Design Of Range And Speed Measurement Sensor Echo Simulator For Lunar Exploration

This thesis is taking the soft-landing in lunar of the detector which is a part of Chang'e lunar exploration project in China as the research background,not only discuss that the key technique of the distance and speed measurement sensor echo simulator,but also discuss the verification method of sensor systematically and comprehensively.At the same time,the stability of the whole detector system and the correctness of the distance and speed measurement algorithm are verified by simulated radar echo data.In this thesis,the echo simulator is designed by combining the software and hardware.Using the host computer software to generate the surface target simulated echo data in the PC and then store it in the hard disk.The hardware platform of the simulator consists of CPCI crate,main board,memory board,analog board and so on.The data communication between the boards is mainly controlled by FPGA.The workflow of the whole system consists of three parts: generation,storage and playback of the echo data.The surface target simulated echo data includes both distance measurement data and speed measurement data.Data storage means that FPGA uses PCI communication to storage the echo data in the FLASH array of the memory board.The data playback is controlled by the distance and speed measurement sensor,the stability of each system of the sensor and the correctness of the radar distance and speed measurement algorithm are verified by surface target simulated echo data.The modeling method of the lunar surface,the echo model of the target signal,the mathematical model of the distance and speed measurement radar,the relative motion model between the sensor and the lunar surface and the antenna configuration mode of the sensor are introduced in this thesis.The software design flow and hardware design flow of the whole echo simulation system are introduced in detail.And the function of data storage test module,data playback test module and distance and speed measurement senor test module are added to the whole simulate system.At the same time,in the process of designing the simulate system,the problem of some module is described,then the problem is analyzed and positioned.Finally,a method is proposed to solve the problem.The simulator uses the CPCI chassis as the hardware platform,and the memory board,as well as the simulation board to complete the function of the surface target simulation echo data storing and playing back.The working flow of the distance and speed measurement sensor echo simulator and the verification method of the sensor system are introduced.Since the lots of models of storage and playback of the surface target distance and speed measurement simulate echo data,the thesis only introduces the storage and playback process of distance data.In this thesis,the improvement of the distance and speed measurement sensor echo simulator is based on the design of data storage test module,data playback test module and sensor test module.The FPGA-based FLASH test software is designed to test the data storage function of the system.The correctness of the radar echo simulator function is verified by comparing the simulated echo data with the data collected during playback,and the test of the data playback is completed.The method of the curve of the distance and speed measurement is compared with its own error curve to prove the stability of the sensor and the effectiveness of the radar distance and speed measurement algorithm,and finally completes the testing of the sensor.