摘要
随着环境污染与能源危机等问题日益严重，节能环保的纯电动汽车成为近年来的研究重点，具有广泛的发展前景，受到各大汽车厂商与各国政府的高度重视。但由于电池成本和续驶里程的双重约束，加上传统单电机驱动时存在的电机负荷率低的问题，使得纯电动汽车难以普及，因此，高效能、低成本的新型电驱动系统的研究与开发是推进电动汽车产业化的关键技术之一。
针对以上问题，本文针对一种前后轴双电机四轮驱动的动力传动系统并开展了以下几个方面的研究：
①对整车的动力性能与动力参数的关系进行分析，以车辆的动力学方程为依据来对动力传动系统的参数进行匹配，在此基础上对几种典型循环工况车速、需求功率和需求扭矩的频率统计分析，通过统计车辆工作点的频次，在匹配车辆的额定参数时尽量使车辆的常用工作频次位于电机的高效率区间，完成了电机参数与传动系统参数的匹配。
②对在不同模式下的整车效率进行研究，计算出任意车速与加速度下的系统最优效率与转矩耦合模式下的动力分配策略，并将各模式下的最优效率在车速-加速度平面上进行投影，比较得出特定模式下的最优驱动模式，获得了相应的模式转换条件。基于MATLAB/Simulink平台，建立双电机四轮驱动模型，进行了典型循环测试工况与不同车速的匀速工况下的续驶里程仿真，并与相同功率的单电机减速驱动电动汽车进行对比，验证了动力传动系统参数匹配的正确性及控制策略的合理性。
③根据路面附着系数与驱动轮滑转率关系确定了驱动轮的最佳滑转率，并制定了驱动力控制策略和驱动力控制系统触发与退出判定逻辑，设计了相应的驱动力控制器。
④根据所建立的双电机四轮驱动汽车离线仿真模型，在复杂路况下对所制定的驱动力控制策略进行了仿真验证。
仿真结果表明：在复杂路况下，本文所制定的驱动力控制策略能有效抑制了驱动轮的过度滑转，使该汽车充分利用了当前路面附着条件，保证了汽车的加速性能。
关键词：双电机四轮驱动，参数匹配，模式切换，驱动力防滑控制
ABSTRACT
With the increasing serious problems of environmental pollution and energy crisis, pure electric vehicles which is energy saving and environmentally friendly has become the focus of research in recent years, and it has broad prospects for development, and has been attached importance by major automobile manufacturers and governments. Due to the constraints of the battery cost and the driving range, and the low load rate of the traditional single-motor-driven pure electric vehicle, it is difficult to popularize the pure electric vehicle, therefore, research and development of a new type of electric driv
e system with high efficiency and low cost is one of the key technologies to promote the industrialization of electric vehicles.
To solve the above problems，this paper focus on a kind of power transmission system of electric vehicle with front and rear axles wheel independent drive, The several aspects of research content as following:
①study on the relationship of dynamic characteristics and dynamic parameters of the vehicle, According to the performance requirements of the vehicle, matching the suitable parameters includes two motors and final drive, On the basis of this, analyze the frequency statistics of vehicle speed, power demand and demand torque by doing statistics of vehicle operating point at rated frequency, when matching parameters of the vehicle, try to make the vehicle working frequency range at high efficiency of the motor, the parameters of each component of the system are preliminarily determined.
②The optimized mode and power split plan in any vehicle speed, acceleration and SOC scopes are calculated, respectively, the control strategy is made up, and the boundary of each mode is obtained by projecting the efficiency surfaces of each mode. Detail transmission simulation model is developed by using Simulink, with which the range simulations with a 60-km/h constant speed and NEDC, 10-15,
and UDDS driving cycles are implemented, verified the correctness of the power transmission system parameters matching and the rationality of the control strategy .
③According to the relationship between road adhesion coefficient and drive wheel slip ratio, determined the optimum slip ratio of drive wheel; formulated traction control strategy and the trigger/exit decision logic of traction control system; designed a traction controller to realize above control strategies.
④Established an offline simulation model for this vehicle by using Simulink
software, simulated and verified those control strategies in complex road conditions.
The simulation results show that under complex conditions, traction control strategy can effectively suppress the excessive slip of driving wheels, and make the full use of the current road conditions, ensure the vehicle’s speedup performance
Key words:Dual Motor Four-wheel Electric Vehicles, Parameter matching, Model Shifting, Traction Control System
目录
目录
中文摘要................................................................................................................................................ I 英文摘要............................................................................................................................................. I II 1 绪论 . (1)
1.1研究背景及意义 (1)
1.2 纯电动汽车动力传动系统分类 (2)
1.2.1 单电机集中驱动 (3)
1.2.2多电机独立驱动 (4)
1.3双电机纯电动汽车国内外研究现状 (5)
1.3.1动力传动系统匹配设计方面 (5)
1.3.2动力传动系统最优控制策略方面 (6)
1.4 本文主要研究内容 (6)
2 双电机四轮驱动汽车动力总成参数匹配及建模 (9)
2.1前言 (9)
2.2 电动汽车基本参数及设计要求 (9)
2.3动力源总参数匹配 (10)
2.3.1 基于动力性指标的动力源总功率匹配 (10)
电动汽车电机
2.3.2基于循环工况的双电机纯电动汽车整车功率匹配 (11)
2.3.3电机额定转速与最高转速 (18)
2.3.4电机额定扭矩和峰值扭矩 (19)
2.4 双电机纯电动汽车传动比参数匹配 (19)
2.5电池参数匹配 (20)
2.5.1 电池选型 (20)
2.5.2电池组参数的选择 (20)
2.6动力性仿真分析 (22)
2.7 动力传动系统关键部分建模 (24)
2.7.1电机MG1、MG2数值模型 (24)
2.7.2蓄电池数值模型 (25)
2.8本章小结 (27)
3 双电机纯电动汽车模式切换研究 (29)
3.1基于系统效率最优的模式切换策略 (29)
3.1.1不同驱动模式下的最优效率 (29)
3.1.2双电机纯电动汽车系统最优效率 (31)
3.2 基于系统效率最优的模式选择控制策略 (33)
3.3基于系统效率的动力分配控制策略 (33)
3.4 双电机纯电动汽车动力传动系统经济型仿真分析 (34)
3.4.1工况车速跟随试验 (34)
3.4.2NEDC工况下工作模式转换情况 (35)
3.5本章小结 (38)
4 双电机四轮驱动汽车驱动力控制策略研究 (39)
4.1汽车动力学模型简化设计 (39)
4.1.1 整车模型 (39)
4.1.2传动系统模型 (41)
4.1.3轮胎模型 (43)
4.1.4 车轮坐标系速度估算 (46)
4.1.5车轮垂直载荷估算 (47)
4.2双电机四轮驱动汽车驱动力整体分层控制概述 (48)
4.2.1前后轴驱动转矩的分配 (49)
4.2.2驱动防滑层 (50)
4.3基于驱动力目标滑转率的驱动力控制策略 (50)
4.3.1驱动轮目标滑转率的确定 (51)
4.3.1驱动力控制策略 (52)
4.4驱动力控制系统的控制算法比较 (53)
4.4.1逻辑门限控制算法 (53)
4.4.2PID控制算法 (53)
4.4.3滑模变结构控制算法 (54)
4.4.4最优控制算法 (54)
4.4.5模糊控制算法 (54)
4.4.6神经网络控制算法 (54)
4.5驱动力控制系统触发及退出判定 (55)
4.6驱动力控制器 (56)
4.6.1前后驱动轴需求转矩控制器 (56)
4.7本章小结 (57)
5 双电机四轮驱动汽车驱动力控制策略仿真研究 (59)
5.1仿真结果及分析 (59)
5.1.1 两轮驱动模式下驱动力控制仿真结果分析 (59)