The Design Of Adaptive System Of Electrochromic Device Based On FPGA

Electrochromic device(ECD) is a new discolour device,which have the advantage of ignored the blind corner, wide operating temperature range, low manufacturing cost, low driving voltage, flexible, ultra-thin, etc, and the device has broad application prospect in electrochromic smart windows, electrochromic auto anti-dazzle mirror, electrochromic display device, aerospace and military stealth fields. Because of electrochromic device's important properties in the visible spectrum's color change, designing electrochromic color adaptive systems for electrochromic device has important research significance.According to the study and analysis of color theory of collection and processing, access to color information using a color image sensor has the advantage of broad detection range and obtaining abundant information in the image processing and color recognition. Comparing with the CCD image sensor, the development of CMOS image sensor has make it gradually become the main stream image sensor in the field of image acquisition. For field programmable gate array(FPGA) has its powerful parallel processing capabilities and high speed hardware logic compared to traditional single-chip microcomputer(include ARM microprocessor), so FPGA is more suitable to be applied for real-time control and image processing. Some high-speed devices often require high precision clock, FPGA can meet this requirements of the frequency and phase of the clock, thus avoiding data loss for lacking of precise clock, so this paper uses FPGA to acquire image, process image and drivers all modules in the system.In order to satisfy the color consistency demand of electrochromic device and external environment, the design of adaptive system of electrochromic device based on FPGA is proposed in this paper. In the hardware part, the color data are collected by CMOS imaging sensor and saved in SDRAM. The color signal are processed and corrected by FPGA and then the color signal is outputted to the drive module to drive ECD, drive mode of electrochromic devices include two kinds of constant voltage and constant current. Section of hardware logic gives the detailed description on how to use FPGA to process logic control and color correction using hardware description language. After analyzing the experimental result, it shows that the system can display image in real time, and has the advantage of the high identification accuracy and range, small size and low cost, can achieve good performance of color consistency.