Algorithms And Hardware-in-the-loop Simulation For Micro-satellite Attitude Determination And Control

As the research hotspot of the aerospace,the design of micro-satellite is limited by the physical size,power consumption,data storage,development cost and so on.Attitude control system is the core part of the micro-satellite,which will be different from the traditional satellite.On the background of the design of micro-satellite attitude control system,studies on attitude determination and attitude control algorithm for micro-satellite,as well as the hardware-in-the-loop simulation experiment based on rapid prototyping design are made.The main contents are follows:(1)The attitude determination strategy of micro-satellite is studied.For the micro-satellite attitude measurement system composed of the gyro,magnetometer and sun sensor,four kinds of state estimation algorithms are designed,including EKF algorithm,UKF algorithm,EKF algorithm based on federal information fusion and EKF algorithm based on information preprocessing.The simulation analysis is carried out on the problem of attitude determination in the case of small initial state error,large initial state error and partial sensor failure,then,the performance of various algorithms are compared and the attitude determination strategy is determined.(2)The attitude control strategy of micro-satellite is studied.The attitude control algorithm is studied in four stages: the rate damping,the attitude capture,the three axis stability and the attitude maneuver.The first three stages of the active actuator is magnetic torque,and maneuver actuator is micro-jet thruster.B-dot,PID and two layer control algorithms are designed for the rate damping stage.The PD,sliding mode variable structure and the two layer control algorithm are designed respectively for the attitude capture stage.The channel decoupling control algorithm and LQR control algorithm are designed respectively for the three axis stabilized phase.Among them,the two layer control algorithm achieved the attitude control of the equal inertia satellite using only magnetic torque.Based on attitude path planning,the PD and sliding mode variable structure attitude maneuver control algorithm is designed.The performance of the different algorithms and the attitude control strategy is determined for different stages are compared.(3)The hardware-in-the-loop simulation system of micro-satellite attitude control is studied based on rapid prototyping.Based on the idea of rapid prototyping,the embedded object code of the attitude determination and control model is developed,the hardware-in-the-loop simulation system is constructed,which combined with the rapid prototyping attitude control unit and the RT-LAB real-time simulation platform.Then the attitude determination and attitude control algorithm by above system are simulated,and the feasibility of the simulation system and the effectiveness of the control algorithm are verified.In summary,the micro-satellite attitude determination strategy,attitude control strategy,and the hardware-in-the-loop simulation system based on rapid prototyping are studied for the limited configuration of attitude measurement device and control device.The research results of this paper can be used as a reference for the micro-satellite attitude control system design.