查询词典 unstable solution

When the power is too high, the unstable conditions may happen for various methods of autoregression spectra analysis.

自相关法的分辨率略低，但其稳定性较好，可优先考虑使用。

Based on the analysis of the mechanism of robot manipulators, a trajectory tracking controlling research model is first built up with ADAMS, and its mathematical model is formulated through the study of robot kinematics and dynamics. After the modeling errors are analyzed in practical robotic systems, a conception of centralized error is brought forward according to the theory of weighting functions. In the case of modeling errors' exist, the robotic uncertain model is derived by introducing an auxiliary control variable into inverse dynamic analysis. The control strategy of robust exponential convergence is applied to the robotic uncertain model, the applicable conditions and the applicable controller with this application are presented. The stable control effect under three main model uncertainties (parametric errors, joint disturbs, joint frictions) are systematically studied on the previously built research model. The problems of robust exponential convergence controller which often results in unstable output and so produces a large relative error when the input trajectory is in a small range are resolved by adjusting the control parameters based on the controller's structure.

本文在机械手的机械结构分析基础上，利用ADAMS建立了用于机械手轨线跟踪控制研究的机械手模型；通过对机器人运动学和动力学问题的研究，建立了机械手研究的数学模型；分析了机器人系统中模型误差的主要来源，根据加权函数法分析，提出了模型集中误差的概念；在存有模型误差的情况下，采用逆动力学结构并引入辅助控制量，由机器人误差模型推导了机器人非确定性模型；提出了采用鲁棒指数收敛法对上述机器人非确定性模型进行鲁棒镇定的控制策略，并给出了对机器人进行鲁棒指数收敛控制时系统不确定因素应满足的匹配条件；针对机械手研究模型，深入研究了鲁棒指数收敛控制器对机器人系统中常见的模型参数误差、关节扰动、关节摩擦等不确定因素的镇定控制效果；针对鲁棒指数收敛控制器易产生控制量振荡的问题以及在小范围内系统轨线跟踪的稳态误差过大问题，本文分别提出了基于控制器结构的控制参数调整法和基于轨线跟踪范围大小的控制参数分段切换法。

In high speed offset printing ,unstable performance of bailer has adverse effect on the quality of presswork.

在高速胶印生产中，水斗液的性能不稳定对印刷品的质量产生不良影响。

A ship without ballast is unstable and will not go straight.

一条没有载重的船是不稳定的，不会走的很远。

A ship without a ballast is unstable and will not go straight.

船舶无镇流器是不稳定的，并不会直行。

Objective To study the Bax expression in stable and unstable carotid atheromatous plaques and its clinical significance.

目的 研究Bax基因在稳定和不稳定粥样斑块中的表达及临床意义。

In order to resolve these questions, we try to find some new protecting group which could be used in the preparation of such unstable nucleotides analogues.

对于一些寡核苷酸的类似物，由于它们在某些化学环境下的不稳定性而使它们的合成具有一定的困难，为了解决这些问题，人们一直在开发新的保护基，以消除这些副反应的影响，更方便地制备这些化合物。

Because of their chemical affinity, one base must be paired with another, and this makes them very unstable.

由於盐基阴阳相吸的作用力，必须与另一半组合成对，所以很不稳定。

Such a world would be unstable and prone to conflicts.

这将导致世界不稳定并易起冲突。

Any of three processes of radioactive disintegration in which a beta particle is spontaneously emitted by an unstable atomic nucleus in order to dissipate excess energy.

某些不稳定原子核为耗散其过剩能量而自发发射一个β粒子的三种放射性衰变过程的统称。

I want to be a big fish in a small pond.

我要做一条在小池塘里的大鱼。

While the software functioned well, we did not feel the same about their customer support!

虽然该软件运行良好，我们没有同样的感觉他们的客户支持！