Control design for integrator hybrid systems

The authors define controllability for hybrid systems as the existence of correct control laws that transfer the hybrid plant between predefined subsets of the hybrid state space. A methodology for analyzing controllability and synthesizing control laws for a class of hybrid systems, applicable especially in batch control, is proposed. They use a framework consisting of a hybrid plant and a hybrid controller that interact in a feedback fashion     

On consensus algorithms design for double integrator dynamics

This paper considers the consensus problem of double integrator multi-agent systems where: (i) each agent is subject to input saturations, and (ii) the velocity (second state) of each agent is not available for feedback. We present new consensus algorithms that handle simultaneously the above mentioned situations. Sufficient conditions are derived such that consensus algorithms developed for first- and second-order multi-agent systems in ideal situations can be used to account for input saturations and remove the requirement of velocity measurements. To illustrate the effectiveness of the proposed approach, we propose solutions to two different second-order consensus problems in the case where the input is saturated and the velocity states are not available for feedback and simulation results are provided in each case.     

Delayed static output feedback control of a network of double integrator agents

This paper considers a network of vehicles moving in a two dimensional plane. The overall network, described by a collection of double integrator dynamics, is controlled by a novel distributed static output feedback methodology to maintain a desired formation. The distributed control architecture stabilizes the network using static output feedback of position information only, by exploiting delays in communication of the relative information. An optimization algorithm, based on Linear Matrix Inequalities together with the DIRECT search algorithm, is used to synthesize the controller gains and the delay.     

Optimal input design for an AR model with output constraints

The output power constraint problem of optimal input design for parameter estimation for an autoregressive model is considered. A simple method to obtain an optimal design by solving two sets of $\text{p}\text{2-}\text{linear}$ simultaneous equations and a polynomial equation of $\text{p}\text{2}\text{th}$ order is proposed and two nontrivial examples are given to illustrate this methodology.     

Adding an integrator for the stabilization problem

We study the relationship between the following two properties: P1: The system is locally asymptotically stabilizable; and P2: The system is locally asymptotically stabilizable; where . Dayawansa, Martin and Knowles have proved that these properties are equivalent if the dimension n = 1. Here, using the so called Control Lyapunov function approach, (a) we propose another more constructive and somewhat simpler proof of Dayawansa, Martin and Knowles's result; (b) we show that, in general, P1 does not imply P2 for dimensions n larger than 1; (c) we prove that P2 implies P1 if some extra assumptions are added like homogeneity of the system. By using the latter result recursively, we obtain a sufficient condition for the local asymptotic stabilizability of systems in a triangular form.     

Optimal design and implementation of compact fractional order microwave integrator

The implementation of novel, stable, accurate, and wideband infinite impulse response fractional order microwave integrators (FOMIs) is presented. The formulation of FOMIs is employed with equal length line elements in cascading. The optimum values of characteristic impedances of the line elements are determined by approximation to the ideal fractional order integrator (FOI). The hybrid algorithm (HPSO‐GSA) combining particle swarm optimization (PSO) and gravitational search algorithm (GSA) which integrates PSO's exploitation and GSA's exploration ability is used. The comparison of HPSO‐GSA with PSO and GSA is carried out for the proposed FOMIs. The performance criteria used are magnitude response, absolute magnitude error, phase response, pole‐zero response, percentage improvement graph, and convergence rate. The simulation analysis affirms the superiority of proposed FOMI using HPSO‐GSA. The absolute magnitude error of proposed 0.5 order HPSO‐GSA‐based FOMI is as low as 0.9436. The structure of the designed FOI is implemented with microstrip configuration on RT/Duroid substrate with permittivity 2.2 and thickness 0.762 mm that is eligible for wideband microwave integrator. The designed FOMI is compact in size and suitable to cover microwave applications. The measured results are established in fine agreement with simulation results in the frequency range of 2‐9 GHz in MATLAB and Advanced Design Software environment.     

Convergence properties of an optimal filter design with correlated output noise

This note studies the convergence and stability properties of an optimal filter for systems with Markov measurement noise. The convergence and stability conditions for the design analyzed are the same as those for the optimal f'dter when the measurement noise is assumed to be a nonsingular white noise process.     

基于加幂积分方法的制导控制一体化设计

针对高超声速飞行器纵向制导控制一体化设计问题展开研究.首先建立纵向制导与控制系统一体化设计模型;然后结合非线性干扰观测器与加幂积分方法设计制导与控制一体化算法,并借助相关基础理论证明级联系统是全局有限时间稳定的.所提出的方法可以使制导与控制系统协调配合,更充分地利用飞行器控制能力.通过与反步滑模制导控制一体化设计方法进行对比仿真,验证了该方法有效且更具优势,并通过模拟外扰及参数拉偏情况下的仿真验证了所提出方法亦具备较强的鲁棒性.     

A generic object-oriented design methodology incorporating database considerations

Generic lifecycle methodologies for object-oriented development have, to date, not given serious consideration to the need for persistence; either in terms of storage of objects in a relational database or in an objectbase. Here, consideration of traditional staged database design methodologies identifies features currently lacking in object-oriented lifecycle methodologies. A new generic methodology (or metamethodology) is proposed which offers more complete support for an information systems development involving persistent objects.     

Collaborative intelligent CAD framework incorporating design history tracking algorithm

This paper shows a new and efficient collaborative intelligent Computer Aided Design (CAD) framework in a theoretical study. While other collaborative CAD frameworks or protocols focus on decreasing the waiting time for updating design or communication methods for design review among collaborative designers, the suggested collaborative design protocol determines the next design ownership criterion with the objective of minimizing redundant design stages and design bottlenecks using the design history. In addition, the suggested framework generates an efficient reverse-engineered process for achieving the final design target with identification of redundant designs and how these can be prevented while resolving other existing collaborative design issues. As a design history mechanism, a feature-based design history tracking algorithm is suggested. In each design stage, the modeling activities are mapped to the related geometry and topology information. This information is reasoned into features using the feature design history graph (FDHG) and modified attribute adjacency graph (MAAG). The identified features are utilized for determining the redundant design stage and how it can be changed efficiently using the tracking algorithm. As the size of the design history increases with the number of collaborative designers and their design stages, this design history mechanism contributes to a decrease in size and captures the characteristics of design using features. As possible directions for future research this suggested framework can provide an insight into the design tendencies of designers and also be used as a reference model for intelligent CAD systems with an extracted design history-based knowledge database.     

output feedback control design for uncertain fuzzy singularly perturbed systems: an LMI approach

This paper examines the problem of designing a robust H_∞ output feedback controller for a class of singularly perturbed systems described by a Takagi–Sugeno fuzzy model. Based on a linear matrix inequality (LMI) approach, LMI-based sufficient conditions for the uncertain singularly perturbed nonlinear systems to have an H_∞ performance are derived. To eliminate the ill-conditioning caused by the interaction of slow and fast dynamic modes, solutions to the problem are presented in terms of LMIs which are independent of the singular perturbation . The proposed approach does not involve the separation of states into slow and fast ones and it can be applied not only to standard, but also to nonstandard singularly perturbed nonlinear systems. A numerical example is provided to illustrate the design developed in this paper.     

Subclass problem-dependent design for error-correcting output codes

A common way to model multi-class classification problems is by means of Error-Correcting Output Codes (ECOC). Given a multi-class problem, the ECOC technique designs a code word for each class, where each position of the code identifies the membership of the class for a given binary problem. A classification decision is obtained by assigning the label of the class with the closest code. One of the main requirements of the ECOC design is that the base classifier is capable of splitting each sub-group of classes from each binary problem. However, we can not guarantee that a linear classifier model convex regions. Furthermore, non-linear classifiers also fail to manage some type of surfaces. In this paper, we present a novel strategy to model multi-class classification problems using sub-class information in the ECOC framework. Complex problems are solved by splitting the original set of classes into sub-classes, and embedding the binary problems in a problem-dependent ECOC design. Experimental results show that the proposed splitting procedure yields a better performance when the class overlap or the distribution of the training objects conceil the decision boundaries for the base classifier. The results are even more significant when one has a sufficiently large training size.     

Robust output feedback controller: indirect design

In this sequel (see Chen 1987), two classes of controllers are constructed for uncertain dynamical systems using measured output via an indirect design approach.     

Interactive structural design with computer graphical output

A study has been made of cost patterns of precast concrete portal framed buildings. Studies carried out into fabrication, haulage, foundations, cladding and erection have been used to develop a Cost Model Computer Program. Data describing the structure is input into this Cost Model and the resulting overall cost is used to generate cost contour maps for precast concrete portal framed buildings. The Cost Model program is interfaced with a computer graphical system which enables engineering drawings and bar bending schedules to be output interactively.     

Robust output feedback controller: direct design

A class of dynamical systems in which the system and input matrices, as well as the output, are uncertain, is considered. A class of controllers, utilizing the measured output, to cope with the uncertainties is presented. This control, based on the direct design approach, renders the systems practically stable for uncertainties with known bounds. The theoretical results are illustrated by an example.     

带记忆比例–积分–时滞输出滑模控制器设计

传统的比例–积分–微分(PID)滑模控制具有高频测量噪声鲁棒性差、参数整定方法复杂等缺点. 针对上述问题, 本文设计了一种基于带记忆输出反馈的比例–积分–滞后(PIR)滑模控制器, 并提出了基于频域分析的控制器参数自整定方法. 在控制器选型上, 将“带记忆”反馈机制引入到滑模面设计中, 提高滑模面的平滑滤波和高频噪声抑制能力. 首先, 基于PIR滑模面设计了等效控制律, 实现输出反馈下的闭环系统的滑模态稳定. 其次, 分析了基于输出反馈的PIR滑模面的有限时间可达性, 确保系统在存在匹配扰动时仍保持良好的鲁棒性. 最后, 在控制器参数整定方面, 通过迭代消除法消去时滞项在闭环特征方程中的影响, 同时基于衰减速率对系统进行极点配置, 实现PIR参数的在线自整定. 仿真结果表明, 该整定方法能够保证闭环二阶系统具有良好的鲁棒性和抗干扰性能.     

An evolutionary approach to incorporating intradepartmental flow into facilities design

Minimizing material transportation is an important design object for many facilities. In traditional facility design, departments and work centers have been located based on interdepartmental flow patterns. We introduce a methodology that extends the planning process to also consider intradepartmental flow patterns. A math programming approach is developed that uses an objective function and constraints that specifically addresses both the intradepartmental and the interdepartmental material flows together. The math programming approach can be used to solve small problems but it is difficult to scale this method to problems with realistic sizes. Therefore, we devise an evolutionary optimization methodology for this same problem. The evolutionary method can readily solve both large and small problems. The effectiveness of the evolutionary approach is demonstrated on a suite of test problems.     

Parallel implementation of an adaptive and parameter-free N-body integrator

Previously, Pruett et al. (2003) [3] described an N-body integrator of arbitrarily high order M with an asymptotic operation count of O(M²N²). The algorithm's structure lends itself readily to data parallelization, which we document and demonstrate here in the integration of point-mass systems subject to Newtonian gravitation. High order is shown to benefit parallel efficiency. The resulting N-body integrator is robust, parameter-free, highly accurate, and adaptive in both time-step and order. Moreover, it exhibits linear speedup on distributed parallel processors, provided that each processor is assigned at least a handful of bodies.

Program summary

Program title: PNB.f90Catalogue identifier: AEIK_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEIK_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC license, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 3052No. of bytes in distributed program, including test data, etc.: 68 600Distribution format: tar.gzProgramming language: Fortran 90 and OpenMPIComputer: All shared or distributed memory parallel processorsOperating system: Unix/LinuxHas the code been vectorized or parallelized?: The code has been parallelized but has not been explicitly vectorized.RAM: Dependent upon NClassification: 4.3, 4.12, 6.5Nature of problem: High accuracy numerical evaluation of trajectories of N point masses each subject to Newtonian gravitation.Solution method: Parallel and adaptive extrapolation in time via power series of arbitrary degree.Running time: 5.1 s for the demo program supplied with the package.     

Decentralized adaptive output feedback design for large-scalenonlinear systems

In this paper, we present a global, decentralized adaptive design procedure for a class of large-scale nonlinear systems, which utilizes only local output feedback. The advocated scheme guarantees robustness to parametric and dynamic uncertainties in the interconnections and also rejects any bounded disturbances entering the system. The systems belonging to this class are those which can be transformed using a global diffeomorphism to the output feedback canonical form, where the interconnections are a function of subsystem outputs only. The uncertainties are assumed to be bounded by an unknown pth-order polynomial in the outputs. The resulting controller maintains global robustness and disturbance rejection properties. The output tracking error is shown to be bounded within a compact set, the size of which can be made arbitrarily small by appropriate choice of the control gains. For the case where the objective is regulation, global asymptotic regulation of all the states of the closed-loop system is achieved