Observer-based multi-objective parametric design for spacecraft with super flexible netted antennas

2021

121

In this paper, high-order fully actuated (HOFA) models with multiple orders for general dynamical control systems are firstly proposed, for which controllers can be easily designed such that the closed-loop systems are constant linear ones with completely assignable eigenstructures. Based on this special feature of the type of HOFA models, controllability of general dynamical control systems is proposed. It is revealed that a general dynamical control system can be represented by a controllable subsystem described by a HOFA model, and an extra uncontrollable one or supplementary one. While a general dynamical control system is called stabilisable if its uncontrollable (autonomous) subsystem does not exist, or is stable in a certain sense. Finally, two parametric design approaches for control of the type of general HOFA models are proposed, which provide all the design degrees of freedom. Several examples, including ones of sub-fully actuated systems, are treated, which demonstrate the effect of the proposed theories.

“…These degrees of freedom can be properly utilised to achieve additional system performance (see, e.g. Duan, 1992Duan, , 1993Duan et al, 2000, 2002, and Duan & Zhao, 2020.…”

Section: Decoupled Designmentioning

confidence: 99%

High-order fully actuated system approaches: part VII. Controllability, stabilisability and parametric designs

2021

121

“…All these degrees of freedom can be further utilised to achieve the additional performance of the system (see, e.g. Duan, 1992Duan, , 1993Duan & Zhao, 2020;Duan et al, 2000Duan et al, , 2002.…”

Section: Solutions Ofmentioning

confidence: 99%

High-order fully actuated system approaches: Part V. Robust adaptive control

2021

123

A type of high-order fully actuated (HOFA) systems with both nonlinear uncertainties and timevarying unknown parameters is considered, and a direct approach for the designs of robust adaptive stabilising controllers and robust adaptive tracking controllers is proposed based on the Lyapunov stability theory. The established controller is composed of three parts, the basic part cancels the known nonlinearities in the system and simultaneously assigns the linear dominant term in the closed-loop system, the robustness part overcomes the effects of the nonlinear uncertainties in the system, and the adaptation part adjusts online the controller to suit the effect of the unknown timevarying parameter vector. The proposed controller guarantees that the tracking error of the state to a given signal and the estimation error of the parameter vector finally converge globally into a bounded ellipsoid. Particularly, in the case that the unknown parameter vector is constant, an adaptive scheme that enables global asymptotical tracking is presented. An example demonstrates the effect of the proposed approach.

“…All these degrees of freedom can be further utilised to achieve additional performance of the system (see, e.g. Duan, 1992Duan, , 1993Duan et al, 2002Duan et al, , 2000Duan & Zhao, 2020. To end this section, we give the following summingup points:…”

Section: The Closed-loop Systemmentioning

confidence: 99%

High-order fully actuated system approaches: Part I. Models and basic procedure

2020

299

The state-space approaches have stayed in an absolutely dominant position in the field of systems and control for over a half century. Although a state-space representation is more suitable for deriving the state-response solution and observation (estimation), it does not provide as much convenience as desired for the control problem. In this paper, the concept of high-order fully actuated (HOFA) systems is firstly revisited, and it is pointed out that HOFA systems serve really as models for control systems rather than representing a small portion of physical control systems. Based on the HOFA model, a basic procedure is proposed for control of nonlinear systems satisfying certain conditions, whose first step converts the nonlinear systems into a pseudo strict-feedback system, and the second step establishes the HOFA model of the system. Once an HOFA model is derived, a controller can be immediately designed to make the closed-loop system a constant linear one with a desired eigenstructure. All the design degrees of freedom existing in the closed-loop system are also provided, which can be further utilised to achieve additional system performance. An example demonstrates the design procedure and shows the effect of the proposed HOFA approach.