Genliang Chen

TL;DR: This paper presents an analytical approach to determine and eliminate the redundant model parameters in serial-robot kinematic calibration based on the product of exponentials formula and shows that the redundant errors are simply equivalent to the commutative elements of the robot's joint twists.

TL;DR: Based on the theory of envelope, a geometric method is employed to uniformly construct the indeterminate influences of these two error sources on the pose (position and orientation) deviation of the manipulators.

TL;DR: Using the product of exponentials (POE) formula, orthogonal partitioning matrices can be constructed in a straightforward way to determine and eliminate the redundant error components and the maximal number of identifiable parameters for both serial and parallel manipulators can be unified by one unique formula.

TL;DR: Using the principal axes decomposition, some physical appreciations, such as the center of stiffness, the wrench-compliant axes, and the correspondence of compliance and stiffness, can be derived to reveal the inherent structure of spatial stiffness in an intuitive manner.

TL;DR: In this article, the accuracy enhancement of a 3-P RRU parallel manipulator and the influence of imperfect universal joints on calibration result through kinematic calibration is investigated. But the results of the simulations and experiments show that the defects of universal joints have smaller effect on the accuracy improvement for this manipulator when compared with the cases that the universal joints are perfectly manufactured and assembled.