基于BP神经网络的隧道围岩分类

应用BP神经网络建立了隧道围岩分类模型,对其影响因素进行分析,并对模型进行优化,将训练好的分类模型运用到贵安隧道,为隧道围岩分类提供了一种简便可行的方法。     

心理因素影响下游客节假日错峰旅游出行行为研究

错峰出行是解决出行时间集中引起交通拥堵问题的重要措施. 本文以节假日游客错峰出行行为为研究对象，探究心理潜变量对其错峰出行意向及行为的影响机理. 基于计划行为理论，同时考虑节假日旅游满意度，构建节假日游客错峰旅游出行行为的结构方程模型. 定量研究了态度、主观规范、知觉行为控制、节假日旅游满意度4 个心理因素对游客节假日错峰旅游行为意向及行为的影响. 最后通过问卷调查数据进行了实例分析. 研究结果表明，4 个潜在变量对节假日错峰旅游出行行为意向具有显著影响，其中知觉行为控制是关键因素且影响最大，节假日旅游满意度对节假日错峰出行行为意向及行为有显著负向影响. 本研究可为节假日游客错峰旅游出行措施的制定提供参考依据.     

船舶主机数字调速仿真训练器的研制

为了研究船舶主机调速系统的特性和控制算法,将船舶主机调速系统的性能要求转化为复合PID控制算法的问题,研制基于Nabtesco MG-800Ⅲ的数字调速仿真器。非线性PID实现主机转速控制,其比例增益、微分增益和积分增益分别是控制偏差的非线性函数。模糊自整定PID实现主机油门的位置控制,其PID的3个参数随着偏差和偏差变化速度,根据模糊控制原理进行在线修改。物理仿真结果表明,数字调速器的非线性模糊自适应PID算法能提高调速系统的动态精度和抑制扰动的能力。     

Application of time-variant predictive control to modelling driver steering skill

The paper addresses the need for improved mathematical models of human steering control. A multiple-model structure for a driver's internal model of a nonlinear vehicle is proposed. The multiple-model structure potentially offers a straightforward way to represent a range of driver expertise. The internal model is combined with a model predictive steering controller. The controller generates a steering command through the minimisation of a cost function involving vehicle path error. A study of the controller performance during an aggressive, nonlinear steering manoeuvre is provided. Analysis of the controller performance reveals a reduction in the closed-loop controller bandwidth with increasing tyre saturation and fixed controller gains. A parameter study demonstrates that increasing the multiple-model density, increasing the weights on the path error, and increasing the controller knowledge range all improved the path following accuracy of the controller.     

K型、双K型圆管相贯节点极限承载力的非线性有限元分析

利用非线性分析的有限元方法对K型和双K型圆管相贯节点进行了数值计算，揭示了节点极限承载力随各几何参数的变化规律及主管作用荷载对节点极限承载力的影响，分别绘制出各影响参数的载荷一位移曲线，并将分析结果和钢结构标准GB50017—2003进行了比较，所得结论供工程设计参考应用。     

抗滑桩设计锚固长度影响因素分析

文章分析了岩层地基横向容许承载力[σH]、土层地基系数随深度变化的比例系数m、土层内摩擦角φ及地面横坡对抗滑桩锚固段长度H2的影响程度和影响规律,对工程设计中相关参数的确定和计算方法的选取提供了参考依据。     

Roll- and pitch-plane-coupled hydro-pneumatic suspension. Part 2: dynamic response analyses

In the first part of this study, the potential performance benefits of fluidically coupled passive suspensions were demonstrated through analyses of suspension properties, design flexibility and feasibility. In this second part of the study, the dynamic responses of a vehicle equipped with different configurations of fluidically coupled hydro-pneumatic suspension systems are investigated for more comprehensive assessments of the coupled suspension concepts. A generalised 14 degree-of-freedom nonlinear vehicle model is developed and validated to evaluate vehicle ride and handling dynamic responses and suspension anti-roll and anti-pitch characteristics under various road excitations and steering/braking manoeuvres. The dynamic responses of the vehicle model with the coupled suspension are compared with those of the unconnected suspensions to demonstrate the performance potential of the fluidic couplings. The dynamic responses together with the suspension properties suggest that the full-vehicle-coupled hydro-pneumatic suspension could offer considerable potential in realising enhanced ride and handling performance, as well as improved anti-roll and anti-pitch properties in a very flexible and energy-saving manner.     

Simultaneous observation of the wheels’ torques and the vehicle dynamic state

The goal of the present study is to show how it is possible to estimate online the individual torques applied at each wheel of an automotive vehicle by using an unknown input observer together with a simple nonlinear state-space model. The necessary measurements are the steering angle, the usual rotation speed of each wheel plus the vertical load at the centre of each wheel. By doing this, this study anticipates the affordability of a new generation of wheel bearing with embedded measurements of transmitted forces. Successful simulated experimentations using a realistic simulator are shown. Validations are done using classical case studies of longitudinal, lateral and coupled dynamics. The present limits and some possible improvements of the proposed method are also discussed.     

Impact of inerter nonlinearities on vehicle suspension control

This paper discusses the nonlinear properties of inerters and their impact on vehicle suspension control. The inerter was recently introduced as an ideal mechanical two-terminal element, which is a substitute for the mass element, where the applied force is proportional to the relative acceleration across the terminals. Until now, ideal inerters have been applied to vehicle, motorcycle and train suspension systems, in which significant performance improvement was achieved. However, due to the mechanical construction, some nonlinear properties of the existing mechanical models of inerters are noted. This paper investigates the inerter nonlinearities, including friction, backlash and the elastic effect, and their influence on vehicle suspension performance. A testing platform is also built to verify the nonlinear properties of the inerter model.     

基于正交基神经网络的热敏电阻温度传感器非线性补偿方法

针对热敏电阻温度传感器应用中存在的非线性问题，提出了应用正交基（0BF）神经网络进行非线性补偿的方法。研究结果表明，OBF神经网络非线性补偿算法具有补偿精度高、计算量小的优点，因而是一种有效的非线性补偿方法。