Design And Implementation Of FPGA Software For Landing Sensor Signal Processor

High-precision measurement of the landing sensor is the prerequisite for a successful landing of a detector,and signal processor is an important part of a landing sensor that provides digital signal processing and control functions for landing sensors.According to the different forms of transmitting signals,the measurement system of the landing sensor can be divided into several types.The measurement range and accuracy of different working systems are different,and each has its own advantages and disadvantages.For example,the pure continuous wave and intermittent continuous wave although the speed accuracy is high,but there is no ranging ability;the Linear Frequency Modulation Continuous Wave(LFMCW),Sinusoidal Frequency Modulation Continuous Wave(SFMCW)and pulse system have ranging and speed measurement capability,but the measurement range and accuracy are quite different,that is,LFMCW has higher ranging accuracy but lower speed accuracy,SFMCW has higher speed accuracy but lower ranging accuracy,the measurement range and accuracy of pulse system is affected by the pulse repetition period and the pulse width.Based on the advantages and disadvantages of each working system,this paper presents a scheme of using different working systems to measure according to the distance range.That is,the pulse working system is used for the long-distance section and the LFMCW working system is used for the short distance section so as to obtain higher measurement range and accuracy.First of all,this paper introduces the working principle of the landing sensor signal processor,including band-pass sampling principle,digital down-conversion,moving target detection,LFMCW measurement principle and pulse measurement principle.Secondly,this paper introduces the overall design of the landing sensor signal processor,including the composition,function and measurement system of the signal processor.Finally,this paper describes the FPGA software of the landing sensor signal processor,including the block diagram and test results of the FPGA software program of each function module,and gives the analysis of the test results,proves that the signal processing FPGA software program is feasible.