PC Software Design For Three-axis Attitude Control Simulation System

Ground simulation and testing of spacecraft dynamics is a very important partin its development process, Rigorous ground testing will significantly reduce therisks of its development. Large centroid offset of spacecraft can be caused byattitude control and orbit control severe coupling, load separation, fuel consumptionetc. For this case, there is currently lack of effective simulation testing device, so athree-axis attitude control simulation system has been developed. This system isused to simulation and verification thrust vector control technology in a situationwhere the centroid offset is large.The system is divided into several subsystems, such as PC software system,lower machine, angle measuring system etc. This paper mainly completes PCsoftware design and balance adjustment. PC software system is divided into twoparts, balance control system and monitoring system. The main task of balancecontrol system is to complete power management, supporting mechanism controland air-floating platform balance adjustment. Monitoring system is used to monitorangle, angular rate and other system information, save communication data, andquery historical data.To accomplish functions above, serial communication module, network clientmodule and network server module are been designed as the underlyingcommunication module. This module provides communication interface for lowermachine and other subsystems, thus ensuring PC software system is able to acquiredata and send control commands. Then it can achieve the control of lower machineand the monitor of system information, so underlying communication moduleactually provides the basic functions for PC software system.In order to achieve balance adjustment of air-floating platform, this paperanalyzes the force characteristics of air-floating platform in the coarse balanceprocess, and gets the relationship between barycenter offset and the measured valuesof force sensor. Then it analyzes the air-floating platform dynamics in the finebalance process, simplifies the motion state of platform and Euler’s dynamicalequations, and gets the general relationship between barycenter offset and angularacceleration. After this analysis, the amount of movement of balance slider can bedetermined, and the balance adjustment programs of air-floating platform can beprovided.After the joint debugging of PC software system, it is proved to be able tocomplete the desired function. It can adjust the center of gravity by establishing a connection with lower machine, and then lay the foundation for the simulation ofspacecraft attitude.