Development of a Calibration and Monitoring System for GD-1 High Pressure Common Rail Diesel Engine

IntroductionEngine performance and exhaustemissions arecontrolled by a great number of control parameters( constants,curves and maps) in the ECU relatedto injection system,combustion chamber geome-try,boost pressure and EGR percentage. As iswell known,all these parameters are required tobe changed and calibrated again and again,so thecalibration workload is very big.And many itemsof exhaust emissions,such as good NOX and sootengine- out level predictions,are strictly linked notonly to the …     

舰船 RCS 测试内外结合定标方法

针对舰船 RCS 测试的定标问题，讨论从接收机前端注入标准微波信号或从发射机耦合发射功率输入接收机前端的2种内定标方法，作为修正外场定标的依据。根据雷达方程分析外场定标 RCS 测量设备、标准体加工、目标跟踪定位、测试区域环境等主要误差因素。讨论发射功率、系统非线性、系统稳定性、极化损耗等引入的误差，提出外场定标对标准体几何尺寸、表面光洁度以及所需信噪比等要求。通过内定标与外定标相结合的方法，解决由于定标与测试间隔时间过长接收机状态出现漂移导致测试误差的问题，保障舰船 RCS 长时间测试的精度和稳定度。     

船载航行数据记录仪时间校准机制研究

对船载航行数据记录仪的时间校准方式进行了阐述，提出了防止校时产生文件顺序混乱的方法。     

Techniques for the inference of mileage rates from MOT data

Abstract

Mathematical and computational techniques are developed for the processing and analysis of annual Ministry of Transport roadworthiness (MOT) test data that the UK Department for Transport has placed in the public domain. First, techniques are given that clean erroneous records and a linking procedure is provided that permits the inference of an individual vehicle's mileage between consecutive tests. Methods are then developed that analyse aggregate mileage totals, as a function of vehicle age, class and geography. The inference of aggregate mileage rates as a function of time is then considered.     

高压共轨柴油机怠速控制标定研究

针对高压共轨柴油机,分析怠速控制原理,提出高压共轨柴油机怠速控制的标定方法.运用INCA标定软件,对2.5L柴油机进行怠速控制参数标定试验,使柴油机怠速稳定,速度响应较快,取得了较好的效果.     

基于多尺度随机动态模型的惯性器件数据融合估计

结合离散小波变换、动态系统理论及随机过程理论,建立了以尺度为变量的多尺度随机动态模型,并给出状态基于多尺度随机动态模型的多尺度递归数据融合算法,实现了在状态基于全局观测信息的优化估计值。该算法可以在无状态模型情况下进行数据融合,适用于难以获得或获得的状态模型不精确的情况。将此方法用于陀螺信号处理中,通过不同尺度下陀螺观测值的融合,陀螺信号的精度有明显的提高。仿真和实验均证明该算法是一种有效的数据融合算法。     

重要零件表面品质检测手段的提升和应用

在以批量生产为特征的汽车零部件行业,凸轮轴、万向节、轴承、气门和活塞销等重要零件的表面品质是产品质量的一项重要指标,但传统的测试方法却难以满足准确和快速检测的要求。文章对零件的表面品质及其惯用检测手段进行了描述,着重推出了一种新颖和高效的磨削烧伤检测方法——磁弹法。文章介绍了这种方法的工作原理,以及在这基础上研制的专用仪器的基本结构和组成,叙述了应用磁弹法时的评定特征值mp和仪器的定标,并通过所举实例予以说明。     

手动变速器换挡过程纵向冲击问题研究

某款自主研发的匹配6MT手动变速器的国六SUV车型,在1挡加速过程中,松油门快踩离合器时,车辆产生明显的纵向冲击现象,且发生频率较高,严重影响了乘客地主观感受和乘车舒适性。通过对故障车辆进行实车诊断测试,对纵向冲击现象分析,发现发动机扭矩突变是导致整车产生纵向冲击的原因,最终通过优化发动机EMS标定策略的方法解决了该问题,以较低的成本达到了改善整合NVH性能的目的。     

Uncertainty quantification in vehicle dynamics

ABSTRACT

This paper presents a review of various works that highlight the importance of introducing the variability of the road-track/vehicle system into dynamic simulations as soon as this latter is meant to be predictive. The first section of the paper presents the Uncertainty Quantification, Verification and Validation method (UQ-VV). This latter proposes tools to model uncertainties, to associate a confidence to the prediction of quantities of interest and to estimate the probability of occurrence of different scenarios. The method is illustrated by various examples mainly from the rail domain but also from the road sector. The second section summarises application examples of predictive modelling, robust optimisation and calibration.     

Bayesian calibration of mechanistic aquatic biogeochemical models and benefits for environmental management

Aquatic biogeochemical models have been an indispensable tool for addressing pressing environmental issues, e.g., understanding oceanic response to climate change, elucidation of the interplay between plankton dynamics and atmospheric CO₂ levels, and examination of alternative management schemes for eutrophication control. Their ability to form the scientific basis for environmental management decisions can be undermined by the underlying structural and parametric uncertainty. In this study, we outline how we can attain realistic predictive links between management actions and ecosystem response through a probabilistic framework that accommodates rigorous uncertainty analysis of a variety of error sources, i.e., measurement error, parameter uncertainty, discrepancy between model and natural system. Because model uncertainty analysis essentially aims to quantify the joint probability distribution of model parameters and to make inference about this distribution, we believe that the iterative nature of Bayes' Theorem is a logical means to incorporate existing knowledge and update the joint distribution as new information becomes available. The statistical methodology begins with the characterization of parameter uncertainty in the form of probability distributions, then water quality data are used to update the distributions, and yield posterior parameter estimates along with predictive uncertainty bounds. Our illustration is based on a six state variable (nitrate, ammonium, dissolved organic nitrogen, phytoplankton, zooplankton, and bacteria) ecological model developed for gaining insight into the mechanisms that drive plankton dynamics in a coastal embayment; the Gulf of Gera, Island of Lesvos, Greece. The lack of analytical expressions for the posterior parameter distributions was overcome using Markov chain Monte Carlo simulations; a convenient way to obtain representative samples of parameter values. The Bayesian calibration resulted in realistic reproduction of the key temporal patterns of the system, offered insights into the degree of information the data contain about model inputs, and also allowed the quantification of the dependence structure among the parameter estimates. Finally, our study uses two synthetic datasets to examine the ability of the updated model to provide estimates of predictive uncertainty for water quality variables of environmental management interest.