节点文献
船舶动力定位容错控制方法研究
Research on Fault-tolerant Control Methods for Dynamic Positioning of Ships
【作者】 宁继鹏;
【导师】 付明玉;
【作者基本信息】 哈尔滨工程大学 , 控制理论与控制工程, 2013, 博士
【摘要】 随着人们日益重视对深海的探索和开发,深海装备飞速发展,对船舶动力定位(Dynamic Positioning,DP)系统的依赖性日益提高,使其得到了更广泛的应用,随之而来,对其安全性和可靠性提出了更高的要求,不但要求船舶在进行正常动力定位作业的过程中满足控制性能要求,而且对于某些特殊作业,在出现可接受的故障之后要求仍然能够继续完成作业,甚至满足降低的性能指标,或至少在一定时间内不会发生重大事故。容错控制可提高系统的安全性和可靠性,因此对船舶动力定位进行容错控制是必要的。目前高等级的船舶动力定位系统皆具有物理冗余和解析冗余。在动力定位系统已具备一定物理冗余度的前提下,通过解析冗余充分利用已有冗余关系来实现船舶动力定位的容错控制,可保证船舶在故障情况下仍能持续动力定位作业,同时应尽可能保持原控制器的控制性能和船舶的定位能力,因此研究基于解析冗余的容错控制方法对于船舶动力定位的容错控制具有十分重要的理论和工程意义。本文围绕此前沿性课题,对船舶动力定位作业过程中传感器和推进器故障的诊断方法,以及传感器和推进器故障船舶的动力定位容错控制方法展开了深入研究,提出了基于有向图和支持向量机(Support Vector Machine,SVM)的故障诊断方法,以及基于鲁棒滑模虚拟传感器和鲁棒自适应滑模虚拟执行器的容错控制方法。本文主要完成了以下研究内容:为了对可能发生的故障进行及时诊断,并对故障船舶进行容错控制,同时,真实反映船舶在容错过程中对环境干扰及控制输入的响应特性,根据国内外已公开发表的文献资料,建立了3自由度船舶运动学和动力学模型,环境载荷模型以及推进系统模型,给出了可用于验证容错控制方法的试验船数学模型。为了实现船舶动力定位的传感器故障诊断,利用二叉树分类法将多种故障类型的多分类问题转换为多个二分类问题进行分类,利用差值法对样本数据进行特征提取,将提取后的特征向量作为支持向量机输入,实现故障诊断。仿真结果验证了所提方法可快速、准确、有效地实现传感器故障的检测和隔离。为了实现船舶动力定位的推进器故障诊断,利用有向图相关理论中求解系统结构图的最大匹配算法,得到动力定位船舶及其推进系统中变量与约束间的完全匹配,根据得到的匹配,针对每个推进器的螺距控制和转速控制约束,设计可用于故障诊断的解析冗余关系。提出基于有向图和支持向量机的故障诊断方法,将得到的冗余关系的残差值经过处理后输入支持向量机,使得阈值根据支持向量机学习的结果变化,降低了故障诊断中漏报和误报的概率,在保证了诊断结果完备性的同时,大大提升了故障诊断的分辨率。为了进行传感器故障情况下的船舶动力定位容错控制,提出一种基于滑模观测器和虚拟传感器技术的控制重构策略。设计了虚拟传感器来跟踪故障船舶的运行状态,虚拟传感器的作用等同于故障传感器,通过虚拟传感器的状态来重构故障后的船舶控制回路。结合滑模观测器解决船舶动力定位系统中存在的模型非线性、建模误差、扰动和参数不确定等问题,设计了一种鲁棒滑模虚拟传感器来改善虚拟传感器的适用范围。仿真结果表明所设计的方法可以较好地完成传感器故障的船舶动力定位容错控制。为了进行推进器故障情况下的船舶动力定位容错控制,提出一种基于滑模变结构控制、自适应控制和虚拟执行器技术的控制重构策略。在故障船舶与标称控制器之间设计虚拟执行器来重构船舶,虚拟执行器的作用与故障执行器一致,使得重构后的船舶输出仍然保持正常船舶的输出特征,而无需进行标称控制器的重新调整和重构。结合滑模变结构控制和自适应控制技术解决船舶动力定位系统中存在的模型非线性、建模误差、扰动和参数不确定、不确定项上界未知等问题,设计了一种鲁棒自适应滑模虚拟执行器改善虚拟执行器的适用范围和控制性能。仿真结果表明所设计的方法可以较好地完成推进器故障的船舶动力定位容错控制。本文在物理冗余的基础上,通过解析冗余实现了船舶动力定位的故障诊断和容错控制,从软件层面提高了船舶动力定位的可靠性和安全性,与物理冗余相比提供了更加切实有力的保障。
【Abstract】 As the increasing focus on the exploration and development of the ocean, the deep-seaequipment develops rapidly. The dependence on dynamic positioning system is markedcausing its comprehensive appliance, simultaneously, its security and reliability are requiredstrictly. Control performance must be satisfied in normal dynamic positioning operations,even after occurring fault, some special task must have the ability to continue working withdegraded performance, which insures the system far from serious accident in limited time. Itneeds fault-tolerant control for dynamic positioning of ship which can improve security andreliability of the system.At present, high-level dynamic positioning system of ship all equip physical andanalytical redundancy. With physical redundancy, fault-tolerant control for dynamicpositioning of ship is achieved based on redundancy relationship used by analyticalredundancy, which can ensure durative dynamic positioning operation of ship with fault andhold performance of nominal controller and ability of dynamic positioning of ship. So theresearch of fault-tolerant control method based on analytical redundancy is significative totheory and engineering for dynamic positioning of ship.This paper focused on this frontier subject. Sensor and thruster fault diagnosis method,and sensor and thruster fault-tolerant control method were researched. The fault diagnosismethod based on oriented graph and Support Vector Machine (SVM) was proposed. Thefault-tolerant control method based on virtual sensor with robust sliding mode and virtualactuator with robust adaptive sliding mode were designed.Works achieved in this paper are present as follows.To find the potential fault timely, implement fault-tolerant control for the faulty ship andtruly reflect the ship response characteristics of environmental disturbance and control inputduring the fault-tolerant control process, the3-DOF kinematics and dynamics models of ship,the environmental load model and the propulsion system model were established according tothe literatures. To validate the fault-tolerant control method proposed, the parameters of theship were given.To achieve sensor fault diagnosis for dynamic positioning of ship, binary treeclassification was used to convert multi-classification problem of various fault type to manydimidiate-classifications. The difference method was used to extract feature from the sampling data, then the feature was as the input of SVM. Simulation shows that the methodproposed can achieve the detection of sensor fault quickly and accurately.To achieve thruster fault diagnosis for dynamic positioning of ship, maximum matchingalgorithm from oriented graph theory which can get the structural graph of system was usedto get complete matching between variables and constraints of dynamic positioning ship andpropulsion system. According to the matching, analytical redundancy relation based residualswere designed for constraints of pitch and shaft speed control of each thruster. The faultdiagnosis method based on oriented graph and SVM was proposed, residuals of redundancyrelation were as input of SVM after processing, which make the threshold change with theresult of SVM. The method above can reduce the probability of missing and false alarm,which can insure completeness and improve resolution of fault diagnosis greatly.To achieve fault-tolerant control for dynamic positioning of ship with sensor fault,reconfiguration strategy based on sliding mode observer and virtual sensor technology wasproposed. Virtual sensor was designed to track the state of faulty ship. Virtual sensor isidentical with faulty sensor, which reconfigured control loop of faulty ship from the state ofvirtual sensor. To solve nonlinear, error, disturbance and parameter uncertainties of systemmodel for dynamic positioning of ship, based on sliding mode observer, virtual sensor withrobustness sliding mode was designed to improve the applicability range of virtual sensor.Simulation result shows that the method proposed can well complete the fault-tolerant controlfor the dynamic positioning ship with sensor fault.To achieve fault-tolerant control for dynamic positioning of ship with thruster fault,reconfiguration strategy based on sliding mode control, adaptive control and virtual actuatortechnology was proposed. Virtual actuator was designed between faulty ship and nominalcontroller to reconfigure ship. Virtual actuator is identical with faulty actuator, which makesoutput of reconfigured ship hold the same output feature as nominal ship, insteads ofreadjustment and reconfiguration of nominal controller. To solve nonlinear, error, disturbance,parameter uncertainties and unknown boundary of the uncertainties of system model fordynamic positioning of ship, based on sliding mode control and adaptive control, virtualactuator with robust adaptive sliding mode was designed to improve the applicability rangeand control performance of virtual actuator. Simulation result shows that the method proposedcan well complete the fault-tolerant control for the dynamic positioning ship with thrusterfault.In this paper, with physical redundancy, fault diagnosis and fault-tolerant control fordynamic positioning of ship were achieved by analytical redundancy. Reliability and security of dynamic positioning of ship were improved with standpoint of software, which can providepowerful guarantee compared with physics redundancy indeed.
【Key words】 Dynamic positioning of ships; fault diagnosis; fault tolerant; support vectormachine; oriented graph; sliding mode control; virtual sensor; virtual actuator;