Selecting a robot joint actuator is not simply a matter of matching motor torque or achieving a suitable inertia ratio. In a real robotic system, reduction ratio, load spectrum, thermal performance, mechanical stiffness, transmission nonlinearity, encoder architecture, control bandwidth, and service life all interact to determine the final result. A joint may meet its peak torque requirement and still experience vibration, overheating, positioning errors, or premature wear in real operation. This article examines the engineering logic behind robot joint actuator selection and explains why moving from single-parameter matching to system-level optimization can lead to more reliable and predictable robotic joint performance.

The concept of Industry 4.0, which corresponds to Industry 5.0, first appeared in Germany. In short, Industry 4.0 is to promote industrial transformation through information technology. It is an intelligent industrial era based on the Internet of Things, big data, artificial intelligence, etc. 5G technology, known as the "new engine of digital economy", is a product that closely fits the core concept of Industry 4.0 and is recognized by the world.