Development and performance analysis of a data-reduction algorithmfor automotive multiplexing

Automotive multiplexing allows sharing information among various intelligent modules inside an automotive electronic system. In order to achieve an optimum functionality, the information should be exchanged among various electronic modules in real time. Data-reduction techniques are used to send the data over a transmission medium at a high speed. They can be employed in automotive multiplexing systems to improve the information exchange rate among various intelligent modules. Some off-the-shed data-reduction algorithms have been considered for automotive multiplexing. However, their applications have been limited to test data classes only. This paper introduces a data-reduction algorithm that can be applied to all data classes found in automotive multiplexing, including body- and engine-related data. Detailed performance analysis of the algorithm is presented. Although this algorithm has been developed to fit in the automotive environment, it can also be applied to nonautomotive applications in which extensive information exchange is performed among control modules via a multiplexing bus. The proposed algorithm uses SAE J1939 as a base protocol. However it can be used with other automotive multiplexing protocols without loss of generality     

某会展中心的综合布线系统设计

综合布线系统GCS（generic cabling system）是智能化建筑的最基本的基础设施,被称之为智能化建筑的神经系统,它既能使话音与数据通信设备、交换设备以及其它信息系统之间彼此相连,又能实现内部设备及系统与外部通信网络的相连,是现代建筑物群落连接和信息传输的基础设施系统。     

Reliability analysis of an automotive transmission system

The complexity of vehicles and equipment in present day defence services is growing considerably, and the importance of equipment availability as a prime battle-winning factor for the defence services cannot be overemphasized. In defence services the reliability in totality of an automotive system such as a battle tank, troop carrier, etc. is essential to meet the inescapable warlike requirements. It is not in the interest of any fighting force to go into operation with the slightest doubt about the performance of the equipment. To keep the warlike equipment/vehicles rolling, all subsystems need to be in serviceable condition in all types of terrain. One of the most essential subsystems whose reliability cannot be compromised at any stage is the transmission system. In the present paper a reliability analysis of an automotive transmission system of the general service type of vehicle being used by the Indian Army is reported. The complete transmission system has been subdivided into 12 subsystems and maintenance policies for these 12 subsystems have also been suggested.     

Digital transmission over in-home coaxial wiring

The wiring of a customer's premises network (CPN) may be the weakest link in the end-to-end transport of residential broadband digital services such as digital video. Detailed knowledge of how such premises wiring will affect digital service delivery is critical to the cost-effective deployment and robust operation of digital technologies. This paper reports selected results from a series of experimental and analytical studies of coaxial-cable premises-wiring impairments for digital broadband signals. The investigations included return loss, isolation and attenuation measurements of a wide variety of components, as well as measurements and simulations of bit-error-rate performance for several inside-wiring test-bed configurations. The components showed a broader range of performance, and in some cases considerably worse performance, than indicated in previous studies. The premises wiring generated signal reflections which can severely degrade digital transmission. Some reflections can cause destructive interference that effectively decreases the received signal power by 10 dB more than the nominal attenuation, and this decrease is not mitigated by set-top or cable-modem adaptive equalization     

Integrated wiring system for construction equipment

Advances in electronic technology have brought numerous changes in design of most types of construction equipment. Due to the electronic devices and electric loads, such as lamps and motors, a typical construction vehicle has many wires and connectors. The next phase of the changes is to focus on how to reduce these complex wires by using digital communications. This paper presents the development of an integrated wiring system for construction equipment. More specifically, an excavator that has more than 40 devices has been chosen in order to apply the concept of the integrated wiring system. After grouping electrical devices by their locations and functions, two communication controllers, i.e., an instrument controller and an engine-hydraulic controller, are defined. Two test controllers have been developed in order to prove the concept     

Frequency multiplexing in an optical system using a Mach-Zehnder waveguide frequency translator

A Mach-Zehnder waveguide frequency translator is used to assemble an optical frequency multiplex. The linearity of the process is reported and experimental measurements are compared with theory.     

A sensorless optimal control system for an automotive electric power assist steering system

This paper considers the analysis and design of a double-pinion-type electric power assist steering (EPAS) control system. A simplified model of the augmented steering assembly-electric motor system is developed using Lagrangian dynamics, and an optimal controller structure for the model is proposed. Three main advances to the state of the art are presented in this paper. First, a state-space design model is used rather than an input-output model. A state-space formulation for a system model that incorporates motor electrical dynamics is obtained with the assist motor angular position as the output. Second, linear quadratic regulator (LQR) and Kalman filter techniques are employed to arrive at an optimal controller for the EPAS system. The selection of weighting coefficients for the LQR cost function is discussed. Finally, the authors present a control strategy that eliminates the steering column torque sensor, a critical component in existing EPAS controller designs. The proposed control strategy presents an opportunity to improve EPAS system performance and also reduce system cost and complexity.     

Lightwave system using microwave subcarrier multiplexing

We present a demonstration of subcarrier multiplexing in a lightwave multiple-access network. Three 44 Mbit/s digital signals are transmitted along a single-mode fibre bus by intensity-modulating two 1.3 ?-wavelength, multimode laser diodes with FSK subcarriers, at frequencics between 3.5 and 4.0 GHz. Intermodulation distotion, generated when two or more subcarriers are transmitted by the same laser, does not degrade the tranmission quality.     

Two-channel system demonstration of differential frequency-deviation multiplexing

A two-channel lightwave system using differential frequencydeviation multiplexing (DFDM) is presented. Both 90Mbit/s channels are differentially detected using a fibre interferometer. The performance is independent of the absolute optical frequencies and received state of polarisation. Interchannel interference results in a 1 dB penalty for channel separations of 700 MHz.     

汽车电磁仿真技术与应用

随着汽车智能化和网联化的发展,对汽车电磁兼容（electromagnetic compatibility,EMC）设计提出了更高的要求.在这一背景下,需要加快提升汽车EMC仿真预测的设计方法和手段,将电磁仿真预测融入整车开发过程中,减少后期整改的时间和成本,以适应新趋势所提出的EMC需求.本文主要介绍了汽车电磁仿真国内外的发展现状,对基于FEKO软件的汽车电磁仿真方法、仿真过程中发现的问题进行了阐述.     

Susceptibility analysis of wiring in a complex system combining a3-D solver and a transmission-line network simulation

This paper deals with the application of electromagnetic field-to-transmission-line coupling models for large cable systems analysis. It emphasizes the use of Agrawal's (1980) model applied here in a numerical simulation of an electromagnetic susceptibility problem up to 500 MHz. Based on the concepts of EM topology, the proposed methodology consists in calculating the incident fields with a three-dimensional (3-D) computer code and the coupling on cables with a multiconductor transmission-line network computer code. In order to validate the efficiency of this methodology in an industrial context, an experiment has been performed on a prototype wiring installed in a Renault Laguna car, stressed by an EM plane wave. Numerous validation configurations have been carried out. First, the prototype cable network under study has been tested on a ground plane to validate the coupling model but also, to validate the cable-network topology itself. Second, EM fields have been measured onto the structure and inside the structure. Then, they have been compared to 3-D calculations, performed with an FDTD code. Third, comparisons between measurements and calculations of bulk currents and voltages on 50 Ω loads on the wiring have been achieved     

Active attenuation of electromagnetic noise in an inverter-fed automotive electric drive system

Electromagnetic noise, typical for systems with switching power converters, is especially troublesome in automotive electric drive systems because of the multitude of sensitive electronic equipment onboard of modern cars. To satisfy the relevant engineering norms, passive radio-frequency (RF) filters must be installed in the power electronic part of a drive. The RF filters add to the cost and size of the drive, which car designers strive to minimize to increase the passenger space. In this paper, active attenuation of the electromagnetic noise by means of the so-called random-delay pulse width modulation is described in application to an inverter-fed automotive ac drive. Based on computer simulations and experimental investigation, this simple and inexpensive method is shown to be highly effective.     

Simple fibre-optic multiplexing system using pseudorandom sequence

A simple method of multiplexing intensity sensors in a fibre-optic network has been demonstrated using the autocorrelation property of pseudorandom sequences. An experimental network consisting of three demonstration sensors has been assembled. Measurements show that signals from different sensors can be suppressed by about 30 dB using a 255 bit code     

Transmitter multiplexing system in UHF mobile radio

At a base station of a UHF mobile radio telephone system in a large city, many transmitters are used. In such a case it is not practical to use an individual antenna for each transmitter from the viewpoint of system economy and interference. Common use of one antenna for many radio-frequency channels is suitable and transmitter multiplexing devices should be used for this purpose. A transmitter multiplexer has been developed which can be used for multiplexing more than twelve 100-W transmitters in the 450-MHz band with a channel spacing of 150 kHz. The multiplexer consists of circulators, cavity resonators, and junction boxes. The principal features of this multiplexer are H101mode cavity resonators which are ultrastable with respect to the variation of environment conditions such as temperature and humidity. The resonators are temperature compensated to maintain the variation of resonant frequency within 5 kHz at the ambient temperature variation of 40°C. The voltage standing-wave ratio (VSWR) of the multiplexer, looking from the transmitter side, is less than 2.0 and the insertion loss is less than 3 dB at the operating frequency. Design objectives, over-all performance, and characteristics of cavity resonators and circulators are also presented.     

微波SDH复用系统配置与维护应用经验点滴

从日常维护管理出发，理论与实际相结合，以比较的方式，主要阐述了“汉－昌－福”SDH网管在复用系统运行维护中的几个应用侧面，提供电路连接、在线测试的指令、方式。     

论智能建筑中的综合布线系统

综合布线系统是智能建筑的根基,本文主要介绍了综合布线系统的概念与特点,然后说明了综合布线系统与智能建筑的关系,最后简要阐述了智能建筑中综合布线系统的设计。     

Design and simulation of single-source single-electron complementary 4-bit multiplexing nano-circuits

The Single-Electron Transistor (SET) and Linear Threshold Gate (LTG) are among the basic functional Single-Electron Nano-Devices (SENDs). In this paper, these basic SENDs are used to design a single-source (SS) single-electron (SE) complementary 4-bit (4–1) multiplexer. This design is compared with the previously reported multiple-source SE complementary 4-bit multiplexer. The first reported SS SE complementary 4-bit demultiplexer is also introduced. The detailed schematic diagrams as well as the corresponding simulation results of the designed SE 4-bit multiplexer/demultiplexer (using SIMON 2.0 and SECS Monte Carlo SE simulators) are illustrated. The simulation results include input, control, and output signals; free energy and stability diagrams; and maximum allowed signal frequency. The estimated delay and energy consumption is calculated and presented.     

某医院计算机网络综合布线系统设计

在分析某医院基本概况的基础上,本文设计了该医院的计算机网络综合布线系统,绘制了综合布线系统拓扑图,以便于提高医院的管理水平与服务水平.     

Asynchronous multiplexing for an optical-fibre local-area network

By trading some of the very high bandwidth capability of an optical-fibre channel it is possible to produce an attractively simple asynchronously multiplexed local-area network.     

DVB系统码流复用的软件实现

在介绍基于MPEG-2标准的系统层结构的基础上，提出了一种DVB码流复用的软件实现方案，这使得多个节目的高效传输成为可能。