Weight ~38 kg
Arm Payload 5 kg extended (10 continuous cycles); 10 kg elbow-supported (10 continuous cycles)
Max Speed > 4 m/s (~13 km/h)

Full-Body Joint Parameters

Detailed motor specifications can be found in Joint Actuator Modules.

Joint Motor Min (rad) Max (rad) Peak Torque (Nm) Peak Speed (rad/s) Inertia (kg*m^2)
waist_y_joint BXI7010-19 x 2 -0.5236 0.5236 90 20 0.0274702
waist_x_joint BXI7010-19 x 2 -0.2618 0.2618 100 20 0.0412054
waist_z_joint BXI8515-19 -2.8798 2.8798 150 20 0.044688
l_hip_y_joint BXI8515-19 -2.8798 2.8798 150 20 0.044688
l_hip_x_joint BXI8515-19 -0.48869 3.0543 150 20 0.044688
l_hip_z_joint BXI7010-19 -2.8798 2.8798 45 20 0.0137351
l_knee_y_joint BXI8515-19 -0.087266 2.618 150 20 0.044688
l_ankle_y_joint BXI5018-19 x 2 -0.87266 0.7854 40 20 0.00848397
l_ankle_x_joint BXI5018-19 x 2 -0.34907 0.34907 15 20 0.00551458
r_hip_y_joint BXI8515-19 -2.8798 2.8798 150 20 0.044688
r_hip_x_joint BXI8515-19 -3.0543 0.48869 150 20 0.044688
r_hip_z_joint BXI7010-19 -2.8798 2.8798 45 20 0.0137351
r_knee_y_joint BXI8515-19 -0.087266 2.618 150 20 0.044688
r_ankle_y_joint BXI5018-19 x 2 -0.87266 0.7854 40 20 0.00848397
r_ankle_x_joint BXI5018-19 x 2 -0.34907 0.34907 15 20 0.00551458
l_shoulder_y_joint BXI7010-19 -2.8798 2.8798 45 20 0.0137351
l_shoulder_x_joint BXI7010-19 -0.34907 3.0543 45 20 0.0137351
l_shoulder_z_joint BXI5014-19 -2.8798 2.8798 21 20 0.00424198
l_elbow_y_joint BXI7010-19 -0.95993 1.6581 45 20 0.0137351
l_wrist_x_joint BXI5014-19 -2.8798 2.8798 21 20 0.00424198
l_wrist_y_joint BXI5014-19 -1.309 1.309 21 20 0.00424198
l_wrist_z_joint BXI5014-19 -0.7854 0.7854 21 20 0.00424198
r_shoulder_y_joint BXI7010-19 -2.8798 2.8798 45 20 0.0137351
r_shoulder_x_joint BXI7010-19 -3.0543 0.34907 45 20 0.0137351
r_shoulder_z_joint BXI5014-19 -2.8798 2.8798 21 20 0.00424198
r_elbow_y_joint BXI7010-19 -0.95993 1.6581 45 20 0.0137351
r_wrist_x_joint BXI5014-19 -2.8798 2.8798 21 20 0.00424198
r_wrist_y_joint BXI5014-19 -1.309 1.309 21 20 0.00424198
r_wrist_z_joint BXI5014-19 -0.7854 0.7854 21 20 0.00424198
neck_z_joint BXI5014-19 -1.57 1.57 21 20 0.00424198
neck_y_joint BXI5014-19 -0.7854 0.7854 21 20 0.00424198

Mechanical Structure

Degrees of Freedom

Item Specification
Total DOF 31 (including 2-DOF neck)
DOF per Leg 6 (Hip XYZ x 3 + Knee Y x 1 + Ankle XY x 2)
DOF per Arm 7 (Shoulder YXZ x 3 + Elbow Y x 1 + Wrist XYZ x 3)
Motor Series BXI Hollow Planetary

Electrical System

Item Specification
Operating Voltage 48 V
Rated Current 50 A
Max Current > 100 A
Battery Capacity 432 Wh, lithium
Battery Life ~1 hour walking
Hot-Swap Supported

Control Communication Architecture

Item Specification
Control Communication Architecture PCIE-CANFD, FPGA
System Control Frequency >1000 Hz

Computing & Perception

Computing Unit - CPU

Item Specification
CPU 13th Gen Intel Core i7-1370P
Cores 14 (6 P-cores + 8 E-cores)
Threads 20
Max Turbo Frequency 5.20 GHz
Processor Base Power 28 W
Max Turbo Power 64 W
Memory 16 GB DDR4 3200 MHz
Storage 512 GB
GPU Intel Iris Xe Graphics (96 EU)
GPU Max Dynamic Frequency 1.50 GHz
Instruction Set 64-bit (SSE4.1 / SSE4.2 / AVX2)

Computing Unit - GPU

Item Specification
NPU/GPU NVIDIA Jetson series supported (optional or user-installed)

IMU

Item Specification
Operating Voltage 3.3 ~ 5.5 V
Operating Temperature -40 ~ 85 C
Interface UART / CAN
Accelerometer Range +/-12 g
Accelerometer Resolution 0.001 g
Gyroscope Range +/-2000 deg/s
Gyroscope Resolution 0.001 deg/s
Magnetometer Range +/-8 Gs
Magnetometer Resolution 0.25 mg
Barometer Range 300 ~ 1100 hPa
Barometer Resolution 0.06 Pa

Sensors & Peripherals

Item Specification
Depth Camera Intel RealSense D435i
LiDAR Optional (Livox Mid360)
Microphone HAOKAI 8-array omnidirectional microphone
Speaker Yuexin active speaker (DC 5V)
Wi-Fi / Bluetooth Onboard

Software Ecosystem

Item Specification
OS Ubuntu 22.04
Motor Interface CANFD SDK, MIT protocol (torque / position / velocity / temperature)
Robot Framework ROS2-based hardware control node SDK
Simulation MuJoCo-based RL training and deployment framework
Pre-installed Algorithm Flat-ground walking and running
URDF Provided

Accessories

Item Notes
Dexterous Hand Paid add-on (independent unit)
Xbox-compatible Gamepad Included
Tablet Control App Included