Extended state observer–based output feedback control for spacecraft pose tracking with control input saturation

Abstract

This article proposed an extended state observer (ESO)–based output feedback control scheme for rigid spacecraft pose tracking without velocity feedback, which accounts for inertial uncertainties, external disturbances, and control input constraints. In this research, the 6-DOF tracking error dynamics is described by the exponential coordinates on SE(3). A novel continuous finite-time ESO is proposed to estimate the velocity information and the compound disturbance, and the estimations are utilized in the control law design. The ESO ensures a finite-time uniform ultimately bounded stability of the observation states, which is proved utilizing the homogeneity method. A non-singular finite-time terminal sliding mode controller based on super-twisting technology is proposed, which would drive spacecraft tracking the desired states. The other two observer-based controllers are also proposed for comparison. The superiorities of the proposed control scheme are demonstrated by theory analyses and numerical simulations.

Design of Particle Swarm Optimization Adaptive Sliding Mode Controller Based on an Extended State Observer for the Longitudinal Motion of a Supercavitating Vehicle with Input Saturation

“…In reality, dynamics uncertainty and the external disturbances induced by ocean currents are huge obstacles to the trajectory tracking accuracy which may cause instability. Many researchers have proposed a diversity of methods to address this kind of control problem in terms of AUV, USV, and spacecraft [18][19][20] other than supercavitating vehicles. In addition, the actuators of a supercavitating vehicle unlikely provide unlimited control inputs, and the limitation of physical input saturation always leads to the undesirable inaccuracy [21,22].…”

A 6-DOF extended state observer–based adaptive generalized super twisting algorithm of fault-tolerant control for coupled spacecraft with actuator saturation

“…Since the Lie group SE(3) can describe the translational and rotational motions of a rigid body compactly, so the 6-DOF kinematics and dynamics of a single rigid spacecraft can be described on the Lie group SE(3) by the authors of Ref. 19 aswhere g=[bold-italicRbold-italicbbold01×31]∈SE(3) is an element in SE(3), R∈SO(3) is the rotation matrix that describes the relative orientation from the body-fixed frame of the spacecraft to the ECI frame, and b∈ℝ3 is the position vector expressed in bold-italicϒI. ξ=[bold-italicvTbold-italicωT]T∈ℝ6 is the unified velocity vector, including the translation velocity bold-italicv and angular velocity bold-italicω, where bold-italicξ˄=[bold-italicω˄bold-italicvbold01…”

“…Among these algorithms, when it concerned about the spacecraft attitude dynamics, Euler angles, modified Rodrigues parameters (MRPs), and quaternions will lead to the unwinding problem because that two different quaternions correspond to the same attitude. 19,20 Since the Special Orthogonal Group SO(3) can describe the spacecraft attitude globally and uniquely, so some researchers have devoted effort to the special Euclidean group SE (3), which can unify the 3-dimensional translation and SO(3) of a rigid body compactly. 8,21 Although some works related to the translational and rotational dynamics control of the spacecraft have been done, there are several significant issues in applications need to be further taken into consideration.…”

Observer-Based Robust Finite-Time Trajectory Tracking Control for a Stratospheric Satellite Subject to External Disturbance and Actuator Saturation

“…In general, due to the limitations of the stratospheric satellite sensors, the exact velocity states are difficult to measure by sensors precisely, and only the system output is available, including the position, attitude, and control input [32]. State observer can be utilized to online estimate the values of the velocity states, which can substantially reduce the cost, size, weight, and even noise of measuring them physically by using sensors [33][34][35]. Therefore, it is rather significant to design a suitable state observer to offer the necessary information to the controller design, and many researchers have done much work.…”