Bipartite output synchronization of heterogeneous multiagent systems on signed digraphs

This paper studies the bipartite output synchronization problem of general linear heterogeneous multiagent systems on signed digraphs. We first show that, for heterogeneous multiagent systems, the bipartite output synchronization over the structurally balanced signed digraphs and the conventional output synchronization over the associated nonnegative digraphs are equivalent. Then, 3 different control protocols, using full‐state feedback, static output feedback, and dynamic output feedback are designed at each agent to solve the bipartite output synchronization problem based on solutions to the corresponding output regulator equations. Explicit local design procedures are proposed for all 3 control protocols. The compensators employed in these protocols incorporate only one copy of the virtual exosystem's dynamics, regardless of the dimensions of the outputs. This results in lower‐dimensional compensators and controllers and, hence, is more computationally tractable compared to the popular internal model principle‐based control protocols. Numerical simulations over 3 different signed communication digraphs validate the proposed control protocols.     

基于数据源向图的数据库设计中数据关系的表示工具

数据库设计是信息系统需求分析到系统实现中的一个关键环节。传统的数据库设计方法需根据需求分析阶段的结果,依赖人的构造性思维抽象出对象和关系,由于对所需数据结构和关系的描述能力不足,缺少对数据项之间关系的描述,导致数据关系不明确,数据库设计结果容易出现偏差。在新的数据库设计工具——数据源向图的帮助下,对象、关系以及各数据项之间的关系能被直观、简洁、准确地表示,同时其也能极大地消除各种关系不明确而带来的二义性问题,可有效提高信息系统实现的效率。     

Bipartite output consensus in networked multi-agent systems of high-order power integrators with signed digraph and input noises

In this paper, we concentrate on investigating bipartite output consensus in networked multi-agent systems of high-order power integrators. Systems with power integrator are ubiquitous among weakly coupled, unstable and underactuated mechanical systems. In the presence of input noises, an adaptive disturbance compensator and a technique of adding power integrator are introduced to the complex nonlinear multi-agent systems to reduce the deterioration of system performance. Additionally, due to the existence of negative communication weights among agents, whether bipartite output consensus of high-order power integrators can be achieved remains unknown. Therefore, it is of great importance to study this issue. The underlying idea of designing the distributed controller is to combine the output information of each agent itself and its neighbours, the state feedback within its internal system and input adaptive noise compensator all together. When the signed digraph is structurally balanced, bipartite output consensus can be reached. Finally, numerical simulations are provided to verify the validity of the developed criteria.     

Consensus Control for Directed Networks Under Quantized Information Exchange

In this paper, without assuming balanced network topologies, we address the weighted average consensus problem for discrete‐time single‐integrator multi‐agent systems with logarithmic quantized information communication. By incorporating generalized quadratic Lyapunov function with the discrete‐time Bellman–Gronwall inequality, a new upper bound about the quantization precision parameter of the infinite‐level logarithmic quantizer is derived to design quantized protocol, under which agents in strongly connected directed networks can attain weighted average consensus. The obtained new upper bound clearly characterizes the intimate relation between the quantization precision parameter and the directed network topology. The proposed quantized protocol is particularly applicable to digital networks where balanced message passing among agents is not available.     

网络化拉格朗日系统协调跟踪控制:算法与实验（英文）

This paper considers the coordinated tracking problem for a group of Lagrange systems in the presence of parametric uncertainties. Distributed adaptive controllers are proposed with the aid of Lyapunov techniques. Compared with the previous work in the context of networked Lagrange systems control, the results in this paper are suitable for the general digraph communication topologies. Under the condition that the desired trajectory is only available to a portion of Lagrange systems, we discuss the cooperative tracking problem with general digraph communication topology, which contains a spanning tree with the root node being the active target system. Under the case where the neighbor s velocity is unavailable, a distributed filter is introduced to overcome this deficiency. Experimental results on networked robot-arms are provided to show the effectiveness of the proposed control algorithms.     

Extended Elementary Siphons and Their Application to Liveness‐Enforcement of Generalized Petri Nets

As a significant structural object, siphons are extensively employed to implement a large number of deadlock prevention and liveness‐enforcing methods for flexible manufacturing systems modeled by Petri nets. By linear combinations, a set of elementary siphons is chosen from all strict minimal ones to be controlled and thus the structural complexity of a supervisor is greatly reduced. The concept of elementary siphons is originally proposed for ordinary Petri nets. When applied to generalized Petri nets, their selection and controllability require an additional study. In this work, the concept of augmented siphons is proposed to extend the application of the elementary ones to a class of generalized Petri nets, GLS³PR. Based on graph theory, a siphon extraction algorithm is developed to obtain all strict minimal siphons, from which augmented elementary ones are computed. In addition, the controllability conditions of dependent siphons are developed. Through fully investigating the net structure, especially weight information, the set of augmented elementary siphons is more compact and well suits for generalized Petri net models under consideration. Some examples are used to illustrate the proposed method.     

基于稀疏列表法的新型换流变压器数学模型

稀疏列表法是一种用于建立电网络方程的有效方法,具有能同时求解所有支路电压和支路电流的特性.文章以变压器耦合电路原理为基础,以实际变压器设计参数为依据,并结合新型换流变压器耦合电路的有向图,首次通过稀疏列表法建立了反映新型换流变压器绕组联结特点、电气参数等信息的基本数学模型.通过对基本模型的拓展,建立了更为详细的计及中性点接地阻抗的节点拓展模型和计及二次侧角接三角形绕组抽头处滤波装置的支路拓展模型,便于在实际工程中灵活运用.实际算例验证了所建数学模型的正确性.文章的建模方法输入参数少、简单灵活,对于解决各种复杂多绕组变压器建模问题具有普遍意义.     

Structural properties of Cayley digraphs with applications to mesh and pruned torus interconnection networks

Despite numerous interconnection schemes proposed for distributed multicomputing, systematic studies of classes of interprocessor networks, that offer speed-cost tradeoffs over a wide range, have been few and far in between. A notable exception is the study of Cayley graphs that model a wide array of symmetric networks of theoretical and practical interest. Properties established for all, or for certain subclasses of, Cayley graphs are extremely useful in view of their wide applicability. In this paper, we obtain a number of new relationships between Cayley (di)graphs and their subgraphs and coset graphs with respect to subgroups, focusing in particular on homomorphism between them and on relating their internode distances and diameters. We discuss applications of these results to well-known and useful interconnection networks such as hexagonal and honeycomb meshes as well as certain classes of pruned tori.