Kinematic model and calibration of a robot manipulator

Abstract

In the next generation of industrial robot systems, the absolute positioning accuracy of a robot manipulator is necessary for the manipulation of robot programming systems based on a CAD model database and for integration with multiple robots and hand-eye systems. This paper identifies sources of absolute positioning error, and discusses methods of creating kinematic models and robot calibration including tool-reference-point measurements.High-precision absolute positioning is a key breakthrough required to implement robot systems that can reliably execute control programs generated by offline programming.

Inverse kinematic solution of 6R robot manipulators based on screw theory and the Paden–Kahan subproblem

“…9 It should be noted that d i can’t be determined when the adjacent revolute joint axes are parallel. 4…”

“…However, this model suffers from singularity when the adjacent joint axes are parallel or close to parallel. [3][4][5][6][7][8] This singularity refers to the slight deviation from the parallel joint axes, which causes significant changes to the parameters of the model. 9 It should be noted that d i can't be determined when the adjacent revolute joint axes are parallel.…”

“…9 It should be noted that d i can't be determined when the adjacent revolute joint axes are parallel. 4 It is in fact very difficult to manufacture completely parallel joints. A slight twist angle deviating from the parallel joint axes will cause the distance d i to become extremely large and the origin of the coordinate frame to deviate from the joint position.…”

“…A slight twist angle deviating from the parallel joint axes will cause the distance d i to become extremely large and the origin of the coordinate frame to deviate from the joint position. 4,7,34 The graphic representation is presented in Figure 3.…”

“…The main deficiency is that the kinematic parameters of the D-H model employed for calibration are discontinuous, leading to singularity when the adjacent joint axes of robots are parallel or close to parallel. [3][4][5][6][7][8] As a result, the actual parameters of this model are difficult to identify, and it cannot be considered as a suitable model for kinematic calibration. 9 With the aim of addressing the problem of singularity, several other kinematic models have been proposed, such as the S-model, 10 the complete and parametrically continuous (CPC) model, [11][12][13] and the zero reference position model.…”