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Abstracts: Based on the structure of 6-TPS parallel kinematic machine
tools, the mapping from machine’s kinematics errors to tool’s motion
errors is formulated, and the relations between input errors and output
errors of both single kinematic link and whole machine are analyzed. The
singular values of Jacobian matrix are used to define three error
sensitivity measures, which are comprehensive error sensitivity,
absolute error sensitivity and directional error sensitivity. According
to these, two terms are defined, which are named comprehensive error
coefficient and comprehensive error degree, and used to evaluate the
precision of various configurations of this type of mechanisms. At last,
based on a real parallel kinematic machine tool – VAMT1Y, the kinematic
precisions under various tool trajectories are compared, and a
relatively optimal trajectory is chosen.
Key words: Parallel kinematic machine tool (PKMT) Stewart
platform Precision measure Comprehensive error coefficient
Comprehensive error degree
CLC No: TG659
TP242
国家973重点基础研究项目(G1998060307). Received 20010822, received in revised form
20020420
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