模态系统

A novel sliding-mode control is designed with a load thrust observer for the Linear Permanent Magnetism Synchronous Motors,in order to compensate the disturbance and effectively minimize the system chattering;introducing an integral action in the sliding mode to eliminate the system error and chattering.

针对永磁同步直线电机提出了一种基于负载推力观测器的新型滑模变结构控制，从而实现对推力扰动的补偿，且大大削弱了推力纹波及系统的抖振；在滑动模态中引入积分环节来进一步消除系统的稳态误差和系统抖振。

The results show that more modalities can be excited from asymmetric system and that there is little difference between the power flow spectra of rigid raft system and flexible raft system in middle and low bands of frequency, but there is considerable difference at high frequency.

研究结果表明，非对称系统能激励出更多的模态；在中低频段弹性浮筏系统和刚性浮筏系统的功率谱没有很大的区别，但是在高频段差别则很明显，浮筏的弹性模态起着主要作用；减小隔振器的刚度并适当增加隔振器阻尼不仅可以降低传递到基础的功率谱，同时还可以抑制共振减小冲击。

Vibration Modal analysis and parameters identify is an analysis method which is used in "athwart question" in the Structure Dynamics.

模态分析的最终目标是识别出系统的模态参数，为结构系统的振动特性分析、振动故障诊断与预报以及结构动力特性的优化设计提供依据。

Firstly, modal responses were estimated by the application of robust second-order blind identification technique on the measured vibration signals. And then, modal shapes were extracted from the de-mixing matrix above. Finally, frequency and damping ratios could be obtained from the modal responses using each single degree of freedom mode.

运用该法提取系统／结构模态参数的步骤为：首先利用稳健SOBI的盲源分离方法采集的信号进行分离，然后将分离矩阵作为结构／系统的模态振型矩阵，最后再对各个分离后的单自由度信号提取频率、阻尼比参数。

Performance evaluation method system of hierarchical IFFCS in air-to-air gunnery mission: The IFFC essence in air-to-air gunnery mission is a problem of space pointing track. Its hierarchical structure consists of three level loops: flight control system loop, space pointing track loop and tactical mission loop.

多重递阶的综合飞行/火力控制系统空/空机炮模态性能评价方法体系；综合飞行/火力控制系统空/空机炮模态本质上是一个空间指向跟踪问题，其多重递阶结构从内到外包括三个层次的回路：飞行控制系统回路、空间指向跟踪回路和战术任务回路。

The relation between the result accuracy and the element number of the system is studied and shows the minimal element number to ensure the response result accuracy is determined by the excitation frequency and the modal modes of the system.

研究指出，保证计算结果精确性的最小网格划分数目与激励频率及管道系统的振动模态有很大关系，即由对管系响应贡献较大的最高阶模态振型决定，这一研究成果对实际管道系统振动响应计算中时间与空间节点的划分提供了理论依据。

Sampling points were obtained by using optimal Latin hypercube design of experimental method,meantime,in order to improve computing efficiency,application of stepwise regression response surface approximate method in the MDO system of the vehicle crashworthiness and free mode of Body-In-White,the approximate model was optimized by using sequential quadratic programming method.

采用最优拉丁方试验设计方法进行样本数据设计，同时，为了提高计算效率，采用了一种新型的响应面构建方法——逐步回归响应面方法构建了整车耐撞性与白车身自由模态多学科系统的近似模型，利用序列二次规划优化方法对此近似模型进行优化，避免了整车碰撞传统优化设计方法计算量大，在碰撞非线性系统优化中常常易导致收敛缓慢甚至不收敛的缺点，在满足了CMVDR294安全法规的同时，使得白车身的扭转模态值得到提高，汽车重量得到较大程度的减轻。

The reciprocal effects between the frequency veering and the sensitivity ofmistuning for a bladed disk are studied. The investigation is based on a finite elementmodel. The reason and features of frequency veering of the bladed disk are analyzed.By using the localization parameter, the effects of mistuning on the system modallocalization of the bladed disk are analyzed in the frequency veering region.

分析了叶盘系统频率转向现象产生的原因及其特点；利用本文提出的模态局部化参数，研究了频率转向区域内叶盘系统的高密集模态对失谐的敏感性；分析了频率转向区域内失谐叶盘系统的振动响应局部化特性。

In order to improve the dynamic quality of the whole system, the dynamic balance precision of the high speed rotor should be improved. Dynamic behavior of geared rotor system was analyzed using modal synthesis method

应用模态综合法分析齿轮传动转子系统的动力学特性，结果表明模态综合法能有效地降低系统的自由度，提高计算速度，对于复杂的多转子-轴承系统的动力学研究具有广泛的应用前景。

The effect of the thickness on the buckling critical pressure is calculated first.

本文还对减压转油线进行了振动特性分析，研究了总体管道系统在刚性支撑和弹性支撑下的固有频率及振动模态，得出了支撑刚度对固有频率和振动模态的影响；计算了进口端竖直管两种不同的约束方式对减压转油线整体固有频率及振动模态的影响，为以后对转油线进行进一步的振动分析提供了宝贵的数据。

They weren't aggressive, but I yelled and threw a rock in their direction to get them off the trail and away from me, just in case.

他们没有侵略性，但我大喊，并在他们的方向扔石头让他们过的线索，远离我，以防万一。

In slot 2 in your bag put wrapping paper, quantity does not matter in this case.

在你的书包里槽2把包装纸、数量无关紧要。