船舶可控被动式减摇水舱的试验研究

可控被动式减摇水舱是一种新型高性能的船舶减摇装置,它是对被动式减摇水舱的一种改进.通过对气体的受力进行分析,推导了气阀的控制方程,在查德惠克U型被动式减摇水舱理论的基础上,建立了"船舶-可控被动式减摇水舱"系统的数学模型,推导了最佳控制策略的理论依据,当横摇角度与边舱液位的相位差成90°时,可控被动式减摇水舱能够得到最大的减摇力矩,减摇效果最佳.通过摇摆台试验确定了水舱模型的固有周期,实现了气阀开启和关闭的最佳控制问题,为实船装备可控被动式减摇水舱提供了试验数据和参考依据.     

船舶自适应逆控制操舵

经典反馈控制将对象动态响应的控制和噪声的消除放在同一个过程中进行,这种方法往往会产生为了满足一个指标而牺牲另外一个指标的矛盾.本文介绍了一种新的控制方法--自适应逆控制,阐述了自适应逆控制的特点,讨论了自适应逆控制系统的三个基本单元--对象建模、逆控制器建模和扰动消除器.自适应逆控制将对象动态响应的控制和噪声的消除分开来考虑,解决了上述经典反馈控制的矛盾.在仿真软件Matlab上进行船舶自动舵仿真时,分别采用了自适应逆控制方案的ELS(增广最小二乘)算法和经典反馈控制的PID(比例积分微分)算法.仿真结果表明了自适应逆控制的优点.     

可控被动式减摇水舱的建模与气阀控制规律研究

基于查德惠克被动式减摇水舱理论,分别建立了单侧气阀和两侧气阀控制的可控被动式减摇水舱系统数学模型.推导了最佳相位关系和气阀控制规律的理论依据,对不规则波作用下的可控被动式减摇水舱系统进行了仿真研究.仿真结果表明,水舱内水的流动与船舶横摇运动基本符合最佳相位关系,气阀控制规律是可行的.通过对单侧或者两侧气阀进行控制,都能够使水舱内水流的振荡周期及时地适应变化的横摇周期.两侧气阀控制的减摇效果要优于单侧气阀控制.     

A new GPS deformation monitoring algorithm applied to Donghai Bridge

A real-time, long-round global positioning system (GPS) bridge-deformation monitoring technology was proposed, which processes the carrier phase of multiple GPS receivers in an operation center. It was demon- strated an extended Kalman filter with triple differential ionospheric-free measurement (EKF-TIF) which can eliminate the ionospheric delay, whiten the TIF noise and optimize the results of EKF, consequently, achieves a better performance than existing real time kinematic (RTK) solution. An experiment, which takes an active ionosphere condition into consideration, proves the feasibility of this system by comparing its records to that of a traditional RTK solution, practically, the system installed on the Donghai Bridge has survived a non-break running for five months. The analysis to the monitoring records shows the system achieves the designed accu- racy and reliability.     

一种新型自动舵控制策略研究

本文基于预测控制的基本思想,利用神经网络技术,提出了一种新型自动舵控制策略。仿真结果表明了其优良性能。     

PID自动舵的自整定专家系统

提出了一种基于专家系统的PID自动舵,利用专家的经验知识和控制规则调节PID控制舵的参数,从而达到对船舶的平稳控制,仿真结果表明控制性能好且实现成本低.     

微机控制的船舶自适应操纵研究

本文在阐述了自适应理论应用于船舶操纵领域的应用以后，结合自己的观点设计了一自校正自适应自动操纵舵系统，并对如何用微型计算机实现进行了探讨，最终由实船海试结果表明该系统具有良好的操纵性。本文最后对自适应操纵的将来发展趋势亦进行了探讨。     

一种新的GPS变形监测算法及其在东海大桥上的应用

在建筑物变形监测中,嵌入GPS实时动态(Real-time Kinematic,RTK)方法的普通双频RTK接收机不能应对基线较长且电离层比较活跃的情况。因此,提出一种基于无电离层三差观测量的扩展Ka1man滤波模型,并通过试验与普通RTK接收机进行比较,证明了其可行性。     

Micro-electro-mechanical-sensor inertial navigation system-assisted global navigation satellite system receiver acquisition scheme and performance evaluation

When an aircraft moves under a low carrier-to-noise ratio (CNR) or at a high speed, increasing the sensitivity of global navigation satellite system (GNSS) receiver is a goal quite hard to achieve. A novel acquisition scheme assisted with micro-electro-mechanical-sensor (MEMS) inertial navigation system (INS) is presented to estimate the Doppler caused by user dynamics relative to each satellite ahead of time. Based on tightly coupled GNSS/INS estimation algorithm, MEMS INS Doppler error that can be achieved is first described. Then, by analyzing the mean acquisition time and signal detection probability, the MEMS INS-assisted acquisition capabilities in cold, warm and hot starts are quantitatively determined and compared with the standard GNSS acquisition capability. The simulations and comparisons have shown that: the acquisition time in cold start can be shortened by at least 23 s, the time in warm start can be shortened to 1 s and the acquisition capability is improved 95%, and the reacquisition time in hot start can be shortened by around 0.090 s and the capability can be enhanced 40%. The results demonstrate the validity of the novel method.     

大深度多普勒计程仪方案研究

多普勒计程仪是一种利用多普勒效应原理制成的自主式测速导航设备。即便在GPS导航高速发展,INS系统已提高到很高精度的今天,多普勒计算仪仍郄有其不可替代的导航作用,尤其在军事领域更是如此。本文简要介绍船用多普勒计程仪的基本原理及其目前的国内外技术动态,列举上海航海仪器总厂多普勒计程仪的技术现状,在此基础上,提出开发大深度多普革计程仪所应解决的关键技术。