Based on fine optical grating and micrometer, one closed-loop high-precision position control system with two modes has been made. The system is used to control the optical elements moving in two ways. That is, one control mode is automatically control with optical grating feedback system and the other mode is manually control with micrometer. Under the support of conservative PID control algorithm, the precision of the system is up to ±0.1&mgr;m while operating on automatically way, otherwise, the position precision is ±1&mgr;m.
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.
Infrared camera with IR FPA (Focal Plane Array) has often been used in the fields of target detection, temperature test,
surface detection, and so on. And it is very important to run the Non Uniformity Correction (NUC) correction firstly to
solve the non-uniformity of FPA which is the inherent character of IR FPA. The NUC character is the inherent
performance of IR FPA which has different response rate among pixels for the same IR radiant. This NUC can decrease
sensitivity of IR FPA and reduce the resolution of sensor. There are two kinds of methods to do this correction. One is
hardware method which is using the DSP. Another one is software method. Within this device, two-point correction
method is used to correct the NUC. The Field Programmable Gate Array (FPGA) is used. The FPGA can do better
parallel arithmetic and has more programmability. After the NUC correction, the error analysis of this correction is also
made. After the correction, the BPR (Bad Pixel Replacement) can be more than 98%.