变换

The metamorphic and mobile robot proceeds on flat road and slope of twenty degree and it changes motive postures meantime, then the torques of changing postures and proceeding are measured and the motive parameters are abstained through feedback measure while the arms and pedrails of the robot change their postures.

论文中通过对变形机器人在平坦路面上运动和进行20度斜坡的爬坡运动，以及在运动过程中各种姿态的变换的仿真，得出了运动过程中姿态变换和运动每个时刻所受到的力矩大小，通过反馈测量得出了姿态变换时加长臂和履带的运动参数。

However it can not be widely used in industry because of commutation problem, low voltage transformation ratio and complicated PWM method.

本文介绍了一种新型的矩阵变换器—稀疏矩阵变换器，它具有传统的矩阵变换器的优点：四象限运行；没有直流环节的储能元件和高质量的输入电流/输出电压波形。

The control signals of the PWM rectifier are obtained by comparing the current of AC side with triangular wave (or saw-tooth wave) directly, which can implement the steadiness of the voltage of DC side and unit capacity factor of the system. At the same time, harmonic component of the system is abstracted through Instant Reactive Power Method, which can be smoothed by Integrated Learning Boost Converter Control.

本文采用重复学习Boost变换技术，利用滑模变结构控制技术对单相PWM整流器恒频Boost变换进行了分析，提出将交流侧电流直接与三角波相比较得到开关控制信号的方法，实现直流电压恒定不变及系统单位功率因数；同时，利用瞬时无功功率法分析系统谐波，并在谐波域内使用重复学习的控制方法，结合Boost变换技术，有效滤除系统谐波有功电流。

Based on one-cycle control having such merits as anti-perturbation of source, fast dynamic response, robustness, constant frequency, but when converter works in light load its power factor becomes very poor. The modified OCC was proposed, adopting feed-forward compensation control improves influence of power factor at light load, further study adopting independence saw tooth wave completely eliminate influence of power factor at light load.

基于单周期控制有源前端变换器具有抗电源扰动能力强、动态响应快、鲁棒性强、恒频控制等优点，但在轻载时变换器的功率因数变差，提出了改进OCC策略，采用前馈补偿控制改善轻载时对功率因数的影响，进一步研究采用独立的锯齿波电路完全消除轻载时对功率因数的影响，建立改进OCCAFE变换器的数学模型。

However, PSM also has some disadvantages: large output voltage ripple and audio noise at light load.

本文主要工作包括以下几个方面内容： 1对工作于DCM模式的PSM变换器变换效率及输出电压纹波进行研究，并与相同条件下的PWM和PFM变换器模式性能进行比较。

In particular, it is found that the output ripple voltage of boost and buck DC-DC converters are related to the duty ratio of input pulse.

本文提出了开关DC-DC变换器的线性空间建模法，并将其成功地用于升压型和降压型DC-DC变换器的分析，首次导出了上述两类变换器的输出纹波表达式，特别是输出纹波与控制脉冲占空比之间的关系。

A new modeling method for DC-DC power coverter is proposed in chapter 3, and it is applied to the analysis of output ripple voltage of boost and buck DC-DC converters.

本文提出了开关DC-DC变换器的线性空间建模法，并将其成功地用于升压型和降压型DC-DC变换器的分析，首次导出了上述两类变换器的输出纹波表达式，特。。。

In the process of designing the Digital Scan Converter of the B-mode ultrasound- tomography, there is a key technique that transforms the coordinate and interpolates the data. This research discusses a new algorithm used in the Digital Scan Converter called CORDIC.

在设计B 型超声诊断仪中数字扫描变换器的过程中，坐标变换和数据插补是关键的技术，本研究论述了应用在数字扫描变换器中的一种新的算法——CORDIC 算法。

Gray operation, image filtering, geometric transf...

灰度操作，图象滤波，几何变换，形态学变换，正交变换，图象分割，图像复原，纹理特征，人工神经网络等。

The principle is stated of asynchronous and synchronous voltage-frequency converter s with VFC110 and AD652 as examples.

以VFC110和AD652为例，介绍异步和同步两种电荷平衡式电压频率变换器的工作原理、计数测频方案，进行变换误差分析，比较两种电压频率变换器的特点。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。