【摘要】：當(dāng)前,無(wú)人機(jī)發(fā)展如火如荼,無(wú)人直升機(jī)由于能夠垂直起降、能夠低速飛行、定點(diǎn)懸停的優(yōu)勢(shì)應(yīng)用更加廣泛,發(fā)展勢(shì)頭更加迅猛。國(guó)際國(guó)內(nèi)各大科研院機(jī)構(gòu)爭(zhēng)相研發(fā)新型無(wú)人直升機(jī),投入到民用或者軍用。但是由于無(wú)人直升機(jī)平臺(tái)的具有強(qiáng)干擾、強(qiáng)振動(dòng)等惡劣的工作環(huán)境。其飛行控制器對(duì)于傳感器的要求較高。一旦發(fā)生傳感器故障,會(huì)導(dǎo)致無(wú)人直升機(jī)的誤控制甚至失控墜機(jī)。所以就出現(xiàn)了針對(duì)無(wú)人直升機(jī)飛行控制系統(tǒng)的傳感器故障診斷與容錯(cuò)控制。無(wú)人直升機(jī)飛行控制系統(tǒng)的傳感器故障診斷與容錯(cuò)控制有很多種方法,目前,最常用的就是傳感器多余度設(shè)計(jì),一旦有傳感器故障就用余度傳感器代替故障傳感器,實(shí)現(xiàn)容錯(cuò)控制。由于無(wú)人直升機(jī)的成本和載重有限,這樣多余度故障診斷與容錯(cuò)控制系統(tǒng)就使其增加了成本,降低了任務(wù)能力。所以本論文提出了一種新的基于解析模型的故障診斷與容錯(cuò)控制方法。該方法只需要一套傳感器就可以實(shí)現(xiàn),大大降低了無(wú)人直升機(jī)的成本。主要的研究過(guò)程如下:首先針對(duì)某型無(wú)人直升機(jī)建立數(shù)學(xué)模型,為后面仿真驗(yàn)證該故障診斷與容錯(cuò)控制方法做準(zhǔn)備。又分析了無(wú)人直升機(jī)IMU模塊傳感器的工作原理,分析并建立了IMU模塊傳感器的常見(jiàn)故障模型。進(jìn)一步提出無(wú)人直升機(jī)飛行控制系統(tǒng)傳感器故障診斷與容錯(cuò)控制方法:利用所建立的無(wú)人直升機(jī)模型,設(shè)計(jì)全維主觀測(cè)器和針對(duì)每個(gè)輸出的降維觀測(cè)器,實(shí)現(xiàn)對(duì)無(wú)人直升機(jī)模型的解耦輸出。求出全維主觀測(cè)器與無(wú)人直升機(jī)模型輸出的主殘差,以及各個(gè)降維觀測(cè)器解耦輸出與無(wú)人直升機(jī)模型輸出的次殘差。先應(yīng)用序貫概率比準(zhǔn)則判斷該主殘差,確定系統(tǒng)是否發(fā)生故障。一旦確定發(fā)生故障,就對(duì)比次殘差,此時(shí)會(huì)發(fā)現(xiàn)只有發(fā)生故障傳感器所對(duì)應(yīng)的那個(gè)降維觀測(cè)器的輸出次殘差變化非常明顯,其他次殘差基本為零。這樣就確定了故障的傳感器,此時(shí)立即隔離故障傳感器,用其他傳感器輸出的加權(quán)值(重構(gòu)信號(hào))來(lái)代替故障傳感器的輸出值。然后將重構(gòu)信號(hào)反饋給無(wú)人直升機(jī)飛行控制器。無(wú)人直升機(jī)飛行控制算法采用滑模變結(jié)構(gòu)控制算法,這樣會(huì)針對(duì)每一種傳感器故障模型切換到相應(yīng)的滑模面進(jìn)行控制,實(shí)現(xiàn)更好的容錯(cuò)控制。最后利用Matlab的GUI環(huán)境建立了一個(gè)簡(jiǎn)單的仿真系統(tǒng),來(lái)完成該算法的仿真驗(yàn)證。仿真時(shí),分別假設(shè)各姿態(tài)角傳感器發(fā)生了故障,以此驗(yàn)證該方法的有效性和實(shí)用性。仿真結(jié)果表明該傳感器故障診斷與容錯(cuò)控制方法可行,且具有比較高的實(shí)時(shí)性。
[Abstract]:At present, the development of UAV is in full swing, unmanned helicopter can take off and land vertically, can fly at low speed, the advantages of fixed-point hovering are more widely used, and the momentum of development is more rapid. Research institutes at home and abroad are scrambling to develop new unmanned helicopters for civilian or military use. However, due to the unmanned helicopter platform has strong interference, strong vibration and other harsh working environment. Its flight controller has higher requirements for sensors. In the event of sensor failure, the unmanned helicopter will be miscontrolled or even out of control. Therefore, sensor fault diagnosis and fault tolerant control for unmanned helicopter flight control system appear. There are many methods of sensor fault diagnosis and fault-tolerant control in unmanned helicopter flight control system. At present, the most commonly used method is the redundancy design of sensors. If there is a sensor fault, the redundant sensor is used to replace the fault sensor. The fault-tolerant control is realized. Because the cost and load of unmanned helicopter are limited, the redundant fault diagnosis and fault tolerant control system increases the cost and reduces the mission capability. Therefore, a new fault diagnosis and fault tolerant control method based on analytic model is proposed in this paper. This method can be realized only by a set of sensors, which greatly reduces the cost of unmanned helicopter. The main research process is as follows: firstly, a mathematical model for a certain unmanned helicopter is established to prepare for the later simulation verification of the fault diagnosis and fault-tolerant control method. The working principle of IMU module sensor of unmanned helicopter is analyzed and the common fault model of IMU module sensor is established. Furthermore, a sensor fault diagnosis and fault tolerant control method for unmanned helicopter flight control system is proposed. Based on the model of unmanned helicopter, a full-dimensional master observer and a reduced-order observer for each output are designed. The decoupling output of unmanned helicopter model is realized. The main residuals of the output of the full-dimensional master observer and the unmanned helicopter model, and the sub-residual of each reduced-order observer decoupling output and the unmanned helicopter model output are calculated. First, the sequential probability ratio criterion is used to judge the principal residual to determine whether the system is faulty or not. Once the fault is determined, the sub-residuals are compared, and it is found that only the output sub-residuals of the reduced-order observer corresponding to the fault sensor are very obvious, and the other sub-residuals are basically zero. In this way, the fault sensor is determined, the fault sensor is isolated immediately, and the output value of the fault sensor is replaced by the weighted value (reconstruction signal) of the output of the other sensors. Then the reconstructed signal is fed back to the unmanned helicopter flight controller. The flight control algorithm of unmanned helicopter adopts sliding mode variable structure control algorithm, which can control each sensor failure model to the corresponding sliding mode surface and realize better fault tolerant control. Finally, a simple simulation system based on the GUI environment of Matlab is established to complete the simulation verification of the algorithm. In the simulation, each attitude angle sensor is assumed to fail, so as to verify the effectiveness and practicability of the proposed method. The simulation results show that the sensor fault diagnosis and fault-tolerant control method is feasible and has high real-time performance.
【學(xué)位授予單位】：南昌航空大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：V279
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本文編號(hào)：2455199