Research On Integration Of On-board Computer And Electronic System Of Star Sensor

On-board computers and star sensors are both important components of microsatellite platforms.To improve the integration,reliability,and resource utilization of satellite electronic platforms,while reducing the weight,volume,and power consumption of the platform,this paper focuses on on-board computers Integrated design with star sensor electronic system.This article firstly investigates and analyzes the present research status of the microsatellite on-board computer,electronic system of micro star tracker,and microsatellite integrated electronic system.On this basis,combined with the functional requirements and technical indicators of the integrated platform,The overall design plan of the integrated platform is presented.This solution consists of three layers: hardware layer,firmware layer,and software layer,where the hardware layer contains the processing unit,the communication unit,the acquisition unit,instruction unit,and power supply unit;the firmware layer contains the integrated management module,time management module and star map preprocessing Modules,etc;the software layer consists of drivers for each functional module.Secondly,based on the overall design plan,this paper completes the design and implementation of the integrated platform of the on-board computer and the star sensor electronic system.The system architecture is mainly composed of ARM,FPGA,DSP,and ZYNQ.Among them,ARM mainly completes the satellite performing service management function,DSP mainly completes the star map processing function,and highly reliable FPGA mainly completes the integrated management of platform resources.ZYNQ is a coprocessor,Cooperate to complete the tasks of the satellite performing service management and star map processing tasks.To improve the reliability of the system,the system has been designed for reliability at the device level,circuit level,and system level,and at the same time enables the system to support three modes of normal working mode,backup working mode,and emergency working mode,further improving the system’s reliability.Thirdly,based on the hardware system architecture,this paper completes the design and development of each functional module of the firmware layer,including integrated management module,time management module,and star map preprocessing module.Among them,the integrated management module is used to monitor the operating status of each processor in the platform and configure the working mode of the platform;the time management module can realize selftimekeeping,uniform instruction timing,autonomous timing,ground timing,and centralized timing,etc.Provide time generation,maintenance,and distribution functions for the platform;the star map preprocessing module is used for star map preprocessing,including star map filtering,background segmentation,and star point extraction.This module uses pipeline technology.Finally,this paper conducted board-level tests to verify the functions of power supply,processing,communication,instruction and acquisition of each hardware module;firmware simulation was performed to verify the integrated management,time management,HDLC communication and star map preprocessing of each firmware module and other functions;Based on the above two tests,the system level functions of integrated management and time management are verified.The test results show that the functions of the integrated platform are normal,and the weight and power consumption meet the design requirements.