Attitude Estimation Algorithm of Portable Mobile Robot Based on Complementary Filter

In robot inertial navigation systems, to deal with the problems of drift and noise in the gyroscope and accelerometer and the high computational cost when using extended Kalman filter (EKF) and particle filter (PF), a complementary filtering algorithm is utilized. By combining the Inertial Measurement Unit (IMU) multi-sensor signals, the attitude data are corrected, and the high-precision attitude angles are obtained. In this paper, the quaternion algorithm is used to describe the attitude motion, and the process of attitude estimation is analyzed in detail. Moreover, the models of the sensor and system are given. Ultimately, the attitude angles are estimated by using the quaternion extended Kalman filter, linear complementary filter, and Mahony complementary filter, respectively. The experimental results show that the Mahony complementary filtering algorithm has less computational cost than the extended Kalman filtering algorithm, while the attitude estimation accuracy of these two algorithms is similar, which reveals that Mahony complementary filtering is more suitable for low-cost embedded systems.

Transient Attitude Motion of TNS-0#2 Nanosatellite during Atmosphere Re-Entry

Attitude motion reconstruction of the Technological NanoSatellite TNS-0 #2 during the last month of its mission is presented in the paper. The satellite was designed to test the performance of the data transmission via the Globalstar communication system. This system successfully provided telemetry (even during its atmosphere re-entry) up to an altitude of 156 km. Satellite attitude data for this phase is analyzed in the paper. The nominal satellite attitude represents its passive stabilization along a geomagnetic field induction vector. The satellite was equipped with a permanent magnet and hysteresis dampers. The permanent magnet axis tracked the local geomagnetic field direction with an accuracy of about 15 degrees for almost two years of the mission. Rapid altitude decay during the last month of operation resulted in the transition from the magnetic stabilization to the aerodynamic stabilization of the satellite. The details of the initial tumbling motion after the launch, magnetic stabilization, transition phase prior to the aerodynamic stabilization, and subsequent satellite motion in the aerodynamic stabilization mode are presented.

Control of satellites using environmental forces : aerodynamic drag / solar radiation pressure

The dynamics of a satellite involves orbit and attitude motion. Both orbit and attitude motion are required to be controlled for achieving any mission objectives. This thesis examines both of these motion with a focus on formation flying and attitude stabilization using aerodynamic drag or solar radiation pressure. The concept of satellite formation flying involves the distribution of the functionality of a single satellite among several smaller, cooperative satellites. Autonomous multiple satellite formation flying space missions offer many promising possibilities for space exploration. A large quantity of fuel is typically required onboard any conventional satellite to carry out its attitude and orbital positioning, and satellite formation flying has a higher fuel requirement. As on-board fuel is a scarce commodity, it is important to have control methods requiring little or no fuel. Keeping this in mind, this thesis presents the results of using aerodynamic drag or solar radiation pressure for satellite formation flying. This methodology has potential to have significant commercial advantage as it pertains to almost negligible fuel requirements. A leader/follower formation architecture is considered for the formation flying system. The control algorithms are derived based on adaptive sliding mode control technique. Aerodynamic drag is used to accomplish multiple satellite formation flying in low Earth orbit whereas solar radiation pressure is used in geostationary orbit. Due to the nature of the aerodynamic drag, in-plane control can only be accomplished by the suitable maneuvering of the drag plates mounted on the satellites. Solar radiation pressure is able to accomplish in-plane and out-of-plane control by maneuvering of the solar flaps. Efficacy of the control methodology in performing various scenarios of formation flying including formation reconfiguration is validated by numerical simulation in both the cases. The numerical results demonstrate the effectiveness of the proposed control techniques for satellite formation flying using aerodynamic drag or solar radiation pressure. Formation flying accuracies of less than 5 m are achieved in both the cases. Next, this thesis investigates the use of aerodynamic drag or solar radiation pressure for satellite attitude control. In the case of the aerodynamic drag stabilized satellite, the drag plates are considered to be attached to the satellite while the solar flaps are fixed to the satellite in the case of the solar radiation pressure stabilized satellite. In both the cases, the control algorithm is developed based on adaptive sliding mode control technique. The effectiveness of this methodology is numerically evaluated under various scenarios including the pressure of failure/fault in the solar flaps or drag plates attached to the satellite. The satellite attitude is stabilized within reasonable limits in all the cases thereby demonstrating robust performance in the presence of external disturbances.

Control of satellites using environmental forces : aerodynamic drag / solar radiation pressure

The dynamics of a satellite involves orbit and attitude motion. Both orbit and attitude motion are required to be controlled for achieving any mission objectives. This thesis examines both of these motion with a focus on formation flying and attitude stabilization using aerodynamic drag or solar radiation pressure. The concept of satellite formation flying involves the distribution of the functionality of a single satellite among several smaller, cooperative satellites. Autonomous multiple satellite formation flying space missions offer many promising possibilities for space exploration. A large quantity of fuel is typically required onboard any conventional satellite to carry out its attitude and orbital positioning, and satellite formation flying has a higher fuel requirement. As on-board fuel is a scarce commodity, it is important to have control methods requiring little or no fuel. Keeping this in mind, this thesis presents the results of using aerodynamic drag or solar radiation pressure for satellite formation flying. This methodology has potential to have significant commercial advantage as it pertains to almost negligible fuel requirements. A leader/follower formation architecture is considered for the formation flying system. The control algorithms are derived based on adaptive sliding mode control technique. Aerodynamic drag is used to accomplish multiple satellite formation flying in low Earth orbit whereas solar radiation pressure is used in geostationary orbit. Due to the nature of the aerodynamic drag, in-plane control can only be accomplished by the suitable maneuvering of the drag plates mounted on the satellites. Solar radiation pressure is able to accomplish in-plane and out-of-plane control by maneuvering of the solar flaps. Efficacy of the control methodology in performing various scenarios of formation flying including formation reconfiguration is validated by numerical simulation in both the cases. The numerical results demonstrate the effectiveness of the proposed control techniques for satellite formation flying using aerodynamic drag or solar radiation pressure. Formation flying accuracies of less than 5 m are achieved in both the cases. Next, this thesis investigates the use of aerodynamic drag or solar radiation pressure for satellite attitude control. In the case of the aerodynamic drag stabilized satellite, the drag plates are considered to be attached to the satellite while the solar flaps are fixed to the satellite in the case of the solar radiation pressure stabilized satellite. In both the cases, the control algorithm is developed based on adaptive sliding mode control technique. The effectiveness of this methodology is numerically evaluated under various scenarios including the pressure of failure/fault in the solar flaps or drag plates attached to the satellite. The satellite attitude is stabilized within reasonable limits in all the cases thereby demonstrating robust performance in the presence of external disturbances.

Design And Development Of Power And Attitude Control Subsystems For RYESAT

This thesis describes the design and development of Ryerson University's first CubeSat (RyeSat) with a focus on power and attitude control subsystems. This satellite is intended to become the initial of a series of CubeSats built by Ryerson University to perform research in spacecraft control algorithms and actuators. RyeSat is built around a standard interface, which specifies both a data-bus and a switchable power supply system for non critical systems. To facilitate the development of this satellite a prototype power subsystem was created, programmed and tested. In addition to developing the system's architecture and power subsystem; analysis was preformed to size both reaction wheels and magnetic torquers. This analysis showed that a commercially available motor could be adapted to fulfill the attitude control requirements of a CubeSat and also showed that miniature magnetic torque rods would be more efficient that magnetic torque coils typically used on CubeSats. Finally, control laws for these actuators were designed and an adaptive nonlinear sliding mode controller for reaction wheels was applied to control the 3-axis attitude motion of RyeSat.

Design And Development Of Power And Attitude Control Subsystems For RYESAT

This thesis describes the design and development of Ryerson University's first CubeSat (RyeSat) with a focus on power and attitude control subsystems. This satellite is intended to become the initial of a series of CubeSats built by Ryerson University to perform research in spacecraft control algorithms and actuators. RyeSat is built around a standard interface, which specifies both a data-bus and a switchable power supply system for non critical systems. To facilitate the development of this satellite a prototype power subsystem was created, programmed and tested. In addition to developing the system's architecture and power subsystem; analysis was preformed to size both reaction wheels and magnetic torquers. This analysis showed that a commercially available motor could be adapted to fulfill the attitude control requirements of a CubeSat and also showed that miniature magnetic torque rods would be more efficient that magnetic torque coils typically used on CubeSats. Finally, control laws for these actuators were designed and an adaptive nonlinear sliding mode controller for reaction wheels was applied to control the 3-axis attitude motion of RyeSat.