标题: | 非线性积分顺滑模容错控制及其应用 Nonlinear Integral Sliding Mode Fault-Tolerant Control and Its Applications |
作者: | 陈智强 梁耀文 Chen, Chih-Chiang Liang, Yew-Wen 电控工程研究所 |
关键字: | 非线性系统;容错控制;积分顺滑模控制;nonlinear systems;fault-tolerant control;integral sliding mode control |
公开日期: | 2016 |
摘要: | 本论文探讨基于积分顺滑模控制策略之非线性系统主动式容错控制(active fault-tolerant control,active FTC)设计问题。透过对于积分型顺滑模控制设计之改造,我们提出了一种适用于非线性仿射系统(nonlinear affine systems)之积分顺滑模容错控制律(ISMC-based FTC law)。由于现存的积分顺滑模容错控制研究成果仅适用于一类n 组非线性二阶仿射系统(a class of n second-order nonlinear affine systems),故本论文所提出之设计方法涵盖了现存之结果。在所提之控制方法下,受控系统被证明了可保有传统顺滑模控制(sliding mode control)的优点,包含反应快速、易于实现与强韧的稳健特性;再者,我们也证明了在所提出的控制律下,对于每一种容许损坏之情况,匹配型不确定(制动器)错误系统(matched uncertain (actuator) faulty system)的状态响应会与其对应之标称健康子系统(nominal healthy subsystem)的状态响应一致。因此,对于每一种容许损坏之情况,设计者可根据其对应之标称健康子系统之状态性能(state performance)事先地对于不确定错误系统之状态性能进行规范与设计。为了验证所提出之控制方法的有效性,我们将其应用到车辆煞车容错控制的问题上,模拟结果充分验证了所提设计的有效性与特点。 虽然上述所提之积分顺滑模容错控制律能够使得闭回路系统具有理想的状态性能,但其设计必须经过较繁复的程序,即必须针对每一种容许损坏之情况下的标称健康子系统进行控制律设计。为了有效降低设计的复杂度,在此论文的第二部分我们进一步提出了一种改良型积分顺滑模容错控制律(improved ISMC-based FTC law)。在此改良型容错控制方法下,欲达成控制目的所需要的理想控制力(desired control effort)能够被自动地分配到良好无损坏的制动器,藉此降低了设计复杂度,并能使得闭回路系统(closed-loop system)不论处于良好无错误的运作(nominal/fault-free operations)或某些可容许错误之情况(allowably faulty situations)下,其状态响应都会与一个预先选定系统(preselected system)的状态响应十分接近。因此,设计者可事先地预测在各种运作情况下闭回路系统所具有的同一种状态响应;值得注意的是,此项优点在现存的非线性容错控制方法当中较难被达成。最后,所提出之改良型方法也被应用于卫星姿态稳定化容错控制的议题上,并成功地展示了该方法的有效性与优点。 This dissertation addresses the issue of nonlinear active fault-tolerant control (FTC) design using the integral sliding mode control (ISMC) strategy. By revamping the ISMC technique, an ISMC-based FTC law is first proposed for a class of nonlinear affine systems, which covers the existing ISMC-based FTC results because only a class of n second-order systems was considered previously. With the presented scheme, it is shown that the advantages of conventional sliding mode control design can be retained, including rapid response, ease of implementation and high robustness to model uncertainties and/or external disturbances; moreover, the state responses of each matched uncertain allowably (actuator) faulty system and its corresponding nominal healthy subsystem are shown to be identical. As a result, designers can predictively address the state response of each matched uncertain allowably faulty system in light of the performance of its corresponding nominal healthy subsystem, which can be pre-determined. To verify the effectiveness of the proposed FTC scheme, the analytic results are also applied to a vehicle brake FTC system. Simulation results clearly demonstrate the effectiveness and benefits of the presented scheme. Though the aforementioned FTC scheme can achieve satisfactory performances for closed-loop systems, it suffers from a complicated design procedure because it needs to organize the control laws for every nominal healthy subsystems in different allowably faulty condition. To mitigate the design burden, an improved ISMC-based FTC scheme is presented in the second part of the dissertation. The improved scheme not only can simplify the design procedure, but also has the flexibility to preselect a (sub)system and design its control law so that the state responses of closed-loop systems for normal (fault-free) operation and differently allowably (actuator) faulty situations are almost the same as that of the preselected system, because the improved scheme is shown to have the ability to automatically distribute the desired control effort to healthy control channels (actuator). Consequently, designers can predict a same state response of the closed-loop systems regardless of systems’ operation conditions, which is not easy to be realized by existing results. Finally, the improved scheme is also utilized to investigate the fault-tolerant issues of the attitude stabilization control of a spacecraft, and the simulation results clearly show the effectiveness and advantages of the improved FTC scheme. |
URI: | http://etd.lib.nctu.edu.tw/cdrfb3/record/nctu/#GT070080001 http://hdl.handle.net/11536/140189 |
显示于类别: | Thesis |