This paper focuses on the interaction of manual and automaticcontrol in a demanding task where the process is unstable and has actuator limitation. The problem is inspired by control of high performance aircrafts but...
详细信息
The quality of a model resulting from (black-box) system identification is highly dependent on the quality of the data that is used during the identification procedure. Designing experiments for linear time-invariant ...
详细信息
The quality of a model resulting from (black-box) system identification is highly dependent on the quality of the data that is used during the identification procedure. Designing experiments for linear time-invariant systems is well understood and mainly focuses on the power spectrum of the input signal. Performing experiment design for nonlinear system identification on the other hand remains an open challenge as informativity of the data depends both on the frequency-domain content and on the time-domain evolution of the input signal. Furthermore, as nonlinear system identification is much more sensitive to modeling and extrapolation errors, having experiments that explore the considered operation range of interest is of high importance. Hence, this paper focuses on designing space-filling experiments i.e., experiments that cover the full operation range of interest, for nonlinear dynamical systems that can be represented in a state-space form using a broad set of input signals. The presented experiment design approach can straightforwardly be extended to a wider range of system classes (e.g., NARMAX). The effectiveness of the proposed approach is illustrated on the experiment design for a nonlinear mass-spring-damper system, using a multisine input signal.
This paper describes the phenomenon of integrator windup and various ways of avoiding it. It first covers a number of ad hoc schemes. A general procedure to avoid windup which admits a unification of the ideas is give...
详细信息
This paper describes the phenomenon of integrator windup and various ways of avoiding it. It first covers a number of ad hoc schemes. A general procedure to avoid windup which admits a unification of the ideas is given and the results are illustrated on a number of examples.
In the paper a strategy for discrete-time model identification of linear dynamic subsystem in simple block-oriented nonlinear systems operating under feedback is presented. In the proposed procedure a discrete-time fr...
详细信息
In the paper a strategy for discrete-time model identification of linear dynamic subsystem in simple block-oriented nonlinear systems operating under feedback is presented. In the proposed procedure a discrete-time frequency response of this linear part is identified using integrated bispectra or trispectra. Based on the identified frequency response the corresponding rational parametric approximation is calculated. The nonlinear system is excited by higher-order non-gaussian multisine excitation during identification experiment designed in a special way. The discussion included in the paper is illustrated by simulation examples demonstrating properties and effectiveness of the given approach.
21 years ago it was a joint idea with Hans Rottenkolber to organize a workshop dedicated to the discussion of the latest results in the automatic processing of fringe patterns. This idea was promoted by the insight th...
详细信息
ISBN:
(数字)9783642030512
ISBN:
(纸本)9783642030505;9783642431692
21 years ago it was a joint idea with Hans Rottenkolber to organize a workshop dedicated to the discussion of the latest results in the automatic processing of fringe patterns. This idea was promoted by the insight that automatic and high precision phase measurement techniques will play a key role in all future industrial and scientific applications of optical metrology. A couple of months later more than 50 specialists from East and West met in East Berlin, the capital of the former GDR, to spend 3 days with the discussion of new principles of fringe processing. In the stimulating atmoshere the idea was born to repeat the workshop and to organize the meeting in an olympic schedule. And thus meanwhile 20 years have been passed and we have today Fringe number six. However, such a workshop takes place in a dynamic environment. Therefore the main topics of the previous events were always adapted to the most interesting subjects of the new period. In 1993 the workshop took place in Bremen and was dedicated to new principles of optical shape measurement, setup calibration, phase unwrapping and nondestructive testing, while in 1997 new approaches in multi-sensor metrology, active measurement strategies and hybrid processing technologies played a central role. 2001, the first meeting in the 21st century, was focused to optical methods for micromeasurements, hybrid measurement technologies and new sensor solutions for industrial inspection.
Regarding the mechanical engineering area, over the last 40 years a lot of effort has been undertaken to find very exact descriptions for the dynamic behavior of road vehicles based on mathematical models. All those m...
详细信息
Regarding the mechanical engineering area, over the last 40 years a lot of effort has been undertaken to find very exact descriptions for the dynamic behavior of road vehicles based on mathematical models. All those models include certain parameter values which may be taken from data sheets or which have to be measured or determined by real driving tests. Using these physical models for vehicle simulation purposes, the problem arises, that some of the model parameters are time-variant. They vary over a smaller or larger time period, e.g. due to aging, different vehicle loads or changing environmental conditions like a transition from dry to wet or icy road. Parameter variations lead to systematic modeling errors which makes simulation results turn out incorrect. To overcome that problem, this paper describes the use of hybrid models to reduce modeling errors. Within hybrid models, conventional mathematical process models are combined with adaptive learning structures, e.g. neural networks. In this contribution, an extended radial basis function network called LOLIMOT (local linear model tree) is used to compensate the influences of changing road conditions affecting a vehicle dynamics simulation model.
Airborne wind energy generators aim to produce renewable energy by means of aerodynamic lift from tethered wings controlled to fly crosswind paths. The problem of optimizing the operation of such a generator in presen...
详细信息
ISBN:
(纸本)9781467357159
Airborne wind energy generators aim to produce renewable energy by means of aerodynamic lift from tethered wings controlled to fly crosswind paths. The problem of optimizing the operation of such a generator in presence of limited information on wind speed and direction is considered, aiming to maximize the average power developed. First, a study of the traction force is presented for a general path parametrization. Then, the results of this analysis are exploited to design an algorithm to maximize the force, hence the power, in real-time. The algorithm uses only the measured traction force on the tether, and it is able to adapt the system's operation to maximize the average force with uncertain and time-varying wind. Numerical simulations are presented to highlight the effectiveness of the approach.
This paper presents the application of a statistical method for model structure selection of lift-drag and viscous damping components in ship manoeuvring models. The damping model is posed as a family of linear stocha...
详细信息
Fixed-wing unmanned aerial vehicles(UAVs) fly in a complex environment,which leads to multiple uncertainties in the flight control ***,nonlinear disturbances are inevitable in the dynamics of fixed-wing *** this paper...
详细信息
ISBN:
(数字)9789887581536
ISBN:
(纸本)9781665482561
Fixed-wing unmanned aerial vehicles(UAVs) fly in a complex environment,which leads to multiple uncertainties in the flight control ***,nonlinear disturbances are inevitable in the dynamics of fixed-wing *** this paper,we focus on neural network-based adaptive attitude control for fixed-wing UAVs subjected to stochastic multiple uncertainties and state *** the control scheme,radial basis function neural networks are used to approximate unknown nonlinear uncertainties,which can effectively reduce the adverse impact caused by unknown time-varying disturbances and random *** the signals in the closed-loop system are allowed to be semi-globally uniformly ultimately bounded,and the state constraints are guaranteed by establishing a stochastic Lyapunov *** results show the effectiveness of the proposed control scheme in this paper.
暂无评论