查询词典 discretization error

On the basis of the study on the mathematical model of the closed-loop location control, the analysis of contour error in the process motion control and error calculation model, according to the lack of using normal contour error model not to calculate contour error of curve in real-time, combining real-time contour error compensation control strategy and fuzzy logic theory, the fuzzy logic and real-time contour error calculation based self-discipline control strategy is proposed.

2在研究闭环位置控制数学模型、加工轮廓运动控制中的误差分析和轮廓误差计算模型的基础上，针对利用一般运动轮廓误差计算模型不能实时计算出曲线轮廓误差的不足，结合实时轮廓误差补偿控制策略和模糊逻辑理论，研究了基于模糊逻辑理论和实时误差计算的轮廓自律控制策略。

The evaluation method and algorithm of shape error (roundness, plane straightness, space straightness, cylindricity) were discussed. A new kind of algorithm, namely mesh searching method, which can be used to evaluate the roundness error, plane straightness error, space straightness error and cylindricity error, were put forward. With this algorithm, the shape error can be obtained by transferring the distance formula repeatedly and simple judgment without linearzing the distance formula (from point to point or point to line) and choosing optimal direction and step length.

对形状误差(圆度、平面直线度、空间直线度、圆柱度)的评定方法及算法进行了讨论，提出了一种评价圆度误差、平面直线度误差、空间直线度误差及圆柱度误差的新算法——网格搜索法，该算法不需要对距离公式线性化，也不需要选定优化方向和优化步长，只需重复调用距离公式和简单的判断即可得到符合定义的形状误差。

In the paper, a generalized error model for the robots is set up by using DH coordinates. Moreover, a new analytical technique called"analysis on the error prominency factors for the robot pose error"is proposed. Numerically, the error prominency factor can express the extent of influence on the pose error of the end effector resulted form every DH parameter error within the whole working space of the robot.

在这一研究过程中，除了建立了用DH坐标描述的机器人末端位姿误差和轨迹误差的通用模型之外，还提出了一种新的机器人位姿误差分析技术——机器人位姿误差的显著性分析法。

Based on the discussion about fitting normal error's definition, constitution and properties, it was suggested that fitting normal error represented the error of fitting plane linear in old highway. The accuracy index of fitting plane linear in old highway based on fitting normal error was set up. The algorithm of swinging approach on compressible size step that could be used to calculate the fitting normal error was put forward. The method and basic norm of decision about fitting normal error's symbolic were discussed.

在论述拟合法线偏差定义、构成及性质的基础上，提出以拟合法线偏差表征旧路平面线形拟合偏差；建立了基于法线偏差的旧路平面线形拟合精度指标；提出了采用步长压缩摆动趋近法计算拟合法线偏差的算法，并就拟合法线偏差的符号判定准则及方法进行了讨论。

On a grating type gear integrated error measuring equipm ent, this technique employs the three-point method error separation technique fo r separation of the systematic error of the measuring chain of equipment spindle system including measuring worm error, grating transducer error, bearing rota ry error etc.

在一台光栅式齿轮整体误差测量仪上，它用三点法误差分离技术能分离开仪器轴系测量链的系统误差(包括测量蜗杆误差、光栅传感器误差、轴承回转误差等)和被测齿轮的全谐波误差。

To solve the difficulties of the discretization and application of fractional order controllers, evaluation strategies of digital realization of FOC are investigated. The realization principle and process of various discretization methods are discussed.

针对分数阶控制器数值计算和应用难的问题，提出了分数阶微积分算子数字实现方法的评估策略，分析了分数阶微积分算子的多种数值计算法的机理和实现步骤。

A third order ENO finite volume method for hyperbolic conservation laws on unstructured triangular mesh is introduced.In order to obtain the third order accuracy on spatial discretization,a weighted quadratic interpolation is constructed on every triangular mesh.Two point Gauss quadrature formula is also used on each edge of every triangular mesh and the third order TVD Runge-Kutta method is used for time discretization.The numerical order of convergence and the numerical result of a mesh 3 wind tunnel with one step are given.

摘 要 基于双曲型守恒律方程，对非结构三角形网格给出了一种ENO(Essentially Nonoscillatory Scheme)型有限体积格式，方法的主要思想是先对每一个三角形单元构造一个加权的二次插值多项式，而在计算交界面的流通量时采用了两点高斯积分公式以保证格式的整体精度，时间离散采用三阶TVD Runge-Kutta方法。

Finite element discretization was carried out on the mathematical model to get a fully coupled finite element equation with the parameters of element nodal displacement and element nodal pore pressure as unknown variables. Finally, the transient nonlinear finite element equation in incremental form for reservoir fluid-solid coupling is obtained by means of time discretization in implicit difference scheme.

基于与微分方程等价的加权余量公式，在空间域采用有限元离散，对时间域进行隐式差分格式离散，导出了以单元节点位移和单元节点孔隙压力为未知量的储层流固耦合的非线性有限元增量方程。

According to the special structure of the coefficient matrix arising from the SUPG discretization of convection-diffusion problem, or the MAC discretization of the Oseen problem, we use Kronecker product approximation to design the preconditioner.

第一章讨论预条件技术，针对对流扩散问题和 Oseen 问题离散后系数矩阵所具有的特殊结构，用近似 Kronecker 积构造预条件子。

The common method, that all strong-correlation terms of the model are eliminated, can bring the loss in the engineering application, so the new method is proposed that the identified model reserves some correlation. The augmented matrix A is constructed by the outputΔW and the matrix S. The"determinating order based on ratio of determinant"is brought out to screen the strong-correlation terms in the structure identification. The latent root estimation is improved in screening the eigenvalues and eigenvectors. Thus the estimation precision is improved greatly.The consistence check of guidance instrument error coefficients of flight test and ground test is the purpose of flight experiment. The causes of inconsistency of the two models are analyzed. The hypothesis test of linear regression model based on F statistics is proposed to check the consistence.Finally, the instability of error coefficients is probably caused by the change of the flight environments, therefore, the relation between the error coefficients and flight environment is analyzed. The approach is presented to identify SINS guidance instrument error models and compensate the error in the segmented sections corresponding to the change of vertical acceleration of aircraft.

在结构辨识中，常用的方法由于将模型中的强相关项全部剔除而给工程应用带来损失，因此，本文提出了新的有益思想，即在保留一定相关性的基础上进行辨识：将输出向量ΔW与环境函数矩阵S构成增广矩阵A，然后采用"比定阶行列式"来剔除相关向量的方法，这样既可以尽可能多地保留了对落点影响大的强相关参数，又可以对落点影响小的强相关参数给予剔除；在参数估计中，改进了特征根估计中特征根和特征向量的筛选方法，提出"近零"准则，从而大大提高了参数估计的精度；再者，鉴于天地模型"一致性"检验是飞行试验和SINS制导工具误差系数分离的主要目的，因此，本文又深入分析了造成天地模型不一致的原因，提出了采用基于F统计的线性回归模型假设检验方法来进行捷联制导工具误差模型的天地"一致性"检验；最后，鉴于飞行环境剧烈变化可能会对惯性仪表误差系数稳定性带来一定的影响，因此本文深入地分析了SINS制导工具误差系数与外界环境的关系，提出了基于过载变化大小的分段辨识和分段实时补偿的算法。

Salt is good, but if the salt becomes flat and tasteless, with what do you season it?

14：33 盐本是好的，盐若失了味，可用什么叫它再咸呢？

He reiterated that the PLA is an army of the people under the leadership of the Communist Party of China.

他重申，人民解放军是在中国共产党领导下的人民军队。