共查询到20条相似文献,搜索用时 0 毫秒
1.
Takahiro Nomura Hiroshi Iwata Kohji Higuchi Kazushi Nakano 《Artificial Life and Robotics》2010,15(1):83-88
Recently, it has been found that the bandwidth of pulse-width modulation (PWM) power amplifiers needs to be extended, for
example, in an application for testing the power supply of a low-frequency immunity examination or a class-D amplifier. In
this article, we show that the bandwidth of a PWM power amplifier can be extended by using an approximate 2DOF digital controller.
This controller is implemented in digital signal processing (DSP). It is demonstrated by experiments that the bandwidth can
be made wider with this controller. 相似文献
2.
3.
以PIC单片机为控制核心,提出了一种基于自适应PID控制器的160WLED16位数字调光系统的PWM恒流控制器的设计方案。用串联在160WLED电路中的电阻对LED电流进行检测得到电压信号,经过放大后,送PIC16F873A单片机的A/D转换器转换为量化值,通过与给定的亮度等级的PWM信号的第一次电流采样为基准电流信号进行比较,改变PWM输出的占空比控制LED的亮度等级。经测试,本系统能够实现160W白光LED在16位各级不同亮度时的恒流控制。 相似文献
4.
5.
通信系统中功率放大器(PA)的效率和线性度影响着整个系统的性能,而Doherty技术是提高效率的一种有效方式,但在提高效率的同时,它的线性度也会变差。数字预失真(DPD)是一种最具有前景的线性化技术,近年来各种模型被不断提出。通过在一种合适阶数、记忆深度的记忆多项式DPD中采用新的RLS与LMS混合算法,实现Doherty功放(DPA)快速、高效的线性化。仿真结果表明所提算法能够快速收敛,对系统的非线性和记忆效应有明显改善。 相似文献
6.
7.
This paper presents the design and test of a 6-degree-of-freedom(DOF) precision positioning system, which is assembled by two different 3-DOF precision positioning stages each driven by three piezoelectric actuators (PEAs). Based on the precision PEAs and flexure hinge mechanisms, high precision motion is obtained. The design methodology and kinematic characteristics of the 6-DOF positioning system are investigated. According to an effective kinematic model, the transformation matrices are obtained, which is used to predict the relationship between the output displacement from the system arrangement and the amount of PEAs expansion. In addition, the static and dynamic characteristics of the 6-DOF system have been evaluated by finite element method (FEM) simulation and experiments. The design structure provides a high dynamic bandwidth with the first natural frequency of 586.3 Hz. Decoupling control is proposed to solve the existing coupling motion of the 6-DOF system. Meanwhile, in order to compensate for the hysteresis of PEAs, the inverse Bouc-Wen model was applied as a feedforward hysteresis compensator in the feedforward/feedback hybrid control method. Finally, extensive experiments were performed to verify the tracking performance of the developed mechanism. 相似文献
8.
Yasin Alekajbaf Nasser Masoumi Mahmoud Mohammad‐Taheri Safieddin Safavi‐Naeini 《国际射频与微波计算机辅助工程杂志》2020,30(5)
In this article, a 2 to 6 GHz solid‐state power amplifier with 53 dBm output power has been analyzed, designed, and fabricated. To achieve a wideband high output power, we introduce a 16‐way hybrid power combiner based on microstrip planar binary and parallel structures. The simulation and measurement results of the proposed hybrid power combining network (PCN) show that the maximum power combining efficiency is around 86% with the insertion loss of around 0.6 to 1.5 dB and an isolation of 20 dB between the ports. Also, to compensate the output power variations due to the thermal and operating frequency changes across the bandwidth, a digital level control (DLC) unit utilizing an agile control algorithm is proposed which decreases the output power variations to 2% of the desired output power. A cooling heatsink fan system has been also designed in order to transfer the heat generated power to the air. The measured output power for the applied input continuous wave is higher than 52.5 dBm. In addition, the power added efficiency (PAE) is better than 15% across the wide portion of the bandwidth and the measured third‐order intermodulation is about 20 dBc (average). 相似文献
9.
Cire Sall El houcine Chakir El Alaoui Saïd Doubabi El Mostafa El Warraki 《Simulation Modelling Practice and Theory》2011,19(1):301-313
This paper is concerned with the design of a robust AQM control scheme for congestion control in Internet. The design of efficient control schemes is challenging since the TCP congestion window model presents both time-varying time delay, appearing in the state and the control signal, and model uncertainties, due to variations of network characteristic parameters. Hence, our paper begins firstly by giving sufficient conditions for stability and stabilizability for the class of systems whose dynamic is similar to the TCP congestion window one, in term of LMI. After, the general results obtained are applied to congestion control, resulting in a new AQM which is implemented in NS2 and compared to other ones in the literature, as PI and REM. The simulations emphasized the effectiveness of our AQM and its improvements with respect to the other control schemes. 相似文献
10.
开关类功率放大器相对于传统的线性功率放大器有更高的效率,其中E类开关功率放大器由于其高效、易于实现等特点被广泛运用,但在低频率时E类功率放大器难以达到足够的输出功率和效率。设计实现的多频段开关功率放大器在高频段(433 MHz)采用E类匹配方式,在较低的频段(315 MHz、230 MHz)采用新颖的方波匹配。在Cadence软件平台下进行仿真及版图绘制,结果显示该多频段开关功率放大器各频段都实现了20 dBm的输出功率,漏极效率均达到40%,同时,通过控制晶体管尺寸,可以对输出功率进行数字控制。 相似文献
11.
T. C. Hsia 《野外机器人技术杂志》1994,11(6):517-521
Asymptotically stable robot manipulator control in both joint space and Cartesian space can be achieved by using a PD controller with gravity torque compensation. However, the stability of this class of control law has not been analyzed with the use of estimated gravity torques. The objective of this article is to present such a stability proof assuming uncertainty in the gravity estimate. The proof is carried out for the Cartesian space controller. The result is supported by computer simulation. © 1994 John Wiley & Sons, Inc. 相似文献
12.
13.
为实现音频功率放大器无线音量调控、可携带、能方便地与CPU和MP3连接等功能,采用TDA2030功放芯片、M62429(数字电位器)和PT2272无线接收模块设计了一个具有无线调音功能的便携式音频功放,具有体积小、输出功率大、失真小等特点。Abstract: In order to make audio power amplifiers(PA) have the features of wireless audio volume control,portable and easily connected with CPU and MP3,a small audio PA is designed using the TDA2030 PA IC,M62429 digital potentiometer IC and PT2272 wireless receiver 相似文献
14.
The design of a digital controller by the method of inequalities is proposed, and a computer program is developed for such a purpose. In the program, the time response of the closed-loop system is calculated in continuous time, not at the sampling time, and the inequalities are checked. An approach for determining a stability point is described. 相似文献
15.
16.
This article proposes a new technique for the tuning of a discrete adaptive controller that is designed based on Lyapunov stability concepts. The tuning is based on the minimisation of a performance index that can be calculated from a generalised eigenvalue problem (GEVP) using LMI's (Linear Matrix Inequalities). The proposed technique results in an adaptive controller with time-varying tuning gains. The solution is based on an approximation of the optimal dual adaptive control problem. The tuning technique was used to perform on-line control of a first-order system and an isothermal and a non-isothermal CSTR. The results show that the proposed approach provides better performance than an adaptive algorithm with the same structure, but with constant adaptation gains. Also, the proposed algorithm is shown to be superior to an adaptive controller based on a Recursive Least Squares (RLS) estimator during sudden changes in model parameters. 相似文献
17.
In-Kyu Choi Jong-An Kim Chang-Ki Jeong Joo-Hee Woo Ji-Young Choi Gihun Son 《International Journal of Control, Automation and Systems》2009,7(1):67-73
A digital turbine control system (TCS) has been developed for retrofitting an old analog TCS in a nuclear power plant. The
developed TCS, which controls the speed of a turbine and the power load of a generator, is based on a triple modular redundant
structure to ensure the system reliability. In addition, a turbine simulator has been developed to verify the perfection of
the TCS prior to its actual installation. The simulator is composed of a graphic editor, a component model builder, and a
system simulation solver. The tested TCS has been successfully applied to a CANDU type nuclear power plant. This paper describes
major features of the developed TCS and the turbine simulator including thermal-hydraulic models. Also, the simulation result
in a laboratory is compared with the pre startup simulation and the actual operation result.
Recommended by Editor Hyun Seok Yang.
In-Kyu Choi was born in Jeonjoo, Korea in 1967. He obtained his Master’s degree in Electrical Engineering from Chungnam National University
in 2004. His research interests include control in power plant machines such as boilers, drums, turbines, and generators.
He is now a Senior Member of the KEPCO Research Institute.
Jong-An Kim received the B.S. degree in Electronic Engineering from Won-Kwang University, Ik-San, Korea in 1985. He joined the Korea
Electric Power Corporation (KEPCO) in 1976, and has mainly worked in the control systems engineering areas of power plants.
He is now a Principal Engineer in the Korea Electric Power Research Institute (KEPRI) and his research interests include the
design of power plant control systems as well as new technology development.
Chang-Ki Jeong was born in Daejeon, Korea in 1956. He obtained his Master’s degree in Electrical Engineering from Daejeon Industry College
in 1998. His research interests include control in power plant machines such as boilers, drums, turbines, and generators.
He is a Principal Member of the KEPCO Research Institute.
Joo-Hee Woo was born in Sangjoo, Korea in 1970. He obtained his Master’s degree in Electrical Engineering from Kyungbook National University
in 1995. His research interests include control in power plant machines such as boilers, drums, turbines, and generators.
He is now a Senior Member of the KEPCO Research Institute.
Ji-Young Choi received the B.S. degree in Mechanical Engineering from Sogang University in 2005. He is a graduate student of the Department
of Mechanical Engineering at Sogang University in Seoul, Korea. Choi’s research interests are in the areas of heat transfer,
PEM fuel cells, and microfluidics.
Gihun Son received the B.S. and M.S. degrees in Mechanical Engineering from Seoul National University in 1986 and 1988, respectively.
He obtained the Ph.D. degree in Mechanical Engineering from UCLA in 1996. Dr. Son is currently a Professor in the Department
of Mechanical Engineering at Sogang University in Seoul, Korea. His research interests are in the areas of multiphase dynamics,
heat transfer, and power system simulation. 相似文献
18.
This paper addresses an effective digital implementation of fuzzy control systems via an intelligent digital redesign (IDR) approach. The purpose of IDR is to effectively convert an existing continuous-time fuzzy controller to an equivalent sampled-data fuzzy controller in the sense of the state-matching. The authors show that, under reasonable assumptions, the IDR based on the exact discrete-time models can be reduced to the IDR based on the approximate discrete-time models. The state-matching error between the closed-loop trajectories is carefully analyzed using the integral quadratic functional approach. The estimation of the state-matching error is presented using the linear matrix inequality (LMI) techniques. The problem of designing the sampled-data fuzzy controller to minimize the estimation as well as to guarantee the stability is formulated and solved as the convex optimization problem with LMI constraints. It is also shown that the resulting sampled-data fuzzy controller recovers the performance of the continuous-time fuzzy controller as the sampling period approaches zero. A numerical example is used to demonstrate the effectiveness of the proposed design technique. 相似文献
19.
This paper proposes a new asymptotic attitude tracking controller for an underactuated 3-degree-of-freedom (DOF) laboratory helicopter system by using a nonlinear robust feedback and a neural network (NN) feedforward term. The nonlinear robust control law is developed through a modified inner-outer loop approach. The application of the NN-based feedforward is to compensate for the system uncertainties. The proposed control design strategy requires very limited knowledge of the system dynamic model, and achieves good robustness with respect to system parametric uncertainties. A Lyapunov-based stability analysis shows that the proposed algorithms can ensure asymptotic tracking of the helicopter’s elevation and travel motion, while keeping the stability of the closed-loop system. Real-time experiment results demonstrate that the controller has achieved good tracking performance. 相似文献