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991.
摩托车燃油蒸发排放污染及其控制技术研究 总被引:1,自引:0,他引:1
制定并实施严格的车辆排放标准,是促进污染控制技术发展的动力,控制车辆排放污染的根本途径是成熟的污染控制技术.因此,在制定国家标准时,应充分考虑标准制定的适时性,结合国家有关环境保护的长远规划、行业技术水平、技术实施可行性、经济合理性等诸多因素,避免技术壁垒. 相似文献
992.
Riccardo Marino Stefano Scalzi Fabio Cinili 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2007,45(12):1149-1168
Vehicle steering dynamics show resonances, which depend on the longitudinal speed, unstable equilibrium points and limited stability regions depending on the constant steering wheel angle, longitudinal speed and car parameters.
The main contribution of this paper is to show that a combined decentralized proportional active front steering control and proportional-integral active rear steering control from the yaw rate tracking error can assign the eigenvalues of the linearised single track steering dynamics, without lateral speed measurements, using a standard single track car model with nonlinear tire characteristics and a non-linear first-order reference model for the yaw rate dynamics driven by the driver steering wheel input. By choosing a suitable nonlinear reference model it is shown that the responses to driver step inputs tend to zero (or reduced) lateral speed for any value of longitudinal speed: in this case the resulting controlled vehicle static gain from driver input to yaw rate differs from the uncontrolled one at higher speed. The closed loop system shows the advantages of both active front and rear steering control: higher controllability, enlarged bandwidth for the yaw rate dynamics, suppressed resonances, new stable cornering manoeuvres, enlarged stability regions, reduced lateral speed and improved manoeuvrability; in addition comfort is improved since the phase lag between lateral acceleration and yaw rate is reduced.
For the designed control law a robustness analysis is presented with respect to system failures, driver step inputs and critical car parameters such as mass, moment of inertia and front and rear cornering stiffness coefficients. Several simulations are carried out on a higher order experimentally validated nonlinear dynamical model to confirm the analysis and to explore the robustness with respect to unmodelled dynamics. 相似文献
The main contribution of this paper is to show that a combined decentralized proportional active front steering control and proportional-integral active rear steering control from the yaw rate tracking error can assign the eigenvalues of the linearised single track steering dynamics, without lateral speed measurements, using a standard single track car model with nonlinear tire characteristics and a non-linear first-order reference model for the yaw rate dynamics driven by the driver steering wheel input. By choosing a suitable nonlinear reference model it is shown that the responses to driver step inputs tend to zero (or reduced) lateral speed for any value of longitudinal speed: in this case the resulting controlled vehicle static gain from driver input to yaw rate differs from the uncontrolled one at higher speed. The closed loop system shows the advantages of both active front and rear steering control: higher controllability, enlarged bandwidth for the yaw rate dynamics, suppressed resonances, new stable cornering manoeuvres, enlarged stability regions, reduced lateral speed and improved manoeuvrability; in addition comfort is improved since the phase lag between lateral acceleration and yaw rate is reduced.
For the designed control law a robustness analysis is presented with respect to system failures, driver step inputs and critical car parameters such as mass, moment of inertia and front and rear cornering stiffness coefficients. Several simulations are carried out on a higher order experimentally validated nonlinear dynamical model to confirm the analysis and to explore the robustness with respect to unmodelled dynamics. 相似文献
993.
利用动力响应模型试验装置,研究了高填路堤不同拓宽方式,以及工后重载动力响应高填路堤变形与破坏问题,新老路基不均匀沉降、新老路基的不稳定拓宽衔接是产生危害的主要原因,高填路堤不同拓宽方式下的重载动力响应试验研究成果为高速公路高填路堤拓宽改扩建工程提供了借鉴。 相似文献
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996.
GM(1,3)模型在交通系统公路客运量预测中的应用 总被引:4,自引:0,他引:4
交通系统公路客运量预测不仅具有模糊性和动态性等特点,而且受多个因素影响。许多交通研究人员只根据客运量一个因素,用GM(1,1)模型预测。文章运用GM(1,N)系统综合预测模型,考虑系统中多个相关因素,并结合GM(1,1)模型,以原始离散的公路客运量、人口和国内生产总值GDP三组数据数列为基础,建立GM(1,3)模型来预测公路客运量。在详细论述了系统综合预测模型GM(1,3)的建立过程后,用后验差检验法对预测结果进行了检验,预测精度较好,表明此模型对公路客运量预测有一定应用价值。 相似文献
997.
高速公路路基养护评价方法研究 总被引:2,自引:0,他引:2
针对高速公路路基养护评价方法,首先从养护对象的角度建立了高速公路路基的评价指标体系,然后根据指标体系与养护对象的关系构建了模型框架,最后利用在江苏省现场采集的30个高速公路路段数据建立了主观评分值和客观评分值的主客观联系。通过线性回归的方法得到了江苏省高速公路路基评价模型,并验证了模型的合理性。 相似文献
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999.
城市立交隧道小净距分岔部位施工技术 总被引:1,自引:0,他引:1
文章介绍了厦门万石山立交隧道小净距分岔部位的特殊性,以及施工中采取的开挖工序、超前支护、中间岩柱注浆、对拉锚杆加固、锚喷支护、监控量测等技术措施。 相似文献
1000.
AMT车辆变速系统及控制过程的研究 总被引:2,自引:0,他引:2
介绍了AMT的工作原理、系统组成及AMT车辆发动机的电控调节方式。针对评价换挡品质的3项指标、影响换挡品质的因素及存在的问题,分析了AMT车辆换挡过程中对发动机、离合器、变速器的综合控制及对换挡品质的影响,为进一步提高AMT换挡品质提供参考。 相似文献