This study investigates H-infinity fault-tolerant control for Markov jump systems with actuator time delay. The main objective is to obtain some theorems such that the corresponding Markov jump systems with actuator time delay to be H-infinity stable and with some fault-tolerant performances. First, based on an integral transformation, the Markov jump systems with actuator time delay are described in a system description with a distributed time-delay item. Second, based on utilizing the linear matrix inequality theory, a positive energy functional, which includes a double integral item, is constructed. Then, after some mathematical operations, a sufficient condition is obtained for the Markov jump systems with actuator time delay to be H-infinity stable. If the condition is solvable, faulttolerant controller can be gotten to guarantee the controlled system to be H-infinity stable no matter there are some actuator faults existing in the system or not. Finally, examples are given to show the usefulness of the obtained theorem.

In this paper, considering the difference in social distancing among individuals, according to the extent of social distancing, a group composed of N mobile agents is divided into multiple different subgroups. Especially, from the perspective of differential game theory, the flocking problem of different subgroups can be regarded as collision avoidance between neighboring agents, or obstacle avoidance between agents and virtual static/dynamic obstacles. To explore the internal mechanism of this interesting problem, a novel flocking algorithm with multiple virtual leaders is designed. The proposed algorithm is a modified version of the traditional flocking and semi-flocking algorithms. Based on the Lyapunov stability theorem and LaSalle's invariance principle, the stability analysis of the proposed algorithm is then proven. Furthermore, considering the complex environment that swarm robots or unmanned aerial vehicles (UAVs) may face when performing military missions such as surveillance, reconnaissance, and rescue, etc., we also investigate the flocking problem of multi-agents in both virtual static and dynamic obstacles environment. Finally, three kinds of simulation results are provided to demonstrate the effectiveness of the proposed results.INDEX TERMS Flocking, multi-agent systems, collision avoidance, obstacle avoidance, social distancing.

Concept development is the first and most knowledge-intensive step in the development process of manufacturing technology. Its core is to find a solid scientific foundation for the manufacturing requirements in order to propose a feasible manufacturing technology concept. However, the lack of formal methods and finiteness of personal knowledge result in high randomness and low efficiency of this step. This paper presents a formal design knowledge recommendation method for manufacturing technology concept development by calculating the morphological similarity between manufacturing requirements and multi-domain effect knowledge. In this method, the morphological matrix of general manufacturing technology is constructed first as a template. Then, manufacturing requirements and multi-domain effect knowledge are both expressed as matrices based on this template. Finally, through quantitatively calculating the normalized weighted Euclidean distance between manufacturing requirements and multi-domain effect knowledge, suitable effects of knowledge which are from different domains and have the domain-highest similarity are recommended as the initial design foundation for the concept of new manufacturing technology (NMT). A software system has been developed and a concept development case of composite machining technology was provided to validate this method. The result shows that the proposed approach can reduce the randomness and increase the efficiency of manufacturing technology concept development.

This paper investigates the flocking problem of multi-agents with partial information exchange, which means that only part, but not all, of the agents are informed of the group objective. A distributed flocking model based on the inclusion principle is provided to simplify the design and analysis of multi-agent systems. Furthermore, to reduce the communication energy consumption, an improved flocking algorithm based on the model is proposed to achieve stable flocking for all the agents. The stability of the multi-agent system is then established, with the help of the Lyapunov stability theorem and LaSalle’s invariance principle. Especially, considering the individual heterogeneity in both nature and engineering applications, we also investigate the flocking problem of multi-agents with different sensing radiuses and equilibrium distances. Finally, two kinds of simulation results are presented to demonstrate the validity of the proposed results. This work provides an insight not only into the properties of the different species of individual flocking, but also into the theoretical framework for the engineering design of multi-agent systems considering individual heterogeneity.

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