Rollover prevention for heavy trucks using frequency shaped sliding mode control

Control and handling of heavy commercial vehicles carrying liquid cargo are influenced by liquid movement within the partially filled tank. During steering and braking maneuvering tasks, the truck may exhibit unstable behavior at lateral acceleration levels of 0.3 g to 0.4 g [m/s²]. The fluid slosh forces and dynamic load transfers in the lateral and longitudinal directions and parametric uncertainties caused by moving liquid cargo affect the overall dynamics of the vehicle. To solve a physical problem about the minimal excitation of the slosh dynamics associated with the longitudinal and lateral excitation of the vehicle, dynamic sliding surface design combined with recursive backstepping algorithm is introduced. Compensator dynamics are introduced in the sliding mode through a class of switching surfaces which has the interpretation of linear operators such that the resulting closed-loop system retains the insensitivity to uncertainties in the sliding mode while minimizing the excitation of flexible modes and unmodeled dynamics. The frequency shaped backstepping sliding mode algorithm, proposed by Acarman and Özgüner [Frequency shaping compensation for backstepping sliding mode control. Paper presented at the 15th IFAC World Congress, Barcelona, Spain, 2002], is designed to stabilize and to attenuate the sloshing effects of moving cargo by properly choosing the crossover frequencies of the dynamic compensators in accordance with the fundamental frequencies of the slosh dynamics.     

Automatic path-tracking controller of a four-wheel steering vehicle

The present paper proposes an automatic path-tracking controller of a four-wheel steering (4WS) vehicle based on the sliding mode control theory. The controller has an advantage in that the front- and rear-wheel steering can be decoupled at the front and rear control points, which are defined as centres of percussion with respect to the rear and front wheels, respectively. Numerical simulations using a 27-degree-of-freedom vehicle model demonstrated the following characteristics: (1) the automatic 4WS controller has a more stable and more precise path-tracking capability than the 2WS controller, and (2) the automatic 4WS controller has robust stability against system uncertainties such as cornering power perturbation, path radius fluctuation, and cross-wind disturbance.     

Literature review and fundamental approaches for vehicle and tire state estimation*

ABSTRACT

Most modern day automotive chassis control systems employ a feedback control structure. Therefore, real-time estimates of the vehicle dynamic states and tire-road contact parameters are invaluable for enhancing the performance of vehicle control systems, such as anti-lock brake system (ABS) and electronic stability program (ESP). Today's production vehicles are equipped with onboard sensors (e.g. a 3-axis accelerometer, 3-axis gyroscope, steering wheel angle sensor, and wheel speed sensors), which when used in conjunction with certain model-based or kinematics-based observers can be used to identify relevant tire and vehicle states for optimal control of comfort, stability and handling. Vehicle state estimation is becoming ever more relevant with the increased sophistication of chassis control systems. This paper presents a comprehensive overview of the state-of-the-art in the field of vehicle and tire state estimation. It is expected to serve as a resource for researchers interested in developing vehicle state estimation algorithms for usage in advanced vehicle control and safety systems.     

标准化司机室入口门的改进设计

从结构、密封方式、铰链形式三方面分析老式司机室入口门存在的问题,并对其进行改进,使其达到现在的技术要求。     

屏蔽门系统顶部结构的应力分析

介绍了屏蔽门系统顶部结构的功能，针对传统的机械结构应力分析方法，以屏蔽门系统顶部结构在静力条件下的不同工况为例，应用ANSYS软件建立顶部结构的有限元模型，并对模型在不同工况下进行应力状态分析，找出结构的危险点和应力集中区，对顶部结构设计有一定的指导意义。     

A vehicle stability control strategy with adaptive neural network sliding mode theory based on system uncertainty approximation

Modelling uncertainty, parameter variation and unknown external disturbance are the major concerns in the development of an advanced controller for vehicle stability at the limits of handling. Sliding mode control (SMC) method has proved to be robust against parameter variation and unknown external disturbance with satisfactory tracking performance. But modelling uncertainty, such as errors caused in model simplification, is inevitable in model-based controller design, resulting in lowered control quality. The adaptive radial basis function network (ARBFN) can effectively improve the control performance against large system uncertainty by learning to approximate arbitrary nonlinear functions and ensure the global asymptotic stability of the closed-loop system. In this paper, a novel vehicle dynamics stability control strategy is proposed using the adaptive radial basis function network sliding mode control (ARBFN-SMC) to learn system uncertainty and eliminate its adverse effects. This strategy adopts a hierarchical control structure which consists of reference model layer, yaw moment control layer, braking torque allocation layer and executive layer. Co-simulation using MATLAB/Simulink and AMESim is conducted on a verified 15-DOF nonlinear vehicle system model with the integrated-electro-hydraulic brake system (I-EHB) actuator in a Sine With Dwell manoeuvre. The simulation results show that ARBFN-SMC scheme exhibits superior stability and tracking performance in different running conditions compared with SMC scheme.     

安全滑触线的优化设计

安全滑触线适用于各种移动式用电设备的供电,既安全可靠又节能经济。江西省建筑陶瓷产业基地铁路专用线工程采用了滑触线的施工,对安全滑触线进行了优化设计,由电杆式安装改为悬挂式安装,并分别从安装、造价、维修、安全、节能等方面详细介绍了其优点。     

上海明珠线二期地铁车辆车门安装调试

介绍上海明珠线二期地铁车辆车门的结构和安装调试工艺,分析车体挠度对车门的影响,并将分析结果用在地铁车辆车门的安装调试工艺中作为参考。     

地铁屏蔽门系统设计分析

以苏州地铁1号线屏蔽门为研究对象,介绍其主体结构、锁紧装置的设计问题。对应急门、端门部分以及解锁装置进行了说明,还对屏蔽门与土建、装修、机电各专业接口问题进行了分析。通过优化产品设计、工程设计、接口设计以及现场管理,为保质、按期完成屏蔽门工程项目提供有利的保证。     

某车型车门强度技术研究

本文首先通过CAE软件Pam-Crash完成了某车型的车门强度仿真分析,并与试验结果进行了对比,结果显示数据一致性较好,故可用于指导车门的设计及优化。