Torque-based optimal vehicle speed control

This paper describes an optimal vehicle speed controller that uses torque-based control concepts. The controller design was divided into two steps: first, for a given vehicle speed trajectory, the engine torque demand was determined; in the second stage, a torque controller was implemented to track this torque demand. The torque demand was determined by a primary component and a correction component. The primary component was determined by solving an off-line optimization problem, and the correction component was added to compensate for the error caused by the off-line optimization. A modelbased proportional-integral (PI) feedback torque controller was employed to realize the engine torque tracking. Simulation results generated by a benchmark simulator were given to demonstrate performance of the optimal vehicle speed controller and a conventional PI speed controller that was included for comparison.     

Reducing the memory footprint of OSEK-based systems via stack sharing and light-weight ready queues

OSEK OS (Offene Systeme und deren Schnittstellen für die Elektronik in Kraftfahrzeugen Operating System) is an open, real-time operating system standard for ECU software in vehicles. Because it was originally designed to be used in an extremely resource-constrained environment, an OSEK-compliant operating system must incur low processing overhead and memory usage. Unfortunately, as OSEK OS has evolved over time, it now specifies nontrivial kernel features along with multiple conformance classes and application modes. This may lead to unwanted dynamic resource usage in a system using OSEK OS unless the standard is carefully interpreted and designed into an OSEK OS implementation. In this paper, we analyzed the various kernel features of OSEK OS and their interactions to identify areas in the standard that warrant further resource usage optimization. In particular, we attempted to reduce the run-time memory footprint. Based on our analyses, we present two kernel mechanisms: (1) stack sharing among tasks and (2) light-weight ready queue handling specialized for OSEK OS conformance classes. We also offer implementation methods for the proposed mechanisms by extending OIL and associated tools. Finally, we show the effectiveness of the proposed mechanisms via extensive experiments. Our mechanisms allow OSEK-based systems to use only 36% of the memory requirements of conventional OSEK-based systems on average.     

基于Eclipse RCP的隧道施工通风风机选型系统研究

为实现隧道施工通风风机自动优选,根据通风工程基础理论和隧道施工通风管理的业务需求,运用Java编程语言、Eclipse RCP技术,设计并开发了隧道施工通风风机选型系统并对风机选型的基础参数计算、风机性能曲线的拟合方法、选型曲线的自动绘制进行了介绍。实践证明,所选风机机型系统稳定可靠、操作简单、求解结果准确、实用性强。     

新型限滑差速器及空间凸轮结构的优化

针对现有轮式车辆中限滑差速器存在的问题,提出了一种新型限滑差速器总成结构．首先根据凸轮机构从动件数学模型及运动规律,利用共轭曲面包络原理及微分几何理论,推导出新型限滑差速器关键元件空间凸轮机构的工作廓面方程及在接触点处的诱导法曲率方程,然后以接触点处的诱导法曲率最小化,作为新型限滑差速器空间凸轮结构优化设计目标．结果表明,诱导法曲率随从动件半径和运动周期增大而减小,有利于减小曲面间的接触应力;但由于从动件参考工作区域变小,局部磨损加剧,使新型限滑差速器机构工作寿命缩短．     

污水回用深度处理中有机物对反渗透膜污染研究

应用牛血清蛋白（BSA）和海藻酸钠代表反渗透进水中的蛋白质和多糖,采用带有交互作用的正交试验分析污染因素的影响,使用环境扫描电镜和原子力显微镜对污染后的膜面进行监测．实验表明,海藻酸钠对膜污染的影响高于BSA的影响,BSA与海藻酸钠共同存在时会产生明显的交互作用,增大了有机物污染．溶液中Ca＾2＋会结合羧基官能团,以架桥作用连接有机物,能够显著影响有机物污染,Mg2＋对有机物污染的影响次之,离子强度会改变有机物的带电性,从而影响了有机物的污染．监测结果表明,有机物可在反渗透膜面形成厚密的凝胶层,引起严重的膜污染．     

虹桥综合交通枢纽指路标志系统分析及仿真评价

从分析虹桥综合交通枢纽的路网结构及行车路径出发,针对复杂路网情况下指路引导系统进行信息过载量的研究及评价,构建枢纽指路系统的仿真模型,来模拟枢纽道路运行情况,并首次通过网上公示的方式,广泛地征询驾驶人意见,优化调整设计方案,充分体现了以人为本的设计和管理理念。     

公路生态型植草沟研究

通过对国内外生态型植草沟工程的研究分析,分别介绍生态型植草沟的典型断面形式以及实用性,在总结以往经验的同时,可为以后的工程设计及施工提供依据。     

虹桥综合交通枢纽指路标志系统分析及仿真评价

从分析虹桥综合交通枢纽的路网结构及行车路径出发,针对复杂路网情况下指路引导系统进行信息过载量的研究及评价,构建枢纽指路系统的仿真模型,来模拟枢纽道路运行情况,并首次通过网上公示的方式,广泛地征询驾驶人意见,优化调整设计方案,充分体现了＂以人为本＂的设计和管理理念。     

Monte Carlo simulation of B2-L2<Subscript>1</Subscript> ordering transitions in Au-Cu-Al alloy systems

The B2-L2₁ ordering transitions in Au-Cu-Al shape-memory alloys are studied by the Monte Carlo exchange simulations, where a set of the first, the second and the third nearest-neighbor mixing potentials for Cu-Al in the Au-Cu-Al alloys are calculated from first principals using the Connolly-Williams methods. To ensure the phase stability of the β-Au-Cu-Al, the investigation includes the range of compositions Au₂Cu_1−x Al_1+x (−0.15 ⩽ x ⩽ 0.15). The B2-L2₁ transition temperatures are predicted, and are in agreement with the experimental results. The atomic ordering around vacancy of the L2₁ structure is further discussed.     

Multi-element ultrasound phased array applicator for the ablation of deep-seated tissue

High-intensity focused ultrasound (HIFU) has attracted increasing interests as a promising noninvasive modality for the treatment of deep tumors in the thoracic and abdominal cavity. A 90-element HIFU spherical phased array applicator operated at 1MHz has been developed for deep tissue ablation. The spherical array with a 5 cm wide central hole has a 21 cm diameter and an 18 cm radius of curvature. Annular element distribution with unequal element spacing is used to reduce the number of elements. The array is constructed with piezoelectric lead zirconate titanate (PZT-8) circular elements that are 1.4 cm in diameter and have a wall with thickness of 0.2 cm. The array offers an effective ablating depth of at least 8 cm in the tissue for both simulations and ex vivo experiments. The simulations demonstrate that the developed array can steer the focus with good quality of intensity distributions up to 6mm off center over ranges from 17 to 21 cm when the water depth is set at 11 cm. We also present the beam focusing capability in deep tissue through a series of ex vivo experiments by measuring discoloration areas after sonications. These results indicate that the developed array is ideal for the ablation of deep-seated tissue.