The controlling system of the levitated permanent magnetic ring is setted-up and simulated via the Simulink software for the perpose of stable control.The required stable controlling parameter ranges are obtained via the Routh-Hurwitz stability criterion

and the PID control strategies are tested.To optimize the controlling process

the importance of the start-up path to the power of the controlling system and the range of the parameters to PID strategies are discussed.The results are presented below.The PID

controlling strategies can realize stable levitating the levitated permanent magnetic ring while k

d

is in the range from 5.43×10

-5

to 119.2 and k

p

from 0.041 2 to 757.6k

d

-6.356k

d

2

.The tilt start-up signal for the power of the controlling system can decrease the requirement of the power system

and the required current peak is also reduced from 25 A to 22 A.The optimized PID parameters

which are k

p

=5.4

k

i

=8.3 and k

d

=1.2

can significantly shorten the required time

and stabilize the floating matters to the given position in 1.3 s.In general

the designed feedback controlling system based on the PID can effectively stabilize the LPMR at the given working position for the long term stable levitation.