EPS中更精确的电机转速估计方法研究

电动助力转向系统中需要用到准确的助力电机转速信号,因此本文提出一种变内阻变反电动势系数的助力电机转速估计方法.通过测试直流电机内阻和反电动势系数随电机电流的变化曲线,从而得到电机转速更精确的估计表达式.通过对比试验验证可知,本文提出的电机转速估计方法能够显著提高估计精度.     

Application of observer-based fault detection in vehicle roll control

This paper describes how observer-based techniques for intelligent fault detection were applied to monitoring an active suspension control system in an experimental articulated heavy vehicle. The aim was to define a practical method for detecting faults, taking into account the nonlinearities of the vehicle. The experimental vehicle was divided conceptually into subsystems, namely the passive dynamics of the trailer, the dynamics of the hydraulic actuators, and the expected response of the closed-loop system. A linear dynamic model was designed for each subsystem. A fault detection observer was then designed for each dynamic model. The observer feedback gains were chosen to optimise estimation by the observer residual of specified errors on the output measurements. The observer residuals were then normalised and combined logically to provide a fault diagnosis. The performance of the fault detection scheme is demonstrated in the case of sensor faults and changes in the operation of the active control system.     

Fault detection and diagnosis of the electromechanical brake based on observer and parity space

In the future, the conventional hydraulic brake system in automobiles will be removed and replaced by an electrically operated brake system called brake-by-wire. The brake-by-wire units, such as the EMB (Electro-Mechanical Brake), provide better braking performance by directly controlling the brake motor and are environmentally friendly because they do not use hydraulic fluid. For implementation of the EMB systems, reliable and robust fault detection and diagnosis methods become increasingly important. In this study, a sensor fault diagnosis method is proposed with parity space and observer approaches to detect faults in the motor current sensor, speed (or position) sensor and clamping force sensor. The proposed method is verified through a closed-loop simulation using Matlab/Simulink, and the simulation result is compared with the HILS bench test results.     

线控转向系统故障检测及容错控制协同设计

为解决线控转向系统故障可能导致车辆失控的问题,提出一种故障检测及容错控制协同设计方法。首先,建立了包含线控转向系统加性故障的车辆动力学模型;其次,联合车辆动力学模型及故障检测/容错控制器,建立跟踪误差闭环控制系统;然后,求解满足闭环系统H∞性能的线性矩阵不等式,得到故障检测/容错控制器参数;最后,基于dSPACE Full-Size HIL进行硬件在环仿真测试。结果表明,该方法可快速检测出转向系统故障,同时实现了车辆的容错控制。     

纯电动汽车MCU母线电流采样电路及故障机制

设计一种纯电动汽车电机控制器直流母线电流采样电路,在此基础上提出一种电流采样故障的故障处理方法,该方法根据驱动系统当前状态实现了对电机控制器输入端直流母线电流的有效估算。当发生电机控制器直流母线电流采样回路故障后,利用估算值继续保证整车控制逻辑的正常执行,在保证安全行车的前提下,尽可能对驾驶员的驾驶感受进行保护。最后通过实车对该采样电路及故障机制进行验证。     

基于SVD-UKF的车用锂离子动力电池传感器故障诊断研究

针对传感器故障诊断问题,提出通过分析模型预测电压与传感器观测电压的残差来诊断传感器是否发生故障的方法。使用无迹卡尔曼滤波 （Unscented Kalman Filter,UKF） 算法估计电池的端电压,并提出使用奇异值分解（Singular Value Decomposition,SVD） 代替平方根法分解,以解决协方差矩阵非正定导致的算法无法正常运行的问题。提出使用累积和 （Cumulative Sum,CUSUM） 法对残差进行分析,通过监测 CUSUM 的变化来判断传感器是否发生故障。以动应力测试 （Dynamic Stress Test,DST） 工况作为验证工况,用 3类常见的传感器故障对提出的方法进行验证。 结果表明,提出的传感器故障检测方法在一些微小故障的检测中,相比于传统的设定残差阈值的方法更灵敏,能更快检测出微小的数据偏移情况。     

一种电动车电路故障防护新方法

作为保证电动汽车正常运行的水泵支路,在实际运行中有可能出现多种故障.论文从实际出发,对电机回路异常导致的功率电阻爆炸故障进行分析,并给出检测防止故障的方法.对电动汽车水泵支路功率电阻上的电压进行实时监测,并与标准曲线做相关度分析.以相关度作为判断水泵支路电机部分是否发生异常的判据,在支路故障时及时断开支路以保证支路安全.     

Vehicle distance estimation using a mono-camera for FCW/AEB systems

For robust vision-based forward collision warning (FCW) and autonomous emergency braking (AEB) systems, not only reliable detection performance including high detection rate and low false positives but also accurate measurement output of a target vehicle is required. Especially, in order to reduce false alarm or activation of FCW/AEB systems, the systems require the precise measurement output of a target object, such as position, velocity, acceleration, and time-to-collision (TTC). In this study, we developed a measurement estimation algorithm of a target vehicle using a monocular camera. This method estimates two cases of vehicle widths for a target vehicle by using the detected lane information and a pin-hole camera model. After that, the position, velocity, acceleration, and TTC of a target vehicle are estimated by using a Kalman filter for the each estimated vehicle width. To improve robustness, the both estimation results using the detected lane information and the pinhole camera model are fused. This estimation algorithm was evaluated and compared with the state-of-the-art technology. As a result, the proposed measurement output estimation method can improve the performance of the FCW/AEB systems.     

Design and implementation of a new clamping force estimator in Electro-Mechanical Brake systems

In this paper, an improved clamping force estimator is proposed for Electro-Mechanical Brake (EMB) systems by using the motor rotor position information and the hysteresis characteristics of mechanical parts in the EMB. A cascaded type of a force/position control system with a force sensor or an estimator was designed and implemented to control the clamping force and to keep the clearance gap in EMB systems. The EMB Hardware-In-the-Loop-Simulation (HILS) results show that the proposed force estimator yields better estimation performance than the existing estimator and that the clamping force control system based on the estimator can be also used for the fault tolerant control of the system.     

Model-based fault detection and isolation in automotive yaw moment control system

This paper presents a model-based fault detection and isolation technique for automotive yaw moment control system. For this purpose, a novel fault detection and isolation algorithm for a class of actuator-plant systems is proposed. Compared with the existing fault detection and isolation techniques that can only isolate a target fault or require multiple observers to isolate multiple faults, a unique strength of the proposed algorithm is its ability to isolate faults at the component level solely based on the residuals generated by a single observer. The validity of the proposed algorithm, applied to automotive yaw moment control system, is investigated via a simulation study based on a realistic vehicle dynamics model. The results suggest that the proposed algorithm can isolate the component subject to fault while effectively handling two perennial nuisances: sensitivity to disturbances and false alarms due to uncertainties.     

A signal-based fault detection and classification method for heavy haul wagons

This paper proposes a signal-based fault detection and isolation (FDI) system for heavy haul wagons considering the special requirements of low cost and robustness. The sensor network of the proposed system consists of just two accelerometers mounted on the front left and rear right of the carbody. Seven fault indicators (FIs) are proposed based on the cross-correlation analyses of the sensor-collected acceleration signals. Bolster spring fault conditions are focused on in this paper, including two different levels (small faults and moderate faults) and two locations (faults in the left and right bolster springs of the first bogie). A fully detailed dynamic model of a typical 40t axle load heavy haul wagon is developed to evaluate the deterioration of dynamic behaviour under proposed fault conditions and demonstrate the detectability of the proposed FDI method. Even though the fault conditions considered in this paper did not deteriorate the wagon dynamic behaviour dramatically, the proposed FIs show great sensitivity to the bolster spring faults. The most effective and efficient FIs are chosen for fault detection and classification. Analysis results indicate that it is possible to detect changes in bolster stiffness of ±25% and identify the fault location.     

简易法确定发动机缸孔泄漏点

表面或内部泄漏是缸体、缸盖最常见的故障之一。泄漏产生的原因有砂眼、气孔、裂纹等，而确定泄漏点、并将故障件维修处理是此类问题的关键。通常较大的砂眼或气孔（直径1mm以上）、裂纹肉眼或者借助漏液痕迹，都能找到相应的泄漏点，而较小的泄漏点、且出现在缸孔内部、缸盖燃烧室用常规的办法很难确定，有时需要用到专用的检测设备，而缸孔内部的细小漏点用专用泄漏检测设备能识别零件泄漏测试不合格，但无法锁定泄漏点的位置。本文将通过一个故障案例阐述一种特别简易且适合查找发动机内部泄漏的漏点检测方式—即简易法漏点检测。     

专用短程通信辅助的车辆卫星定位故障检测方法

为了确保卫星定位性能满足特定协作式智能交通应用需求,提高车辆定位系统的故障容错能力,针对车辆卫星定位的自主故障检测与性能优化问题,提出基于专用短程通信辅助的卫星定位故障检测方法,充分利用专用短程通信设备的测距率观测信息,实现故障检测对不同类型卫星可视条件的有效适应。基于专用短程通信多普勒观测特性,构建基于载波频偏的车间测距率观测模型;设计卫星定位与专用短程通信组合观测与解算框架;基于容积卡尔曼滤波提出适于非线性观测特征的故障检测、识别与排除算法,并叠加量测噪声方差矩阵动态调整策略,对故障检测性能进行优化;基于实测试验检验车间测距率的观测性能,并运用实车轨迹对多车协同运行及定位采集过程进行仿真,检验所提出方法的故障检测性能。研究结果表明：提出的方法有效解决了常规接收机自主完好性监测算法受卫星可视条件限制的问题,所引入的量测噪声方差矩阵调整策略提升了故障检测及故障排除性能的稳定性,在给定仿真场景中,常规卫星观测条件下阶跃故障、斜坡故障排除率相对常规方法最高可分别提升52%、18%,受限观测条件下不同水平2类故障的排除率最高分别可达100%、89%,边界观测条件下不同水平2类故障的检测率最高分别可达100%、96%。研究结果对于充分发挥车-车协同模式的核心优势、保障车辆定位性能具有重要价值。     

Discerning the operational state of a vehicle’s distributed electronic systems from vehicle network traffic for use as a fault detection and diagnosis tool

This paper suggests a novel approach to finding faults in a vehicle’s electronic systems by monitoring the network traffic directly and generating statistical traits. The nature of the data in a CAN network is considered, and a case for the use of statistical analysis presented. Statistical traits extracted from the temporal behavior of network messages are investigated as a metric for fault detection. It is shown how this trait information can be extracted from network data, and how this information could be used for fault detection of an unknown fault on a CAN network. It is then demonstrated that combining multiple types of trait data can be used to correctly identify a fault once detected.     

Fault detection and isolation for a nonlinear railway vehicle suspension with a Hybrid Extended Kalman filter

Fault detection is considered to be one way to improve system reliability and dependability for railway vehicles. The secondary lateral and anti-yaw dampers are the most critical parts in railway suspension systems. So far, the dampers have been modelled as linear components in the fault detection and isolation observer design. In this work, a Hybrid Extended Kalman filter is used to capture the nonlinear characteristics of the dampers. In order to detect and isolate faults, a nonlinear residual generator is developed, which can distinguish clearly between different types of faults. A lateral half train model serves as an example for the proposed technique. The results show that failures in the nonlinear suspension system can be detected and isolated accurately.     

一种坦克发动机电起动系统故障诊断新方法

基于起动电流信号中非平稳特征能有效反映坦克电起动系统的故障状态,提出一种坦克电起动系统故障诊断的新方法。应用小波奇异性检测技术,对起动电流信号中的奇异点进行定位和诊断。针对某型坦克的实际应用表明,基于小波奇异性分析的电起动系统故障诊断方法能有效提取起动电流信号中的关键特征信息,实现电起动系统常见显性和隐性故障的准确诊断及定位。     

迈腾B8电动后视镜控制系统的检测方法

鉴于现代轿电动后视镜控制系统功能繁多、结构复杂,故障排除难度较大。以迈腾B8电动后视镜控制系统为研究对象,通过分析其线路图工作原理,进而重点分析了后视镜转换开关EX11信号的检测信号和后视镜左右调节电动机V17控制电路的工作过程、常见故障与检测方法。结果表明:通过该检测方法能够有效地排查出该控制系统常见故障,并能够为其他车型控制系统提供规律性参考。     

Fault tolerant nonlinear control with applications to an automated transit bus

This paper presents an integrated structure for a passive and active fault tolerant control (FTC) design approach in the framework of a robust nonlinear control technique called Dynamic Surface Control (DSC). As motivated by the automated vehicle application, we consider two categories of possible faults: pre-specified (a priori) and non-specified faults. It is first shown that DSC can be considered as a passive FTC approach in the sense that it gives simultaneous robust stability to a set of nonlinear systems even in the presence of model uncertainties and the pre-specified faults. Then, the non-specified fault is classified depending on the fault’s impact on the closed-loop system and isolatability from a fault detection and diagnosis (FDD) system. If a fault is both intolerable and isolatable, an active FTC approach is taken which includes FDD and controller reconfiguration. More specifically, trajectory reconfiguration is considered to accommodate the actuator fault, i.e., to compensate for the performance loss due to the fault within the framework of a switched hierarchical structure. Finally, the integrated structure for the longitudinal control of an automated transit bus is designed through the proposed method. Simulation results of the fault tolerant controller are shown for both single and multiple multiplicative faults. This controller was implemented on the California PATH transit buses in a demonstration of automated public transportation technology in San Diego, California in August of 2003.     

花岗岩风化残留体地震法探测应用研究

花岗岩风化残留体会给城市地铁盾构施工带来极大的风险,为保证盾构在存在残留体的地层中顺利掘进,需提前探测出其在隧道沿线的分布情况。较之传统的钻探探测方法,地震法探测具有环境干扰小、效率高、覆盖范围广且成本低廉的优势。文章针对南方地区花岗岩地层特征及城区环境特点,对目前常用地震探测方法的适用性进行了试验研究,认为浅层地震反射法对于孤石探测是行之有效的,采用横波探测可以提高探测准确度。所得出的结论可供以后孤石探测工作参考借鉴。     

Kriging assisted on-line torque calculation for brushless DC motors used in electric vehicles

Torque is one of the most important control factors for a vehicle’s motion. Compared with internal combustion engines, electric motors can have a more accurate torque feedback which brings a lot of advantages to vehicle dynamics and stability control. However, motors used in electric vehicles are facing more difficult conditions than those in conventional applications, such as extreme high/low temperature changing, vibration, aging, etc. The variation of motor parameters due to harsh working conditions can lead to serious problems for motor torque estimation and thus dynamic control of electric vehicles. In this paper, a new method using kriging to estimate the back EMF and thus accurately calculate motor torque in an on-line fashion is presented. With motor speed and rotor position as inputs, kriging predicts back EMF as the output that is used to calculate the motor torque with three phase currents. Using this novel method, motor torque can be accurately calculated even facing high/low temperatures or aging conditions. Experimental tests under the high temperature have been conducted to verify the applicability of the proposed method.