Integrating discrete controller synthesis into a reactive programming language compiler

We define a mixed imperative/declarative programming language: declarative contracts are enforced upon imperatively described behaviors. This paper describes the semantics of the language, making use of the notion of Discrete Controller Synthesis (DCS). We target the application domain of adaptive and reconfigurable systems: our language can serve programming closed-loop adaptation controllers, enabling flexible execution of functionalities w.r.t. changing resource and environment conditions. DCS is integrated into a1 programming language compiler, which facilitates its use by users and programmers, performing executable code generation. The tool is concretely built upon the basis of a reactive programming language compiler, where the nodes describe behaviors that can be modeled in terms of transition systems. Our compiler integrates this with a DCS tool, making it a new environment for formal methods. We define the trace semantics of our contracts language, describe its compilation and establish its correctness, and discuss implementation and examples.     

A knowledge-base generating hierarchical fuzzy-neural controller.

We present an innovative fuzzy-neural architecture that is able to automatically generate a knowledge base, in an extractable form, for use in hierarchical knowledge-based controllers. The knowledge base is in the form of a linguistic rule base appropriate for a fuzzy inference system. First, we modify Berenji and Khedkar's (1992) GARIC architecture to enable it to automatically generate a knowledge base; a pseudosupervised learning scheme using reinforcement learning and error backpropagation is employed. Next, we further extend this architecture to a hierarchical controller that is able to generate its own knowledge base. Example applications are provided to underscore its viability.     

A hierarchical model-following controller for certain non-linear systems

In this note a hierarchical solution is developed for non-linear dynamical systems with linear controls. The method involves defining a linear model which incorporates a desirod response for the system and then following this model without using excessive control effort. This latter problem is solved within a two-level structure using a modified pseduo-model coordination method.     

Design of a microprocessor-based process controller using multilevel hierarchical

The problems of replacing existing process controllers with microprocessor-based systems are discussed. A design methodology for implementing a microprocessor-based process control system from an existing design is given, such that strict functional equivalence between the original design and the microprocessor is maintained. The design methodology combines multilevel hierarchical systems and graph theory to deduce a low complexity model of the process control system, which is then analysed and verified interactively on a host computer. The resulting data is formatted and then downloaded into the microprocessor memory of the process controller.     

多模型自适应控制的分层递阶构造与覆盖性质分析

针对一类非最小相位系统,设计一种多模型自适应控制器.该控制器由固定控制器模型、常规自适应模型和可重新赋值自适应模型构成.固定控制器模型采用分层递阶结构用来减少模型集的数目,根据切换指标选出的上一层最优控制器,动态设计本层固定控制器模型实现对其参数变化范围的覆盖.该控制器采用直接自适应算法,通过加权多项式的选取,消除了稳态误差.文末对系统的覆盖性、模型数目等进行了分析.仿真结果表明当采用相同数目的模型时,其控制效果明显优于常规多模型控制器.     

Low order integral-action controller synthesis

A simple controller synthesis method is developed for certain classes of linear, time-invariant, multi-input multi-output plants. The number of poles in each entry of these controllers depends on the number of right-half plane plant zeros, and is independent of the number of poles of the plant to be stabilized. Furthermore, these controllers have integral-action so that they achieve asymptotic tracking of step input references with zero steady-state error. The designed controller’s poles and zeros are all in the stable region with the exception of one pole at the origin for the integral-action design requirement. The freedom available in the design parameters may be used for additional performance objectives, although the only goal here is stabilization and tracking of constant references.     

Simultaneous deadbeat tracking controller synthesis

A direct and simple design algorithm for the problem of simultaneously deadbeat tracking a prespecified class of inputs by only one controller is presented. This novel approach is based on polynomial algebra and the principle of system realizability. Without solving linear polynomial diophantine equations, the proposed procedure consists of solving a set of linear equations depending on system dynamics, and yields the deadbeat controller in a compact form well suited for system with inaccessible states and changeable reference signals. Since all solutions are described in a parametric form, some performance criteria can be easily incorporated as well. Examples are presented to illustrate the usefulness and computational easiness of this simple design algorithm.     

动态分等级量子比特共享协议

量子秘密共享是量子密码研究的一个重要分支,针对多方共享量子比特情况进行研究,提出一个新的动态量子比特共享协议。此协议中,参与共享的成员是分等级的,量子信息的管理者在无需建立新的量子信道的情况下可对秘密重构系统中的参与者进行裁员。裁员后,管理者通过量子操作可以对量子信息进行更新,而剩余的有效参与者无需对自己手中的粒子执行额外操作就可完成新信息重构。此外,还讨论了协议的正确性、安全性及共享成员的等级性。     

Designing a hierarchical fuzzy logic controller using the differential evolution approach

In conventional fuzzy logic controllers, the computational complexity increases with the dimensions of the system variables; the number of rules increases exponentially as the number of system variables increases. Hierarchical fuzzy logic controllers (HFLC) have been introduced to reduce the number of rules to a linear function of system variables. However, the use of hierarchical fuzzy logic controllers raises new issues in the automatic design of controllers, namely the coordination of outputs of sub-controllers at lower levels of the hierarchy. In this paper, a method is described for the automatic design of an HFLC using an evolutionary algorithm called differential evolution (DE).The aim in this paper is to develop a sufficiently versatile method that can be applied to the design of any HFLC architecture. The feasibility of the method is demonstrated by developing a two-stage HFLC for controlling a cart–pole with four state variables. The merits of the method are automatic generation of the HFLC and simplicity as the number of parameters used for encoding the problem are greatly reduced as compared to conventional methods.     

Robust controller synthesis using Kharitonov's theorem

The authors present a method based upon Kharitonov's theorem for synthesizing robustly stabilizing feedback controllers. The approach is based upon a multiple plant model formulation with a quadratic cost functional. Sufficient conditions are obtained for characterizing robustly stabilizing static output feedback (proportional) controllers for MIMO (multiple-input multiple-output) plants with denominator polynomial uncertainty     

MIMO controller synthesis with integral-action integrity

A controller synthesis method is presented for closed-loop stability and asymptotic tracking of step input references with zero steady-state error. Integral-action is achieved in two design steps starting with any stabilizing controller and adding a PID-controller in a configuration that guarantees robust stability and tracking. The proposed design has integral-action integrity, where closed-loop stability is maintained even when any of the proportional, integral, or derivative terms are removed or the entire PID-controller is limited by a constant gain matrix. The integral constant can be switched off when integral-action is not wanted.     

A note on reduced-order controller synthesis

It is proposed that reduced-order controllers for single-input single-output plants may be synthesized by first calculating a controller for some, not necessarily accurate, reduced-order model of the plant, and then refining the controller so as to account for the full plant. The controller refinement is formulated in terms of a model-approximation problem within a feedback loop. Closed-loop stability is then guaranteed provided that the approximation error is below a certain bound     

On-line compositional controller synthesis for AGV

This paper deals with the on-line design of a supervisor to coordinate an automated guided vehicle (AGV) fleet. This supervisor ensures the system safety (no collision) and a good coordination between vehicles (no blocking situations). It is the so-called Wonham-Ramadge supervisor, it is the least restrictive, and ensures controllability and nonblocking. We propose a compositional procedure to resolve this problem allowing an efficient on-line synthesis. A calculation on the fly is made at every attribution of a new mission for an AGV, to actualize the supervisor and adapt it to the new situation. This compositional approach allows to increase the number of AGV taken on compared to the monolithic approach. We show on some tests the efficiency of this method for the on-line synthesis of supervisor to coordinate a fleet of mobile robots for real cases.     

动态分级的并行约束优化进化算法

提出一种动态分级的并行进化算法用于求解约束优化问题。该算法首先利用佳点集方法初始化种群。在进化过程中,将种群个体分为两个子种群,分别用于全局和局部搜索,并根据不同的搜索阶段动态调整各种级别中并行变量的数目。标准测试问题的实验结果表明了该算法的可行性和有效性。     

一种动态分级的混合粒子群优化算法

针对粒子群算法早熟收敛和搜索精度不高的问题,提出一种动态分级的混合粒子群优化算法．该算法采取３种级别的并行粒子群算法,分别用于全局搜索和局部搜索及二者的结合,并根据搜索阶段动态调整各种级别中并行变量的数目．在全局搜索中,将混沌机制引入算法中以增强算法的全局搜索能力;在局部搜索中,采用单纯形法对适应度最优解进行局部寻优．仿真实验表明,该算法比其他优化算法具有更好的性能．     

Non-parametric controller synthesis for NMP plants

A non-parametric method for controller synthesis developed earlier is extended to non-minimum-phase (NMP) plants represented by non-parametric impulse response (IR) models. The authors are not aware of the existence of other non-parametric design techniques for NMP plants. The proposed method borrows ideas from Predictive Control, and its effectiveness is confirmed by design examples.     

Simultaneous stabilization: Universal controller synthesis

We consider the simultaneous stabilization problem for linear time-invariant stationary objects of arbitrary order. For such objects, we formulate numerically verifiable necessary and sufficient simultaneous stabilization conditions and show a constructive algorithm for the construction of a stabilizing controller with minimal restrictions on the structure and parameters of the stabilized objects. We give a general scheme of studying simultaneous stabilizability of a family of objects and analyze in detail a numerical algorithm for finding a stabilizing controller with applied interval analysis. To solve the problem, we use an approach based on the study of affine transformations of controller parameter spaces into the spaces of coefficients of denominators of closed-loop objects.