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1.
三轴转台误差对陀螺仪标定精确度的影响   总被引:1,自引:0,他引:1  
为了精确地在三轴转台上标定陀螺仪误差模型系数,分析了三轴转台的各种误差源对陀螺仪误差模型系数标定精确度的影响.介绍了三轴转台的误差源,包括轴线垂直度误差、转台的位置误差和倾角回转误差等,建立与转台误差以及陀螺仪误差模型系数有关的陀螺仪输出全误差方程.经过仿真计算,确立了误差源与误差模型系数的标定精确度之间的量化关系.根...  相似文献   

2.
基于坐标测量机的双目视觉测距误差分析   总被引:5,自引:0,他引:5  
本文针对基于坐标测量机的双目视觉方法的测距误差进行了详细的分析 ,误差来源分为 :1 摄像机坐标系与坐标测量机坐标系不正交引起的测距误差 ;2 坐标测量机的机构误差引起的测距误差 ;3 摄像机CCD像面上像元的量化误差引起的测距误差。本文对以上三种误差因素进行讨论 ,给出了相应的误差公式 ,可在实际测量中进一步提高双目视觉方法的测距精度  相似文献   

3.
电磁与机电暂态仿真在模型处理、积分步长和计算模式等方面存在的诸多差异使得通过接口结合的电磁 机电混合仿真存在不可忽视的固有误差,从而限制了其广泛应用。分别从电磁、机电暂态计算交互信息提取误差与接口交互误差两个方面分析了混合仿真中的误差传递机理,其中交互信息提取误差包括瞬时值转相量提取误差、相量转瞬时值离散误差及接口等值阻抗计算误差,接口交互误差包括时序交互误差、数据传输延时误差及机电暂态计算迭代误差。最后,通过基于PSCAD+C的电磁 机电混合仿真平台对上述接口误差机理分析结论给予验证,理论分析与仿真结果表明,相量提取算法、交互步长及数据传输延时是影响混合仿真精度的关键因素.  相似文献   

4.
提高电能计量装置准确性的方法   总被引:1,自引:0,他引:1  
1电能表误差分析 电能表在安装之前,要进行基本误差的测定,不合格的表计,一般均做退厂处理,所以电能表的误差一般都在检定规程允许的误差范围内。安装之后。由于电能表运行条件与测定基本误差时的条件不同,从而使电能表的误差发生变化,产生附加误差。全电子式电能表误差主要包括电压采样器、电流采样器、乘法器、转换器等方面。对于电压和电流采样器及转换器,只要硬件选配适当,负荷在一定的范围内变动,其误差很小。  相似文献   

5.
短路电流仿真值与录波值的比对分析   总被引:1,自引:0,他引:1  
对电网某短路故障进行仿真计算,再与实际录渡比对,结果基本吻合,存在少量误差.误差由录渡取值误差和仿真计算误差共同组成,录波取值的误差包括电流互感器误差、保护(故障录波仪)录渡误差、有效值计算误差,仿真计算误差包括不能完全真实再现电网运行方式以及电网元件仿真参数误差.因此,在短路电流计算中,选择好基于潮流还是不基于潮流,并且控制好诸如零序互感、低压小机组、负荷模型等短路计算的影响因素,可以将短路电流计算值与实测值的误差控制在5%以内,说明目前采用的常规短路电流计算方法是可取的.  相似文献   

6.
利用GPS进行弹道测量进而预测落点偏差是弹道修正弹采用的一种常用方法,GPS测量误差对基于GPS的落点预测算法精度有直接影响,该文以摄动落点偏差预测算法为例分析了GPS误差对弹道修正弹落点预测算法误差的影响,确定了GPS误差引起的落点预测算法误差标准差与极限误差求解方法,这可为合理利用基于GPS的落点预测算法提供参考。最后进行的仿真实验表明,GPS误差是落点预测算法误差的主要来源,落点预测算法随机误差分布在GPS误差引起的落点预测算法预测误差极限误差内。  相似文献   

7.
带CCD 图像处理的窄间隙焊缝跟踪系统中,存在执行调节误差、传感导前误差、弧光干扰误差、光学参数误差、初始给定误差、标定参数误差等。上述误差直接影响跟踪精度,可从硬件和软件方面采取综合措施,以减少上述误差对跟踪系统的精度产生影响。目前,在采取相应的硬件和软件措施后,开发的窄间隙焊自动跟踪系统的横向跟踪精度可达±0. 1 mm。  相似文献   

8.
在放大器所组成的反馈系统中通常会产生一些误差,然而不同的误差对反馈系统所造成的影响也不同。在对反馈系统的分析中,很多人只注意到幅值误差的影响而忽略了相位误差的影响,这将会对反馈系统的精度造成影响。对此,本文先通过对普通反馈放大器的分析得知反馈系统中存在幅值误差和相位位差,然后再通过具体实例计算发现幅值误差和相位误差对反馈系统的影响相差很大,最后通过MATLAB仿真以及实验验证后发现,相位误差的影响比幅值误差的影响更大。因此,在对反馈系统的分析中,相位误差的影响也应加以重视。  相似文献   

9.
针对目前数字量输入电能表误差等级的争论,本文从其电能计量的原理出发,分析了目前有争议的几种误差来源,指出波形误差、同步误差与量化误差不是数字量输入电能表的误差组成.分析结果与试验结果表明在不考虑网络异常的情况下,单纯的数字量输入电能表的电能计量误差几乎为0,数字量输入电能表作为1类关口表时,不适合以0.2S级为其误差指...  相似文献   

10.
滚珠丝杠副是精密伺服驱动系统核心零部件,随着丝杠运行,温度升高会导致丝杠单轴伺服系统直线度误差增加。为了明确该误差及其产生规律,建立滚珠丝杠副热误差模型,分别对滚珠丝杠副的热源、温度场以及热误差模型进行了研究。根据滚珠丝杠副的结构特点,确定其内部热源及温度场分布规律,分析热误差的特性。设计实验,检定温度变化前后的直线度误差,设定5 min间隔分段运行,明确温度和直线度误差的变化过程及规律。实验结果表明,随着温度升高,丝杠直线度误差随着丝杠本身的弯曲状态会出现更为明显的弯曲,剔除丝杠自身存在的直线度误差和检定过程中斜率误差后,直线度误差增加了11.4 μm。本文得到丝杠直线度误差随温度变化的规律,可以应用于其他空间驱动系统整体几何误差的检定和补偿,具有较强的工程应用前景。  相似文献   

11.
采用SIMPLE算法和k-ε模型,对一凝汽器喉部建立数值模型。对低压加热器在凝汽器喉部不同布置方式、不同布置位置进行了三维的数值模拟,得到喉部流场的速度分布情况。表明无论低加在凝汽器喉部采取何种布置形式,都会对喉部流场的速度分布的不均匀性产生极大影响;在扩散角的影响下,低加横向布置速度流场的均匀性略优于纵向布置;在布置位置较低时,喉部出口流场较其布置在较高位置均匀,但通过改变低加布置高度对喉部流场的改善并不明显。  相似文献   

12.
基于Ansys多物理场仿真软件平台,对高速异步电动机的转轴进行疲劳特性分析,校核高速异步电动机转轴的疲劳强度和高速运行的可靠性,预测电机转轴的寿命;分析电磁力对转轴疲劳寿命的影响,判断疲劳特性的类型。对比分析作用于电机结构的电磁力波频率、幅值和电机转轴各阶模态的固有频率,校核电机转轴的强度。在转轴不会因电磁振动发生断裂的前提下,将电磁力等效为静应力分析转轴的疲劳特性,校核电机轴在电机寿命周期内是否会发生短周疲劳损坏;并采用凹圆角设计进一步提高转轴的结构可靠性,提高电机的转轴寿命。  相似文献   

13.
为了研究XLPE材料交联度对其电气性能的影响,制备不同交联度的XLPE样本并对其进行电气击穿实验,分析在不同的交联度区间范围内样本击穿场强变化。利用温度-时间控制法制备六组不同交联度的XLPE样本;利用差式扫描量热仪测量得到样本结晶度;利用交流变压器测量得到样本的击穿强度。实验结果表明,随着交联度上升,样本击穿场强呈先上升后下降趋势。在交联度为0%~75%区间范围内,样本击穿场强增加2%。在交联度为75%~88%范围内,样本击穿场强增加21.2%。而在交联度为88%~92%范围内,样本击穿场强下降5.3%。分析认为,样本的击穿强度与样本交联度和材料均匀程度有关。当交联度较低时,样本的击穿强度主要由样本交联度决定,随着交联度上升,样本击穿强度增加。但由于此时局部材料结构较为不均匀,因此击穿强度增加幅度不大。而当交联度上升至75%时,材料形成较为密集、均匀的三维网状结构,导致样本击穿场强大幅上升。而当交联度继续增加时,此时样本结晶度下降幅度较大,局部材料结构变得不均匀,导致样本击穿强度下降。  相似文献   

14.
特高压电晕笼防护段的设计   总被引:3,自引:8,他引:3  
为了克服特高压电晕笼设计中电晕笼两端部的电场畸变,确保电晕特性测试准确有效,需要增设一定长度的防护段。采用三维有限元方法精细计算了电晕笼内导线表面电场分布,分析了导线弧垂对防护段长度的影响并提出了新颖的电晕笼防护段设计方法。计算说明新型结构的防护段能有效平滑和抑制电晕笼端部附近导线表面电场的畸变,使电晕笼内导线表面电场更趋于一致,提高了电晕特性试验的准确性。  相似文献   

15.
16.
A method of the analysis of dynamics of the thermal field in a DC lead is presented in this article. The cooling of the system is modeled by the convectional boundary condition. Field functions are determined analytically by the method of states superposition and the separation of variables. The coefficients of field functions and eigenvalues of the boundary–initial problem are computed by the numerical method. The coefficients are the solution of the respective systems of equations. Those systems are the result of scalar products of the functions non-orthogonal in the region of the core and insulation. On the other hand, the eigenvalues are determined with the aid of the original algorithm, which, among others, takes advantage of field properties and the method of golden partition. Consequentially, the spatial–temporal distribution of a temperature is computed, as well as the averaged time constant of the system and the admissible long-lasting ampacity. The influence of the heat transfer coefficient and thickness of insulation is discussed. The obtained results have been verified with the aid of a finite element method.  相似文献   

17.
The article reports the results of investigation into the possibility of using off-design coals as an additional fuel in connection with predicted reduction in the heat of combustion of shale oil and more stringent environmental regulations on harmful emissions. For this purpose, a mathematical model of a TP-101 boiler at the Estonian Power Plant has been constructed and verified; the model describes the boiler’s current state. On the basis of the process flow chart, the experience of operating the boiler, the relevant regulations, and the environmental requirement criteria for evaluation of the equipment operation in terms of reliability, efficiency, and environmental safety have been developed. These criteria underlie the analysis of the calculated operating parameters of the boiler and the boiler plant as a whole upon combustion with various shale-oil-to-coal ratios. The computational study shows that, at the minimal load, the normal operation of the boiler is ensured almost within the entire range of the parts by the heat rate of coal. With the decreasing load on the boiler, the normal equipment operation region narrows. The basic limitation factors are the temperature of the steam in the superheater, the temperature of the combustion products at the furnace outlet and the flow rate of the combustion air and flue gases. As a result, the parts by heat rate of lignite and bituminous coal have been determined that ensure reliable and efficient operation of the equipment. The efficiency of the boiler with the recommended lignite-to-coal ratio is higher than that achieved when burning the design shale oil. Based on the evaluation of the environmental performance of the boiler, the necessary additional measures to reduce emissions of harmful substances into the atmosphere have been determined.  相似文献   

18.
Approaches to developing software for solving numerical problems using the finite-element method are briefly compared. Their conceptual advantages and disadvantages are determined. An example is presented of the computation of the dynamic magnetic field of a magnetizer of a magnetic-flaw detector of steel ropes uniformly moving along an open rope, the linear dimensions of individual parts of which differ by several orders of magnitude. The problems of adaptation and application of the GMSH + GetDP software package for the calculation of dynamic magnetic fields of electrical devices are considered. Features of the finite-element-mesh generation, its optimization, and the subsequent solution of systems of linear algebraic equations of higher orders are noted. The importance of choosing the necessary configuration of the GMSH + GetDP software package is shown by the comparison of the efficiency of application of different matrix-ordering algorithms and the appropriateness of taking into account the features of the hardware of the computer. The results of modeling a dynamic electromagnetic field under conditions of uniform motion are obtained, and a comparison with the results of modeling the electromagnetic field of objects without motion is carried out. The obtained results of comparison are analyzed. The areas of the greatest changes in the electromagnetic-field distribution at the poles of the magnetizer and in the region of the local rope defect are identified.  相似文献   

19.
Ease of use is one of the main criteria that customers consider when making a purchase decision. To provide a pleasant experience to the customers, offering products or services consisting of advanced features and functions is no longer enough, due to the existing competition in the global market. In reality, the ease of use of any product is influenced by the conditions of the product and the familiarity of the user. This study examines the influence of the familiarity and the product conditions on the ease of use of a product. This only explains how the conditions of the product and the fa-miliarity of the user, influence on the ease of use of a product when the usage hours of a product increases. A case study would be conducted to validate the results. The results of this study indicate that in the case where both the product conditions and the familiarity has been varied, the ease of use of the product has been increased from 0.229 to 0.380 gradually within the 10 weeks period. Through these results valuable guidance could be obtained by the manufacturers to identify how the ease of use level of a product deviates from the standard level when the usage hours of the product would increase.  相似文献   

20.
电磁流量计在工业生产过程中扮演着重要角色,但易受流体中气泡的影响导致测量结果出现波动进而影响测量精度。定量分析气泡在电磁流量计测量过程中产生影响的规律对提高电磁流量测量精度和实现气液两相流测量具有重要工程意义。针对上述问题,首先从权重函数角度入手,采用解析法建立了气泡尺寸、气泡偏心以及气泡数量对电磁流量测量影响的理论模型;其次,通过仿真和实验研究了管径为100 mm,圆形点电极半径为5 mm的电磁流量系统受气泡不同状态的影响,并采用输出电压灵敏度分析了气泡不同状态下对电磁流量测量的影响规律。研究结果表明,随着气泡尺寸增加其影响大小随之增加,气泡尺寸变化过程中影响在0.3%~5%范围内变化,最大为5%;气泡(直径为10 mm)沿电极方向偏心产生的影响在0.25%~0.6%范围内,且随偏心距离的增加而增加;气泡沿垂直电极方向偏心距离增加产生的影响微小,在-0.2%~0.2%范围内波动;同时,在气泡流动过程中,气泡越靠近电极截面影响越大并在电极截面位置产生影响最大值,单气泡最大值分别为0.18%、0.22%、-0.20%,随着气泡数量增加产生的影响逐渐增加,3气泡和6气泡影响最大值分别为0....  相似文献   

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