The calibration and error compensation techniques for an Articulated Arm CMM with two parallel rotational axes

摘要

The calibration and error compensation techniques for an Articulated Arm Coordinate Measuring Machine (AACMM) with two parallel rotational axes are proposed. An improved six-parameter D-H model is established. The reversal techniques are used to calibrate the parallelism errors, arm lengths and zero position of the AACMM. The effects of the bending and torsion deformations caused by the gravity of the arms are removed. The experiments prove that the calibration method is simple and the measurement expanded uncertainty (2_(u_c)) of the developed AACMM with a measuring range of (φ200-φ1000 mm) × 250 mm is less than 10 μm after error compensation.