Novel six-axis robot kinematic model with axis-to-axis crosstalk

Conventionally, the volumetric error compensation of six-axis robots is mostly based on a kinematic model with position and orientation errors of the rotary axis average lines, known as Denavit–Hartenberg (D–H) parameters. This study proposes a novel kinematic model with angular positioning deviation of each rotary axis, modeled as a function of the command angle and rotation direction. The error motions of one rotary axis can be dependent on the angular position of other axes owing to changes in the moment of inertia or center of gravity. The prediction accuracy of the proposed model was experimentally evaluated. Compensation experiments showed a significant reduction in the static volumetric error over the entire workspace.