On the Relationship between the Desired Feedrate and Contour Error Constraints for 2-DOF Robot Manipulators Performing Parametric Curve Following

Contour error is an important accuracy index in contour following problems. For servomechanisms with orthogonal axes of motion such as CNC machine tools, reduction in desired feedrate is one of the most convenient approaches to reduce contour error, as contour error depends on the feedrate. However, the above approach may not be suitable for the case of articulated robot manipulators with non-orthogonal axes of motion. As a result, this paper focuses on the case of 2-DOF servomechanisms with non-orthogonal axes of motion. In particular, under certain simplification assumptions, this paper shows that the theoretical value of the contour error of a circle contour following motion depends on the feedrate for the case of 2-DOF servomechanisms with non-orthogonal axes of motion. As a result, one can use this fact to design a suitable feedrate profile so that the theoretical value of contour error will satisfy the constraints.