Session
Weekend Session I: Advanced Technologies Research & Academia 1
Location
Utah State University, Logan, UT
Abstract
Simulation of a 3U-sized standard platform with four control panels attached to the rear part of the satellite at an altitude of 300 km was performed in Simulink to verify the feasibility of the aerodynamic control. The entire controller is composed of three loops: one outer loop and two inner loops. The outer loop is based on the robust and tested quaternion error feedback regulator to provide the target torque input for the two inner loops. The inner loops are responsible for actuating the control panels, using the square-root-based PI controller and a dedicated designed Panel Selecting Method (PSM) to achieve high-precision attitude control. The inner loop torque generation controller will determine when to switch to either a PSM or square-root PI controller based on the attitude error measured in the quaternion form. During the initial phase of the maneuver, the PSM will be in charge of pointing the satellite close to the desired attitude before the square-root PI controller takes over the control authority to achieve a smooth, steady-state response. The proposed aerodynamic control method will be compared with other controllers often used on the CubeSat platform, including the magnetorquer, to analyze the benefits of using aerodynamic control in various scenarios. Advantages like natural stabilization of the satellite's attitude in both pitch and yaw axes using almost zero electricity compared to magnetorquers will be discussed. However, the lifetime of a VLEO CubeSat is of concern at very low orbit where the atmosphere air density is relatively high, and the reduction of the lifetime on the given orbit from the increased drag of aerodynamic control surfaces will be addressed in the present work to discuss the impact of aerodynamic control on the operation of CubeSat at VLEO. With the results showing a reasonable detumbling time compared to the traditional magnetorquer at 300 km and a high degree of control accuracy with moderate variations of attitude near the level flight, the aerodynamic controller and the proposed algorithms are proven to be effective in the applications of near nadir pointing missions or missions requiring only the fast response of the rolling motion at VLEO environment. In the last section, some directions of future works will be shortly discussed, which include data-driven control for handling atmospheric conditions of other planets and the formation flight by using pure aerodynamic control.
Aerodynamic Satellite Attitude Control in Very Low Earth Orbit
Utah State University, Logan, UT
Simulation of a 3U-sized standard platform with four control panels attached to the rear part of the satellite at an altitude of 300 km was performed in Simulink to verify the feasibility of the aerodynamic control. The entire controller is composed of three loops: one outer loop and two inner loops. The outer loop is based on the robust and tested quaternion error feedback regulator to provide the target torque input for the two inner loops. The inner loops are responsible for actuating the control panels, using the square-root-based PI controller and a dedicated designed Panel Selecting Method (PSM) to achieve high-precision attitude control. The inner loop torque generation controller will determine when to switch to either a PSM or square-root PI controller based on the attitude error measured in the quaternion form. During the initial phase of the maneuver, the PSM will be in charge of pointing the satellite close to the desired attitude before the square-root PI controller takes over the control authority to achieve a smooth, steady-state response. The proposed aerodynamic control method will be compared with other controllers often used on the CubeSat platform, including the magnetorquer, to analyze the benefits of using aerodynamic control in various scenarios. Advantages like natural stabilization of the satellite's attitude in both pitch and yaw axes using almost zero electricity compared to magnetorquers will be discussed. However, the lifetime of a VLEO CubeSat is of concern at very low orbit where the atmosphere air density is relatively high, and the reduction of the lifetime on the given orbit from the increased drag of aerodynamic control surfaces will be addressed in the present work to discuss the impact of aerodynamic control on the operation of CubeSat at VLEO. With the results showing a reasonable detumbling time compared to the traditional magnetorquer at 300 km and a high degree of control accuracy with moderate variations of attitude near the level flight, the aerodynamic controller and the proposed algorithms are proven to be effective in the applications of near nadir pointing missions or missions requiring only the fast response of the rolling motion at VLEO environment. In the last section, some directions of future works will be shortly discussed, which include data-driven control for handling atmospheric conditions of other planets and the formation flight by using pure aerodynamic control.
