【作者】 曾智刚；

【导师】 陈国华；

【作者基本信息】 华南理工大学 ， 机械设计及理论， 2010， 博士

【摘要】 本研究拟构造一个具有升沉运动补偿功能的波浪补偿模型平台,通过一定的控制策略驱动液压系统进行广义升沉运动补偿,使平台的广义升沉运动幅值较舰船甲板的广义升沉运动幅值大幅度降低,使得在海上航行的船舶具有一局部区域,能够克服船舶在恶劣海况下由于波浪作用而产生的横摇运动、纵摇运动、升沉运动以及这些运动互相耦合的影响,保持与运动船舶的相对平稳。如直升机起降平台、船舶之间的货物补给甚至是作战舰艇上的导弹补给、海底电缆和管道的铺设和深海采矿作业系统等,从而提高海上作业的安全性和工作效率。本文采用理论研究、计算机仿真和模型试验相结合的研究方法对平台升沉运动补偿系统进行研究。主要研究工作包括:升沉补偿系统的建立,通过耐波理论和试验分析,利用电液比例技术建立了船舶试验模型、船舶运动模拟系统模型和升沉补偿系统模型,为后续关键问题研究提供试验平台。船舶运动数据的获取、预处理及可用性提高;本文建立了基于FFT时频转换的频域积分方法结合滤波技术以及积分结果趋势项去除技术来处理加速度信号积分问题的处理方案,解决了波浪补偿稳定平台随船运动响应所测得的加速度信号通过时域直接积分变换为位移信号时不可用的缺陷,同时减少了积分耗时,能够获得比较满意的波浪补偿稳定平台的响应位移,为进一步实现波浪补偿平台的升沉补偿奠定了基础。建立本系统电液比例阀控缸机构模型及升沉补偿系统数学模型,在原电液比例阀控缸的机理模型基础上,使用系统辨识技术分别建立了电液比例阀控缸机构的差分方程模型和NARMAX模型,并对两类建模方案进行了对比分析和试验研究。构建“新息-贡献”准则和矩阵求逆定理的双向回归递推识别算法只需通过少量的运算就可同时得到模型的结构和参数,从而得到最优多项式NARMAX模型,对系统的运动机构进行了详细的受力分析和联合建模,得到了各机构相互的位移-力数学关系。通过船舶模型预报试验,对广义升沉运动预报的有效性及仿真预报结果进行分析。构建以时间差分(TD)方法和动态反向传播(DBP)算法相结合的网络学习算法(TD-DBP学习算法)来克服BP算法不能对Elman网络进行直接在线训练的局限性,实现Elman网络的在线渐进训练。分别验证了、基于AR模型的实时多步预报算法、基于具有艏前波观测量的ARMA模型的实时多步预报算法和基于PAR模型的实时多步预报算法,比较了时间序列分析法的几种不同模型的实时预报算法(包括非线性模型PAR模型)。船舶运动模拟系统和升沉补偿系统的仿真以及控制策略研究,在仿真实验的基础上采用了前馈和反馈相结合的控制方法,使系统响应加快,补偿精度增加;位移协调控制策略的引入,限制了液压缸运动步调不一致造成的各液压缸间矛盾力的产生;力反馈控制策略则有利于系统振荡的衰减和力的协调;预测控制解决大滞后、大惯量等问题。针对各种控制算法,并对其控制效果进行了分析和研究。更多还原

【Abstract】 The dissertation focuses on building a wave compensation hydraulic platform which has the generalized heave motion compensation function. The generalized heave motion amplitude of platform will decline more than the deck’s generalized heave motion by hydraulic system. So there will be a local zone on the ship, which can overcome the impact of ship movement (rolling, pitching and heaving) and keep the relative balance of the ships. Thereby, the system can enhance work efficiency and the safety of jobs , such as landing platform of shipborne helicopters, cargo replenishment between ships, missilery replenishment of warship, and abyssal mining.The research is carried out by theory analysis, computer simulation and model test in the dissertation. The main problems that will be solved in this paper are as the following:Scheme design of the heave compensation platform system is completed by using the electro-hydraulic proportional technique after seakeeping capability testing, arranged for afterward research.Data acquisition、pretreatment and usability enhancing of ship movement. This paper builds up a processing scheme of acceleration signal integral based on frequency domain integral of FFT time-frenquency transforming blending filter technique and polynomial trend eliminating. We solve the problem of acceleration signal transform to displacement signal, which is not available by time domain integral, and condenses the integral time consuming, and establishes the basement for afterward research.The mathematic model of the heave compensation experimental system is established in the paper. A differential equation and an NARMAX model are set up according to system identification theory and combining with experimental data. This paper applies a two-way recursive identification algorithm based on equal dimension new information and inverse matrix calculation to determine the parameters of the optimal NARMAX model only by littleness arithmetic labor. After force analysis and Joint Modeling for moving mechanism of the system, we get displacement-force mathematical relation of the system.Using time series analysis to forecast generalized heave motion, a real-time multi-step prediction algorithm based on auto-regressive model (AR model), a real-time multi-step prediction algorithm based on auto-regressive moving average model (ARMA model) and a real-time multi-step prediction algorithm based on nonlinear polynomial auto-regressive model (PAR model) are analyzed and compared .A multiplex controller, combining feedforward and feedback control strategy, can improve the compensating precision of the heave compensation system. The displacement coordination control strategy can suppress the inconsistent forces that result from the inconsistent movements of the cylinders. The force feedback control strategy is advantaged for attenuation of oscillations and coordination of forces. A predictive control scheme can effectively solve the big delay problem of the heave compensation system.更多还原