The purpose of this project is to is to investigate the possibility of exploiting the flexibility inherent to micro air vehicle structures to create small-amplitude oscillations that delay stall and increase lift. Initially two-dimensional rigid airfoils undergoing small amplitude plunging oscillations are considered, this is then expanded to finite wings and finally flexible wings. For the 2D airfoil case two mechanisms of lift generation are identified: deflected jets for pre-stall angles of attack and convected leading- edge vortices for post-stall angles of attack. For rigid airfoils plunging with small-amplitude, two mechanisms of lift enhancement have been identified: deflected jets and convected LEVs. For finite wings oscillating at post-stall incidence, similar lift-enhancing convected LEVs are observed, however the flow field is more complicated. For oscillating flexible wings appropriate spanwise flexibility can significantly enhance lift performance. In terms of the flow field, the rigid wing exhibits weak vortical structures near the leading-edge, which are essentially the three-dimensional version of the LEV dipole observed for flat plate airfoils. Conversely the flexible wing exhibits a strong convected LEV, strong tip vortex and thus high lift.

关键词：翼型；攻角；长宽比；非对称流动；岔流

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转弯制动性能对半挂汽车列车的制动安全有重大影响,针对我国目前半挂汽车列车转弯制动试验标准缺失,传统的单车试验设备不适用于半挂汽车列车等问题,本文中从试验系统搭建、系统安装方式和试验方法与评价等方面对半挂汽车列车转弯制动试验进行了探索性研究。结果表明:半挂汽车列车转弯制动过程中侧向加速度、制动减速度、横摆角速度和牵引车的俯仰角随车速的升高而增加。建议半挂汽车列车转弯制动试验中车速不超过30km/h,转弯半径不小于25m。

关键词：半挂汽车列车；转弯制动；试验系统；试验方法

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Catalytic converters (CATCONs) are required by Federal law to be installed in nearly all gasoline- and diesel-fueled onroad vehicles used in the United States. About 85 percent of the light-duty vehicles and trucks manufactured worldwide are equipped with CATCONs (Ashok Kumar, Director, A1 Specialized Services & Supplies, Inc., written commun. July 10, 2012). These vehicles include buses, cars, light- and heavy-duty trucks, and motorcycles. Many offroad vehicles, such as trail bikes and all-terrain recreational vehicles, are also equipped with CATCONs, but offroad vehicles are not addressed in this paper (Manufacturers of Emission Controls Association, 2008). Portions of the CATCONs (called monoliths) are recycled for their platinum-group metal (PGM) content and for the value of the stainless steel they contain. The cerium contained in the monoliths, however, is disposed of along with the slag produced from the recycling process. Although there is some smelter capacity in the United States to treat the monoliths in order to recover the PGMs, a great percentage of monoliths is exported to Europe and South Africa for recycling, and a lesser amount is exported to Japan. There is presently no commercial-scale capacity in place domestically to recover cerium from the monoliths. Recycling of cerium or cerium compounds from the monoliths could help ensure against possible global supply shortages by increasing the amount that is available in the supply chain as well as the number and geographic distribution of the suppliers. It could also reduce the amount of material that goes into landfills.

关键词：大气；稀有气体；空气污染

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基于1台高压共轨涡轮增压柴油机,采用不同的预喷正时、预喷油量与后喷正时等,研究了多次喷射对燃烧放热、排放生成与燃油经济性的影响,以实现均质压燃和低温燃烧过程。研究结果表明:随预喷正时提前,缸内峰值压力降低,主燃阶段的滞燃期缩短,NOx和炭烟排放均降低;随预喷油量增加,预喷阶段燃烧的放热率和最大压力升高率增大,NOx和HC排放增大,而PM和CO排放降低;随后喷始点推迟,缸内压力与主放热率峰值差异变小,NOx排放降低,但炭烟排放先增大后逐渐降低。

关键词：直喷式柴油机；多次喷射；预喷正时；放热率；排放

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在高压共轨燃油喷雾试验台上对正丁醇体积掺混比分别为0%,5%,10%和20%的柴油-正丁醇混合燃料的宏观喷雾特性进行了研究。结果表明:在相同共轨压力下,随着背压的增加,喷雾锥角增大,喷雾贯穿距减小;在相同背压下,随着共轨压力的增加,喷雾贯穿距和喷雾锥角均逐渐增大,但当共轨压力增大到110 MPa时,二者不再增大;在相同背压和相同共轨压力下,喷雾贯穿距和喷雾锥角随着正丁醇比例的增加逐渐增大,说明在柴油中混合一定比例的正丁醇可以提高燃料的雾化质量。

关键词：柴油；正丁醇；混合燃料；背压；共轨压力；喷雾贯穿距；喷雾锥角

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The paper proposes a method to reduce operational force in a bilateral teleoperation system that realizes simultaneity property under communication delay. A bilateral control that realizes simultaneity property is previously proposed, which is achieved by buffering the force information. It focused on the fact that force information from the master motor is the pure information that actuates the motor, therefore, timing of the force information input is corrected. However, the control system requires large force when operator tries to operate the system. The paper clears the reason and the problem is solved by utilizing the delayed position information of the own system. The proposed control system is designed to mix present and buffered position information to reduce the operational force. The delayed information can easily affect the stability problem, therefore, phase compensator is used. The validity of the proposed method is confirmed by experiments.

关键词：加速度控制；双向控制系统；通信延迟

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This report describes the current state of knowledge regarding the effectiveness of several advanced collision-avoidance technologies (ACATs) and presents an assessment of the effect of each technology on traffic safety. The report covers only ACATs for light-duty vehicles. The literature reviewed is primarily restricted to English language publications from the last ten years (2003 to 2013). The technologies included in the assessment address vehicle instability (electronic stability control); forward impact collisions (forward collision warning, autonomous emergency braking); and crashes related to lane/road departure (lane departure warning and prevention, blind spot detection). The methodologies and data used to evaluate ACAT effectiveness are also discussed. Data on the penetration of the technologies into the light-duty fleet are also presented. Overall, the systems reviewed here were estimated to be substantially effective in reducing their target crash types. The studies reviewed had a range of estimated reductions, and in some cases the differences were fairly substantial. However, even the lower-bound estimates are significant in most cases. Most studies relied on simulation or limited field operational tests to evaluate effectiveness.

关键词：事故减少；先进的防碰撞技术（简称ACATS）；防撞

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This chapter considers sliding mode control of nonlinear discrete time systems with matching perturbations. The nonlinear sliding mode controller, whose parameters assure the closed-loop system stable, is designed in order to drive the state trajectories toward to a small bounded region. The controller is approximated by a polynomial equation in current control term u(k) according to Taylor series expansion. The algebraic solutions can be obtained by resolving a polynomial equation in the latest control term u(k). The integrated procedure provides a straightforward methodology to apply sliding mode control design technique for nonlinear systems. The simulation results are provided to illustrate the effectiveness of the proposed scheme.

关键词：非线性离散时间系统；非线性控制器；滑模控制

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In this chapter, the problem of approximate linearization of affine nonlinear control systems by a static state feedback is considered. First of all, we propose an analytical method, based on the development into generalized Taylor series expansions and the Kronecker product tools, in order to simplify the complex implementation of the input-state feedback linearization formalism. Next, to improve the synthesized polynomial feedback control, the genetic algorithm, as an optimization method, is used. Finally, the new approach presented in this work is applied to investigate the control problem of a chemical reactor. Moreover, we prove that the controlled process is locally asymptotically stable in a wide region around the operating point, in the Lyapunov sense.

关键词：反馈线性化；多项式非线性控制；优化程序

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利用定容容器模拟增压发动机缸内高温高压条件,利用高速摄像机观察二甲醚喷雾,探讨了喷射压力对喷雾贯穿距离、喷雾蒸发等喷雾发展过程的影响规律。结果表明:在喷射初期喷雾贯穿距离与喷射时间成正比关系,在喷射后期,环境气体卷入喷雾中,喷雾贯穿距离与喷射时间平方根成正比关系;二甲醚燃料液态喷雾贯穿距离相对于气态来说非常短,DME液态喷雾贯穿距离基本不随时间的增加而增长。

关键词：二甲醚；喷雾贯穿距；燃油雾化；喷射压力

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