Self-Triggered Consensus Filtering over Asynchronous Communication Sensor Networks

In this paper,a self-triggered consensus filtering is developed for a class of discrete-time distributed filtering systems.Different from existing event-triggered filtering,the self-triggered one does not require to continuously judge the trigger condition at each sampling instant and can save computational burden while achieving good state estimation.The triggering policy is presented for pre-computing the next execution time for measurements according to the filter’s own data and the latest released data of its neighbors at the current time.However,a challenging problem is that data will be asynchronously transmitted within the filtering network because each node self-triggers independently.Therefore,a co-design of the self-triggered policy and asynchronous distributed filter is developed to ensure consensus of the state estimates.Finally,a numerical example is given to illustrate the effectiveness of the consensus filtering approach.

Self-triggered Consensus Control for Linear Multi-agent Systems With Input Saturation

In this paper, we study the consensus problem for a class of linear multi-agent systems(MASs) with consideration of input saturation under the self-triggered mechanism. In the context of discrete-time systems, a self-triggered strategy is developed to determine the time interval between the adjacent triggers. The triggering condition is designed by using the current sampled consensus error. Furthermore, the consensus control protocol is designed by means of a state feedback approach. It is shown that the considered multi-agent systems can reach consensus with the presented algorithm. Some sufficient conditions are proposed in the form of linear matrix inequalities(LMIs) to show the positively invariant property of the domain of attraction(DOA). Moreover, some sufficient conditions of controller synthesis are provided to enlarge the volume of the DOA and obtain the control gain matrix. A numerical example is simulated to demonstrate the effectiveness of the theoretical analysis results.

A low-jitter self-triggered spark-discharge pre-ionization switch: primary research on its breakdown characteristics and working mechanisms

MV pulsed switch plays a key role as the transfer switch in large electromagnetic pulse simulators. To broaden the range of self-triggering time, a novel spark-discharge pre-ionization switch, in which the main gap electric field is superposed at the trigger gap to let the electrons in its spark channel also become initial electrons, is proposed and tested. The design idea is: as electrons in the spark channel of the trigger gap always exist after its breakdown, the injection time of pre-ionization should have a more negligible effect on reducing the switch jitter. The experiment results under pulses with a rise time of ~100 ns support the above assumptions.When the operating voltage is from ~300 to ~800 kV and the self-triggering time is ~45% to~75% of the peak time, the breakdown time delay jitter is less than 2 ns, and the breakdown voltage jitter is smaller than 1.25%. Under specific self-triggering time, the breakdown time delay jitter is less than 1.5 ns, and the breakdown voltage jitter is smaller than 0.8%.

Robust distributed model predictive consensus of discrete-time multi-agent systems:a self-triggered approach

This study investigates the consensus problem of a nonlinear discrete-time multi-agent system(MAS)under bounded additive disturbances.We propose a self-triggered robust distributed model predictive control consensus algorithm.A new cost function is constructed and MAS is coupled through this function.Based on the proposed cost function,a self-triggered mechanism is adopted to reduce the communication load.Furthermore,to overcome additive disturbances,a local minimum-maximum optimization problem under the worst-case scenario is solved iteratively by the model predictive controller of each agent.Sufficient conditions are provided to guarantee the iterative feasibility of the algorithm and the consensus of the closed-loop MAS.For each agent,we provide a concrete form of compatibility constraint and a consensus error terminal region.Numerical examples are provided to illustrate the effectiveness and correctness of the proposed algorithm.

基于级间自触发Marx电路的高压阻尼振荡发生器

为了增大输出电压的同时减小高压阻尼振荡发生器的体积和降低其成本,建立了一种4×4级间自触发Marx结构的阻尼振荡发生器模型。该模型每级的主开关采用基于电容触发方式的串联IGBT模块,只需提供一路隔离信号控制一级放电开关管的导通和关断,通过级间电容实现对相邻级放电管的栅极自动充电和放电,使其导通和关断。该模型提高了Marx单级的工作电压和简化了每级的驱动电路,并且通过加入缓冲电路,解决开关管动态、静态均压问题。基于这种拓扑结构搭建了一台高压阻尼振荡发生器样机,在电感负载上输出16 kV、振荡频率1 MHz的阻尼振荡波形,波形上升时间约为75 ns,重复频率500 Hz。样机体积小巧、工作稳定,验证了该方案的可行性。

动态自触发通信下多智能体输出反馈包容控制

针对群系统通信网络带宽受限问题,提出一种动态自触发通信下有向高阶非线性多智能体输出反馈包容控制方法。首先,针对群系统通信网络带宽受限问题,提出一种新型动态自触发通信机制。与传统事件触发通信机制相比,所提出的动态自触发通信机制具有更大的触发阈值,且无需连续监测系统状态信息,进一步节省系统通信资源和传感器资源。其次,为所有智能个体设计输出反馈控制协议,驱使所有跟随者收敛到由多个领导者围成的动态凸包中,从而实现网络的多领导者包容控制。最后,以高超声速飞行器群系统为例,验证了控制方法的有效性和理论分析的正确性。

T-S模糊系统的自触发有限时间H∞控制

为克服事件触发控制对硬件设备的依赖以及控制策略频繁更新的局限,针对一类不确定Takagi-Sugeno(T-S)模糊系统的有限时间H∞控制问题,引入自触发机制,提出一种基于此机制下只与触发时刻状态有关的模糊控制器设计方法;基于自触发机制并结合有限时间控制的思想,通过设计触发间隔函数、推导并求解线性矩阵不等式(LMI),使得系统在保障稳定性的前提下,系统运动轨迹不会超过一定的界限,并达到所期望H∞性能水平;同时相较于事件触发机制,自触发机制位于系统内部,无需额外硬件设备接收触发信号且只需利用当前的触发状态信息来预测下一触发时刻,在一定程度上进一步降低系统资源成本;此外,利用李亚普诺夫函数对系统稳定性进行了严格分析,并提供一个确保能够防止芝诺现象发生的证明;最后,通过数值仿真、单连杆刚性机器人系统实例仿真两个实验说明所提方法的有效性。

浅析剩余电流动作断路器试验回路设计

围绕GB/T 16917.1标准试验装置条款,探讨剩余电流动作断路器在应用端使用过程中测试按钮操作潜在的安全风险。分析了常规试验回路的安匝数设计及电阻选型,提出了试验回路双断点结构、触发式试验回路及自检式试验回路的设计方案,从而提高用电安全性。

Edims: an event-driven internal memory synchronized readout prototype ASIC chip developed for HFRS-TPC

HFRS(HIAF FRagment Separator) will be the radioactive secondary beam separation line on High-Intensity heavy-ion Accelerator Facility(HIAF) in China. Several TPC detectors, with high count rates, are planned for particle identification and beam monitoring at HFRS. This paper presents an event-driven internal memory and synchronous readout(EDIMS)prototype ASIC chip. The aim is to provide HFRS-TPC with high-precision time and charge measurements with high count rates and a large dynamic range. The first prototype EDIMS chip integrated 16 channels and is fabricated using a 0.18-μm CMOS process. Each channel consists of a charge-sensitive amplifier, fast shaper, slow shaper, peak detect-and-hold circuit, discriminator with time-walk compensation, analog memory, and FIFO. The token ring is used for clock-synchronous readout. The chip is taped and tested.

纳秒脉冲电压下两种自触发开关的设计与实验研究

降低纳秒脉冲电压下气体开关的抖动对电磁脉冲模拟装置输出稳定性具有重要意义。特别在受条件约束、外触发不便的条件下,自触发开关抖动的降低值得关注。设计了两种自触发开关,包含阴极刻槽开关和预电离开关,并搭建了纳秒脉冲实验平台,分别在40 ns、70 ns与120 ns三种脉冲前沿下测量了两种开关的击穿电压、时延等参数,通过数据统计与处理,获得了两种开关的击穿电压及时间抖动。实验结果表明:通过阴极刻槽控制发射或者阴极预电离注入的方式均可有效降低开关的击穿抖动;在三种前沿的脉冲电压下两种开关的击穿抖动均在1~1.8 ns之间;在40 ns和70 ns前沿脉冲作用下,阴极刻槽的开关击穿抖动更低,可小于1.2 ns,击穿电压分散性小于1.29%;在120 ns前沿脉冲作用下,阴极预电离开关击穿抖动更低,可小于1.6 ns。

煤矿井下原位磁控多向保压取心原理与技术

获取煤岩体原位物理力学参数是煤炭资源开发的首要任务,瓦斯原位参数精准测量是实现煤矿安全开采的基本保障。针对煤矿原位瓦斯参数测不准的技术难题,结合煤矿井下取心的技术特点,创新提出基于磁力控制的多向保压取心技术构想。基于复合磁场特性,自主设计了磁控自触发保压控制器,优化了取心触发及密封结构,关键保压构件实现磁控非接触式自触发及自密封,提升保压触发的容错率。自主研制了多向保压取心性能测试平台,基于该平台验证了保压控制器在不同取心角度的良好触发能力及自密封能力。集成磁控保压模块,形成多向保压取心装备,通过实验室测试验证了该装备可在多个方向实现保压取心,且保压能力可以达到6 MPa,满足煤矿保压取心条件。研究成果为深部煤矿多向保压取心提供了技术支持,为保压控制结构设计提供了全新思路。

自触发驱动的双极性脉冲叠加器

为了简化全固态双极性脉冲发生器中多个开关管的同步隔离驱动电路的复杂性,提出了一种自触发驱动的双极性脉冲叠加器。该电路将自触发驱动结构与特殊全桥电路相结合,只需提供2路隔离信号分别控制正、负极性第1级开关管,其他开关管通过自触发驱动电路逐级导通与关断,从而实现双极性高压脉冲输出。对电路的结构设计、工作原理、参数设计进行了分析,并利用Pspice软件对电路的可行性进行了仿真验证。所研制的15级电源样机上的实验结果表明:在10 k?阻性负载上产生了稳定的重频双极性脉冲,正压与负压幅值2~5 kV可调,脉宽1~10μs可调,频率0~1k Hz可调。该脉冲叠加器体积小巧,结构紧凑,可进行模块化设计,为研制小型化脉冲电源提供了技术支持。

欺骗攻击下弹性自触发模型预测控制

针对在欺骗攻击下自触发模型预测控制系统的安全控制问题,本文提出一种基于关键数据保护的弹性自触发模型预测控制(MPC)策略.对比现有的自触发MPC,该方法仅需对少量关键控制样本进行保护,则可保证闭环系统稳定运行,从而有效节省系统资源.首先,基于自触发MPC和欺骗攻击的特征推导标称系统与被攻击系统状态之间的误差上界,从而定量分析出欺骗攻击对系统的损害.然后,通过所获得误差上界和李雅普诺夫定理建立关键数据的选取条件并对其实施保护.最后,严格证明了在仅对关键控制样本实施保护后,被控系统仍可在欺骗攻击下保持稳定.此外,基于移动机器人和弹簧小车系统对所提算法进行了仿真实验,结果表明所提算法能够显著节省保护资源,验证了算法的有效性.

基于背景光抑制的自触发激光测距系统设计

为有效降低背景光对脉冲激光测距系统精度的影响,提出了一种基于背景光抑制的脉冲激光测距系统设计方法。首先基于脉冲激光TOF(time-of-flight)测距原理构建了一套激光测距系统;然后结合采样保持电路实现背景光的抑制;最后基于自触发原理实现激光回波对激光发射器的控制,采用多次测量求取平均值的方法,达到减小测量误差的目的。实验结果表明,该方法能够有效减小测距误差,满足实际测量需求。

考虑通信状态变化的直流微电网分布式事件驱动优化调度

在复杂的通信条件下,若微电网中分布式控制器无法实时监控与相邻控制器的通信状态,则会导致系统控制失稳。为解决该问题,提出一种微电网分布式控制算法。首先,基于一致性原理设计算法,以各节点分布式电源的增量成本作为一致性变量,实现微电网运行经济性最优,并考虑到直流微电网运行实际,降低了算法设计的复杂性。其次,提出一种设备运行模式自切换机制以改进分布式控制算法,分布式控制器可以根据与相邻节点分布式控制器的通信状态调整节点分布式电源的运行模式。然后,引入事件驱动控制技术,通过设计事件驱动条件降低控制过程中的通信频次,减少分布式控制器的能量损耗。最后,通过算例分析验证了所提微电网分布式事件驱动控制算法可以实现系统的经济调度,相较于下垂控制,可以实现设备在额定运行电压上下更小的波动,相较于未改进的分布式控制方法,可以根据通信状态自动调节运行模式,防止系统控制失稳。

基于张力减径机转矩反馈自适应调整CEC触发时间的方法

钢管头尾进入张力减径机的轧制时间的准确性对张力减径机管端壁厚控制模型的准确性至关重要,由于在张力减径机难以安装检测钢管头尾壁厚的传感器形成有效的反馈机制,从而降低了张力减径机管端壁厚控制模型的应用效果。建议引入主电机的转矩作为咬钢和抛钢的反馈判断依据,同时引入钢管的头部尾部跟踪滤掉多余的转矩波动。根据实测的咬钢、抛钢时间,送入队列计算移动平均得到CEC修正值,使得CEC可以在钢管咬钢、抛钢时准确触发,降低钢管头尾切损。该方法在实践中获得验证,切实可行。

基于CPLD的脉冲激光测距飞行时间测量

研制了基于CPLD的脉冲激光测距飞行时间测量系统。CPLD的使用提高了激光测距仪的精度,并且可灵活修改设计,使同一硬件系统可用于不同类型的脉冲激光测距仪的飞行时间测量。此系统结构简单,体积小,可靠性高,非常适合高性能手持式脉冲激光测距仪。

单自触发脉冲激光测距技术

基于自触发脉冲飞行时间激光测距方法,本文提出并系统性的研究了单自触发脉冲激光测距技术(SSTPLR)。根据不同的单自触发方式,提出了反向单自触发和同向单自触发脉冲激光测距技术。设计了各自的实验测距系统,在3m距离范围内,实现了误差分别为0.96mm和0.62mm的激光测距。

500kV固定串补区外故障间隙自触发问题分析

以南方电网2009年4月10日串补间隙自触发故障为例,对串补区外故障间隙自触发问题进行了深入的研究。在详细介绍等离子火花间隙和强制触发型火花间隙构成的基础上,对两类不同结构的间隙触发原理进行了对比、说明。调取并分析该次故障时所涉及不同串补站串补的故障录波,对各间隙触发过程及触发参数进行分析,找出了本次自触发故障中各不同类型间隙所遵守的相同的自触发规律。最后,对串补站的安全稳定运行提出了若干建议。

限流器晶闸管阀自触发保护动作电压阈值设计

为提高串联谐振型故障限流器(series resonant fault current limiter,SRFCL)旁路电路的可靠性,减小谐振电容的氧化锌避雷器(MOV)能量消耗,研究了晶闸管阀自触发保护动作电压阈值设计方法。限流器控制器失灵是最恶劣的故障态,只能依赖晶闸管阀自触发保护即击穿二极管触发晶闸管(break over diode,BOD)。设计了BOD动作时序,从动作时间和避雷器能耗角度分析阈值影响因素。BOD动作电压阈值决定了晶闸管阀过电压保护水平和触发时间。电压阈值设置低,BOD保护会和保护判据竞争;电压阈值设置高,避雷器能耗水平会提高。以华东电网限流器示范工程为背景,建立限流器仿真模型,通过大量仿真计算,总结了电压阈值变化对避雷器能耗水平影响规律,提出了电压阈值设计指标。研究结果对工程设计具有指导意义。