Singularity is an inherent
property of mechanisms, which severely affects their motion and force
transmission performance. Among six-degree-of-freedom parallel mechanisms, the
Stewart parallel mechanism is the most widely used, yet its singular surface
equation is highly nonlinear, posing significant challenges for singularity
analysis. To address this issue, a reconfigurable Stewart parallel mechanism
with limb redundancy is taken as the research object. Based on Grassmann line
geometry theory, the singular configurations before and after reconfiguration
are identified, and a singularity elimination method is proposed. First, using
the line cluster rank theory of Grassmann line geometry, 36 types of singular
configurations are identified for the mechanism reconfigured into the “3-2-1”
and “2-2-2” configurations, and their geometric conditions and interrelations
are revealed. Second, by analyzing the singularity mechanism, a singularity
elimination method based on topological reconfiguration is proposed. On this
basis, a local transmission index is introduced to measure singular regions,
thereby preventing the mechanism from approaching singular configurations
during motion. Finally, numerical examples and virtual experiments validate the
effectiveness of the proposed method, laying a theoretical foundation for the
practical application of Stewart reconfigurable parallel mechanisms.
ZHANG Yi, YOU Jingjing, WEN Wanghu
. Singularity
Identification and Elimination for Stewart Parallel Mechanisms with Limb
Redundancy[J]. Journal of Shanghai Jiaotong University, 0
: 1
.
DOI: 10.16183/j.cnki.jsjtu.2026.051
