In this study, the authors present an overview of closed‐loop subspace identification methods found in recent literature. Since a significant number algorithms has appeared over last decade, highlight some key that can be shown to have common origin autoregressive modelling. Many literature are variants on discussed here. aim is give clear more successful presented throughout decade. Furthermore, retrace these and show how they differ. The compared both basis simulation examples real data....

The problems of attitude stabilization and disturbance torque attenuation for a small spacecraft using magnetic actuators is considered solution to the problem in terms optimal periodic control proposed, based on an estimation compensation scheme external disturbances linear time-periodic systems.

The problem of Earth-pointing attitude control for a spacecraft with magnetic actuators is addressed and novel approach to the proposed, which guarantees almost global closed loop stability desired relative equilibrium spacecraft. Precisely, proportional derivative (PD)-like state feedback law employed together suitable adaptation mechanism controller gain. Simulation results are presented, illustrate performance proposed

The problem of deriving MIMO parameter- dependent models for gain-scheduling control design from data generated by local identification experiments is considered and a numerically sound approach proposed, based on subspace ideas combined with the use suitable properties balanced state space realisations. Simulation examples are used to demonstrate performance proposed approach.

The problem of control law design for a small scale quadrotor helicopter is considered. decomposed in an outer (position) loop and inner (attitude) one. An approach based on the flatness property position dynamics proposed, while attitude dealt with by means (almost) globally stabilising law.

Accurate dynamic modeling of helicopter aeromechanics is becoming increasingly important, as progressively stringent requirements are being imposed on rotorcraft control systems. System identification plays an important role effective approach to the problem deriving or fine tuning mathematical models for purposes such handling qualities assessment and system design. In this paper, continuous-time dynamics a small-scale quadrotor considered. More precisely, predictor-based subspace adopted...

The paper is devoted to the design of a control system for attenuation vibrations in main rotor helicopter forward flight. problem can be formulated as one rejecting periodic disturbance known frequency acting at output linear time-periodic system. A solution inspired optimal methods proposed. major preliminary issue estimation characteristics disturbance, which two are worked out. performance obtained assessed by means several simulation trials.

A novel approach to the problem of star identification for spacecraft attitude determination based on data provided by a camera is proposed. The algorithm pattern matching ideas and provides improved reliability with respect similar methods available in literature. achievable performance demonstrated via comparison study two published algorithms

Magnetic torquers are frequently adopted as primary actuators for the attitude control of small satellites in low Earth orbit. Such generate a magnetic dipole which, turn, leads to torques thanks interaction with field Earth. The design laws based on is challenging problem generated by coils instantaneously constrained lie plane orthogonal local direction geomagnetic vector, which varies according current orbital position spacecraft. This implies that regulation formulated over time-varying...

The first task a spacecraft attitude control system must perform after separation from the launcher is to detumble spacecraft, i.e., bring it final condition with sufficiently small angular momentum. Magnetic has been used for decades fulfill this task, typically using so-called b-dot law (in all its variants developed and flown through years). In paper reviewed, novel convergence analysis based on tools averaging theory periodic Lyapunov presented simulation study illustrate results.

This paper addresses the trajectory tracking control problem for underactuated unmanned aerial vehicles (UAVs), with specific focus on thrust-vectoring capabilities. According to different actuation mechanisms, most common UAV platforms can achieve only a partial decoupling of attitude and position tasks. Since is utmost importance applications involving vehicles, we propose scheme in which primary objective. To this end, exploits concept planner, dynamical system through desired reference...

In this paper, the authors propose an UAV-based automatic inspection method for photovoltaic plants analyzing and testing a vision-based guidance developed to purpose. The maintenance of PV represents key aspect profitability in energy production autonomous such systems is promising technology especially large utility-scale where manned techniques have significant limitations terms time, cost performance. light, ad hoc flight control solution investigated exploit available UAV sensor data...

This study deals with the problem of continuous-time model identification and presents two subspace-based algorithms capable dealing data generated by systems operating in closed loop. The are developed reformulating from to equivalent ones which discrete-time subspace techniques can be applied. More precisely, approaches considered, former leading so-called all-pass domain using a bank Laguerre filters applied input–output latter corresponding projection onto an orthonormal basis, again...

We present FAST-Hex, a micro aerial hexarotor platform that allows to seamlessly transit from an under-actuated fully-actuated configuration with only one additional control input, motor synchronously tilts all propellers. The FAST-Hex adapts its between the more efficient but under-actuated, collinear multi-rotors and less efficient, full-pose-tracking, which is attained by non-collinear multi-rotors. On basis of prior work on minimal input configurable vehicle we mainly stress three...

Abstract The problem of the recursive formulation MOESP class subspace identification algorithms is considered and two novel instrumental variable approaches are introduced. first one leads to an RLS‐like implementation, second a gradient type iteration. relative merits both analysed discussed, while simulation results used compare their performance with existing techniques. Copyright © 2004 John Wiley & Sons, Ltd.

In this paper a novel identification algorithm for class of non-linear, possibly parameter varying models is proposed. The based on separable least squares ideas. These are given in the form linear fractional transformation (LFT) where ‘forward’ part represented by conventional regression and ‘feedback’ non-linear map which can take into account scheduling variables available measurement. model be parameterized according to various paradigms, like, e.g. neural network (NN) or general...

A considerable amount of work has been dedicated in the past to problem system identification helicopter flight dynamics, while much less activity oriented goal developing suitable procedures for rotor mainly because difficulties associated with task. This paper shows that subspace and optimization based techniques can be used determine discrete-time linear parameter-varying models have potential provide accurate descriptions (intrinsically time-varying) dynamics a blade. The are presented...