The cables of humanoid robots are divided into seven categories according to their functions: power supply, servo feedback, high-speed communication, sensor signals, on-board micro connections, composite integration, and special applications. All of them require ultra-high flexibility, resistance to millions of bending and twisting, strong shielding and anti-interference, and are suitable for continuous bending, extension, and rotation scenarios such as the head, trunk, arms, legs, and wrist joints in Shanghai Rousheng Electric .
Servo motor power cable (joint drive main line)
①Purpose: Deliver three-phase driving high current to all joint servo motors (hip, knee, shoulder, elbow, wrist, neck) throughout the body, including motor brake power supply.
②Structural Specifications
Standard 4-core: 3-phase wire+yellow green ground wire; 6-core high torque joint (with 2 brake wires added)
Conductor: Class6 ultra-fine precision twisted copper wire (single wire 0.08mm), short pitch twisted
Wire diameter: 0.5~16mm ², mainly 48V/72V high voltage platform
Sheath: PUR/TPU wear-resistant and oil resistant, resistant to torsion ± 180 °/m, with a bending life of ≥ 5 million times
Voltage: 600/1000V
③Application location: Internal wiring of high torque joints in thighs, calves, upper arms, shoulders, and waist
Encoder feedback cable (motor position signal)
①Purpose: The position, speed, and magnetic pole zero position signals of the transmission servo motor encoder and rotary sensor, as well as small differential signals, require extremely high anti-interference requirements.
②Structural Specifications
Multiple pairs of twisted pair shielded wires (2~16 cores, 0.2~0.5mm ²)
Double layer shielding: aluminum foil separate shielding+tin plated copper mesh total shielding, coverage rate ≥ 85%
Low capacitance differential design, stable impedance, extremely low delay
300/500V, High flexibility and torsion resistance
③application: All servo motors have built-in encoders, and the feedback line of the six axis force sensor also falls under this category
Industrial high-speed bus communication cable (whole machine control network)
The internal "neural network backbone" of the robot connects the main control, servo drivers, and IO modules, and is divided into three types of buses:
①EtherCAT servo bus (trunk/limb control)
4 pairs of differential shielded twisted pair cables, 100 Ω impedance, 1Gbps high-speed real-time control
Flexible and dynamic bus cable for trunk and arm driver networking
②CAN/CAN FD bus (chassis, battery, BMS, IO)
2-core differential shielded wire, 120 Ω standard impedance, 5Mbps, battery management, chassis joints, emergency stop circuit
③MIPI A-PHY/Vehicle Ethernet (Head Sensing High Speed Data)
2-line high-speed differential transmission of camera, LiDAR, and millimeter wave radar image data streams
Sensor specific signal line (sensing layer cable)
①Tactile/force sensor cable
Six dimensional force sensor, plantar pressure array, skin tactile sensor, multi-core micro shielded thin wire, 0.12~0.2mm ², extremely small bending radius, specially designed for wrist, palm, and sole.
②Simulate sensor control line
Temperature, IMU inertial unit, proximity switch, microphone, RVVP multi-core shielded flexible cable, 3.3V/5V weak current.
③Visual supporting micro cables
FFC/FPC flat ribbon cable (head camera, screen), USB4/Type-C high-speed cable, for transmitting images and audio.
④M8/M12 miniature sensor wiring harness
End clamp, wrist photoelectric switch standard connector harness, small high flexibility shielded wire.
Power distribution low-voltage control line (whole machine power supply branch)
①High voltage battery main line (BMS fire cow line)
48V/72V lithium battery to power distribution board with thick power line, high current, high temperature resistance, flame retardant.
②Low voltage DC-DC output line
24V driver power supply, 12V fan/solenoid valve, 5V/3.3V sensor power supply, multi-core high flexibility control cable (2-30 cores).
③Safety circuit cables
Emergency stop, door lock, overheat protection circuit, shielded control wire, independent wiring to prevent interference.
Composite integrated cable (mainstream lightweight solution)
A single cable integrates power, encoder, and bus, greatly reducing the number of wire harnesses in joints and solving the problems of multiple wire winding and limited space:
①Servo composite cable: power core+encoder twisted pair integrated layered shielding
②Integrated wrist hybrid cable: power+bus+tactile sensor line integration, dedicated for wrist and finger tips, ultra small bending radius
③Trunk trunk composite cable: connects the upper and lower limbs, integrates high-voltage power, EtherCAT, CAN bus
Micro board internal connection cable (interconnection of PCB inside the body)
①FFC/FPC flat flexible cable: ultra-thin cable between the head motherboard, screen, and camera module
②0.35/0.5mm spacing extremely fine coaxial, board to wire micro harness: AI computing board, sensor board internal
③Ultra fine coaxial line: high-definition camera, high-speed radar signal transmission, ultra-low signal attenuation
Special cables for special working conditions
①Ultra small torsion resistant wrist cable: frequent ±360° rotation of fingers and wrist, with millions of twists without interruption
②Low smoke halogen-free flame-retardant cable: wiring for commercial indoor humanoid robots
③Ultra thin and lightweight wire: small humanoid, humanoid palm fingers, weight reduction and volume reduction
④High temperature resistant cable: The heating area around the joint motor can withstand temperatures above 125℃
Quick Overview of Wiring by Robot Body Parts
①Head: MIPI high-speed cable, microphone signal cable, FFC ribbon cable, IMU signal cable, CAN bus
②Trunk: High voltage battery main line, EtherCAT backbone, composite servo cable, BMS harness, power distribution line
③Arm/Shoulder: Servo power cable+encoder composite cable, six axis force sensor cable
④Wrist/finger: Micro hybrid integrated cable, tactile sensor fine wire, M8 sensor harness
⑤Legs/chassis: high current servo power line, CAN FD bus, plantar pressure sensor line, battery main line
