人形机器人产业系列报告（三）：人形机器人关节：从Optimus选型看关节的发展

Investment Rating - The report does not explicitly state an investment rating for the humanoid robot joint industry. Core Insights - The report analyzes various joint selection schemes in humanoid robots, highlighting the advantages and disadvantages of different actuator types, particularly focusing on Tesla's Optimus as a case study for industrialization pathways in humanoid robotics [3][13]. Summary by Sections Joint Selection and Actuator Types - Humanoid robot joint design must balance factors such as stability, dynamic motion control, and high load capacity. Rotational actuators are typically used in high-torque joints, while linear actuators are preferred for positions with lower rotational angles and higher load requirements [4][16]. - The report emphasizes that rotational actuators are primarily used in joints requiring high torque, such as the wrist, shoulder, waist, and hip, while linear actuators are used in the legs and arms for better support and load-bearing [4][13]. Rotational Actuator Selection - The report identifies that the main rotational actuator scheme is "motor + reducer," with harmonic reducers being the most widely used due to their high reduction density. Tesla's Optimus utilizes harmonic reducers across all 14 degrees of freedom [5][41]. - Planetary and RV reducers are noted for their potential growth opportunities, with domestic manufacturers opting for planetary reducers in high-load joints for economic reasons [5][41]. Linear Actuator Selection - Linear actuators in humanoid robots require high rigidity, load capacity, and precise linear motion control. The report discusses the advantages of using roller screws for their high load and precision capabilities, while ball screws are highlighted for their cost-effectiveness in lower-load applications [6][52]. - The report suggests that ball screws could replace roller screws in certain applications, significantly reducing costs by approximately 91% [53][59]. Key Manufacturers and Components - The report recommends focusing on key manufacturers in the humanoid robot industry, including Tesla and domestic companies like UBTECH and Fourier. It also highlights component manufacturers such as Sihua Intelligent Control and Top Group for joint assemblies, and various suppliers for reducers and screws [6][12]. Future Trends - The report anticipates that Tesla's Optimus will continue to utilize the mature rigid actuator scheme, which combines harmonic reducers for high torque output while integrating safety features like clutches to enhance joint flexibility [41][43]. - It also notes that domestic manufacturers are likely to adopt a mixed approach, using both harmonic and planetary reducers based on joint characteristics as the industry moves towards mass production [46].