查询词典 parameter

Rice ; biophysical parameter ; leaf area index ; spectral variable ; biomass ; water content ; leaf shape parameter

水稻；生物物理参数；叶面积指数；光谱变量；生物量；含水率；叶形状参数

ABSTRACT Aiming at problems of trans-vector controller in a vehicle-carried induction motor such as variable rotor and stator resistance following motor temperature, and their inductance varying with flux saturation degrees. Firstly, CSI and VSI are introduced, for CSI, it can hold the advantages both FOC and DTC using stator flux directional, PI parameter and simulation are also introduced. Secondly, equations of IM in the synchronous rotary frame and its static counterpart, as figuring in the saturation condition of magnetic field, are dealt in this paper and the simulation results are presented. Thereafter, the parameter designing of PI trans-vector controller is processed, which features the non-linear model. In practical realization, as neglecting the dynamical change of motor inductance, this paper employs online modification of inductance parameters, according to the flux saturation, then transforms the non-linear equations into linear ones, and so compacts the structure of controller. Thirdly, in view of the maximum torque output is extraordinary requisite when Electrical Vehicle start up, accelerate, and overtake, this paper issues the maximum torque when both inverter and battery capacity is corporeally definite. Fourthly, on-line differentiating and analyzing both rotor's time constants and its flux by using the expanding order reduction and discrete Kalman filter equation are fathomed, in order to realize high-performance trans-vector algorithm, and also the simulation results are presented. Fifthly, the close-loop regenerative brake system, when the EV's torque is set constant, is deduced; at the same time, unification of electric drive model and brake model is executed. Combined with maximum charge current demands, the mathematical model for online yielding torque as a demand.

本论文针对车载异步电机在矢量控制器所遇到的问题：定转子电阻随温度变化及随电机饱和程度变化的转子电感及定子电感而影响电机调速性能提出一套完整的解决方案：分析了电流型逆变器和电压型逆变器在实现矢量控制时控制器参数的计算，分析出对于电流型逆变器在采用定子磁场定向时，其性能同时具有矢量控制和直接转矩控制两者的优势，并对电压型逆变器在转子磁场定向下的模型进行了仿真研究；建立异步电机非线性模型，推导出考虑磁饱和时异步电机在同步旋转坐标系及静止坐标系下的方程，并做出了仿真结果，建立异步电机在非线性模型下的矢量控制调节器的PI参数设计，在实际应用中，若忽略电机电感的动态变化，可以根据当前的磁路饱和状态而在线修正电感参数，从而将非线性方程线性化，降低控制器的复杂度；考虑到电动汽车在起动和加速超车时需要电机有最大转矩输出，本文讨论在逆变器容量一定和电池供电能力有限的情况下电机最大转矩输出问题；推导了异步电机扩展降阶、离散卡尔曼滤波方程在线辨识转子时间常数和转子磁通，用于实现高性能的矢量控制算法，并给出了仿真结果；推导出了电动汽车恒转矩给定的闭环回馈制动系统，实现了电动控制模型和制动模型的统一，而且结合铅酸电池最大充电电流的要求，为制动转矩在线给定建立了数学模型；设计了基于双DSP系统的高性能矢量控制器软硬件框图，并以大量实验数据说明矢量控制在电动汽车应用的实际应用状况。

Because of the universal existence of parameter perturbation and the fault ineluctability for actuator and sensor, it is more important and practical to study robust fault-tolerant control of parameter perturbation for linear system with time-delay.

由于参数扰动的广泛存在性以及执行器和传感器发生故障的不可避免性，使得研究具有参数不确定的时滞系统的鲁棒容错控制问题具有更重要的现实意义。

In order to reduce the influence caused by the controller parameter variations and the plant parameter perturbation, and assurance the tracking performance and the restraint disturbance performance, the improved robust two degree-of-freedom control structure and the linear matrix inequation design method are adopted to design the robust two DOF controller of the servo system in this thesis.

为了降低控制器参数及被控对象参数摄动对系统性能造成的影响，同时，保证系统的跟踪性能和抗扰性能不变。

The study on laser bending-forming is still in starting phase, so the parameters of laser bending-forming (include laser parameter 、 sheet parameter、 property of material etc.) still can't be controlled accurately. It is also a technique difficulty of laser bending-forming and the important impedimental factors to development of the technique that the inscrutability of forming results and the difficulty to select process parameters.

激光弯曲成形的研究还处于起步阶段，关于激光弯曲成形的参数(包括激光参数、板材参数、材料性能等)还没有达到精确控制的程度，同时成形结果难以预测和加工参数难以选定也是激光弯曲成形技术的一个难点，也是阻碍这一技术向前发展的重要因素。

The method of slide-mode variable structure control is such a strategy that is characterized of low mathematical model precision, insensitiveness to system parameter variation and external disturbances, omission of parameter identifications, fast dynamic response and easy implementation. These advantages make it suitable to high performance vector controlled AC motor drives.

滑模变结构控制是一种强鲁棒性的控制方法，对系统数学模型精度要求不高，具有快速响应、对参数及外部扰动变化不敏感、无需系统在线辨识，实现简单而且很适合计算机实现等优点，因此，很适合高性能的交流电机矢量控制系统。

Based on the theory proposed by Alkhalifah, that is the reflection wave is determined by normal moveout velocity V of short-spread and anisotropic parameter η under the condition of long-spread data of vertical and lateral isotropic media and non-hyperbolic curve, a method for long-spread data velocity analysis is studied. A 2 step scanning method is used for the hyperbolic and dual parameter scanning of long-spread data.

根据Alkhalifah提出的垂直横向各向同性介质长排列情况下反射波走时由短排列的正常时差速度v和各向异性参数η确定，并具有非双曲线形式的理论，研究了针对长排列数据的速度分析方法，通过2步扫描方法实现了长排列数据的非双曲线双参数扫描。

In the computation, considering the influence of all of joggle parameter, adopting compound-aitch optimization and intellective distinguish can prevail more reasonable joggle parameter.

采用复合形优化方法和人工判别可得到更加合理的啮合参数。

To develop Linear Fractional Transformation model based on quasi-linear model for ground-to-air missile, state transformation method was used to establish quasi-Linear Parameter Varying model for missile longitudinal short-period dynamics by changing missile states along with an equilibrium trajectory decided by time-varying parameters. Based on the obtained quasi-LPV model, the LFT model of the missile was developed by use of MATLAB functions, and the missile dynamics were explicitly separated into certainty part and time-varying parameter part.

为了建立基于准线性化模型的地空导弹线性分式变换模型，采用状态替换方法将导弹的状态沿着一条由时变参数决定的平衡点轨迹进行变换，建立了纵向短周期动力学的准线性参数时变模型；基于所建立的准LPV模型，采用MATLAB函数建立了导弹的LFT模型，将导弹动力学明确描述为确定性部分和时变参数部分。

The linear sampling method for the inverse scattering problem of acoustic waves is based on the fact that: a linear integral equation of first kind-far field equation including a parameter has an unbounded solution as the parameter approaches the scattering boundary from inside.

本文在此基础上就Dirichlet边界条件的声波反散射问题，利用积分方程理论严格证明了线性抽样方法对其的可用性，具体数值例子表明该方法是有效的。

Bob Eckert has been chairman and chief executive of Mattel for eight years.

美泰董事长兼首席执行官鲍勃·埃克尔特在任已8年。

The outlook for honors and disgraces carries on and surpasses the traditional outlook for honors and disgraces theoretically, and carries on and develops the theory of construction of socialist mora...

社会主义荣辱观的提出在理论上是对传统荣辱观的一次继承和超越，是对社会主义道德建设理论的继承和发展，在实践上有利于形成良好的社会风尚。