【作者】 李天宇；

【导师】 赵丁选；

【作者基本信息】 吉林大学 ， 机械设计及理论， 2014， 博士

【摘要】 工程车辆是进行基础建设作业的重要装备，在国民经济建设中发挥着重要作用。工程车辆采用混合动力技术可以有效改善发动机燃油经济性，改善排放，提高系统能量利用率，降低油耗。自动变速技术可以实现工程车辆自动换挡控制，能够有效减轻驾驶员操作强度，提高作业质量和作业效率，改善换挡品质。近年来，为进一步节能减排，同时提高车辆的动力性和驾驶舒适性，多种车辆相继采用混合动力技术结合自动变速技术，作为交叉领域的混合动力自动变速技术逐渐成为研究的热点。二者的结合能够实现动力传动系统的高效工作，改善车辆经济性和动力性，因此研究混合动力工程车辆自动变速技术具有重要的意义。工程车辆一边行驶一边作业，由于作业环境复杂，其作业载荷波动频繁剧烈，由于负载工况、工作模式、控制系统等方面的不同，汽车领域的相关共性技术不能直接应用于工程车辆。目前对混合动力工程车辆自动变速技术的研究还处于探索阶段。本文结合教育部高等学校博士学科点专项科研基金资助课题重度混合动力车辆自动变速技术研究（20120061110023），以并联式混合动力工程车辆为研究对象，以改善燃油经济性、提高能量利用率、改善动力输出、减轻驾驶员操作强度、提高作业质量和效率、改善换挡品质为目标，结合其工况特点、系统结构、参数优化匹配及能量管理控制策略等，深入研究混合动力工程车辆的自动变速换挡控制策略及控制方法。本文的研究工作主要包括以下几个方面：1)根据混合动力工程车辆的系统结构，研究了系统参数优化匹配方法。建立了混合动力系统主要元件的数学模型以及车辆动力学模型，采用理论公式和经验公式相结合来描述其性能。提出采用从整体到局部最优的方法对系统主要元件进行参数匹配，使各元件与负载工况相匹配，提高系统能量利用率，降低装机功率及成本。在此基础上，提出采用改进粒子群优化算法优化参数匹配，提高参数匹配效果。以5吨装载机为例，实现了参数匹配方法和优化算法，参数匹配效果良好。2)研究了混合动力工程车辆的能量管理控制策略。首先提出了混合动力工程车辆工况识别方法，根据系统需求转矩对混合动力系统进行模式划分。提出了基于模糊逻辑的转矩分配控制策略，调控发动机工作在最优效率转矩曲线附近，同时保证储能元件的充放电平衡。提出驾驶员意图系数的概念，并基于模糊逻辑识别驾驶员意图，根据驾驶员意图系数实现发动机转速控制。提出采用瞬时优化算法提高节能效果，以综合效率最优为目标建立了优化模型。台架试验表明，转矩控制策略能够控制发动机工作在最优效率转矩曲线附近，通过识别驾驶员意图控制发动机目标转速，改善了燃油经济性，对比传统工程车辆节能4.94%。瞬时优化算法能够进一步改善燃油经济性，降低油耗，对比传统工程车辆节能10.08%。3)研究了混合动力工程车辆的自动变速换挡规律和控制方法。以“发动机转速、车速和动力分流系数”为换挡控制参数，提出了以车辆加速度最优为目标的动力性换挡规律，以行走系统工作效率最优为目标的经济性换挡规律，和通过驾驶员意图系数将二者相结合的综合换挡规律。研究了混合动力工程车辆智能换挡控制理论，提出基于BP神经网络的智能换挡控制策略和方法，采用L-M算法克服BP神经网络收敛慢、存在局部最小值的缺点。台架试验表明，动力性、经济性、综合和神经网络换挡规律能够合理准确实现各自换挡目标，液力变矩器平均效率分别可达70.8%、73.6%、73.6%和73.2%，有效提高了系统效率和能量利用率，具有较好的经济性和动力性。4)搭建了国内第一个混合动力工程车辆自动变速试验台。为进行混合动力工程车辆自动变速台架试验，设计开发了基于CAN总线网络的混合动力工程车辆能量管理控制系统和混合动力工程车辆自动变速控制系统。通过台架试验验证了所提出的能量管理控制策略和自动变速理论的正确性和适用性。理论和试验研究表明，在混合动力工程车辆上采用自动变速技术，能够有效提高传动系统效率和能量利用率，减小换挡冲击，改善换挡品质，同时具有较好的动力性能和经济性，控制效果良好。更多还原

【Abstract】 Construction vehicles are important equipment, which play an important role in nationaleconomic construction. Studies have shown that the hybrid power technology caneffectively improve engine fuel economy and system energy efficiency, improve emissionand reduce fuel consumption. Automatic transmission technology can realize automaticshift control in construction vehicles, which effectively reduces the pilot operation intensityand improves the operation quality and efficiency. In recent years, for further energy-savingand emission reduction, improving vehicle dynamic performance and driving comfort at thesame time, a variety of vehicles have adopted hybrid technology combined with automatictransmission technology. Automatic transmission technology with hybrid technology hasbecame a hotspot. The construction vehicles do works while driving, due to the complexityof operating environment, the operating load fluctuates frequently and violently.Due to thedifferences in load condition, work mode, control system, related technologies inautomobile industry cannot be directly applied to construction vehicle. The study ofautomatic transmission technology for hybrid construction vehicle (HCV) is still in theexploratory stage at present.This research was supported by the Specialized Research Fund for the Doctoral Programof Higher Education of China (SRFDP)"Research on Severe Hybrid Vehicle AutomaticTransmission Technology"(Grant No.20120061110023). The parallel HCV was as researchobject, to improve fuel economy and energy efficiency, improve power performance, reducework intensity, improve operation quality and efficiency, improve shift quality, combinedwith the working characteristics, system structure, parameters optimization matching andenergy management control strategy, the automatic shift strategy and control method werein-depth studied. The main research works of this paper include the following aspects:1) System parameters matching method was researched according to the structure of HCV.Math models of main components of hybrid system and vehicle dynamic model wereanalyzed and established, the combination of theoretical and empirical formulas was used todescribe their characteristic. From overall optimum to local optimum, the main components’parameters were matched to match load conditions, improve energy efficiency, and reduceinstalled cost and power. Improved particle swarm optimization was used in optimizingparameters matching to improve parameters matching effect. Taking5tons loader as object,parameters matching method achieved good results. 2) Energy management control strategy for HCV was studied. Identification method ofHCV’s working conditions was proposed according to the system needed torque. Torquedistribution control strategy based on fuzzy logic was proposed, which could control theengine work around optimal efficiency torque curve, and ensure balanced charging anddischarging of energy storage elements. Based on fuzzy logic, a driver’s intention coefficientwas defined to identify the driver’s intention, and the engine target speed was controlledbased on the coefficient. Instantaneous optimization was proposed to improveenergy-saving, an optimization model was established for the target of overall optimalefficiency. Experimental results show that the torque distribution control could ensure theengine work in the vicinity of the optimal efficiency torque curve. The hybrid systemreduced4.94%fuel consumption compared to traditional construction vehicle.Instantaneous optimization could further improve fuel economy, which reduced10.08%fuelconsumption.3) Automatic shift schedules and control methods applicable for HCV were researched."Engine speed, vehicle speed and power distribution coefficient" were used as the shiftcontrol parameters. Dynamic shift schedule with the optimal vehicle acceleration as target,economical shift schedule with travel system optimal efficiency as target, and compositiveshift schedule combining the two schedules through the driver’s intention coefficient wereproposed. Intelligent shift control theory for HCV was researched, and intelligent shiftcontrol strategy and method based on BP neural networks were proposed.Levenberg-Marquardt algorithm was used to overcome the disadvantages of BP neuralnetworks: slow convergence and local minimum. Experimental results show under thedynamic, economical, compositive and intelligent shift schedule, it shifted accurately andproperly, achieved shift target under different schedules. The average efficiency of hydraulictorque converter were up to70.8%,73.6%,73.6%and73.2%respectively, which improvedsystem efficiency and energy utilization and with good economic and dynamicperformance.4) The first HCV automatic shift test bench of China was established. For bench test,energy management control system based on CAN bus network and automatic shift controlsystem were designed and developed. The proposed energy management control strategyand automatic shift theory were verified through bench test.Theoretical and experimental researches show that HCV with automatic shift technologyturn out to be more efficient, with more utilization of energy and less shift shock, whichimproves shift quality and is more economic and dynamic. Automatic shift technology for HCV has preferable applicability and practical value.更多还原