Development of Multi-Degree-Of-Freedom Displacements and Euler Angles Measurement Technology

The measurement of multi-degree-of-freedom motion is very essential for the calibration of the space position of the machine tools and robot arms. The laser interferometer has excellent performances such as long measurement range and high measurement resolution, and it is the main measurement tool for multi-DOF motion. However, due to the linear propagation properties of the laser light beam, the location of the object is limited to the area where the light beam can reach. Therefore, the light must be directed to the position of the object by the rotation device, and it complicates the measurement process.To solve the current problems of measuring multi-degree-of-freedom motion systems, based on the grating diffraction and combined with the wavelength-modulated heterodyne interferometers, an innovative "diffraction polarization interferometry" is proposed for the measurements of 3D displacements and Euler angles. Also, this project proposes an innovative "wavefront division stellar interferometer" to overcome the limited motion range of the object and to achieve the measurement and calibration of multi-degree-of-freedom motion.