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1.
A simplified version of the dedicated observer scheme for detecting incipient instrument failures in automatic systems is presented. This scheme requires only a single observer, driven by a single instrument. Simple logical combinations of estimated instrument outputs from the observer with the actual instrument outputs allow small faults in all the instruments to be detected. Tests on a simulation of a practical system indicate the scheme is robust with respect to a small uncertainty in a dynamic parameter of the controlled plant. 相似文献
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飞机全电刹车机电作动系统上电自检测 总被引:1,自引:0,他引:1
提出了一种飞机全电刹车机电作动(EMA)系统的上电自检测(POST)方法,以保证系统在运行前处于安全工作区域。通过检测,可及时准确地定位和更换故障部件,提高飞机出勤率。在系统运行之前,尽可能在有限的检测次数内全面准确地检测敏感元件,定位故障部件,避免造成刹车系统的二次伤害。针对逆变器和电机三相绕组组成的驱动回路,利用母线电容放电产生电流,完成检测。检测过程利用电容电压而非电源为逆变器供电,可防止过高的短路电流对电源的冲击,且电容上存储的能量有限,可有效避免短路故障对系统的二次伤害。检测方法在原有电路的基础上并未增加传感器和检测电路,但实现了逆变器功率管以及电机绕组,短路和开路故障的全面检测,且可定位出故障部件和故障原因。该机电作动系统上电自检测方法能够保证在一秒内完成系统全面自检测,经过1 000次正常及带故障试验,故障的误报率和漏报率保持在1‰以下。在现场试验中,系统可抵御飞机复杂的电磁环境(EME),工作性能稳定。通过软件设置不同故障阈值,可方便移植到其他机电作动系统中。 相似文献
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Sensor faults are detected in an operating automatic system by a simplified version of the dedicated observer scheme. Control inputs are augmented by a random disturbance of moderate intensity. The dedicated observer in this case is a Kalman filter, driven by a single sensor. This filter provides estimates of the outputs from the other, nonredundant, sensors. A logical combination of these functionally redundant signals with the actual sensor signals provides prompt detection of incipient faults on all instruments without false alarms. The scheme is applied to a simulation of the lateral axis control system of a hydrofoil boat in which four sensors are to be covered by the fault detection scheme. Tests indicate that the scheme is robust with respect to variations in the intensity of the random disturbance. 相似文献
4.
针对传统卫星导航接收机在卫星数小于5颗及卫星星座构型不佳的情况下无法实现卫星故障识别与隔离的问题,结合卫星导航接收机在弹上的实际应用情况,利用惯导的辅助数据设计了一种基于多级Kalman滤波的北斗接收机完好性监测方案,给出了卫星导航接收机的RAIM滤波器结构与故障检测和隔离方法,并对其可用性进行了推导。该方案经过仿真分析及实验测试,结果表明在4颗可见星的条件下,可有效检测并隔离单星阶跃、慢速漂移、慢速随机等北斗卫星伪距和伪距率故障,从而使北斗接收机能够提供连续、精确的导航定位功能。 相似文献
5.
A procedure is presented for the design of a pair of sensitivity discriminating Luenberger observers for instrument failure detection (IFD). The proposed IFD scheme permits detection of instrument malfunctions with reduced sensitivity to process parameter variations. The efficiency of detecting instrument malfunctions and the influence of parameter variations are illustrated with an example. 相似文献
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Adaptive fault-tolerant attitude tracking control for spacecraft with time-varying inertia uncertainties 总被引:1,自引:0,他引:1
This paper is devoted to adaptive attitude tracking control for rigid spacecraft in the presence of parametric uncertainties, actuator faults and external disturbance. Specifically, a dynamic model is established based on one-tank spacecraft, which explicitly takes into account changing Center of Mass(CM). Then, a control scheme is proposed to achieve attitude tracking.Benefiting from explicitly considering the changing CM during the controller design process, the proposed scheme possesses good robustness to parametric uncertainties with less fuel consumption.Moreover, a fault-tolerant control algorithm is proposed to accommodate actuator faults with no need of knowing the actuators' fault information. Lyapunov-based analysis is provided and the closed-loop system stability is rigorously proved. Finally, numerical simulations are presented to illustrate the effectiveness of the proposed controllers. 相似文献
9.
The article focuses on the design and application of an active reconfigurable controller that mitigates the effects of gust load and actuator faults on a flexible aircraft. A novel integrated adaptive output feedback scheme is investigated to address the actuator faults. The real-time fault values provided by the fault estimation module are considered in the reconfigurable control law to improve the fault-tolerant capability. The estimate values of faults and control gains are calculated by anal... 相似文献
10.
针对多无人机协同执行任务过程中遭遇执行器增益故障下的安全飞行控制问题,设计了 1种预设性能反步容错姿态跟踪控制方案,以实现故障下的多无人机姿态同步跟踪控制。首先,定义飞行器的姿态同步跟踪误差和姿态角速率跟踪误差,分别利用预设性能函数对 2种误差进行约束,将不等式约束转化为等式约束。其次,基于转换误差设计反步容错姿态同步跟踪控制器,应用 Nussbaum函数解决由增益故障引起的未知控制增益问题。Lyapunov稳定性分析表明,姿态同步跟踪误差与姿态角速率跟踪误差稳定且收敛。仿真结果验证了控制方案的可行性以及有效性。 相似文献
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Instrument failure detection using the dedicated observer scheme (DOS) depends on partial state observability through each instrument which is monitored. For instrument fault detection by the DOS technique, a quantitative measure of partial state observability is established for each instrument and used to determine a necessary condition on the output structure of the system. This measure, called the internal redundancy of the instrument, indicates the complexity of the logic required for failure detection, and it also indicates where some hardware redundancy can be introduced into the system to improve the fault detection capability of the DOS. The principles developed are applied to a simulation of the pitch axis autopilot of the A7 jet aircraft. 相似文献
12.
空中客车公司的数字化维修技术 总被引:1,自引:0,他引:1
顾铮 《中国民航学院学报》2005,23(4):25-28,32
数字化维修是航空维修的大势所趋,空中客车公司是这一领域的先拓者。空中客车公司发展的数字化维修技术,主要可以分为3部分:第1部分是机载自检、显示、打印和空地传输维修信息数据的设备;第2部分是对机载维修信息进行分析和电子排故的软件;第3部分是将各种与维修相关的数据进行数字化管理的电子数据处理工具。采用这些技术,可大大缩短飞机的排故和维修时间。 相似文献
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针对飞机通信寻址与报告系统依托的数据链关联复杂,不同数据链失效对系统影响存在较大差异的问题,全面总结各个数据链与系统的关联、失效后对系统的影响与签派放行的处置方案。首先,介绍了飞机通信寻址与报告系统的组成和传输原理,指出系统由空地网络和地地网络组成,并对上行和下行数据链的传输进
行了解析。其次,分析了系统依托的数据链,指出了甚高频、卫星通信和高频失效都可能会对系统产生影响,这三类设备的故障可能导致系统不可用。最后,列举了系统常见的七个故障,对故障进行了解析,并给出了签派放行的处置方案。 相似文献
14.
根据高铁轨道静态检测的测量需求,设计了一种利用定位定向技术的0级轨检仪,并详细阐述了其构成和工作原理,介绍了其特点。通过对比性分析论证,优选了一种测量精度高、操作方法简单且可大幅度提高测量效率的设计方案。理论仿真表明该系统测量精度能够达到优于1.3mm/km的水平。根据理论仿真结果搭建了原理简易验证设备,结合高铁测控网的测量基准,在一段高铁的弯道铁轨上进行了验证测试,测试结果表明采用定位定向技术的0级轨检仪具备实际工程化的潜力,以及提高测量效率和精度的能力。 相似文献
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Clark R.N. Fosth D.C. Walton V.M. 《IEEE transactions on aerospace and electronic systems》1975,(4):465-473
A scheme for automatically detecting incipient failures in the feedback sensors (or instruments) of control systems is described. The feasibility of the scheme is investigated by applying it to a simplified version (fourth order) of the flight control system for a hydrofoil boat. A single set of inertial instruments is used to provide the feedback signals; the redundancy which is normally obtained by multiple instrument sets is obtained here, artificially, by a subsystem of multiple Luenberger observers and logic circuits. Tests indicate that scale factor errors, errors due to threshold effects, and bias errors in the instruments are detected as they occur. The tests also indicate further analytical work which should be done to explore the limitations of the basic scheme. 相似文献
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Chi Pei Chen Zongji Zhou Rui Wei Chen 《中国航空学报》2007,20(5):443-451
未来空天飞行器跨空天两域飞行,要求有较高的自主性以适应由故障和环境变化带来的不确定因素。针对空天飞行器的不确定性,提出了自主控制重构方案。研究了线性模型的时变控制效益的估计方法,提出并证明了效益矩阵可估计的充分条件,给出了相应的算法并证明了其收敛性和对噪声的鲁棒性;提出了基于线性规划和模糊逻辑的控制分配算法,通过冗余效应器实现了不确定条件下的自主控制重构。系统集成和仿真结果分析验证了方案和算法的有效性。 相似文献
17.
卫星姿态时延反步容错控制 总被引:1,自引:0,他引:1
针对卫星在轨飞行过程中存在执行机构故障及带有常值干扰的控制问题,提出了一种将时延控制(TDC)与反步技术相结合的鲁棒容错控制方法。该方法在继承反步控制优点的同时,引入积分环节用于减小常值干扰引起的稳态误差;同时,利用TDC的逼近能力来补偿执行机构的故障,且对设计者而言,故障信息不需要进行在线的检测和分离,而仅需要一步状态迭代。基于Lyapunov方法从理论上证明了系统的稳定性。最后,将该方法应用于卫星的姿态调节控制,仿真结果表明该控制器能有效地抑制外部干扰、参数不确定性和执行机构故障的约束,在完成姿态调节控制的同时,具有良好的过渡过程品质。 相似文献
18.
This paper studies a robust adaptive compensation Fault Tolerant Control(FTC) for the medium-scale Unmanned Autonomous Helicopter(UAH) in the presence of external disturbances,actuator faults and input saturation.To improve the disturbance rejection capacity of the UAH system in actuator healthy case, an adaptive control method is adopted to cope with the external disturbances and a nominal controller is proposed to stabilize the system.Meanwhile, compensation control inputs are designed to reduce the negative effects derived from actuator faults and input saturation.Based on the backstepping control and inner-outer loop control technologies, a robust adaptive FTC scheme is developed to guarantee the tracking errors convergence.Under the presented FTC controller, the uniform ultimate boundedness of all closed-loop signals is ensured via Lyapunov stability analysis.Simulation results demonstrate the effectiveness of the proposed control algorithm. 相似文献
19.
《Aerospace Science and Technology》2007,11(2-3):245-252
Computer systems operating in space environment are subject to different radiation phenomena, whose effects are often called “Soft Error”. Generally, these systems employ hardware techniques to address soft-errors, however, software techniques can provide a lower-cost and more flexible alternative. This paper presents a novel, software-only, transient-fault-detection technique, which is based on a new control flow checking scheme combined with software redundancy. The distinctive advantage of our approach over other fault tolerance techniques is the lower performance overhead with the higher fault coverage. It is able to cope with transient faults affecting data and the program control flow. By applying the proposed technique on several benchmark applications, we evaluate the error detection capabilities by means of several fault injection campaigns. Experimental results show that the proposed approach can detect more than 98% of the injected bit-flip faults with a mean execution time increase of 153%. 相似文献