Research On Tiantong Satellite Beam Automatic Tracking System Based On ARM

With the rapid development of mobile communication technologies,satellite automatic tracking systems have been widely used in various communication fields.Compared with the mechanical scanning tracking technology,the beam automatic tracking technology based on phased array antenna has the advantages of fast scanning speed,high anti-interference ability and flexible beam pointing.Therefore,an automatic tracking system using a phased array antenna is becoming a hot topic.The traditional automatic tracking system based on the PC104 processor has limited computing ability.In order to shorten the design cycle of the system,many researchers use digital signal processing(DSP)combined with Field Programmable Gate Array(FPGA).Although this kind of scheme is flexible,due to the limitations of FPGA applications,the system reliability is low and the cost is high.Based on this situation,this paper proposed a new phased array antenna beam automatic tracking system.The specific research work is as follows.1)This system uses ARM Cortex-M3 as the core processor,Global Positioning System(GPS)and Inertial Measurement Unit(IMU)as position sensitive devices,and electronic beam scanning as the scanning method.This design can reduce the hardware and peripheral circuits of the system,eliminate the servo system,and reduce the cost of the system to a certain extent.2)In terms of hardware design,according to the idea of miniaturization,we combined the interface configuration and functional requirements of the system,and finally determined the overall hardware scheme.Among these the main control module takes STM32F103ZET6 as the control core,the power circuit,clock circuit and reset circuit are relatively designed,and the SWD interface is designed to debug the system.In addition,this paper designs GPS inertial navigation module,serial communication interface module and phase shifter module.3)In terms of software design,according to modular programming idea,the software architecture of the system is determined.We completed the software development of the system and proposed two improvements.Firstly,a mathematical model for the beam of the ground receiving antenna relative to the Tiantong satellite beam is proposed.In this paper,the mathematical model of antenna beam pointing in geographic coordinate system and carrier coordinate system is derived by using space rotation coordinate system.Based on the influence of attitude angle variation on system performance,and the improvement of the original model,a more accurate mathematical model of the antenna beam pointing angle is proposed.Secondly,aiming at the characteristics of the abrupt value of the directional data,we propose a filtering scheme combining the limiting filter and the averaging filtering to improve the stability of the system.Through the step-by-step debugging of hardware and software,and verified by the experiments,the expected purpose has been achieved.After the second development and improvement,The characteristics of low-cost?fast scanning and advantages of accuracy,enable this system has practical value.