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141.
研制了一块微操作机器人控制板,采用USB接口通信和C8051单片机做规划器。介绍了PDIUSBD12和C8051F236的内部结构、性能指标,并给出了波导耦合机器人控制系统软硬件和系统结构设计。该控制板在实际工作中运行良好,性能稳定。 相似文献
142.
An LQ strong stabilization problem is proposed. To determine when a controller with periodic gains is locally superior to a linear time invariant compensator for this problem, a Π test is presented. For systems with strictly proper transfer functions, it is proven that the frequency range where stable periodic controllers based on weak variations about the LTI case can give better performance than stable LTI compensators is finite. In the development, a means to evaluate the second partials of functions with respect to matrix-valued parameters is introduced. For those systems where periodic control is warranted, techniques for designing optimal periodic strongly stabilizing controllers are presented. Two examples detailing the application of the Π test are provided, as well as an optimal periodic controller design example. 相似文献
143.
有功功率及功率因数的加权算法 总被引:14,自引:1,他引:14
提出了一种能有效地抑制由非同步采样引起的有功功率及功率因数的测量误差的加权算法。推导出任意电压、电流信号的有功功率、功率因数随相对频偏及采样相位变化的一般公式;传统算法的有功功率、功率因数的测量误差与相对频偏成正比;而用该文所提出的三角窗加权算法。有功功率、功率因数的测量误差与相对频偏的平方成正比。该算法实现简单,精度高,当相对频偏不大时,无须专门的同步采样措施即可取得较高的测量精度。 相似文献
144.
This article considers feedback control systems wherein the control loops are closed through a real-time network, and expresses
the linear time-invariant system with the constraint in an input or output as a periodic discrete time system. It is shown
that this system is stabilized by using output sample hold contol. This method has the merit that the capacity of a sensor-controller
communication bus is small.
This work was presented, in part, at the 8th International Symposium on Artificial Life and Robotics, Oita, Japan, January
24–26, 2003 相似文献
145.
Pure and rare earth doped gadolinium oxide (Gd2O3) waveguide films were prepared by a simple sol-gel process and dip-coating method. Structure of Gd2O3 films annealed at different temperature was investigated by X-ray diffraction and transmission electron microscopy. Oriented growth of (400) face of Gd2O3 has been observed when the films were deposited on amorphous substrate. The refractive index and thickness of films were determined by m-lines spectroscopy. The laser beam (λ= 632.8 nm) was coupled into the film by a prism coupler and the propagation length is about 3.5 cm. Luminescence properties of europium ions doped films were measured by waveguide fluorescence spectroscopy, which shows disordered environment for Eu^3 at 400℃. 相似文献
146.
147.
A combined 2D numerical-analytical algorithm for electromagnetic (EM) fields computation in one-counter waveguides with arbitrary cross section is proposed. The developed algorithm is employed to investigate the influence of the normalized propagation constant and dielectric loading on the field distribution in a rectangular T-septum waveguide with an E-plane dielectric insert. Dominant-mode varieties of a given transmission line are represented. © 2004 Wiley Periodicals, Inc. Int J RF and Microwave CAE 14, 201–205, 2004. 相似文献
148.
The performance of porous bearing under different lubricants and lubricating conditions was experimentally investigated in
this study. In order to carry out the experiments, a new test rig was designed to determine the tribological properties of
based sintered bronze journal bearings that were manufactured by powder metallurgy (P/M) techniques. To determine the effects
of lubricating conditions with and without oil supplement (OS) on the tribological characteristics of these bearings under
static loading and periodic loadings, some experiments were carried out using different lubricants. In the tests, pure base
oil (SAE 20W50), two fully formulated commercial engine oils (SAE20W50) and lubricating oils with commercial additive concentration
ratio of3% were used. The worn surfaces of test bearings were examined using optical microscopy. Experimental results showed that the
change in friction coefficient was more stable and in smaller magnitude under static loading than that of periodic loading.
In addition, the friction coefficient and the wear rate conducted with base oil resulted in higher values than those of fully
formulated oils with and without OS lubricating conditions. The experimental results obtained in this study indicated that
the correct selection of lubricant and suitable running conditions were very important on the tribological characteristics
of porous bearings. 相似文献
149.
通过对典型零件的加工工艺分析,介绍了用北京迪蒙卡特线切割机床加工锥度、上下异形类零件的程序编制规则和方法,该方法相比TurboCAD软件自动编程操作简单快捷,编程者更易掌握。 相似文献
150.
The periodic structure of the underlying support of paintings on canvas can become quite prominent and disturbing in high resolution digital recordings. In this paper, we construct a new model and method for the digital removal of canvas which is considered as a noise component superimposed on the painting artwork. The high resolution of the images prohibits the efficient application of existing adaptive denoising filters. Hence, a two-step approach is proposed. First a (smoothing) Wiener filter is applied to the complete image. The second step consists of a spatially adaptive extension with low-complexity to obtain a generic digital canvas removal filter. 相似文献