JSAE-SICE benchmark problem for vehicle dynamics control

Recently many new types of small vehicles for future urban societies have been proposed and developed. Such small vehicles tends to have reduced stability and handling ability than conventional vehicles because of their lighter weight and reduced tire performance. To cope with this problem by active collaboration of Japanese academia and industries, a benchmark problem of designing vehicle control logic for an articulated In-Wheel-Motor vehicle was settled by Japanese society of automotive industries and academia. For this purpose, simulation models of the new vehicle using multi-physics acausal modeling language Modelica were provided from the industry side. Challengers were requested to design controllers of tire steering angle, tire camber angle and tire driving force to satisfy requested vehicle dynamic characteristics. There also were some restrictions about the range of actuators. Four test scenarios were given to evaluate the control performance. Many challengers from Japanese Universities have tackled with this benchmark problem. Some results of their researches are also introduced in this paper.     

基于Modelica的弹道导弹三自由度仿真

基于面向对象思想在Modelica语言平台上开发了弹道导弹三自由度仿真系统。在导弹三自由度动力学模型基础上,通过系统分解、功能实现和系统搭建3个步骤建立了Modelica语言平台上的仿真模型。所建立的仿真模型充分利用了Modelica语言的优势,具有较好的通用性和灵活性。最后,将建立的Modelica仿真模型与相应的C＋语言版本仿真系统进行了对比,结果表明全弹道仿真的结果位置误差在10m以内。     

基于Modelica的回热型微型燃气轮机动态模拟

以Bowman TG80微型燃气轮机为研究对象,采用模块化的建模方法,基于Modelica/Dymola平台建立了回热型微型燃气轮机的全工况动态热力系统及控制系统模型。根据试验数据对模型不同负荷下的发电效率进行了对比,并通过验证模型的启动、连续变负荷和停机动态过程,确定了多个关键技术参数。最后,分析了阶跃升降25%负荷过渡过程中不同回热器热惯性、转轴转动惯量、燃烧室容积惯性和控制器参数的系统动态响应。结果表明：不同负荷下的发电效率与试验值吻合良好,设计工况相对误差为0.11%,部分负荷最大相对误差为3.58%;根据停机工况确定的转动惯量和高温气道质量分别为0.016 kg·m²和5 kg,启动和连续变负荷过程与试验数据吻合较好;回热器热惯性和转轴转动惯量是影响系统响应特性的主要因素,回热器和转轴轻量化有利于实现更优的动态响应;合理的PID控制参数可以优化控制品质,比例增益和积分时间对控制效果的影响较大,微分时间作用不明显。     

基于Dymola的变量泵温度仿真与试验验证

基于瑞典Dymola软件,利用容积建模法,分析变量泵的热力学特征,建立其热力学数学模型,并编写温度仿真程序。对变量泵在典型状态参数下进行温度仿真,并在实验室进行试验验证。结果表明,所建立的变量泵热力学模型是有效的,对液压系统的热力学研究具有一定的参考意义。     

基于Modelcia的空调半实物仿真系统的设计与实现

为进行多领域空调系统的整体性能分析,基于Modelica建立了串口通信模型和空调模型,利用自编程的信号调理电路和已建立的串口通信模型将空调模型与空调控制器进行连接,建立了空调半实物仿真系统,仿真实验结果证明了本系统的有效性。本空调半实物仿真系统为多领域系统的半实物仿真提供了一套新的解决方案,可有效提高产品研发效率,降低研发成本。     

陈述式基于方程仿真模型的约简

为解决复杂多领域连续系统的高效仿真问题,研究了陈述式基于方程仿真模型的约简策略.基于符号处理技术,提出了一种模型约简方法.该方法从方程的规范转换入手,通过消除特定形式方程缩减系统规模,将整个方程系统规划分解为一个可顺序求解的子系统序列.给出的实例表明文中约简方法效果显著.文中策略与算法已在多领域物理系统混合建模与仿真平台EMWorks中实现.     

A Bayesian network model for the optimization of a chiller plant’s condenser water set point

To implement the condenser water set point optimization, one can employ a regression model. However, existing regression-based methods have difficulties to handle non-linear chiller plant behaviour. To address this problem, we develop a Bayesian network model and compare it to both a linear and a polynomial regression model via a case study. The results show that the Bayesian network model can predict the optimal condenser water set points with a lower root mean square deviation for both a mild month and a summer month than the linear and the polynomial models. The energy-saving ratios by the Bayesian network model are 25.92% and 1.39% for the mild month and the summer month, respectively. As a comparison, the energy-saving ratios by the linear and the polynomial models are less than 19.00% for the mild month and even lead to more energy consumption in the summer month (up to 3.73%).     

基于Modelica的多领域统一建模系统开发

给出了基于Modelica的多领域统一建模系统的体系结构,包括显示层、功能层和处理层.详细讨论了系统实现的关键技术,即文本建模技术、图形建模技术和模型检查技术.开发了原型系统,并以一个简易的电动机模型验证了系统的可行性.     

Validated air handling unit model using indirect evaporative cooling

This paper presents the validated Modelica model of a Menerga? Adsolair? type 58 Air Handling Unit. The unit consists of two fans, four dampers, three air filters and further allows heat recovery (including free cooling), indirect evaporative cooling and active cooling. The first principles model uses manufacturer data sheet information and optionally also measurement data to calibrate some parameters for increased accuracy. Model validation is based on measurement data and results in an average normalized absolute error for the electrical power consumption of approximately 1%. A custom developed control strategy is compared with the measured performance of a proprietary controller. The model is available open source as part of the IDEAS Modelica library.     

基于Modelica的液压减震装置的建模与仿真

基于Modelica在液压管路系统建模中已获得了成功的应用。液压减震器是液压管路系统中的重要零部件,它的使用对减少液压系统中的振动、冲击和噪声等具有重要的作用。本文通过对两种常用的液压减震器——动压反馈装置和消音器进行工作原理分析,并利用Modelica建立仿真模型,最后给出实例验证了该方法的有效性。