Nonlinear Slewing Control of a Large Flexible Spacecraft Using Reaction Wheels

Abstract

Reorientation maneuvers represent a key task for large satellites. This work considers a space vehicle with solar panels and reaction wheels as actuation devices. Solar panels are modeled as flexural beams, using the modal decomposition technique. An inertia-free nonlinear attitude control algorithm, which enjoys quasi-global stability properties, is employed for the numerical simulation of a large reorientation maneuver. Preliminary analysis with ideal actuation allows sizing the control system and identifying the expected elastic displacements. Then, the actuation dynamics is included, and the actual torque transferred to the vehicle no longer coincides with the commanded one, supplied by the nonlinear control algorithm. Moreover, the solar panels are designed to rotate, in order to maximize the power storage during the maneuver. The numerical results prove that the slewing maneuver is successfully completed in reasonable time and without any saturation of the actuation devices, while the elastic displacements remain modest, in spite of the solar panel rotation aimed at pursuing the Sun direction.

Intersatellite and Downlink Agile Attitude Maneuvers

“…where ω 1 , ω 2 , and ω 3 are the three instantaneous angular velocity components, Ã is a diagonal matrix with elements a i , whereas α 0 and β 0 are two constant parameters, tuned as explained in [21,27], through numerical analysis.…”

Attitude Stabilization of a Satellite with Large Flexible Elements Using On-Board Actuators Only

“…However, the problem of simultaneous angular motion control of the satellite and vibration suppression in flexible elements, by means of actuators and sensors located only on the central body (hub), is still relevant. In this case, the clusters of momentum-exchanging devices are often employed as actuators, such as a system of four pyramid-mounted control moment gyros [1], ortho-skew construction of the four reaction wheels [24], and systems of six reaction wheels [12]. Concerning measuring devices and sensors for the motion estimation of spacecraft with flexible elements, Ivanov et al [25] provided a relevant description as well as an overview of methods for the vibration determination.…”

“…Hence, a reduced (rigid) model of the spacecraft is used to obtain an attitude control law. In this context the following methods are tested: an inertia-free nonlinear attitude control algorithm derived by Sanyal et al [30] and implemented by Posani et al [24]; LQR [5] as well as SDRE techniques; the SDRE algorithm tuned by an input-shaping technique to reduce undesired elastic oscillations [31]. In the present paper, the LQR-PSO strategy is presented.…”