Development Of Laser Radar System Control And Signal Processing Circuit Board Based On CPLD And MCU

As a new detection technology, the laser radar has been widely used in the fields, such as atmosphere, land and ocean detection, aerial rendezvous and docking, investigative imaging, chemical agent detection, etc. Compared with the traditional radar technology, the laser radar is a technology which emits a specific wavelength of laser and then processes and analyzes the return signals to realize the target detection. The laser radar with high measurement precision, high spatial and temporal resolution and the maximum detection range, has become an important active remote sensing tool. In the laser radar system, the hardware circuit is used to complete the processing and analysis of return signals and to realize target measurement on distance, velocity, attitude and other parameters. Therefore the development of return signals processing circuit of high speed, high precision, stable performance, effective cost and high security has very important significance to enhance the overall performance of laser radar detection system.Many ways can be used to design the return signals processing circuit. MCU is a traditional way which is widespread but restricted by the band of thread and difficult to improve system precision. FPGA, ARM or DSP can be used to realize signal processing architecture. To a certain extent, it improves the system bandwidth and complexity, but the cost is high and the development cycle is long. Aiming at the requirements for the speed, performance and price of laser radar return signals processing circuit, this paper proposes an improved scheme based on CPLD circuit and MCU architecture. The scheme adopts the high-speed parallel programmable PLD device to complete real-time processing of return signals and control of related circuit, and uses MCU which has the advantage of the liner processing to realize the control of related signals, transmit-receive of high-speed serial port and communication of designed PC software terminal.Combined with the proposed architecture based on CPLD and MCU, MAX II CPLD of Altera device EPM240T100C5 N, and enhanced MCU STC12LE5A60S2 of Macro-solar Technology Co. are used to control the laser radar system and process therelated signals. The modular design of laser radar signals processing circuit which completes the driving control of related peripherals is introduced in detail in the paper. CPLD and MCU are used to complete functions of the collection, processing and analyzing of the return signals. Eventually real-time data communication with signal processing board is completed combined with supporting PC software terminal.The board working at 100 MHz has completed 10 k Hz laser triggered, return signals real-time processing and analysis, and 921,600 baud rate of serial port communication at a high speed. Combined with the laser radar experiment system, the related functions of the signal processing board is verified and its performance is tested. The testing shows that the designed signal processing board has normal function, stable performance, low power consumption, and meets the design requirements. The experiments show that the proposed scheme has certain feasibility.