Research On Wireless Video Transmission System Of Fire-fighting Robot

Fire-equipment has shown an increasingly important role in the fire-fighting and rescue occasions.Fire-robot is a special robot . As a special fire-equipment , it can replace the fire-fighters near the scene of the fire. The implementation of the effective fire-fighting equipment will greatly enhance the fire department's ability to fight fires , and the fire-robot will play an important role in reducing the casualties and property loss.This paper is part of the Fire-robot system about the wireless video transmission system. Based on the environment and actual apply, the whole plan of the design is given out. After the research and analysis on the hardware,software and arithmetic, the wireless video transmission system designed for fire-fighting robot can meet the needs of the fire department.The apply of the wireless video transmission technology in the fire-robot will increase the capacity of its remote control, and it will become more important in future. Based on the in-depth exposition of the remote video transmission system,we used the efficient processing chip to optimize arithmetic and have analysis on the real-time video communication in wireless conditions combined with the experiment.In view of the system, we choose a common wireless video transmission standard H.263 ,then take into account of the largest motion estimation and DCT in the H.263 standard calculation. Loeffler as the selected algorithm is discussed in detail. Motion estimation is the main part of video coding, which consumed most of the CPU time coding. Good search motion estimation algorithm can quickly complete operations, and guarantee the accuracy of estimates. In the search strategy, a new block-matching motion estimation algorithm-predicted hexagonal search algorithm (PHS) is given out based on the hexagonal search algorithm, this method reflects the vision of certain biological characteristics. PHS algorithm has also accelerate the pace of the campaign estimated and maintain a good image by making full use of the motion vector object-block at the center of the relationship between migration and distribution characteristics performance. Moreover, due tothe motion vector in the search window near the center, the motion vector length is small. The number of bits used to make motion vector expressed greatly reduced. The experimental results show that the algorithm is more excellent than HS and FS coding algorithm,meanwhile the quality is equal to FS coding algorithm.Digital signal processing has a major characteristic of large amount. Digital signal processing's task is completed by the general purpose or Dedicated DSP processor. DSP is a special microprocessor. Series of C6000 chip floating-point DSP are considered , and we choose the C6711 DSP image processing system as the main processor. In other modules, based on practical, economic, Functional range of principles, we choose the exclusive video decoder chip SAA7111A as the A/D converter module high-performance logic device EPM7128A complex variable-timing control module as the main logic chip Waterproof and nRF9E5 integrated camera and infrared transmitter-receiver chip choice.After the choose of the hardware module, the system's design and program design process are confirmed.The entire system is divided into two parts:video transmitter and the receiver. The sending part is consisted of simulated camera, decoder, coding module, wireless transmitter module. The receiving part is consisted of wireless receiver and display module components. TMS320C6711 chip is the core of the whole system, whose main task is when the interrupted signal is received, reading an image from the SDRAM memory , then the image processing algorithm is implied on the whole image.After understanding the characteristics and C6711 processor on the basis of the internal structure, the enhanced DMA transmission mechanisms are discussed and the parameters are set up.Then we had a research on the external program and data memory interface EMIF linked to the Synchronous Dynamic Random Access Memory SDRAM and FLASH memory which preserves data and initialization procedure. Video data is needed before the acquisition. We use acquisition 352×288(CIF) image format, the principle of collecting a detailed analysis.Finally, the data collection system is described, and have some research on the actual use of the nRF9E5.We have some research on the software design in view of the hardware design. First, we discuss the DSP software development tools, and the development of programming steps. Then the system initialization procedures DSP design Video Capture and Conversion program design and CPLD wireless transmitter andreceiver modules are the flow chart in the article. Finally, the video data processing algorithm in software on the core analysis Visual C++6.0 and algorithms for testing and analysis are proven to be effective and can meet the requirements of real-time systerm.The quality of Video Communication is evaluated by standards of video quality which is given to users.We believe that with the rapid development of the communication technology, a better video transmission system of the fire-robots will be required.We also believe that the development of fire-fighting robot video transmission system will be more and more practical and the application will become more extensive.