共查询到20条相似文献,搜索用时 218 毫秒
1.
贯通测量精度预计使用传统的导线预计公式很不方便,特别是当导线加测陀螺边时更加繁琐复杂。本文提出基于间接平差原理的精度预计方法,通过列立水平角、边长和陀螺方位角的误差方程,进而组成法方程,计算协因数矩阵来求解导线终点的误差。由于法方程矩阵是秩亏矩阵,使用了坐标约束的方法,不仅有利于计算机编程处理,还能顾及起算点精度的影响。算例表明了新方法既正确又简单,便于推广使用。 相似文献
2.
3.
《Planning》2019,(23)
陀螺标度因数是光纤陀螺测量系统的重要参数,其准确性对系统的应用性能有较大影响。现有标定方法受到光纤陀螺的标度因数非线性误差和转台速率误差的制约,标定精度不高。设计了一种遍历速率角度基准式的标定方法,以转台的角位置作为标定基准,在标定过程中使光纤陀螺的输入角速率历经从静止到测量范围的遍历过程,可以在不显著增加标定时间的基础上提高标定精度。进行了验证试验,结果表明,新方法的标定误差比现有方法降低一个数量级,可有效提升光纤陀螺测量系统的应用精度。 相似文献
4.
介绍了在上海长江隧道工程中利用Gyromat2000陀螺经纬仪加测方位角对隧道控制导线进行检测的实际应用情况,对陀螺经纬仪方位角测量方案、数据计算方法及成果精度分别进行了阐述,充分证明使用此类型陀螺经纬仪加测方位角能大大提高隧道控制导线的精度和可靠性。 相似文献
5.
结合阳煤集团二矿470水平15号煤十采区轨道巷与二矿龙门立井贯通的实例,通过导线平差各项参数的选择,从加测陀螺定向边和不加测陀螺定向边两方面对贯通精度的影响做出了分析比较,指出在相同的观测方法和条件下,合理加测陀螺定向边能大大提高贯通精度。 相似文献
6.
陀螺全站仪在地铁隧道贯通测量中的应用研究 总被引:1,自引:0,他引:1
为提高地铁隧道贯通测量的精度,通过对陀螺全站仪的工作原理进行分析,介绍并比较了我国国产陀螺全站仪的现状及特点,结合高精度陀螺全站仪在某城市地铁隧道贯通中的工程实例,得出加测陀螺边定向测量后地铁隧道贯通精度将大大提高的结论,从而保证地铁工程建设的顺利进行。 相似文献
7.
8.
9.
10.
介绍一种应用于卧式镗床的阶梯式陀螺防振镗杆的结构,该镗杆长600~800mm,可利用陀螺转动过程中产生的惯性力,抵消切削过程中由刀杆轴线方向连续传递的切削抗力,有效解决镗削深孔时产生的振动,提高深孔加工的加工精度和生产效率。 相似文献
11.
12.
《Building and Environment》2005,40(6):853-866
Simulation of thermal environment around buildings is of great importance for residential microclimate study. In this article, a numerical method is proposed to simulate the outdoor thermal environment around buildings. By the method, temperature distributions of the outdoor air, building surfaces and ground surfaces are achieved by combining computational fluid dynamics (CFD) calculation of air flow and energy balance equations calculation of surfaces. In every computing time step, the outdoor air distribution is calculated as quasi-steady condition. And the surface temperatures of buildings and ground are simplified as “shadow zone temperature” and “sunshine zone temperature” to reduce the calculating time and memory space. Response factor method is employed to deal with the transient heat transfer between outdoor air and surfaces of buildings and ground. The numerical method is validated by the measured data of outdoor thermal environment around one single building and the simulated temperature distributions are illustrated and analyzed at different time in a day. 相似文献
13.
14.
《Building and Environment》2004,39(2):195-199
The present paper introduces a new method for the certification of the energy consumption of a building recording its “energy behavior”. The method utilizes energy indices such as Index of Thermal Charge or Index of Energy Disposition to simulate the heat losses of the building and the heat flow because of the temperature difference (ΔT) from the inner to outer space.The present method and the algorithm that is implemented could be used as a part of a building energy audit or as a single audit method. Additionally it could be used for the inspection of the energy efficiency in public or municipal buildings. The forenamed method is currently under investigation by the present research team. 相似文献
15.
依据卡尔曼滤波器在使用最佳增益时,其余差互不相关的性质,提出一种基于陀螺随机漂移ARMA模型的渐消自适应卡尔曼滤波算法,可以有效地得到系统陀螺随机漂移的最优估计,保证误差补偿的精度。 相似文献
16.
17.
为确保大断面瓦斯隧道揭煤施工的进度和安全,针对大断面隧道揭煤施工存在的瓦斯安全问题,提出了“五步法”预测揭煤新技术。研究表明:(1)以“分步集中实施区域措施、分层预测检验揭煤”为核心的“五步法”预测揭煤新技术,是视多层突出煤层群的邻近层为一层进行区域措施瓦斯治理,减少了逐层处理的重复环节,缩短了瓦斯治理时间;(2)区域措施中增加了对煤层群分组水力压裂的增透方法,与相似区域相比抽采达标时间缩短了35 d,缩短47%;(3)利用“五步法”预测揭煤技术和煤层群分组水力压裂增透技术后,该瓦斯隧道揭煤时间比预期节省200多天。 相似文献
18.
New knowledge about the deformation behaviour of Frankfurt clay und unloading conditions. Tishman and Speyer planed the construction of a new building complex “Opernturm” in the down town of Frankfurt, Germany. The construction of the new High‐Rise building required the demolishing of the old two high rise buildings of the Zurich insurance company. After demolishing the old high rise buildings, a time delay of about 6years has occurred. The deformations of the rest basement of the old buildings as well as the deformation of Neighbouring construction such as the underground tunnel were observed with time as a part of validating the serviceability requirements of the neighbouring constructions. The results of these measurements regarding the time effect on the behaviour of Frankfurt overconsolidated clay under unloading conditions will be presented. Furthermore, the results of cross hole tests that were carried out as a part of the design of the suggested piled raft foundation of the new high rise building to investigate the dynamic behaviour of Frankfurt subsoil will be demonstrated and discussed. 相似文献
19.
The adjoint method can determine design variables of an indoor environment according to the optimal design objective, such as minimal predicted mean vote (PMV) for thermal comfort. The method calculates the gradient of the objective function over the design variables so that the objective function can be minimized along the fastest direction using an optimization algorithm. Since the objective function is controlled by the Reynolds‐averaged Navier‐Stokes (RANS) equations with the RNG k‐ε model during the optimization process, all the corresponding adjoint equations should be solved, rather than the “frozen turbulence” assumption used in previous studies. This investigation developed adjoint equations for the RNG k‐ε turbulence model and applied it to a two‐dimensional ventilated cavity and a three‐dimensional, two‐person office. Design processes with the adjoint RNG k‐ε turbulence model led to a near‐zero design function for the two cases, while those with the “frozen turbulence” assumption did not. This investigation has successfully used the new method to design a two‐person office with optimal thermal comfort level around the two occupants. 相似文献
20.
Replacement of the “Schwebeträger” (Canal bridge) of the high‐level brigde Hochdonn – concept and realisation. The paper article treats the replacement of the “Schwebeträger” (Canal bridge) of the high‐level bridge Hochdonn over the Kiel‐Canal near Hochdonn. In less than 11 months the bridge with a length of 121 m had to be planned, constructed, manufactured und erected 40 m above the Kiel‐Canal. KSH Stahlbau Hannover GmbH had to face the challenge to complete the replacement within the short blocking times of the Kiel‐Canal and the railway line Elmshorn‐Westerland. The efforts were multiplied due to the fact that the erection couldn't be realised as planned with a floating crane. A totally new erection method had to be developed. The components of the new “Schwebeträger” were manufactured and painted in the workshop of KSH Stahlbau Hannover GmbH in Hanover. The assembly was done in the harbour of Kiel from where the new “Schwebeträger” was transported to Hochdonn with a pontoon. The lowering of the “Schwebeträger” took place in a 12 hours blocking time of the Kiel‐Canal using the lifting portals that were mounted on the high‐level bridge. Two days later the new “Schwebeträger” arrived in Hochdonn and was lifted with high stranded jacks. 相似文献