Objective: To evaluate the effectiveness of the upper limb′s encircling motion and feedback machine on the assessment and therapy of hemiplegia on the left and right limbs.

Trajectory planning for the circular motion of manipulator and its implementation;

Doppler effect of sound source of circular motion;

This article gives five new methods of proving acceleration of circular motion.

Some methods of addressing the critical problem of circle movement in mechanics are presented with examples.

Thrcc major drive mechanisms have been compared ,and using an elliptical gear as the drive mechanism can realize non-constant velocity circular motion and increase the power output.