This article provides an in-depth comparison between Direct Drive (DD) motors and harmonic rotary actuators, covering their transmission principles, advantages and disadvantages, and typical application fields.

In the era of Industry 4.0 and advanced robotics, the demand for power sources in automation has reached unprecedented levels: higher torque density, compact footprints, extreme accuracy, and uncompromising safety. **Harmonic Rotary Actuators** have emerged as the definitive solution for high-precision joints and motion control, thanks to their zero-backlash operation, high reduction ratios, and ultra-compact integration. This guide explores the key advantages of Harmonic Rotary Actuators, addresses technical design considerations with practical engineering solutions, and offers a comprehensive technology comparison to streamline your selection process.

Compare Harmonic Rotary Actuator, Direct Drive Rotary Actuator and Hollow Rotary Table for automation. Learn the differences in torque, speed, precision, integration and applications.

Dual encoder robot joints are becoming increasingly important in high-performance robotics. But adding a second encoder is not simply a matter of installing another sensor. The real purpose is to answer two different questions: How much has the motor moved? and How much has the robot joint actually moved? In a robot joint module consisting of a frameless torque motor, precision reducer, encoder and output flange, the motor-side encoder can accurately measure motor position and speed. However, the actual joint output can still be affected by transmission error, torsional deformation, friction, thermal drift, assembly tolerances and changes in external load. This is why a dual encoder robot joint can provide a more complete feedback architecture. One encoder monitors the motor side, while the other measures the joint output side. Together, they allow the controller to observe both the motor dynamics and the actual joint position.