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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Transceiver and Clock Generator for FlexRay-based Automobile Communication Systems

Chen, Po-Cheng 25 June 2008 (has links)
Thanks to the booming of car electronics in recent years, more car electronics devices are installed in ve-hicles. These devices are connected by in-vehicle communication networks. In this thesis, we present the tran-sceiver and clock generator design for the physical layer of a FlexRay-based in-vehicle communication protocol. Regarding the transceiver design, a LVDS-like transmitter is proposed to drive the twisted pair of the bus. By contrast, a 3-comparator scheme is used to carry out the required bit-slicing and state recognition at the re-ceiver end. The reliability and safety are the priority design factors for electronics. A robust 20 MHz clock generator with process, supply voltage, and temperature compensation, a sub-1 MHz oscillator, and a temperature detector are included in our clock generator design. All of these designs are implemented by using a typical 0.18 um single-poly six-metal CMOS process. The proposed prototypical transceiver has been tested by a thermo chamber to justify its operation in the required temperature rage, i.e., -40¢XC to 125¢XC. Moreover, the compatibility of our design is also verified in a real FlexRay-based network. The maximum throughput of the proposed prototypical transceiver can reach 40 Mbps.
2

Implementation of the FlexRay Protocol Module

Ko, Chao-jen 24 July 2009 (has links)
FlexRay communications system protocol is necessary specification of the future digitizing motor vehicle. Though the principal standard of specifications had established in 2005, little correlative commodities have used in the motor vehicle now. In this paper, I implement the hardware circuit of MAC Layer in the Flexray system. In the system, six major sub-modules: Controller Host Interface (CHI) is connecting with the Host processor interface, Protocol Operation Controller (POC) is controlling all sub-modules after receiving the orders from CHI, Clock Synchronization (CS) is synchronizing between all nodes, Media Access Control (MAC) is dividing slot and arranging the style of transmission data, Coding and Decoding (CODEC) is connecting the Physical Layer, and Frame and Symbol Processing (FSP) is detecting the error of receiving data. Because the system increases the function of synchronization between Nodes in the FlexRay system, it can transmit high data rate in the Time Division Multiple Access system (TDMA). Because the transmitter is two channels, it has the characteristic of high fault tolerance. The two characteristics meet the requirements that transmitting data is high data rate and stabilize.
3

Design and Implementation of FlexRay Automotive Communication System Physical Layer and 32-bit High Speed Tree-Structured Carry Lookahead Adder

Juan, Chun-Ying 24 July 2008 (has links)
This thesis comprises two parts : the first one is the design and implementation of FlexRay automotive communication system physical layer; the second part is the design of a high speed pipelined tree-structured carry lookahead adder (CLA). The first part of this thesis is to introduce the physical layer specification of FlexRay automotive communication system. Then, it is realized in an SOC by a typical 0.18 um CMOS process. The second topic is to propose a novel CANT logic. By the CANT logic, a pipelined tree-structured carry lookahead adder is designed and implemented. The dynamic bulk biasing technique is utilized to increase the switching speed of inverting circuits such that the delays of the inverting and non-inverting circuit is very close. The proposed architecture can be easily expanded to long data words CLA. Post-layout simulations reveal that the 32-bit CLA using the proposed CANT logic can operate up to 7.2 GHz by using the UMC 90 nm process.
4

Performance Evaluation Of Flexray Networks For In-vehicle Communcation

Demirci, Ali 01 November 2009 (has links) (PDF)
The increasing use of electronic components in today&rsquo / s automobiles demands more powerful in-vehicle network communication protocols. FlexRay protocol, which is expected be the de-facto standard in the near future, is a deterministic, fault tolerant and fast protocol designed for in vehicle communication. In the near future, safety critical X-by-Wire applications will be available in the automobiles and FlexRay networks can be used to provide communication for the Electronic Control Units (ECUs) that perform related functions of X-by-Wire applications. In this thesis the performance of the FlexRay networks with various communication scenarios is evaluated in a real time environment and the results are presented. Communication scenarios investigate both static and dynamic segment of the FlexRay and allow evaluating the capabilities of the protocol. Several performance metrics such as utilization, static slot allocation, jitter are defined for the evaluation of the results.
5

Verification of FlexRay membership protocol using UPPAAL

Mudaliar, Vinodkumar Sekar January 1900 (has links)
Master of Science / Department of Computing and Information Sciences / Mitchell L. Neilsen / Safety-critical systems embedded in avionics and automotive systems are becoming increasing complex. Components with different requirements typically share a common distributed platform for communication. To accommodate varied requirements, many of these distributed real-time systems use FlexRay communication network. FlexRay supports both time triggered and event-triggered communications. In such systems, it is vital to establish a consistent view of all the associated processes to handle fault-tolerance. This task can be accomplished through the use of a Process Group Membership Protocol. This protocol must provide a high level of assurance that it operates correctly. In this thesis, we provide for the verification of one such protocol using Model Checking. Through this verification, we found that the protocol may remove nodes from the group of operational nodes in the communicating network at a fast rate. This may lead to exhaustion of the system resources by the protocol, hampering system performance. We determine allowable rates of failure that do not hamper system performance.
6

Combining the Good Things from Vehicle Networks and High-Performance Networks

Armide, Misikir, Ecker, Herbert January 2007 (has links)
<p>The aim of this Master’s thesis is to develop a solution for combining speed and performance of switched Ethernet with the real time capability and determinism of sophisticated in- vehicle networks. After thorough research in vehicle network standards, their demands and features, the</p><p>Flexible Time Division Multiple Access (FTDMA) protocol of FlexRay was chosen to be applied on a switched Ethernet architecture since it can accommodate both hard real time tasks and soft real time tasks. To provide hard real time capability, what this paper focuses on, a media access method was developed by creating static TDMA schedules for each node’s sending and receiving</p><p>port according to a certain traffic assumption. To validate the developed media access algorithm several examples with different traffic assumptions and architectures were generated and</p><p>investigated based on their sending and receiving utilization. A second method for validating and thus proving the functionality of the algorithm was by simulation. Therefore the Matlab Simulink</p><p>media library extension TRUE TIME was used to simulate a simple example with 100% sending and receiving utilization for each node.</p>
7

An Effective GA-Based Scheduling Algorithm for FlexRay Systems

TAKADA, Hiroaki, TOMIYAMA, Hiroyuki, DING, Shan 01 August 2008 (has links)
No description available.
8

A SystemC simulator for the dynamic segment of the FlexRay protocol

Podduturi, Venkata Rama Krishna Reddy January 2012 (has links)
FlexRay, developed by a consortium of over hundred automotive companies, is a real-time in-vehicle communication protocol for automotive networks. It is being used as a higher-performance, time-triggered, and deterministic serial bus in automobiles for many safety-critical and x-by-wire systems. In x-by-wire systems the hydraulic parts of systems such as steering and braking are replaced with electronics. As x-by-wire systems are safety-critical, they must be fault-tolerant, deterministic, and should have synchronized time base (global time). FlexRay fulfils all these requirements as it is a deterministic and fault-tolerant serial bus system with data rates of 10 Mbps for extremely safety- and time-critical applications. As, FlexRay has become the de-facto standard for high speed safety-critical communications in automotive domain, and timing analysis of FlexRay still continues to generate significant research interest. The FlexRay allows both time-triggered and event-triggered messages. The static (ST) segment allows time-triggered transmission, while dynamic (DYN) segment allows event-triggered transmission. As the DYN segment transmits messages based on their priorities; so the delay suffered by a message depends on the interferences by its higher priority messages. Computing interferences of the higher priority messages is a challenging problem for the DYN segment of FlexRay [32]. So, in order to compute interferences of the higher priority messages one way is to use simulation technique. The SystemC simulator proposed in this thesis is used to model and simulate the behaviour of the DYN segment of the FlexRay protocol. This modelling and simulation is done on system level using the system description language SystemC. The simulator estimates the delay suffered by a message instances because of the interferences of higher priority messages. This estimation of delay is done by taking no-jitter/jitter into consideration. Finally, in both the cases the delay suffered by each and every message instance is plotted.
9

Combining the Good Things from Vehicle Networks and High-Performance Networks

Armide, Misikir, Ecker, Herbert January 2007 (has links)
The aim of this Master’s thesis is to develop a solution for combining speed and performance of switched Ethernet with the real time capability and determinism of sophisticated in- vehicle networks. After thorough research in vehicle network standards, their demands and features, the Flexible Time Division Multiple Access (FTDMA) protocol of FlexRay was chosen to be applied on a switched Ethernet architecture since it can accommodate both hard real time tasks and soft real time tasks. To provide hard real time capability, what this paper focuses on, a media access method was developed by creating static TDMA schedules for each node’s sending and receiving port according to a certain traffic assumption. To validate the developed media access algorithm several examples with different traffic assumptions and architectures were generated and investigated based on their sending and receiving utilization. A second method for validating and thus proving the functionality of the algorithm was by simulation. Therefore the Matlab Simulink media library extension TRUE TIME was used to simulate a simple example with 100% sending and receiving utilization for each node.
10

Design and Implementation of Physical Layer for FlexRay-based Automotive Communication Systems

Sung, Gang-Neng 05 October 2010 (has links)
In this dissertation, we propose a circuit design and implementation of physical layer for FlexRay-based automotive communication systems which are expected to be widely used in car electronics for the years to come. To reduce the volume of electrical lines in a car and ensure safe connections, the automotive communication systems are more important than ever. FlexRay systems have been deemed as better than other existing solutions for the complicated in-vehicle networks. A low-voltage differential-signaling-like transmitter is proposed to drive the twisted pair of the FlexRay bus. Furthermore, a three-comparator scheme is used to carry out bit slicing and state recognition at the receiver end. A prototype system as well as a chip implemented by using a typical 0.18 £gm single-poly six-metal CMOS process is reported in this dissertation. Furthermore, an accurate clock signal is required in any control system, especially in the vehicle applications, where the ¡§safety¡¨ is the top priority. Because of the TDMA strategy (Time Division Multiple Access) was chosen for the FlexRay communication protocol, the system clock should not be drifting too much. A robust 20 MHz clock generator with process, supply voltage, and temperature compensation and a low-jitter 80 MHz phase-lock loop are proposed in this dissertation to reduce hostile environment effects. Finally, because the ¡§safety¡¨ and ¡§reliability¡¨ are top design requirements in the automobile electronics, we should also focus on the power supply design in the in-car communication networks. Therefore, a high tolerant and high efficiency voltage converter is proposed in this dissertation. By utilizing stacked power MOSFETs, a voltage level converter, a detector and a controller, this design is realized by a typical CMOS process without any thick-oxide device to tolerate input voltage range up to 3 times of the VDD voltage.

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