面向汽车驾驶性的动力传动系统准瞬态建模研究

发布时间：2018-01-03 08:18

本文关键词：面向汽车驾驶性的动力传动系统准瞬态建模研究　出处：《吉林大学》2017年博士论文　论文类型：学位论文

【摘要】：驾驶性是汽车产品的核心竞争力之一,是目前国内外研究热点。是指汽车纵向行驶过程中,驾驶员控制车辆响应的容易程度以及对车辆响应感觉的舒适程度,主要包括驾驶员易操控性、驾驶过程中驾驶舒适性、驾驶员体感、驾驶员路感。车速的提高,发动机动力的增强,变速器换档、离合器结合的冲击,都会使得车体抖振加剧,甚至导致传动轴、仪表盘等总成部件的共振,这些种种不良现象会严重影响车辆的驾驶舒适性。当前汽车制造商主要在汽车产品开发流程后期,根据场地实车实验由评车师的驾驶性主观评价来指导汽车设计,开发成本较高,试验周期较长。建立面向驾驶性的动力传动准瞬态实时模型,并依托驾驶模拟器进行驾驶性主观评价,可以将驾驶性的研究提前到预开发阶段。面向驾驶性研究的动力传动系统模型需要满足以下需求:模型能够实时仿真驾驶性相关瞬态现象,能够仿真驾驶性相关的体感,能够支持硬件在环仿真和多学科混合仿真。现有的汽车实时动力学商业软件中,发动机模型大多是基于MAP图的稳态模型,发动机扭矩与曲轴转角位置不相关,发动机悬置处的力与曲轴扭矩不同相位,导致动力传动系对底盘的高频激励输入相位不一致;将油门踏板位置直接当作节气门输入,不能描述推背感等驾驶感觉。因此这些模型无法实现在汽车开发流程前期进行车辆驾驶性仿真与评价,从而无法为动力传动系统相关总成部件和功能部件的设计与匹配提供依据。近些年,课题组在动力传动系统建模方面进行了大量的探索研究,积累了不少经验,同时课题组有着发展很成熟的整车动力学模型。大量实车场地试验验证了其稳态性能与实车稳态性能一致。为了进一步研究动力传动系统的瞬态过程对整车性能的影响,本文调研了国内外当前动力传动系统模型发展现状,在此基础上总结了面向驾驶性的动力传动系统建模相关的关键问题,并针对这些关键问题做了如下的研究工作:首先,为描述并实时仿真因缸内压力高频激励而引起的曲轴扭矩波动以及悬置力对车体激励力的同相位特征,在原有稳态模型基础上,本文提出了基于示功图的发动机瞬态扭矩模型。该模型能够更为准确的仿真发动机气缸波动产生的高频激励。并且建立了发动机曲柄连杆机构静力学模型、平衡轴模型、发动机机体动力学模型,能够同时同相位输出悬置力,且能够更加准确地描述悬置力对车体的激励。其次,针对驾驶体感的主观评价需要更加真实地描述加速踏板操纵下的加速度瞬态响应,本文建立了面向驾驶体感的发动机虚拟电控系统模型。模型包含计算并协调发动机外部扭矩需求模块(驾驶员、巡航控制、变速器控制等),以及发动机内部扭矩需求模块(怠速控制、附件损失、催化剂加热等),从而决策出快通道的扭矩需求和慢通道的扭矩需求,进一步将不同通道的扭矩需求转化成相应的控制量(节气门、喷射时间、点火提前角)。相对于原有的发动机模型,此模型更为有效的模拟了真实发动机电控系统的扭矩决策,从而更为有效地模拟了驾驶体感。同时,虚拟EMS模型可以服务于动力传动控制系统的前期标定并且支持其他控制系统的同步标定。再次,开展了动力传动系统模块化分解关键问题研究。为了实现动力传动硬件在环仿真以及多学科联合仿真,以及模型升级和替换方便,并且提升模型仿真计算效率,对动力传动系统进行了模块化分解。先将动力传动模型按照汽车结构拆分成发动机、变速器箱等总成,各大总成继续分解为部件。各大总成内部由于复杂程度不同会使仿真频率有所差异,为了解决由此产生的刚性方程问题,本文采用了多速率Runge-Kutta与Rosen-Brock结合的积分方法进行求解,可以有效地提高仿真效率、稳定性以及精度。最后,将本文动力传动系统模型集成到整车模型中进行实车场地客观验证。进行驾驶性相关瞬态过程的离线仿真,将本文所建模型与原有模型进行仿真对比,结果表明该模型对汽车瞬态过程仿真能力有着明显的提升。同时,将该模型集成到驾驶模拟器中,并嵌入成熟的国际商业软件WAVE-RT燃烧模型,进行模拟器驱动下的动力传动系统硬件在环仿真。仿真结果表明,本文模型相比于原有模型在驾驶性相关的汽车瞬态过程中使驾驶员具有更为逼真的驾驶体感,模型明显提升了对汽车瞬态过程的仿真能力,从而更为有效地在预开发阶段进行驾驶性主观评价。
[Abstract]:Driving is one of the core competitiveness of the automobile products, is currently a research hotspot at home and abroad. Refers to the vehicle longitudinal driving, the driver is easy to control vehicle response and the vehicle response comfort degree, including the driver easy handling, driving comfort during driving, the driver body, speed driver road. Improve, improve engine power, transmission shift clutch, combined with the impact, will make the body chattering intensified, and even lead to the drive shaft, the dashboard assembly components of the resonance, these bad phenomena will seriously affect the vehicle ride comfort. The major car manufacturers in the automotive product development process later. According to the field experiments by driving the car division of the evaluation of subjective evaluation to guide the vehicle design, the high cost of development, test period is long. Establish the quasi oriented driving power transmission The real-time transient model, and relying on the driving simulator for driving of subjective evaluation, can be driving of advance to the pre development stage. Driving research for power transmission system model need to meet the following requirements: real-time simulation model can drive related transient phenomena, can simulate the driving related somatosensory, can support the hardware in the loop simulation and multidisciplinary mixed simulation. Automotive real-time dynamics commercial software in the existing engine models are mostly steady state model based on MAP diagram, not related to the engine torque and the crank angle, the engine mounting points of crankshaft torque force and different phase, resulting in high frequency power transmission system of chassis excitation phase imbalance will; the accelerator pedal position as the gate input can describe solar term, push back a sense of driving feeling. So these models can not be achieved in the vehicle development process in the period For vehicle driving simulation and evaluation, so it can't powertrain related assembly provides the basis for design of components and functional components and matching. In recent years, the research group conducted a lot of researches in power system modeling, and accumulated a lot of experience, at the same time, the project group has a vehicle dynamics model is very mature. A large number of vehicle field test proves its steady-state performance and vehicle steady-state performance consistent. In order to further study the effects of transient process of the power transmission system of vehicle performance, this paper investigates the current domestic and international power transmission system model development status, summarized on the basis of the power transmission system for driving related modeling key problems and do the following research work to solve these problems: first, to describe and real-time simulation of crankshaft torque wave for cylinder pressure caused by high frequency excitation With the dynamic and phase characteristics of suspension force on the body of the excitation force, based on the original steady state model is proposed in this paper, the engine transient torque model based on indicator diagram. This model can produce more high frequency excitation wave simulation of engine cylinder accurately. And the establishment of the static model of engine crank shaft balance model. The engine body dynamics model, at the same time to phase output suspension force, and to encourage more accurately describe the suspension force on the body. Secondly, to more accurately describe the accelerated acceleration transient response under the pedal for the subjective evaluation of driving sense, this paper established a virtual engine control system model for driving body feeling. The model includes the calculation and coordinate the external demand torque of the engine module (driver, cruise control, transmission control, etc.) and the internal engine torque demand model Block (idle control, attachment loss, etc., thus making the catalyst heating) torque demand and slow channel fast channel torque requirements, further the different channel torque requirements into corresponding control (solar term door, injection time, ignition advance angle). Compared with the original engine model, this model is more effective the simulation of a real electronic control system of engine torque decision, thereby more effectively simulate the driving body. At the same time, the virtual EMS model can serve the powertrain control system calibration and calibration to support other synchronous control system. Thirdly, to carry out research on the key problems of decomposition of power transmission system in order to realize the power module. Drive the hardware in the loop simulation and co simulation of multi subject, and model upgrade and easy replacement, and improve the computational efficiency of the simulation model, the power transmission system of the modular The first power transmission model decomposition. According to the structure of the automobile is split into engine, gearbox assembly, the assembly continue to decompose into components. Each assembly will make different because of the internal complexity of the simulation of frequency difference, in order to solve the problems arising from the rigid equation, this paper adopts the integral method of multi rate Runge-Kutta combined with Rosen-Brock to solve, can effectively improve the simulation efficiency, stability and accuracy. Finally, the dynamic model of the transmission system is integrated into the vehicle model in the vehicle field test objectively. The off-line simulation related to the transient process of driving, the model was simulated and compared with the original model, the results show that the the model has significantly improved the simulation ability of vehicle transient process. At the same time, the model is integrated into the driving simulator, and embedded into the mature international commercial software WAVE-RT The combustion model of the power transmission system of the hardware simulator under the driver in the loop simulation. The simulation results show that this model compared to the original model in the transient process of automobile driving related to the driver has a more realistic sense of driving body, and significantly enhance the ability of the simulation model of vehicle transient process, thereby more effectively the driving of subjective evaluation in the pre development phase.

【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：U463.2

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