Image Processing System Design For Space Optical Communication Based On Dual DSP

With the increasing demand for communication capacity, the traditional microwave communications become crowded. To improve the signal transmission speed, many countries turn their attention to the more promising space optical communication. Due to far communication distance and narrow beam, acquisition, pointing and tracking (APT) technology turns out to be as a key technology in space optical communication. Image Processing System is laser detecting assembly in APT system, provides feedback position of target for APT servo system. In order to ensure speediness, stability and reliability of system, this paper designs dual DSP-based image processing system.Proposes a dual DSP image processing scheme: two DSP connect through the host machine interface (HPI) provided by the slave machine. The slave machine is used for image acquisition and processing; host machine for external expansion bus. The scheme can effectively isolate noise, improve operating efficiency. Besides, resource sharing can be realized through HPI, reduces system design difficulties. Real-time analysis based on implementation of the scheme demonstrated the feasibility of the scheme.System tracking scheme uses center tracking. Weighted average filter is used for image filtering to filter random noise of system. To avoid disturbances from the star, a threshold segmentation and Connected region labeling method is adopted. Simulation results show that the system can separate target from background noise effectively, and is able to meet the precision of the system.The paper introduces this system according to the function of the modules. The slave system controller uses TMS320VC5416 of TI corp., and designs the link layer and physical layer of the bus for real-time acquisition of CCD image data, combing understanding of the IEEE 1394 bus protocol. The host system controller uses TMS320LF2407A, designs the CAN bus, RS485 and parallel bus expansion. Finally, designs the dual DSP structure based on the HPI according to the overall system, and introduced the methods of the data communications and resource sharing in this structure.Finally, the system test done on the system design platform show that the system guarantees real-time requirements of the premise as well as realizes various functions.