参数变化

To weaken the influences of the position-dependent periodic disturbances and parameter uncertainties, the robust repetitive controller was designed, which associated structure singular value theory with the discrete-time repetitive control theory. The problem of robust repetitive control was transformed into one of H∞ optimal control using linear fractional transformation. The robust repetitive controller was achieved using D-K iteration procedure and made the servo system have stability, robustness and tracking performance.

为了削弱周期性扰动及参数变化不确定性的影响，将重复控制和结构奇异值理论相结合，利用线性分式变换(linear fractional transformation，LFT)将鲁棒重复控制问题转换成H∞最优控制问题，采用D-K迭代法设计鲁棒重复控制器(robust repetitive controller，RRC)，实现系统的稳定性和鲁棒性，提高系统的跟踪特性。

The power spectrum density and mean square value of acceleration at every output position including the driver's seat are computed by means of solving the frequency response function, so as to show the changes of vibration magnitude through parameter-transformation.

在计算中除考虑了多点输入的自谱及前后轮之间的互谱外，还根据有关路面资料考虑了左右轮之间的互谱。结合乘坐舒适性研究，绘出了座椅振动量随各参数变化的一些规律，可为今后设计工作参考。

Because both the control measurer are based on the model, all the factors mentioned above may cause the performance deteriorate considerably.

因为这两种方案都是基于模型的控制方案，它们对参数变化较为敏感。

Further, the paper also discusses the effect of parameter changing to the system; it has important reference value to improve the design of control system in Adding medicament.

此外还讨论了系统的各个参数变化对系统产生的影响，对今后改进加药控制系统的设计有重要的参考价值。

In consideration of these complicated factors, Duncan—Chang model is used for the soil in this paper, and the deep excavation is modeled by using the method of coupling of multiple finite elements such that calculation results approach to actual condition. In addition, based on the theory of increment method, dynamic simulation using the finite element methods is investigated for the deep excavation.

考虑到众多复杂因素的影响，本文采用邓肯—张模型做为土的本构模型，使用该模型进行计算能够较为充分地考虑到各种复杂因素的影响，而且实际工程中对于邓肯—张模型的参数变化情况已积累了较丰富的经验：采用多种形式有限元耦合的方法对深基坑问题进行建模，从而达到使计算结果接近实际的目的。

Simulation results show that AC servo system based on proposed mixed control strategy can satisfy the systems need of speediness、Stability and robustness preferably.

仿真结果表明，应用本文所设计的RBF神经网络与PID复合控制器能获得较高的动态和稳态性能，并对参数变化和负载扰动具有良好的鲁棒性，可很好地满足系统的高性能指标要求。

For the characteristic of ring permanent magnet torque motor used in direct drive numerical control round table suffering from the effect of load disturbances and parameter variations, the H∞ controller design methodology without the orthogonality assumptions is combined with m-K iteration in m synthesis to design a m-H∞ speed controller in this paper.

针对直接驱动数控转台用环形永磁力矩电机易受负载扰动及参数变化影响的特点，将去除正交性假设的H∞控制器设计方法与m综合中的m-K迭代法相结合，设计了一个m-H∞速度控制器。

For the characteristic of the ring permanent magnet torque motor used in direct drive numerical control round table suffering from the effect of load disturbances and parameters variations, a multi-objective mixed H2/H∞ static output feedback controller, which makes all poles of the closed-loop system be located within a prescribed linear matrix inequality region D to achieve pole placement, is designed based on LMI.

针对直接驱动数控转台用环形永磁力矩电机易受负载扰动及自身参数变化影响的特点，文中基于线性矩阵不等式(linear matrix inequality， LMI)，设计了一个多目标混合H2/H￥静态输出反馈控制器，该控制器可使闭环系统的极点均落在预先选定的线性矩阵不等式区域D内来实现极点配置。

The simulation result demonstrate the robustness to the variety of parameter and the good performance of decoupling control.

仿真结果表明：系统对参数变化具有较强的鲁棒性，取得较好的解耦效果和系统控制性能。

Experimental results show that the sliding mode observer with extended Kalman filterhas good dynamic perfor-mances,strong robustness for the parameter variety of system and external interfere.

实验结果表明带有扩展的卡尔曼滤波的滑模观测器具有良好的动态性能，对被控对象的参数变化和扰动有很强的鲁棒性。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。