基于Logistic映射的交通流的混沌态研究

由密度K-速度v的线形模型，导出Logistic映射的差分方程，讨论映射下的交通流及混沌态的有关理论；用Lyapunov指数进一步阐明Logistic映射下的交通流特性；最后从混沌交通流的熵给出混沌程度量的大小。     

对现行公路渗沟计算方法若干问题的思考

分析我国现行<公路排水设计规范>及<公路设计手册*路基>中不完整渗沟的流量计算方法的区别,并进一步分析两种计算方法的局限性,提出分区计算法以及考虑路基干湿状态的渗沟埋深计算方法.     

非线性液压阻尼悬架的优化设计及最优控制

本文对二自由度非线液压阻尼悬架系统进行了统计线性分析，并提出这种半主动非线性液压阻尼悬架系统针对不同路况进行最优控制的控制策略；同时对非线性阻尼系统进行实时仿真，得出此类液压阻尼对振动的抑制优于线性阻尼的结论。     

一种轻型车用催化转化器系统的研制

针对北京切诺基四缸多点喷射轻型车，本文研制成功了一种催化转化器，整车十五工况的试验表明：所研制的催化转化器对于降低原车的排放具有明显的作用。     

天然气发动机电子节气门控制系统的研究

介绍基于电控调压器的增压单燃料CNG发动机的系统组成,在分析电子节气门结构和驱动原理的基础上,开发了以MC68376为主芯片的电子节气门控制系统,采用TLE6209设计了电子节气门驱动电路。设计了基于模糊自整定参数PID控制器,通过电子节气门在CNG发动机试验台架上的阶跃响应试验和油门开度与节气门开度的跟踪响应试验,验证了所设计的节气门控制系统可以实现对电子节气门精确、快速和稳态误差小的闭环控制。     

触觉传感器及感知技术研究现状与发展趋势

触觉感知技术可用于对物体的探索和操作,对环境的交互作用具有重要意义。本文从介绍触觉传感器应满足的机械手操作任务要求出发,全面综述了不同类型触觉传感器的结构和工作原理,并分析了它们的优缺点。分析讨论触觉传感器在人工皮肤和生物医学领域的应用现状,最后总结了先进的机器学习算法和信号处理技术在触觉传感系统中的应用。     

核电站取水口海生物驱赶消杀技术研究

近年来,国内多座滨海核电站海生物频繁入侵,可能引发冷源取水口堵塞、核电站跳堆事故,严重影响核电站的安全可靠运行。本文对国内外核电站冷源防护技术进行了广泛调研,介绍了多种海生物驱赶消杀技术,分析了各种技术的作用原理,论述了各种技术的优缺点,给出了工程指导建议。结合核电站取水口立体纵深防护原则,提出了一种海生物驱赶消杀综合系统模型,为核电站改造以及新建核电站规划设计提供了参考。     

Investigation into untripped rollover of light vehicles in the modified fishhook and the sine maneuvers. Part I: Vehicle modelling, roll and yaw instability

Vehicle rollovers may occur under steering-only maneuvers because of roll or yaw instability. In this paper, the modified fishhook and the sine maneuvers are used to investigate a vehicle's rollover resistance capability through simulation. A 9-degrees of freedom (DOF) vehicle model is first developed for the investigation. The vehicle model includes the roll, yaw, pitch, and bounce modes and passive independent suspensions. It is verified with the existing 3-DOF roll-yaw model. A rollover critical factor (RCF) quantifying a vehicle's rollover resistance capability is then constructed based on the static stability factor (SSF) and taking into account the influence of other key dynamic factors.

Simulation results show that the vehicle with certain parameters will rollover during the fishhook maneuver because of roll instability; however, the vehicle with increased suspension stiffness, which does not rollover during the fishhook maneuver, may exceed its rollover resistance limit because of yaw instability during the sine maneuver. Typically, rollover in the sine maneuver happens after several cycles.

It has been found that the proposed RCF well quantifies the rollover resistance capability of a vehicle for the two specified maneuvers. In general, the larger the RCF, the more kinetically stable is a vehicle. A vehicle becomes unstable when its RCF is less than zero. Detailed discussion on the effects of key vehicle system parameters and drive conditions on the RCF in the fishhook and the sine maneuver is presented in Part II of this study.     

Hierarchical distributed coordination strategy of connected and automated vehicles at multiple intersections

In this paper, we present a hierarchical distributed coordination strategy for connected and automated vehicles (CAVs) that are travelling through multiple unsignalized intersections. The control strategy focuses on the improvement of vehicle fuel efficiency and system mobility. In presence of wireless communication among the involved CAVs and the intersection controllers, our coordination strategy focuses on leading the CAVs travel through a road network without conventional traffic light control and ensuring collision avoidance at the intersection areas. We propose a three-layered coordination strategy in this paper. First, we evaluate the road desired average velocity considering both upstream and downstream traffic to speed up the traffic density balance. Second, the intersection controllers optimally assign reference velocity to each vehicle based on the minimization of velocity deviation from its current velocity and collision avoidance at the intersections. Finally, fast model predictive control (F-MPC) is applied for each vehicle to track their reference velocity in a computationally efficient manner. Two simulation scenarios with different difficulty levels have been implemented on a two-interconnected intersection network. Simulation results indicate the feasibility and scalability of the proposed method, as well as vehicle fuel efficiency and system mobility improvement.     

非线性缆索单元及其在缆索承重桥中的应用

柔性缆索本身所具有的高度几何非线性给缆索计算带来困难,而缆索线形的确定是缆索承重桥能否实现的关键.文中建立了Lagrange坐标系下缆索曲线方程,推导出2节点非线性缆索单元的切线刚度矩阵,并给出了应用该单元求解缆索线形的迭代格式.用该方法计算某大桥方案主缆线形和无应力长度,并将结果与解析法结果对比分析,二者相对误差不大于0.06%,从而证明该方法的可靠性.