Global Sensitivity Analysis of Chosen Harmonic Drive Parameters Affecting Its Lost Motion

Area of Science:

• Mechanical Engineering
• Robotics
• Precision Engineering

Background:

• Harmonic drives are critical components in high-precision applications requiring minimal lost motion.
• Understanding design parameter influence is essential for optimizing harmonic drive performance.
• Lost motion in harmonic drives can significantly degrade positional accuracy.

Purpose of the Study:

• To conduct a global sensitivity analysis of design parameters affecting harmonic drive lost motion.
• To identify the most influential geometric parameters on lost motion.
• To validate findings across different harmonic drive units.

Main Methods:

• Development of a detailed virtual model of a harmonic drive, including key components.
• Utilizing Finite Element Analysis (FEA) to simulate and analyze parameter impacts.
• Performing analyses under specific conditions simulating high-accuracy requirements (4% rated torque).
• Applying the methodology to two harmonic drive units with varying dimensions and power ratings.

Main Results:

• Global sensitivity analysis identified key design parameters influencing lost motion.
• The offset from the nominal tooth shape was determined to be the most significant variable for both analyzed harmonic drives.
• FEA results provided detailed insights into the relationship between geometry and lost motion.

Conclusions:

• The offset from the nominal tooth shape is a critical parameter for minimizing lost motion in harmonic drives.
• Sensitivity analysis provides a robust method for optimizing harmonic drive design.
• Findings are generalizable across different harmonic drive sizes and power ratings.