With the developments of science of art, there are more and more demands on the high resolution control of position of
object to be controlled, such as lathe, product line, elements in the optical resonant cavity, telescope, and so on. As one
device with high resolution, the optical scale has more and more utility within the industrial and civil applications. With
one optical scale and small DC servo motor, one closed loop high resolution position control system is constructed. This
apparatus is used to control the position of the elements of optical system. The optical scale is attached on the object or
reference guide way. The object position is sampled by a readhead of non-contact optical encoder. Control system
processes the position information and control the position of object through the motion control of servo DC motor. The
DC motor is controlled by one controller which is connected to an industrial computer. And the micro frictionless slide
table does support the smooth motion of object to be controlled. The control algorithm of system is PID
(Proportional-Integral-Differential) methods. The PID control methods have well ROBUST. The needed data to control
are position, velocity and acceleration of the object. These three parameters correspond to the PID characters respectively.
After the accomplishments of hardware, GUI (Graphical user interface), that is, the software of control system is also
programmed. The whole system is assembled by specialized worker. Through calibration experiments, the coefficients of
PID are obtained respectively. And then the precision of position control of the system is about 0.1μm.