Dynamic Event-Triggered Fixed-Time Consensus Control and Its Applications to Magnetic Map Construction

This article deals with the consensus problem of multi-agent systems by developing a fixed-time consensus control approach with a dynamic event-triggered rule. First, a new fixedtime stability condition is obtained where the less conservative settling time is given such that the theoretical settling time can well reflect the real consensus time. Second, a dynamic event-triggered rule is designed to decrease the use of chip and network resources where Zeno behaviors can be avoided after consensus is achieved, especially for finite/fixed-time consensus control approaches. Third, in terms of the developed dynamic event-triggered rule, a fixed-time consensus control approach by introducing a new item is proposed to coordinate the multi-agent system to reach consensus. The corresponding stability of the multi-agent system with the proposed control approach and dynamic eventtriggered rule is analyzed based on Lyapunov theory and the fixed-time stability theorem. At last, the effectiveness of the dynamic event-triggered fixed-time consensus control approach is verified by simulations and experiments for the problem of magnetic map construction based on multiple mobile robots.

磁测残余应力方法及特点对比

对几种磁测残余应力的方法和特点进行了归纳对比,它们是巴克豪森效应应力检测方法,利用逆磁致伸缩效应测量应力,利用铁磁类材料的磁记忆检测应力分布,应力致磁各向异性法SMA(Stress-induced Magnetic Anisotropy)和磁致伸缩法(Magnetostriction).从目前研究现状而言,利用Barkhausen效应实施铁磁类结构构件应力检测技术相对来说最为成熟和广泛,但它有自身的缺陷,故又介绍了一台新的磁力仪MAPS,并对MAPS及其他的磁力仪作了比较.

Diagnostic value of magnetocardiography in patients with coronary heart disease and in-stent restenosis

Background In-stent restenosis （ISR） has become one of the most challenging problems in patients with coronary heart disease. At present, using non-invasive methods to assess ISR is a hot topic. In this investigation we attempted to explore the potential of magnetocardiography （MCG） in diagnosis of in-stent restenosis. Methods MCG was analyzed in 52 patients with coronary artery disease for three times： before stenting, one month and 7 months after successful intracoronary stenting. Results The average classification of total maps （ACTM） and the ratio of abnormal maps （RAM） were lower in 1 month after intracoronary stenting compared with that obtained before stent planting （2.91 vs 2.52, 65.74% vs 42.80%, P〈0.01）, while complex ventricular excitation index （CVEI） increased from -42.63 to -20.05 （P〈0.01）. In ISR subgroup （n=16）, RAM decreased in 1 month after intracoronary stenting compared to it before stenting （68.99% vs 45.26%, P〈0.05）. ACTM increased in 7 months compared to that obtained in 1 month after stenting （3.15 vs 2.51, P〈0.05）. According to the ROC curve, ACTM showed its unique diagnostic value in restenosis patients. The sensitivity and specificity of ACTM were 80.0%, 69.40%, respectively. Its positive predictive value and negative predictive value were 54.6% and 88.5%, respectively. Conclusions After successful intracoronary stenting, most parameters of MCG were improved. ACTM was of prognostic value in diagnosing ISR.