首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Midcourse guidance is commonly designed to save as much energy as possible so that the missile’s final speed can be maximized while entering the homing stage. For this purpose, a competitive guidance design should be able to generate an admissible flight trajectory as to bring the interceptor to a superior altitude for a favorable target engagement. In this paper, a new adaptive trajectory shaping guidance scheme based on the adaptive fuzzy inference system, which is capable of generating a variety of trajectories for efficient target interception, is presented. The guidance law is developed with the aim of saving the interceptor’s energy conservation while improving performance robustness. Applications of the presented approach have included a variety of mission oriented guidance, such as cruise missile guidance, anti-ballistic missile guidance, etc.  相似文献   

2.
Three-dimensional trajectory parameter measurement of industrial products is the key technical criteria that drives the product qualification.It has recently become one of the hotspots in the measurement field.This paper presents a method for measuring the eyeglass frame parameters using the inner trajectory as measurement object.The three-dimensional parameters can be measured and calculated from top view and front view.The preprocessing is performed to ensure the reliability of data acquisition.The necessary derivation and explanation for formulas of important parameters are provided.A standard square board is used as the template and is measured multi-times to verify the measurement method.The experimental data are processed and the type A uncertainty is calculated,which concludes that the measurement results are convincible and comply with the product standard,and the proposed method is correct and the design requirements are met.  相似文献   

3.
This paper presents the results of computer simulation of bearing misalignment defects in a power turbogenerator. This malfunction is typical for great multi-rotor and multi-bearing rotating machines and very common in power turbo-sets. Necessary calculations were carried out by the computer code system MESWIR, developed and used at the IFFM in Gdansk for calculating dynamics of rotors supported on oil bearings. The results are presented in the form of a set of journal and bush trajectories of all turbo-set bearings. Our analysis focuses on the vibrational effects of displacing the two most vulnerable machine bearings in horizontal and vertical directions by the maximum acceptable range calculated with regard to bearing vibration criterion. This assumption required preliminary assessment of the maximum values for the permissible bearing dislocations. We show the relations between the attributes of the particular bearing trajectories and the bearing displacements in relation to their base design position. The shape and dimensions of bearing trajectories are interpreted based on the theory of hydrodynamic lubrication of oil bearings. It was shown that the relative journal trajectories and absolute bush trajectories carry much important information about the dynamic state of the machine, indicating also the way in which bearings are loaded. Therefore, trajectories can be a source of information about the position and direction of bearing misalignments. This article indicates the potential of using trajectory patterns for diagnosing misalignment defects in rotating machines and suggests including sets of trajectory patterns to the knowledge base of a machine diagnostic system.  相似文献   

4.
The possibility of modular design of internal (shaping) kinematic chains in the form of hydraulic links based on step hydraulic drives for various machine tools is considered.  相似文献   

5.
针对浪形保持架整形工序中,使用游隙夹具测量径向游隙时,存在测量过程繁琐、时间长、效率低等问题,通过改变模具结构、改进测量方法、采用中心径测量,取代了径向游隙测量,提高了工作效率。  相似文献   

6.
简述了切削力对加工过程的影响和切削力在理论上计算的基本关系;进行高速铣削试验测定了铣削力;且依据铣削初始阶段切削力的变化,推测加工过程中是否存在积屑瘤,并就此验证铣削方式(顺铣或逆铣)的合理性;分析了切削力随切削速度变化的趋势。  相似文献   

7.
火箭弹离轨参数测量中的图像处理方法   总被引:6,自引:0,他引:6  
根据高速摄像系统在火箭弹离轨参数测量中的应用,介绍了火箭弹离轨参数测量原理,提出了帧相减、相关滤波定位、轴线自动提取等多种图像处理方法,并将这些方法应用于工程实际.实践表明,在利用帧相减和边缘跟踪技术进行粗定位的基础上,采用相关滤波技术在小区域进行定位可以减少计算量,使定位精度达到0.2个像元,而在轴线自动提取中,用灰度图像形态学边缘检测方法,可使姿态角测量精度优于0.5°.  相似文献   

8.
9.
10.
抛物线弹道弹丸飞行参数测量模型与 精度分析   总被引:7,自引:0,他引:7       下载免费PDF全文
现有匀速直线弹道六光幕阵列测量模型无法满足终点抛物线弹道弹丸着靶坐标与飞行速度的测量需求。针对终点弹道测试试验中抛物线弹道的实际,提出一种变速抛物线弹道弹丸飞行参数的测量方法,建立六光幕阵列通用测量模型。综合考虑重力和空气阻力对弹丸运动轨迹的影响,建立弹丸的空间运动方程,结合光幕阵列平面方程和测量得到的弹丸穿过光幕阵列时刻序列,计算出弹丸在预定位置的着靶坐标和飞行速度矢量。对研究的抛物线弹道测量模型与现有的匀速直线弹道模型进行了比较分析,仿真计算了在不同靶距与不同飞行速度情况下2种模型测量数据的差值。对研究的测量算法进行了精度分析。采用六光幕阵列天幕靶和木板靶进行7.62 mm步枪弹的着靶坐标比对试验,结果表明在探测靶面内,着靶坐标测量误差不大于3.5 mm。建立的测量模型拓宽了六光幕阵列在终点弹道的测试领域的应用。  相似文献   

11.
In this study, we developed an effective nonattached, noncontact technique for measurement of the human heartbeat. This method detects the human heartbeat by measuring the current generated by variations in the capacitance between a given electrode and the human body. An electrode is placed a few centimeters from the subject's chest, and the electrostatic induction current (on the order of picoamperes) flowing through the electrode is then detected. We propose an occurrence model for the electrostatic induction current generated by variations in the electrostatic capacitance generated because of the human heartbeat, with respect to a given measurement electrode. Furthermore, we compared waveforms of the human heartbeat simultaneously obtained by using conventional electrocardiography (ECG) and our proposed electrostatic induction method. The waveform obtained using the proposed method had the same cycle as that obtained using conventional ECG. This confirms that we can detect the human heartbeat under nonattached, noncontact conditions.  相似文献   

12.
13.
对牛头刨床刨削机构的组成及其工作原理进行了分析,基于再生运动链法,对牛头刨床的刨削机构进行了创新设计,应用ADAMS软件对满足要求的新型机构方案进行运动仿真分析。通过对数据的对比分析,验证了新型机构符合牛头刨床使用要求,并最终选定了最优的新型机构方案。  相似文献   

14.
The deposition of metal droplets has been attracted wide interests for potential applying in microstructures fabrication. A uniform droplet generator with image acquiring system and droplet temperature measuring system was established. A coupling analysis method on combination of droplets dynamic and thermal models was proposed. Effect of experimental parameters on deflected trajectory and the temperature history of the uniform droplets was investigated. The measured trajectory and temperature history agreed well with the predicted results, indicating the validity of the proposed analysis method. The predicted results with different experimental parameters showed that the deflected trajectories and thermal histories of the droplets with diameters close to 100???m or less were strongly dependent on their sizes. Small droplets had a narrow deposition length for obtaining parts with good metallurgical bonding. The predicted results also showed that it was effective in controlling the deflected trajectories and thermal histories of droplets by adjusting the pressure when it was low. At last, micro alloy tubes with good metallurgical bonding were obtained using 50???m diameter nozzle when the experimental parameters were chosen according to theoretical models. The deposited results show that proper parameters for microstructures deposition can be obtained according to the proposed analysis method.  相似文献   

15.
根据板簧的加工工艺要求,主要介绍成形淬火机的传动方案选择及设计计算、总体设计和电气控制设计等内容,实际可行。  相似文献   

16.
提出了一种基于正交基函数的多项式实时拟合方法,并应用于轴角编码器测速,解决了常规算法中拟合多项式阶数大于3阶时法方程组容易出现病态,进而使测速精度降低的问题。光电跟踪测量设备地面目标跟踪实验表明,该算法通过对拟合处理后的角度值进行微分运算得到角速率,能有效地降低编码器角度输出中随机误差对测速的影响。在典型实验条件下,与采用同阶拟合多项式的常规方法进行了比对,前者的测速误差标准偏差为0.013 43°/s,后者为0.028 15°/s,采用本算法提高了编码器的测速精度,适合在工程上应用。  相似文献   

17.
针对8号电雷管的包装生产方式,设计了一种雷管抓取机构,根据工业机器人抓取雷管装盒及抓取雷管盒装箱的运动路径,对机器人进行关节空间轨迹规划。采用5次B样条曲线轨迹规划法,能够实现机器人运动角加加速度的连续性,减少运动产生的冲击及颤振,保证雷管安全、可靠的抓取。最后仿真分析结果证明了该轨迹规划方法的有效性与合理性。  相似文献   

18.
基于三角基函数分解的高精度介损角测量方法   总被引:1,自引:0,他引:1  
为精确测量介损角,克服数字化测量时存在的非同步采样、基波频率波动、谐波变化等因素影响,提出并建立基于三角基函数分解的介损角测量模型,将电力谐波各参数作为未知量,基于最小二乘原理对采样数据进行最速下降迭代求解,准确提取基波电压、电流相位,进而得出介损角,排除直流和谐波分量干扰。从理论上证明该算法的收敛性,针对基波频率波动、介损角真值改变、谐波含量变化、白噪声影响等影响进行仿真实验,结果表明该测量方法使用极少采样点与较低采样率,即可获得较高的测量准确度,测量速度快。设计的基于数据采集卡与虚拟仪器技术的高压电容型设备绝缘在线监测系统,验证了该方法的可行性与有效性。  相似文献   

19.
勾志勇  王江  张悦  王磊 《光学仪器》2006,28(2):42-45
半导体激光器广泛地应用在国防、商业、工业等领域,对其光学准直是一项重要的工作。介绍一种新的半导体激光整形系统——同轴单棱镜整形系统,详细地叙述了单棱镜的设计原理。与其它整形系统比较,该棱镜具有设计、加工和装调简单等优点,最大的优点还能保证光束同轴。最后以一个θ⊥×θ∥=25°×11°半导体激光器为例子,设计一个2.5×单棱镜同轴整形系统,通过软件模拟计算与实际计算结果比较,结果基本相符,证明了设计方法的正确性。  相似文献   

20.
The study of spectral signatures of various elements has been enabled with the ability to diffract light using optical gratings, coupled with the ability to control light using lenses and mirrors. As technological devices seek to become more compact while maintaining or increasing operational efficiency, integration of functions becomes necessary to reduce the overall component count. However, due to the lack of axial flexibility, integrated microstructures on complex forms have shown to be challenging to manufacture. Thus, the need for fabrication techniques to be able to produce such microstructures on non-planar surfaces arises. The Continuous Rotating Freeform Shaping (CRFS) algorithm proposed in this paper utilizes the axial flexibility and precision of Ultra-Precision Machining (UPM) to directly fabricate optical quality blazed gratings on complex profiles which can directly be used as mirrors or molds. The developed algorithm not only maintains the tool along the primary profile of the optical surface, but also the rake angle of the tool at every point along the surface for a constant cutting mechanism. This is coupled with a rotation of the tool to maintain the blazed angle across the surface, optimizing the surface for the efficiency of the grating for a specific wavelength. In this paper, the developed algorithm is presented with experimental verifications of the generation of blazed gratings on a high curvature spherical surface and a freeform tri-axial ellipsoidal surface, followed by the corresponding analysis.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号