The Research And System Design Of Self-scanning Linear Array Detector

With the rapid development of industrial automation, size measurement technique basedon machine vision has played an important role in many industrial fields, such as aerospacemanufacture, ship-building and automobile manufacture. However, traditional sizemeasurement technology is usually complex and time-consuming, sometimes expensivemechanical fixtures would also be employed, so it seriously reduces the production efficiency.A kind of self-scanning linear array detector of the size measurement system is studied in thepaper based on the method of machine vision technology.In the context, structure of self-scanning linear array detector system, design of circuitsand simulation tests are completed on the requirements of size measurement range,measurement speed and accuracy of measurement. Main measures taken in self-scanninglinear array detector design are: the use of FPGA of primary and secondary coordinationmode in the aspect of system design; photodiode array output are controlled by adoption ofMOS transistor switch technology to implement multi-channel signal timeshare acquisition inthe aspect of circuit design, and the module of integral charge amplifier, analog-to-digitalconversion circuits and data transmission depend on USB is used to complete a ping-pongbuffer and high-speed transfer of image data; the processes of primary FPGA and secondaryFPGA and timing of systems control are written in the aspect of software design. The factorsthat may affect the signal output of self-scanning linear array detector are analyzed, includingphotodiode junction capacitance and dark, MOS tube conduction resistance, light source, loadand the noise of MOS transistor switch. Therefore the method of increasing of MOSgate-source and elimination of the proximal collar are used to improve test precision of thesystem. Experiment data show that the testing accuracy of the system is0.5%, meeting thedemand of industrial size measurement. Small circuit size and low cost are adapt to the objectof data acquisition and real time display. At the same time, this thesis about self-scanninglinear array detector system provides an effective method for measuring the size in theindustry.