管道在线检测技术及检测机器人研究

概述了管道检测技术发展现状,介绍了最新检测技术的原理,分析了管道内检测机器人的技术要点,概括介绍了课题组在差压式管内检测机器人周围流场建模与仿真、腐蚀环境下管道钢裂纹群演化的混沌动力学、差压式管内检测机器人的通过性能、管内检测机器人运行速度和姿态分析及运动状态控制、管内检测机器人小型化、小型化管内检测机器人检测精度、小型化管内检测机器人定位精度及管道剩余寿命的预测方法等方面的研究进展,为今后的研究打下了坚实的基础。     

多目标跟踪系统测量结果识别算法分析

首先针对多目标自动跟踪问题,对测量结果的两种识别方法和判定规则进行了讨论,给出了目标状态模型、参数模型和探测模型,并对这些模型进行了评估,在此基础上重点分析了多目标自动跟踪状态下基于状态模型参数识别测量结果的算法。最后指出了这种算法的优缺点。     

Workload distribution of discrete‐time parallel queues with two servers

We study discrete‐time, parallel queues with two identical servers. Customers arrive randomly at the system and join the queue with the shortest workload that is defined as the total service time required for the server to complete all the customers in the queue. The arrivals are assumed to follow a geometric distribution and the service times are assumed to have a general distribution. It is a no‐jockeying queue. The two‐dimensional state space is truncated into a banded array. The resulting modified queue is studied using the method of probability generating function (pgf) The workload distribution in steady state is obtained in form of pgf. A special case where the service time is a deterministic constant is further investigated. Numerical examples are illustrated. © 2000 John Wiley & Sons, Inc. Naval Research Logistics 47: 440–454, 2000     

基于扩展状态机的资源泄漏检测方法

基于扩展状态机对资源泄漏故障进行描述,给出了资源泄漏缺陷状态机,定义了缺陷的状态、状态迁移图和状态转换表。设计和实现了资源泄漏检测算法。该算法在对控制流进行遍历的过程中,按照资源泄漏缺陷状态机给出的转换条件进行状态计算,如果计算结果为故障,则报告1个资源泄漏故障。应用该算法对大型开源软件进行测试,发现多个资源泄漏故障。测试结果表明：该算法具有测试效率高和误报率低等特点。     

一类非完整系统的输出反馈控制问题研究

针对一类具有虚拟控制方向和非线性不确定项的非完整系统,研究了其输出反馈控制器的设计问题。采用状态转换技术和反推方法,设计了只依赖于输出值的输出反馈控制器。同时为了处理初值为零的情况,提出了基于第一个子系统输出值的切换控制策略,通过仿真算例说明了控制器的有效性。     

一种基于模型的系统设计方法

提出一种面向功能需求,基于模型的"V"型系统设计方法,通过图形化行为建模技术对系统功能进行分解,运用多种仿真和验证技术,在设计过程中实现对系统功能、行为以及与需求规范的一致性和完整性进行实时验证,及时发现并纠正错误,从而避免在产品的物理原型阶段或测试阶段才发现系统设计的错误.     

基于模型转换的异步空间配准算法

在分布式融合系统中,融合中心在对传感器发送过来的航迹数据进行融合处理前,需要采用空间配准算法来消除航迹数据中可能存在的系统误差.已有的空间配准算法未考虑滤波处理中的状态方程对配准过程的影响.对不同传感器具有不同状态方程条件下的异步空间配准实现进行了研究,采用将模型误差和系统误差合并处理的思路,提出了基于模型转换的异步空间配准(AMCBA)算法.仿真结果表明AMCBA算法能够实现对模型误差和系统误差的准确估计.     

Integrated guidance and control of guided projectile with multiple constraints based on fuzzy adaptive and dynamic surface

Based on fuzzy adaptive and dynamic surface (FADS), an integrated guidance and control (IGC) approach was proposed for large caliber naval gun guided projectile, which was robust to target maneuver, canard dynamic characteristics, and multiple constraints, such as impact angle, limited measurement of line of sight (LOS) angle rate and nonlinear saturation of canard deflection. Initially, a strict feedback cascade model of IGC in longitudinal plane was established, and extended state observer (ESO) was designed to estimate LOS angle rate and uncertain disturbances with unknown boundary inside and outside of system, including aerodynamic parameters perturbation, target maneuver and model errors. Secondly, aiming at zeroing LOS angle tracking error and LOS angle rate in finite time, a nonsingular terminal sliding mode (NTSM) was designed with adaptive exponential reaching law. Furthermore, combining with dynamic surface, which prevented the complex differential of virtual control laws, the fuzzy adaptive systems were designed to approximate observation errors of uncertain disturbances and to reduce chatter of control law. Finally, the adaptive Nussbaum gain function was introduced to compensate nonlinear saturation of canard deflection. The LOS angle tracking error and LOS angle rate were convergent in finite time and whole system states were uniform ultimately bounded, rigorously proven by Lyapunov stability theory. Hardware-in-the-loop simulation (HILS) and digital simulation experiments both showed FADS provided guided projectile with good guidance performance while striking targets with different maneuvering forms.     

考虑落角约束与驾驶仪特性的自适应径向基空间末制导律

为使舰炮制导炮弹在打击近岸机动目标的末制导段满足落角约束,考虑驾驶仪动态特性,基于自适应径向基逼近网络与动态面提出一种空间末制导律。构建弹目相对运动模型,通过带改进微分跟踪器的扩张状态观测器估计目标加速度。为零化视线角跟踪误差与角速率,采用自适应指数趋近律设计非奇异终端滑模,运用自适应径向基逼近网络削弱控制指令抖振。通过Lyapunov第二法证明了系统的视线角跟踪误差与视线角速率均最终一致有界。仿真实验表明:该末制导律使制导炮弹在空间中打击不同机动形式的近岸目标时,具备良好的末制导性能。     

锂电池储能在电磁发射中的应用

随着电磁发射技术的发展,储能环节成为其中不可或缺的一部分。对基本储能单元需求进行分析,以用电系统功率和能量需求为牵引,以储能系统体积重量适装性最优为目标,充分对比现有各类电池参数指标,从安全性、功率密度、能量密度和循环寿命四个方面进行考虑,确定基本储能单元类型为锂电池。面对舰上不同电磁发射设备电压、电流的需求,需要研究能够实现锂电池组快速灵活串并转换的拓扑结构。在实现电池组稳定并联之前,需保证电池组的一致性,因此需计算出电池荷电状态并进行均衡;针对短脉冲大倍率连续放电工况下荷电状态估算不准确的问题,提出以蓄电池组作为研究对象,采用动态辨识方法进行估算。由于各电池组之间存在不一致性,并联起来放电时可能导致输出电流不均衡,使得本来就处于高倍率放电的电池组超限使用,因此将提出一种电池组均流方法来解决此问题。