Analysis of Manufacturing Precision and Reliability Requirements for Core Components of Humanoid Robots
- Analysis of Manufacturing Precision and Reliability Requirements for Core Components of Humanoid Robots
- 1. Micrometer-level geometric accuracy indicators – Analysis of manufacturing precision and reliability requirements for core components of humanoid robots
- 2. Complex Structure Manufacturing Technology – Analysis of Manufacturing Precision and Reliability Requirements for Core Components of Humanoid Robots
- 3. Construction of a customized manufacturing system
- 4. Service performance assurance technology
- Core reliability requirements for humanoid robot components
- Humanoid robot parts manufacturing processes and core barriers
- How to choose a manufacturer for custom parts for humanoid robots?
- Why was Elimold's team chosen to manufacture humanoid robot parts?
- Conclusion
The joint motion accuracy and structural reliability of humanoid robots depend on the manufacturing quality of their core components. Compared to industrial robots, their parts must simultaneously meet special requirements such as micron-level geometric precision, biomimetic curved surface forming, and rapid iterative adaptation. This article analyzes the technical characteristics of humanoid robot-specific parts and corresponding precision machining solutions from three dimensions: material selection, structural design, and manufacturing process, clarifying the realization path for manufacturing highly complex parts.
1. Micrometer-level geometric accuracy indicators – Analysis of manufacturing precision and reliability requirements for core components of humanoid robots
The following parts require precision requirements exceeding those of conventional industrial robots by 50%, necessitating a five-axis CNC machine tool in conjunction with an online compensation system.
- Coaxiality of the rotary joint ≤ 0.008 mm
- Harmonic reducer tooth profile tolerance ±0.003mm
- The surface roughness Ra of the bearing mating surfaces is ≤0.2μm.
2. Complex Structure Manufacturing Technology – Analysis of Manufacturing Precision and Reliability Requirements for Core Components of Humanoid Robots
- Bionic curved surface forming technology
- Multi-curvature spherical machining of knee joints (contour accuracy 0.02mm)
- Five-axis simultaneous milling of biomechanical cavities (depth-to-diameter ratio > 8:1)
- Lightweight material applications
- Carbon fiber reinforced matrix reduces weight by 40% while maintaining stiffness
- Selective Laser Melting (SLM) Forming of Titanium Alloy Skeleton
3. Construction of a customized manufacturing system
- Small-batch flexible production: When the single batch is less than 50 pieces, the processing changeover time is ≤45 minutes.
- Modular tooling system: adaptable to 23 joint configurations for rapid positioning
- Topology optimization design: The iteration cycle is reduced to 72 hours (traditional processes require 2 weeks).
4. Service performance assurance technology
- Surface strengthening process
- Diamond-like carbon coating on gear surface (coefficient of friction reduced to 0.08)
- The thickness of the anodized film on the aluminum alloy is 30±5μm.
- Material heat treatment system
- Solution treatment of the β phase region of titanium alloy (fatigue strength > 950 MPa)
- Cryogenic treatment of stainless steel (residual austenite <3%)
Core reliability requirements for humanoid robot components
Humanoid robots need to perform complex tasks like humans, which means that their internal components must withstand rigorous durability and environmental tests.
Anti-fatigue and long life
Taking the flexible wheel in a harmonic reducer as an example, its wall thickness is only 0.8-1.5 mm, yet it withstands multiple high-frequency elastic deformations per revolution. The rated life is required to be over 8000 to 12000 hours, and its performance must not degrade at extreme temperatures (such as -40°C). The material needs to balance high elastic limit, fatigue resistance, and wear resistance.
Screw Challenge
Planetary roller screws need to convert point contact into line contact, and their load-bearing capacity and life requirements are several times that of ball screws. The purity of the internal materials and the hardness of vacuum quenching (usually reaching HRC 58-62) directly determine their fatigue life.
Adaptability to harsh environments
The robot’s entire body consists of dozens of joints and must frequently cope with complex external environments such as drop impacts, heavy-duty handling, and sudden temperature changes. The shock resistance and signal stability of core components (including a six-dimensional force sensor and an absolute encoder) are crucial to the overall reliability of the robot.
Environmental adaptability and consistency
Robots need to adapt to complex working conditions such as dust, vibration, and temperature differences. The circuitry of sensors and control motherboards must be resistant to electromagnetic interference and withstand high and low temperatures. In addition, ensuring the performance consistency of thousands of parts during mass production (avoiding the accumulation of motion errors between joints) is currently a core challenge facing the industry.
Security and Redundancy
Close interaction with humans means that component breakage or malfunction could have serious consequences. Mechanical structures must not only withstand overloads but also integrate fail-safe mechanisms to ensure that joints can flexibly cushion or safely lock when subjected to external impacts.
Humanoid robot parts manufacturing processes and core barriers
The manufacturing of humanoid robots faces challenges in producing precision components and limitations in manufacturing technology. Breakthroughs are needed to reduce production costs and enable the products to be truly applied in the market. The Elimold team has summarized the core manufacturing challenges of various parts for custom-made humanoid robots.
Internal thread grinding
Reverse-type nuts have a deep-hole internal thread structure, which presents three major challenges in grinding:
- Insufficient rigidity: The grinding wheel spindle must be very thin to fit into the hole, forming a cantilever beam. During grinding, tool slippage and vibration → taper error.
- Linear speed is limited: with a hole diameter of 30mm, the grinding wheel is only 20mm. To achieve a grinding linear speed of 60m/s, the spindle needs to run at 50,000+ rpm, which places extremely high demands on the thermal stability and dynamic balance of the electric spindle.
- Chip removal difficulties: Grinding chips and coolant are difficult to remove from deep holes, easily scratching the machined surface.
Roller threading
- Multi-start thread, pitch 0.5-2mm, must be perfectly matched with the lead screw and nut.
- With a tolerance of <3μm, the machining difficulty is an order of magnitude higher than that of ball screws for the same precision.
- Precision stamping of the cage ensures equidistant roller distribution; deviations can lead to jamming.
Heat Treatment and Materials
- GCr15 bearing steel, vacuum quenched, hardness HRC58-62, straightness after grinding <5μm/m
- Carbide segregation control: a core factor affecting fatigue life
- The purity of domestically produced special steel still lags behind that of Japan and Sweden.
Flexible wheel manufacturing
The flex wheel is the weakest and most critical component of a harmonic reducer.
- With a wall thickness of only 0.8-1.5mm, it can withstand two elastic deformations per revolution.
- Material requirements: high elastic limit + high fatigue strength + high wear resistance
- Typical failure mode: stress concentration at the tooth root → fatigue crack → fracture
How to choose a manufacturer for custom parts for humanoid robots?
To create a suitable humanoid robot product, the first step is to manufacture precision parts. Therefore, choosing the right manufacturer is the most important issue. So how should one judge and select a suitable manufacturer? The Elimold team has summarized the following key factors for judgment.
Do they have the ability to select raw materials?
Humanoid robot parts typically require simultaneous requirements such as hardness (both surface and core hardness, both hard and tough), uniformity of structure, precision (dimensional accuracy of a few micrometers, straightness requirement of 0.01mm), wear resistance, and fatigue resistance. This necessitates manufacturers to have in-depth experience and understanding of raw materials, and to develop customized raw materials with upstream steel mills to meet specific requirements.
Does it have the capability to machine precision parts?
The planetary ball screws used in humanoid robots require extremely high precision, as the thread machining accuracy directly determines the final product quality. The machining process includes rough machining (external turning, thread rough milling), finish machining (external grinding, thread fine grinding, surface grinding), and assembly (custom-made tooling and fixtures). Simultaneously, various high-precision testing equipment is needed to comprehensively monitor diameter, pitch, lead, straightness, surface finish, and noise in real time. Therefore, factories manufacturing these parts must possess extremely high precision parts manufacturing capabilities.
Does it have heat treatment technology?
The purpose of heat treatment is to improve the material properties and machinability of the leadscrew, as well as to eliminate residual stress. Differences in heat treatment processes are a significant reason for performance disparities in leadscrews; improper heat treatment processes can lead to…This causes it to deform and its lifespan to decrease.
Does it have the capability for large-scale mass production?
Humanoid robot parts manufacturers are required to have the ability to modify and manufacture equipment, the ability to automate production lines, financial strength, skilled workers, and strict process management.
Why was Elimold’s team chosen to manufacture humanoid robot parts?
Key components of robotic actuators also involve the design and manufacture of structural parts. Elimold’s engineers and manufacturing team, leveraging years of experience in precision structural component manufacturing, can extend their technological advantages in lightweight design, heat dissipation, and low cost to the production of robotic actuator structural parts. This is because structural parts have stringent requirements for efficient material utilization and manufacturing precision, which highly align with the requirements of robotic actuators for lightweight shell materials and high heat dissipation. Elimold’s strong mold-making and precision machining technologies enable efficient material utilization and reduced production costs, resulting in a significant cost advantage. Based on Elimold’s expertise in precision manufacturing, we possess the fundamental capabilities to manufacture precision manufacturing solutions for robotic actuator parts. If you need to manufacture prototype parts for humanoid robots or conduct mass production of parts, please contact the Elimold team.
Conclusion
The humanoid robot industry has developed to the point where industry standards have been established, especially for parts manufacturing. This is because core components constitute the bulk of the manufacturing cost of humanoid robots. Once breakthroughs are achieved in core component manufacturing technology, the day when humanoid robots become “dirt cheap” will soon arrive, just as everyone now owns a smartphone; in the future, it will become increasingly common for every household to have a humanoid robot.