Characteristic modeling and attitude control for small satellite via variable inertial reaction wheel
With the functional diversification of modern small satellite, new requirements that large range maneuver, high precision control are proposed. Variable inertia reaction wheel (VIRW) is expected to become the mainstream e actuator for attitude control of a new generation small satellite because of the characteristics of high-resolution and large range of torque. First of all, based on the traditional reaction wheel kinetic model, the kinetic model of small satellite control system via the three-axis orthogonal VIRW is deduced, where, the moment of inertia is treated as the variable. Secondly, the change rate of rotational inertia and the angular acceleration of rotational speed of the VIRW are chosen as state variables. And the attitude angles of the satellite are chose as output. And then the feature model of the control system is established. On this basis, the nonlinear golden section control law is designed and the control system of the small satellite with the three-axis orthogonal VIRW is simulated using Matlab. The simulation results show that the control system is stable with good transition, great anti-interference performance, and without stead-error. And it can meet the requirements of the large range attitude mobility and tracking maneuvering target.
Development of a Variable Inertia Reaction Wheel System for Spacecraft Attitude Control
*† * * ‡ Attitude control is an important basic function for most spacecraft. The primary objective of this experiment was to improve the capability and flexibility of a reaction wheel attitude control system by introducing variable inertia reaction wheels. This enhancement might provide at least two advantages: variable precision and vehicle reorientation without changing the reaction wheel angular velocity. To demonstrate these advantages, a prototype of a variable inertia reaction wheel system was flown in a microgravity environment aboard NASA’s KC-135A “Weightless Wonder V” aircraft as a free floating experiment. The data collected during flight suggests the control system performed well, and that a variable inertia system offers increased flexibility in attitude control.
Designing a low-cost spacecraft simulator
The greatest difficulty in implementing spacecraft control laws is that ground-based experiments must take place in a 1g environment, whereas the actual spacecraft will operate under 0g conditions. This article describes a spacecraft simulator facility used to educate undergraduates in spacecraft attitude dynamics and control.