This patent presents an attitude determination and control system based on a Quaternion Kalman Filter (QKF) with an extendable number of sensors and actuators. Furthermore, it is compatible with the spherical motor as its attitude actuator. The system includes a processor with a QKF, at least one direct attitude actuator, and at least two environmental sensors. Firstly, system dynamics calculates a first propagation attitude determination result. Next, update the first propagation with the attitude sensor measurements. Then, control the satellite's attitude via the attitude actuator closer to the attitude command provided by the user. The proposed system dynamic model could adjust the number of actuators and sensors freely without reprogramming the algorithms for new missions with new configurations on the actuators and sensors. Moreover, if some components fail, the algorithm can automatically remove those related sequences to avoid the overall failure of the system.

This patent presents an attitude determination and control system based on a Quaternion Kalman Filter (QKF) with an extendable number of sensors and actuators. Furthermore, it is compatible with the spherical motor as its attitude actuator. The system includes a processor with a QKF, at least one direct attitude actuator, and at least two environmental sensors. Firstly, system dynamics calculates a first propagation attitude determination result. Next, update the first propagation with the attitude sensor measurements. Then, control the satellite's attitude via the attitude actuator closer to the attitude command provided by the user. The proposed system dynamic model could adjust the number of actuators and sensors freely without reprogramming the algorithms for new missions with new configurations on the actuators and sensors. Moreover, if some components fail, the algorithm can automatically remove those related sequences to avoid the overall failure of the system.

The present technology relates to an artificial satellite and a control method thereof that enable to ensure quality of a captured image while suppressing battery consumption. An artificial satellite includes: an imaging device configured to perform imaging of a predetermined region on the ground; and a management unit configured to change accuracy of attitude control in accordance with a remaining battery amount at an instructed imaging time, and configured to change an imaging condition in accordance with accuracy of the attitude control. The present technology can be applied to, for example, an artificial satellite or the like that performs satellite remote sensing by formation flight.

The invention concerns a method for estimating the angular velocity (and, preferably, also the attitude) of a space platform (for example, a satellite, a space vehicle, or a space station) using only the information provided by one or more optical sensors, such as one or more star trackers, one or more colour and/or black and white cameras or video cameras, one of more infrared sensors, etc.

Disclosed is a method for designing a reentry trajectory based on flight path angle planning, including the following steps: S1. extracting an actual operating parameter of an aircraft, setting a maximum dynamic pressure q.sub.max a maximum stagnation point heat flux {dot over (Q)}.sub.max, and a maximum overload n.sub.max according to a mission requirement, and solving for a velocity-height boundary of a reentry trajectory; S2. solving for a reentry trajectory in an initial descent stage according to differential equations of reentry motion, and setting up a flight-path-angle lower limit γ.sub.min(V) according to the reentry trajectory in the initial descent stage, the velocity-height boundary, and a target point in a velocity-height phase plane; and S3. planning, based on the flight-path-angle lower limit γ.sub.min(V), a flight path angle satisfying terminal constraints, and calculating a corresponding bank angle to obtain a reentry trajectory.

Systems and method for controlling the attitude maneuvers of a spacecraft in space are provided. The method automatically generates optimal trajectories in real-time to guide a spacecraft, providing a much more robust and efficient method than predefined trajectories, to model errors or disturbances. These methods do not rely in predefined trajectories and their associated feed-forward term. The systems comprise sensors, attitude control mechanisms, and a control module to orient the spacecraft in real-time, such that the spacecraft reaches a desired target attitude following an optimal path in the state space and is locally and asymptotically stable.

Systems and methods are described for a satellite control system that exhibits improved stability and increased efficiency by implementing a non-linear dynamic inversion inner-loop control algorithm coupled with an eigen vector outer-loop control algorithm. Thus, the attitude determination and control system (ADACS) may operate using commands to rotate directly about an eigen vector. Additionally, the outer-loop control system includes a feed-forward control element to enhance pointing accuracy when tracking moving targets.

A control system for reducing disturbance torque of a spacecraft is disclosed. The spacecraft revolves around a celestial body surrounded by an atmosphere. The control system includes processors in electronic communication with one or more actuators and a memory. The memory stores data into a database and program code that, when executed by the one or more processors, causes the control system to instruct the spacecraft to enter a safing mode. In response to entering the safing mode, the control system instructs the one or more actuators to align a principal axis of the spacecraft with a vector that is normal to the orbit around the celestial body. The control system also instructs the actuators to rotate the spacecraft about the principal axis, where a rotational orientation of the spacecraft relative to the celestial body is shifted by about one-half a rotation about the principal axis.

A controller controls a spacecraft to rendezvous a non-center-of-mass point of the controlled spacecraft with a non-center-of-mass point of an uncontrolled celestial body. The controlled spacecraft and the uncontrolled celestial body form a multi-object celestial system, and the controller produces control commands to thrusters of the controlled spacecraft using a non-linear model predictive control (NMPC) optimizing a cost function over a receding horizon that minimizes an error between coordinates of the non-center-of-mass point of the spacecraft and the non-center-of-mass point of the celestial body subject to joint dynamics of the multi-object celestial system coupled with joint kinematics of the multi-object celestial system.

Technologies for guidance of a spin-stabilized orbital rocket are described herein. The spin-stabilized rocket includes a guidance controller. The guidance controller computes parameters of a burn of a second-stage engine of the rocket to reach a desired nominal orbit subsequent to burnout of the first stage of the rocket. The guidance controller computes the burn parameters of the second-stage engine based upon one or more desired orbit parameters and a current position and velocity of the rocket. The computation of the burn parameters is based upon a simulated point-mass model of the motion of the rocket. The guidance controller then controls the rocket to initiate a second-stage burn having the computed burn parameters.