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1.
The handling qualities of an aircraft will be improved if the Direct Lift Control (DLC) system is applied. In this paper, an attempt has been made to evaluate the influence of DLC-type system parameters on the aircraft's maneuverability and to determine the desired values of these parameters for the purpose of obtaining required values of the handling maneuverability criteria. Published papers which deal with direct lift control do not list requirements for evaluating handling qualities and maneuverability of aircraft equipped with DLC system. In this paper, three new criteria permitting the evaluation of results of employing DLC have been defined. Analysis of influence of DLC system parameters on selected known handling qualities criteria (for example CAP, C*), as well as new DLC efficiency coefficients, have been illustrated with a numeric example of A4D “Skyhawk” fighter aircraft and PZL M-18 “Dromader” agricultural airplane control system modification.  相似文献   

2.
High power IGBTs have been widely used for medium power inverters up to 200 kVA. Their driver circuits often require multiple-output, isolated power supplies. This paper presents a simple flyback power supply especially designed for the driver boards of three-phase IGBT inverters. The detailed circuit diagrams and typical waveforms are reported. Certain performance data are given. The power supplies have been used in 100 kVA inverters for an electric vehicle drive and for a wind turbine inverter  相似文献   

3.
To improve the reliability of spaceborne electronic systems,a fault-tolerant strategy of selective triple modular redundancy(STMR)based on multi-objective optimization and evolvable hardware(EHW)against single-event upsets(SEUs)for circuits implemented on field programmable gate arrays(FPGAs)based on static random access memory(SRAM)is presented in this paper.Various topologies of circuit with the same functionality are evolved using EHW firstly.Then the SEU-sensitive gates of each circuit are identified using signal probabilities of all the lines in it,and each circuit is hardened against SEUs by selectively applying triple modular redundancy(TMR)to these SEU-sensitive gates.Afterward,each circuit hardened has been evaluated by SEU Simulation,and the multi-objective optimization technology is introduced to optimize the area overhead and the number of functional errors of all the circuits.The proposed fault-tolerant strategy is tested on four circuits from microelectronics center of North Carolina(MCNC)benchmark suite.The experimental results show that it can generate innovative trade-off solutions to compromise between hardware resource consumption and system reliability.The maximum savings in the area overhead of the STMR circuit over the full TMR design is 58%with the same SEU immunity.  相似文献   

4.
《中国航空学报》2016,(6):1774-1787
Since digital circuits have been widely and thoroughly applied in various fields, electronic systems are increasingly more complicated and require greater reliability. Faults may occur in elec-tronic systems in complicated environments. If immediate field repairs are not made on the faults, elec-tronic systems will not run normally, and this will lead to serious losses. The traditional method for improving system reliability based on redundant fault-tolerant technique has been unable to meet the requirements. Therefore, on the basis of (evolvable hardware)-based and (reparation balance technology)-based electronic circuit fault self-repair strategy proposed in our preliminary work, the optimal design of rectification circuits (RTCs) in electronic circuit fault self-repair based on global sig-nal optimization is deeply researched in this paper. First of all, the basic theory of RTC optimal design based on global signal optimization is proposed. Secondly, relevant considerations and suitable ranges are analyzed. Then, the basic flow of RTC optimal design is researched. Eventually, a typical circuit is selected for simulation verification, and detailed simulated analysis is made on five circumstances that occur during RTC evolution. The simulation results prove that compared with the conventional design method based RTC, the global signal optimization design method based RTC is lower in hardware cost, faster in circuit evolution, higher in convergent precision, and higher in circuit evolution success rate. Therefore, the global signal optimization based RTC optimal design method applied in the elec-tronic circuit fault self-repair technology is proven to be feasible, effective, and advantageous.  相似文献   

5.
简述了大功率电动机故障产生原因、诊断方法.文中将由电器元件构成的传统保护电路与由电子元件构成的保护电路进行了比较,详细地介绍了所设计的多功能电子保护电路的电路结构,工作原理,保护功能和特点以及存在问题.电路主要由集成件构成,工作可靠,灵敏度高,可以在电动机自动控制系统的设计中作为单元电路参考应用.  相似文献   

6.
This paper presents a production-oriented chip-set to be used as the circuitry needed to implement the necessary RF functionalities of a new generation of S-band satellite transponders for telemetry tacking and control (TT&C) applications. The RF hardware section integration is achieved by means of a customized chip-set of just four multi-chip multifunction MMIC (MCMM) modules. The functions contained in the monolithic microwave integrated circuits (MMICs) include the active circuits needed for the front-end low noise amplifier (LNA), the RF and IF converters, all the variable gain amplifiers (VGAs), the Voltage Controlled Oscillator (VCO) for both transmit and receive sections, the frequency prescaler and multiplier needed to synthesize the frequency plan as well as the Local Oscillator (LO) amplifiers. The selected technology is GaAs, mainly due to its radiation hardness, essential for aerospace applications, and good reliability. Issues such as suitable circuit topology, efficient dc biasing, circuit area minimization, cost-oriented system design and advanced packaging techniques have been addressed during the design. Measurements and yield results from the manufactured circuits will be presented showing that these components, even though especially designed in the frame of the GALILEO TT&C transponder predevelopment, are suitable for a variety of missions, from Deep space to near Earth, including spread-spectrum transponders with precision ranging function.  相似文献   

7.
用单片机实现对潜油电泵的起停控制和多功能保护是完全可能的。论文以单片机技术为基础,具体介绍了硬件电路的设计思想和方法。说明了软件的编制过程。经部分实验证明完全可行,本控制系统结构简单工作可靠,对石油开采控制有一定的实际应用价值。  相似文献   

8.
进化硬件在航空航天电子系统中有巨大的应用价值和潜力。目前,电路进化设计是进化硬件研究的主要方向之一。本文介绍了进化硬件的原理,并针对平台中算法的早熟和收敛速度慢的缺点,改进了原有算法。同时,指出不同类型数字电路在进化中的区别,并以典型电路为例分别进行进化,对结果进行了比较分析,验证了所用算法对进化不同类型电路的有效性。  相似文献   

9.
介绍了基于MCS51系列单片机AT89C51架构的某型飞机发射装置自动测试系统的设计与实现,系统电路中采用了强电信号隔离电路、抗干扰电路等关键电路,分析了测试系统的硬件电路和软件设计.并给出了控制程序流程图.  相似文献   

10.
类金刚石薄膜(DLC)因具有优异的力学性能和摩擦学性能而受到广泛关注,但内应力高、热稳定性差等问题制约了它的应用和发展。将适量的金属掺入DLC薄膜中,由于金属与碳的键合作用不同,掺杂后形成的纳米晶或纳米金属碳化物颗粒具有高的活性,增加了晶界滑移,改善了薄膜结构,进而提高了薄膜的力学性能和摩擦学性能,为薄膜的应用和发展提供了新思路。对目前金属掺杂DLC薄膜的研究进行了综述,提出了未来一段时间内金属掺杂DLC薄膜的发展趋势。  相似文献   

11.
分析数据电路中不同调制方式下的误码分布,对随机数进行数学变换产生不同的误码图案,从而给出数据电路模拟器中误码的模拟方法。  相似文献   

12.
论述桥式和全波相结合的单相可控整流电路,该电路突破可控整流电路最大输出电流点和最佳功率因数点只能在最高输出电压点上的传统,可在低电压输出电流达到桥式电路的2倍以上。桥全可控整流电路只要在桥式电路上增加一只整流或可控整流器件即可获得,不但吸取全波和桥式二类经典电路的优点,而且把二类电路包含在内,成为性能最好、电路数量最多、最高形式的单相可控整流电路。  相似文献   

13.
类金刚石薄膜的微/纳米机械和摩擦性能   总被引:2,自引:1,他引:2  
采用真空磁过滤等离子电弧沉积的方法在9Crl8钢上沉积不同厚度的DLC膜。为了检测成膜质量,在较宽的载荷范围内分别使用显微硬度、纳米压痕和划痕技术表征9Crl8钢和DLC/9Crl8的机械和摩擦性能。结果显示,9Crl8和DLC的纳米硬度和弹性模量分别为8GPa、250GPa和60GPa、600GPa,9Crl8、DLC和有机膜的摩擦系数分别为0.35、0.20和0.13。纳米压痕和划痕技术能为DLC/9Crl8提供丰富的近表面弹塑性变形和摩擦、磨损等信息。DLC/9Crl8的机械和摩擦性能的研究可以用来评估膜的承载和抗磨损性能。  相似文献   

14.
A new magnetic core circuit that is used to supply power in the proper phase and time sequence to a bidirectional stepping motor is described. This circuit will power a standard voltage stepping motor from a nonstandard voltage power supply and includes a means for maintaining a constant energy pulse excitation over a wide range of dc power supply input voltage, a means for supplying power to the winding of the motor on pairs of isolated conductors, and a means for conductively isolating the low-level logic circuits from the high-level power circuits.  相似文献   

15.
Chaboche热粘塑性损伤模型的应用研究   总被引:1,自引:1,他引:1  
本文讨论了Chaboche粘塑性模型的材料参数确定问题,提出了一种简单实用的模型参数确定方法,并用本文提出的方法确定了TiAl材料的Chaboche模型参数,并用这些参数进行了不同应变率下的拉伸模拟计算、不同应力下的蠕变模拟计算和CT试样在阶梯载荷下的蠕变模拟计算。  相似文献   

16.
朱永甫 《飞行力学》1992,10(2):31-35,52
本文讨论了舰载飞机以小于有利速度着舰时的航迹稳定性问题。在分析飞机航迹稳定性的同时,还对油门杆控制、机动襟翼控制对改善航迹稳定性的作用进行了初步探讨;在此基础上还讨论了舰载飞机加装波束导引系统对着舰过程的影响原理。结果表明:采用油门杆控制、机动襟翼控制来改善着舰阶段的航迹稳定性是可行的:而且用以上两控制系统作为内环的自动驾驶仪在波束导引系统自动导引飞机着舰过程中,能控制飞机的飞行速度、高度,帮助驾驶员操纵。  相似文献   

17.
过滤式阴极电弧沉积类金刚石薄膜工艺研究   总被引:3,自引:0,他引:3  
研究了过滤式阴极电弧沉积系统的稳弧工艺参数,通过正交试验获得最佳稳弧参数。并且研究了弯管内置挡板对宏观粒子过滤效果的影响。采用喇曼光谱研究了偏压对生成的类金刚石薄膜性能的影响,证明-100V偏压下获得的类金刚石薄膜有最佳的SP3含量。扫描电镜测试表明,在(111)硅基片上获得致密的膜,但在高速钢基体上沉膜堆积现象比较严重,不易获得优质类金刚石膜。同时也给出了类金刚石的原子力显微照片(AFM),表明稳弧参数对类金刚石薄膜表面形貌有较大的影响。  相似文献   

18.
The avionics working environment is bad, easy to accelerate aging of circuits. Circuit aging is one of the important factors that influence the reliability of avionics, so circuit aging testing is of great significance to improve the reliability of avionics. As continuing aging would degrade circuit performance, aging can be monitored through precise measurement of performance degradation. However, previous methods for predicting circuit performance have limited prediction accuracy. In this paper, we propose a novel Built-In Self-Test (BIST) scheme for circuit aging measurement, which constructs self-oscillation loops employing parts of critical paths and activates oscillations by specific test patterns. An aging signature counter is then used to capture the oscillation frequency and in turn measure the aging state of the circuit. We propose to implement this measurement process by BIST. Experimental results show that the proposed in-field aging measurement is robust with respect to process variations and can achieve a precision of about 90%. The application of this scheme has a certain value to improve the reliability of avionics systems.  相似文献   

19.
This paper describes research and development efforts in the use of infrared (IR) laser beams for detecting failures in integrated circuits resident on printed circuit boards. This work involves taking advantage of the transparency of the silicon substrate of ICs to radiation in the near infrared (NIR) spectrum to devise a non-invasive method for imaging the component circuitry of the IC. The implication is that a means to see into the physical structure of an integrated circuit can be created by using lasers tuned to these wavelengths. While the silicon substrate is transparent to the laser, the circuit paths and devices embedded within the substrate are readily visible since their metallic composition is opaque to laser energy at this wavelength. A laser test fixture consisting of a 1064 nm continuous wave laser, CCD camera, and image acquisition board is used to generate images from flip-chip integrated circuits. Multiresolution image processing techniques are then applied to the resulting images to identify potential defects.  相似文献   

20.
本文对硅薄片转子调谐式陀螺仪的相关电路进行了研究。给出了整体框图,并结合具体电路对主要模块进行了分析。在一个陀螺敏感方向上进行了实验,绘制了陀螺输出特性曲线。验证了电路的可行性,为进一步改进电路提供了经验和依据。  相似文献   

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