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网络管理能保证车载网络的安全性和可靠性。通过分析OSEK网络管理规范及FlexRay总线的特点,提出在FlexRay总线通信周期动态段中实现OSEK网络管理的方案,给出了FlexRay总线网络管理协议数据单元的定义,分析和研究了FlexRay总线的OSEK网络管理过程及网络管理消息在动态段中延迟发送问题。最后在自行设计的实验平台上进行了实验,验证了本方案的可行性。 相似文献
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为了将车载端与地面端充电设施统一起来,实现不同电动汽车与不同地面端充电桩之间高效、安全地进行无线充电,保证无线通信协议的一致性至关重要。本文首先对新颁布的电动汽车无线充电系统通信协议标准GB/T 38775.2-2020进行解读,梳理得到电动汽车无线充电通信的一般流程;然后,设计了一种电动汽车无线充电通信一致性测试的软硬件架构;最后,提出了电动汽车无线充电通信协议的一致性测试方法。该系统能够完成电动汽车无线充电过程中通信协议的自动化测试,有助于后续标准的修订和测试的进一步完善。 相似文献
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I. Park J. Chung J. Youn W. Lee M. Sunwoo 《International Journal of Automotive Technology》2016,17(4):717-729
This paper presents an integration method of AUTOSAR-compliant ECUs which can evaluate resource constraints in an early-stage of development. There are three types of resources for an ECU (timing, memory, and interface) which should be carefully managed for successful ECU integration. The proposed method consists of three steps: measurement, prediction, and evaluation. In the first step, a method to measure resource factors for AUTOSAR-compliant software architecture is introduced. Based on the method, a worst-case execution cycle of a runnable, memory section usages of a software component, and interface of legacy ECUs can be obtained. In the second step, the obtained factors are quantitatively predicted according to the architectural designs of the integration ECU. In the case of the timing resource, the worst-case execution time of the integration ECU can be precisely predicted by a proposed empirical model. In the last step, the resource constraints such as CPU, memory, network utilizations can be evaluated with predicted resource factors before implementation. The proposed method was applied to the integration of an in-house engine management system composed of two ECUs. The method successfully provided quantitative measures to evaluate architectural designs of three different integration scenarios. 相似文献
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Zheng Ran Hua Yan Huimin Zhang Yun Li 《International Journal of Automotive Technology》2017,18(6):1109-1119
The AUTOSAR has been developed as the worldwide standard for automotive E/E software systems, making the electronic components of different suppliers to be employed universally. However, as the number of component-based applications in modern automotive embedded systems grows rapidly and the hardware topology becomes increasingly complex, deploying such large number of components in automotive distributed system in manual way is over-dependent on experience of engineers which in turn is time consuming. Furthermore, the resource limitation and scheduling analysis make the problems more complex for developers to find out an approximate optimal deploying approach in system integration. In this paper, we propose a novel method to deploy the AUTOSAR components onto ECUs with the following features. First, a clustering algorithm is designed for deploying components automatically within relatively low time complexity. Second, a fitness function is designed to balance the ECUs load. The goal of our approach is to minimize the communication cost over all the runnable entities while meeting all corresponding timing constraints and balancing all the ECUs load. The experiment results show that our approach is efficient and has well performance by comparing with other existing methods in specific and synthetic data set. 相似文献
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车用实时操作系统OSEKkernel的开发 总被引:2,自引:0,他引:2
根据OSEK/VDX的要求,开发了一个车用实时操作系统OSEKkernel,并对其开发方法和关键部分的源代码进行了介绍。该系统可缩短电子控制单元(ECU)的软件开发周期、提高可靠性和共享软件资源。此系统已在TI公司的LF2407DSP上调试成功,并被用于无刷直流电机控制系统。 相似文献
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Virtualization is attracting significant interest in the automotive industry because it enables a highly secure and reliable
computing environment. More importantly, virtualization maintains the same operating environment for legacy automotive software
while exploiting the benefits of widely adopted multicore platforms. To exploit the virtualization technology in an automotive
system, it is important to predict the WCET of an automotive application running on a virtual machine monitor (VMM). Unfortunately,
the task is challenging because of difficulties in analyzing complicated interactions between a VMM and a guest OS. There
are no known attempts to predict the WCET of an application in such an environment. In this paper, we propose a hierarchical
and parametric WCET prediction framework. We divide the problem into two subproblems. First, we model the WCET of an application
as a function of WCETs of system calls provided by a guest OS. Second, we model WCETs of a system call as a function of WCETs
of VMM services. To establish this framework, we clearly identify the places and times of VMM services invoked during the
execution of an application. At the time of deployment, the WCET of an application is instantiated by composing the WCET models
altogether. We have performed experiments with the proposed framework by predicting the WCETs of sample programs on various
virtual and real machine platforms. These experimental results effectively demonstrate the viability of the proposed framework. 相似文献
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M. Antoni 《Recherche - Transports - Sécurité》2012,28(2):101-118
In this article, we discuss on how to solve the following problems: the checks and tests before putting the safety facilities into service, and the results of these tests which are essential, time consuming and may show great variations among each other. Economic constraints and the increasing complexity associated with the development of computerized tools tend to limit the capacity of the classic approval process. In practice, a reduction of the test cover rate is observed. The method presented in this article makes it possible to formally validate the new computerized mechanisms of the existing French interlocking systems with real-time functional interpreted Petri nets. The aim of our project was to provide SNCF with an operating method for the formal validation of interlocking systems. A formal proof method by assertion, applicable to our interlocking system, which covers equally the specification and its real software implementation, is presented in this article. With the proposed method and its associated tools, we completely verify that the system follows all safety procedures at all times and does not show superfluous conditions. This replaces all plateform tests checks. It is included in the existing testing procedures. The advantages of using this method are the following: a significant reduction of testing time and of the related costs, an increase of the test coverage rate (determinisitic safety vs. probabilistic safety), and an answer to the new demand of railway infrastructure maintenance engineering to modify and validate computerized interlocking systems. The mastery of formal methods by infrastructure engineers is surely a key to prove that additional safety is not expensive. 相似文献
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为了高效生成具有低失真度的车载全景,以保证基于此影像信息的辅助驾驶系统的实时性,提出针对运算效率进行优化的车载全景生成方法。首先,利用多扫描线趋近、圆拟合的方法实现鱼眼成像有效区域的准确自动提取,并对参数进行优化以提升算法鲁棒性。基于鱼眼成像有效区域轮廓,计算得到有效区域半径以及圆心。以圆心为原点,半径为单位长度重构笛卡尔坐标系。再基于此坐标系,将鱼眼成像通过经纬映射投射至3D空间球面并在球心建立虚拟相机,利用梯度下降获取视锥体最优旋转角后进行视角重构并成像,直接获取该方向鸟瞰图,实现通过一步变换完成鱼眼校正与逆透视变换,达到提升车载全景影像生成速率与减少图像失真的效果。最后,对图像位置进行配准,使虚拟相机直接成像在指定位置,并对4幅图像进行融合,从而降低由于拼接缝带来的图像信息损失,保证生成的车载全景影像最大程度保留道路信息。研究结果表明:使用该方法在同等硬件平台下,基于标定参数计算生成车载全景影像速率提升接近1倍,从视觉上图像失真程度明显降低;该算法可以提升车载全景生成速率,减少计算资源占用,降低图像失真,从而提升基于车载全景影像的辅助驾驶系统的实时性与可靠性。 相似文献
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理解地下空间的内涵,指出地下空间是城市重要的战略资源。提出转变地下空间发展理念,突出规划的引领作用。以北京市为例,结合北京地下空间规划建设经验,探索构建“全市—分区—特定地区”的地下空间规划编制体系,落实“生态优先、底线约束、专项统筹、刚性管控”的国土空间规划要求,提出各级地下空间规划编制的重点内容和技术方法。指出加强地下空间体制机制建设应从建立地下空间综合管理机制、推进地下空间技术标准整合、健全完善地下空间立法体系、建立国土空间三维信息平台4方面着手,健全地下空间规划实施保障。认为: 地下空间规划作为国土空间规划中的专项规划,应建立与国土空间规划体系相衔接的地下空间规划编制体系;在规划层级上,逐步建立和完善“全市—分区—特定地区”的全域、全要素地下空间规划体系,推动各级地下空间规划编制;在规划内容上,地下空间作为重要的国土空间资源,应立足地下空间资源禀赋和环境承载能力,明确地下空间生态安全底线,科学判断地下空间生态适宜性分区和开发利用重点分区,有效协调各类地下功能设施布局关系;在规划实施方面,应健全地下空间的刚性管控传导机制,加强地下空间的体制机制建设,完善地下空间部门管理、技术标准、权属管理、信息管理等方面的相关法律规范,以科学指导地下空间资源的合理有序利用。 相似文献
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在确定沥青洒布车液压系统驱动方案的基础上,进行了沥青洒布车液压传动系统原理设计,并分别对沥青泵驱动系统和导热油泵驱动系统进行了设计.计算结果证明,所设计的液压系统能满足沥青洒布车的要求,能使得系统工作在高效区. 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(2):244-260
Viability theory proposes geometric metaphors in addition to classical ordinary differential equation analysis. In this paper, advantages of applying viability theory to road safety domain are presented. The exact issue is to determine if, from an initial state of a vehicle/road/driver system, a soft controls strategy is compatible with a safe driving sequence. The case of a car negotiating a curve is considered. The application of the viability theory to this issue offers the advantage to avoid classical full computing of the system. Instead of that, it consists on verifying that the states and the controls belong to a subset called the viability kernel. The construction and the use of the viability kernel for a vehicle system dynamic is proposed by using support vector machines algorithm. Then, the applicability of this theory is demonstrated through experimental tests. This innovative application of the viability theory to vehicle dynamics with road safety concerns could benefit to robust embedded warning systems. 相似文献
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基于GPS/GIS/GSM的公路隧道运营管理系统研究 总被引:11,自引:3,他引:11
为了提高长大公路隧道的运营管理水平,通过分析长大公路隧道的运营特征,追踪GPS、GIS、GSM的最新技术,提出了采用基于GPS/GIS/GSM的公路隧道运营管理模式,实现长大公路隧道的现代远程监控与管理。论述了基于GPS/GIS/GSM的公路隧道运营管理系统的两大组成子系统,即基于GIS的隧道机电管理系统和基于GPS/GIS/GSM的车辆调度系统的功能与组成,同时采用软件系统设计的方法对该两大子系统进行了系统分析与设计。运用企业成本核算法进行了系统经济性分析,论证了基于GPS/GIS/GSM的公路隧道运营管理模式的可行性和科学性。 相似文献
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汽车座舱内的人机交互智能系统一定程度决定了用户的智能体验,对人机交互进行测试研究,形成一套完整的人机交互测试评价方法,可以指导人机交互的设计开发,实现人机交互的迭代和优化。汽车座舱内功能日益增加,给用户带来更丰富的体验,然而功能相同,人机交互不同,给用户带来的驾驶体验却大相径庭。基于典型使用场景,从客观角度,分析不同车型相同场景下车机系统的响应、驾驶员眼部活动和驾驶员手部活动的差异,进一步量化评价参数,形成评价指标,同时根据五感和五觉,设计主观评价表对人机交互进行测评。测评结果表明,该方法具备可操作性和合理性,能从客观和主观角度全面评估人机交互的优劣。 相似文献