复杂曲面类毛坯通常没有定位基准。
Blanks of sculptured surface usually do not exist positioning references.
尽可能在多数工序中用同一个定位基准。
Uses the identical localization datum as far as possible in the most working procedures.
此工装为举升机构的装配提供空间定位基准。
This technology equipment can provide a locating datum for mounting the lifting system.
本文着重探讨工件的定位方法、定位形式和定位基准的选择。
The article lays stress on discussing the choice of the locating methods, the locating styles and the locating datum for the workpiece.
定位基准选择正确与否，对于提高机械加工精度有着重要影响。
Whether the locating datum is chosen correctly or not influences the improvement of the machining precision greatly.
本文讨论了定位基准的概念，试图给出恰当的定位基准的定义。
This paper discusses the concept on position basis and attempts to give proper definition of it.
模板具有固定模具和运动导向的定位基准作用，其结构和受力比较复杂。
The platens of injection moulding machine have the roles of fixing moulding and guiding motion benchmark, they also have rather complex structure and force condition.
定位则需要定位基准，定位基准选择得是否合适，将直接影响零件的加工精度。
To locate, we need the locating criteria, whether a suitable locating criterion is chosen or not will directly influence the machining precision.
精基准选择：要符合基准重合原则，尽可能选设计基准或装配基准作为定位基准。
Fine datum choice: Must conform to the datum superposition principle, chooses the design datum or the assembly datum as far as possible takes the localization datum.
轴承环磨削过程中，以轴承环外径作为定位基准，在电磁无心夹具上磨削轴承环外滚道。
When grinding the bearing ring, the outside diameter of it was taken as locating datum to process the outer raceway with the assistance of electromagnetic centerless clamper.
在分析箱体类零件典型定位方案的基础上，建立了定位基准选择的过程模型和综合评判模型。
Under the base of studying the typical location plans of prismatic parts, process model and fuzzy comprehensive evaluation model of location datum selection are established.
考虑该零件表面结构的不规则性但有较高精度的孔需要加工，定位基准选择“一面双孔”是最佳的方法。
Consider to the irregularity components but have high accuracy holes to be processing. So, "two holes at a face" is the best localization plan.
本文阐明了当工件以回转面定位，计算定位误差时，取定位基准或为回转面某一母线，或为其中心线，计算结果是相同的。
With workpiece located by its rotary surface , either the rotary surface or its center line is regarded as the reference of location , the calculating results of location error are the same.
除了要求有统一的空间参照和定位基准以外，还必须将诸军兵种所需的地理空间信息科学合理地统一在一起，形成一个有机整体。
Besides of uniform spatial reference and positioning datum, modern war must unite all the geographic spatial information needed by all arms of services to a organic integer scientific and reasonably.
在精加工以内孔为定位基准的零件时，所用芯轴类工装如果采用间隙配合定位，由于定位间隙的存在，必然影响零件的加工精度。
When machining parts with bore as positioning reference, if clearance fit positioning is adopted, machining accuracy is certainly affected due to the existence of clearance.
本文通过对工件在数控铣床、加工中心上装夹定位基准选择及定位基准原则的阐述。为我们在加工中工件的定位提供了理论基础及实践依据；
The paper elaborates the norm choice of workpiece loading positioning at milling machines and the processing center, which provides the theoretical and practice basis for the positioning of workpiece.
该方法使特征定位基准在特征造型过程中保持不变，且不随特征定位约束参数的改变而变化，能很好地满足参数化变动设计与拓扑结构变异的要求。
This method keeps the location base of form feature invariance during the feature modeling and editing, and it is suitable for feature parametric variational design and topological variation.
用作精基准的表面应先加工出来，因为定位其准的表面越精确，装夹误差就越小。
Surface should be used as a fine datum to be processed first, because the precision of the positioning of the surface is more accurate, the smaller the clamping error is.
rd全自动钉销机用于印刷电路叠层板在印制电路板数控钻床钻孔前钻作基准定位销钉，从面保证印刷电路板数控钻床能加工出高品质的产品。
RD auto pinning machine is used to make reference positioning pin prior to drill the laminated plates of etched circuit ca rd on drill machine for etched circuit ca rd manufacture premium products.
采取对基准图卫片中特征进行亚像元精度特征定位的方法，可以将匹配精度提高到1／3个像素以内。
The location precision is improved to 1/3 pixel by performing sub - pixel edge detection in fiducial satellite photo image.
然后根据定位杆的基准坐标，得到该层的射影变换算子T；
Then, according to the base coordinate of locating rod, gain the coefficients of projective transformation.
差分gps水下立体定位系统包括GPS差分基准站、GPS浮标、水下收发机、船基控制中心四部分。
Underwater GPS positioning system includes four parts which are GPS differential reference station, GPS buoy subsystem, underwater pinger, ship-based data processing and control center.
针对性对地磁辅助导航定位中基准图制备的需要，采用了建立区域地磁场模型的方法。
The method of regional geomagnetic field modeling is adopted in order to prepare for the reference map of geomagnetism-aided navigation and positioning.
该系统用高稳定度铷钟作为时间基准信号，实现了无源导航定位功能。
Rubidium atomic clock is used for the time reference signal in the system, by which the user can get the positioning information without sending any signal.
在导航系统中，基准站配置的优劣直接关系到定位的精度及系统的可用性。
The positioning accuracy and availability of navigation system are affected directly by the quality of satellite configuration.
利用局域差分GPS进行定位时，只有当流动站位于基准站构成的多边形网内时，才可能得到较高的精度。
The distance from user to reference station influences the positioning accuracy definitively in local area differential GPS.
目前流行的CAD系统具备一定的数据预处理功能，如：去除明显噪音点、对称基准重建、重定位整合等。
The present popular CAD systems can deal with CMM data to some extent, such as: delete noisy points, rebuild symmetrical benchmark, data combination.
目前流行的CAD系统具备一定的数据预处理功能，如：去除明显噪音点、对称基准重建、重定位整合等。
The present popular CAD systems can deal with CMM data to some extent, such as: delete noisy points, rebuild symmetrical benchmark, data combination.
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