Development Of Portable Image Acquisition Equipment

When field tests are conducted,large amount of image data needs to be collected and saved to ensure reliable results.However,efficient tests are always limited by the defects of image acquisition systems mainly involving the large size,poor mobility and high cost,restricting the tests with strict conducting conditions.Aiming at solving limitations of the current image acquisition systems,this study develops a miniaturized portable image acquisition system with the capability of image acquisition and data storage,to meet diverse working conditions such as field,altitude,airborne and so on.The solution to meet the functional requirements and technical indicators in different field experiments stems from the stacked structure of FPGA(Field Programmable Gate Array)and ARM(Advanced RISC Machine).The designed image acquisition equipment takes advantages of both FPGA in logic capability and the flexible interface,and ARM in its powerful peripheral management and computing capability.Finally,with the support of a well-designed structure,the designed system is accordingly capable of acquiring images and storing data in diverse application conditions.1.This thesis analyzed the defects of the existing acquisition systems and put forward the design scheme of a portable image acquisition system utilizing the advantages of FPGA and ARM.The proposed scheme was aimed at dealing with problems involving large volume,high cost,irreplaceable interface,and poor adaptability encountered in current acquisition systems.2.A hardware scheme was designed according to the specific function requirements and performance indexes.It proposed to build the platform based on the modular design approach,which suggests to use a stacked structure to divide the system into a number of boards according to the function and installation of modules.The design enables equipment safety and efficiency improvement.In addition,this thesis further presented the design of a mechanical structure of the equipment ensuring high reliability by considering the board cooling issue.3.Based on analyses of the communication requirements between FPGA and ARM,this study proposed a data transmission interface protocol,which ensured the stable and highspeed data transmission between two processors.This protocol made the adaptive resolution function possible,ensuring the accuracy of data transmission.4.By analyzing the memory management mechanism and data scheduling process of Linux system,we put forward a data transmission and storage method to solve the problem encountered in system transmission.Experiments demonstrated the method could effectively improve the bandwidth in system data transmission and storage by optimizing the program structure.5.An overall test plan was proposed to perfect the equipment design.Tests and debugging to the equipment were accomplished.Finally,we summarized the precautions for the equipment and effectively verified the basic functions of the equipment.Abundant test results validate that the portable image acquisition equipment developed in this thesis can meet the requirements and proposed indicators.It has been widely applied.Application results show that the portable image acquisition equipment can adapt to a variety of harsh environments with an image acquisition bandwidth of 80MB/s.It can work offline several hours continuously even in harsh conditions such as wild fields,high altitude and so on.The designed equipment can realize the desired purpose with advantages of small size,stable performance,strong adaptability,good portability and low power consumption.