For the requirement of trajectory tracking of large spherical radio telesco
pes, a large fine tuning platform based on the Stewart platform is presente
d in this paper. The mathematical model for kinematics control is developed
with coordinate transformation, and a dynamic analysis is made using a Jac
obian matrix. Furthermore, the singularity analysis of the designed platfor
m is also made using the determinant of the Jacobian matrix, which has buil
t a solid base for the tracking control. The kinematics accuracy is obtaine
d by position vector analysis. These results have shown the validity of the
designed fine tuning platform for the feed source trajectory tracking cont
rol of large spherical radio telescopes. (C) 2000 John Wiley & Sons, Inc.