T his book covers basic communications theory and practical imple- mentation of transmitters and receivers. In so doing, I focus on dig- ital modulation, demodulation methods, probabilities, detection of digital signals, and spread spectrum system design and analysis. This book was written for those who want a good understanding of the basic prin- ciples of digital wireless communication systems, including spread spec- trum techniques. This book also provides a good intuitive and practical approach to digital communications. Therefore it is a valuable resource for anyoneinvolvedinwirelesscommunicationsandtransceiverdesignfordig- ital communications. The reader will gain a broad understanding of basic communication principles for transceiver design, digital communications, and spread spectrum, along with examples of many types of commercial and military data link systems.
标签: Transceiver System Design
上传时间: 2020-06-01
上传用户:shancjb
Modern day large power systems are essentially dynamic systems with stringent requirements of high reliability for the continuous availability of electricity. Reliability is contingent on the power system retaining stable operation during steady-state operation and also following disturbances. The subject of power sys- tem stability has been studied for many decades. With new developments, and there have been many over the past couple of decades, new concerns and problems arise that need to be studied and analysed. The objective of this book is a step in that direction though not ignoring the conventional and well-established approaches.
标签: Modelling Stability System Power
上传时间: 2020-06-07
上传用户:shancjb
Simulation is experimentation with models. For system design, research, and edu- cation, simulations must not only construct and modify many different models but also store and access a large volume of results. That is practical only with models programmed on computers [1,2]
上传时间: 2020-06-10
上传用户:shancjb
Human Factors and Systems Interaction aims to address the main issues of concern within systems interface with a particular emphasis on the system lifecycle development and implementation of interfaces and the general implications of virtual, augmented and mixed reality with respect to human and technology interaction. Human Factors and Systems Interaction is, in the first instance, affected by the forces shaping the nature offuture computing and systems development
标签: Interactions Advances Factors System Human and in
上传时间: 2020-06-10
上传用户:shancjb
n recent years, there have been many books published on power system optimization. Most of these books do not cover applications of artifi cial intelligence based methods. Moreover, with the recent increase of artifi cial intelligence applications in various fi elds, it is becoming a new trend in solving optimization problems in engineering in general due to its advantages of being simple and effi cient in tackling complex problems. For this reason, the application of artifi cial intelligence in power systems has attracted the interest of many researchers around the world during the last two decades. This book is a result of our effort to provide information on the latest applications of artifi cial intelligence to optimization problems in power systems before and after deregulation.
标签: Intelligence Artificial System Power in
上传时间: 2020-06-10
上传用户:shancjb
This texts contemporary approach focuses on the concepts of linear control systems, rather than computational mechanics. Straightforward coverage includes an integrated treatment of both classical and modern control system methods. The text emphasizes design with discussions of problem formulation, design criteria, physical constraints, several design methods, and implementation of compensators.Discussions of topics not found in other texts--such as pole placement, model matching and robust tracking--add to the texts cutting-edge presentation. Students will appreciate the applications and discussions of practical aspects, including the leading problem in developing block diagrams, noise, disturbances, and plant perturbations. State feedback and state estimators are designed using state variable equations and transfer functions, offering a comparison of the two approaches. The incorporation of MATLAB throughout the text helps students to avoid time-consuming computation and concentrate on control system design and analysis
标签: 控制系统
上传时间: 2021-12-15
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针对嵌入式产品程序更新问题,提出了一种基于IAP技术的STM32单片机在线固件升级方案,设计了STM32单片机最小系统硬件电路和USB转串口通信电路,并给出了Bootloader程序、APP程序、PC上机程序的实现流程.实验结果表明,该方案具有简单实用、稳定性高、维护成本低和设备使用效率高的特点,适用于嵌入式产品升级.For the problem of updating embedded products program,an online firmware upgrade scheme of STM32 single chip microcomputer based on IAP technology is proposed.This scheme not only elaborates the principle of IAP technology in detail but also provides the design of the minimum system hardware circuit of STM32 MCU,the design of USB for serial communication circuit,and the implementation flow of Bootloader program,APP program and PC program.The experiment results show that the scheme is simple,practical and highly stable.In addition,it can be used to actual embedded product upgrading,significantly reducing maintenance costs and improving the efficiency of equipment.
上传时间: 2022-03-25
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目前电动汽车主要以锂电池作为动力来源,为了提高锂电池的使用时间和安全性,为锂电池提供安全良好的运行环境,电池管理系统应运而生。BMS主控单元基于S32K144汽车级单片机,通过主从式网络控制结构能够对锂电池的各个参数进行采集与分析。采用扩展卡尔曼滤波对电池的荷电状态(SOC)进行估算,克服普通估算方法无法避免电池内阻误差的缺点,通过Matlab/Simulink软件仿真验证可使估算误差达到2%以内。At present,electric vehicles mainly use lithium batteries as the power source.In order to improve the running time and safety of lithium batteries,a safe and good operating environment for power batteries is provided,and a battery management system(BMS) has emerged.The BMS main control unit is based on the S32K144 automotive-grade control chip.Through the master-slave network control structure,it can collect and analyze the various parameters of the lithium battery.The Extended Kalman Filter(EKF) is used to estimate the state of charge(SOC) of the battery,which overcomes the shortcomings of the internal estimation method that cannot overcome the internal resistance error of the battery.It can be verified by Matlab/Simulink software simulation.The estimation error is within 2%.
上传时间: 2022-03-26
上传用户:XuVshu
对某四轮独立驱动电动汽车轮毂电机进行研究,设计一种永磁无刷直流电机控制器.以STM32F103RBT6芯片为基础,对电机驱动电路、采样电路和保护电路分别进行硬件设计与分析;同时,采用模块化软件设计方案,对该控制器的软件系统进行升级.实验验证表明:所设计的电机控制器能使电机响应迅速、转速稳定、无超调,且电动车动力输出性能良好.A permanent magnet brushless direct current motor controller was designed by studying the hub motor of a four-wheel independent drive electric vehicle.Based on STM32 F103RBT6 chip,the hardware design and analysis of motor drive circuit,sampling circuit and protection circuit were carried out respectively.At the same time,modular software design scheme was adopted to upgrade the software system of the controller.Experimental results show that the designed motor controller can ensure the motor fast response,stable speed,no overshoot,and good power output performances.
上传时间: 2022-03-26
上传用户:qingfengchizhu
本系统采用电动机电枢供电回路串接采样电阻的方式来实现对小型直流有刷电动机的转速测量。该系统主要由二阶低通滤波电路,小信号放大电路、单片机测量显示电路、开关稳压电源电路等组成。同时自制电机测速装置,用高频磁环作为载体,用线圈绕制磁环,利用电磁感应原理检测电机运行时的漏磁,将变化的磁场信号转化为磁环上的感应电流。用信号处理单元电路将微弱电信号转化为脉冲信号,送由单片机检测,从而达到准确测量电机的速度的要求。In this system, the sampling resistance of armature power supply circuit is connected in series to measure the speed of small DC brush motor. The system is mainly composed of second-order low-pass filter circuit, small signal amplifier circuit, single-chip measurement and display circuit, switching regulated power supply circuit and so on. At the same time, the self-made motor speed measuring device uses high frequency magnetic ring as the carrier, coil winding magnetic ring, and electromagnetic induction principle to detect the leakage of magnetic field during the operation of the motor, which converts the changed magnetic field signal into the induced current on the magnetic ring. The weak electric signal is transformed into pulse signal by signal processing unit circuit, which is sent to single chip computer for detection, so as to meet the requirement of accurate measurement of motor speed.
标签: 直流电动机
上传时间: 2022-03-26
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