A Method for Simultaneously Measuring 6DOF Geometric Motion Errors of Linear and Rotary Axes Using Lasers

Area of Science:

• Mechanical Engineering
• Metrology
• Manufacturing Technology

Background:

• Geometric motion errors significantly impact CNC machine tool precision.
• Existing methods for measuring six-degrees-of-freedom (6DOF) errors are often complex or indirect.

Purpose of the Study:

• To propose a novel, direct method for simultaneously measuring 6DOF geometric motion errors.
• To develop a versatile measurement system applicable to both linear and rotary axes of CNC machine tools.

Main Methods:

• A single-mode fiber optic system was employed to isolate the measurement unit from the laser source, enhancing thermal stability.
• Laser interferometry was used for linear axis positioning errors and rotary axis radial motion errors.
• Laser collimation techniques were utilized to measure the remaining five degrees of freedom (5DOF) geometric motion errors.

Main Results:

• The developed method demonstrated high efficiency and accuracy in measuring 6DOF geometric motion errors.
• The system proved effective for both linear and rotary axes.
• Experiments confirmed the feasibility and effectiveness of the proposed measurement system.

Conclusions:

• The novel method provides a direct, efficient, and accurate solution for measuring 6DOF geometric motion errors in CNC machine tools.
• The developed system's versatility for linear and rotary axes simplifies error analysis and machine tool calibration.