In this paper

three new schemes

based on State Feedback of the Mordern Control Theory

is proposed to improve the performance of the Servo-Systerm with the Frequency-Method of the Classic Control Theory

the experiment result shows that

after adjustment

it can satiesfy the desigh demand. Then we have used the three schemes

the Full-State Feedback scheme of the Linear-Quadratic metod

the Full-State and Part-State feedback schemes of the Optimal-Transmit-Function method

to design the Servo-System

and have respectively gone about Computer Simulations. The result shows that all of the three schemes have largely improved the trend-state and static-state performances compared with the Frequency-Method design of the Classic Control Theory. In the three schemes

the Part-State feedback scheme of the Optimal-Transmit-Function method is the most valuable to apply and popularize. In the two Full-State feedback schemes

the Luenberger reduced-order state observer are used

and their simulation results show that it is practicable.