智能电动汽车SMA执行机构柔性驱动机理与控制方法研究

According to the problems of structure lightweighting and flexible spatial arrangement when motorizing the movable parts of intelligent electric vehicles, the flexible composite structure which is composed by NiTiPd high-temperature shape memory alloy wire and flexible outer sheath is presented for constructing lightweight flexible actuators with the features of compact structure, lightweight and easy integration according to the necessities of lightweight and flexible installations in the procedure of movable components motorization in vehicles. Firstly, the multi-field coupling function of the force field, electrical field and thermal field for the SMA composite structure is studied. The constitutive equations of the composite structure are solved by using analytical and FE methods considering the rigid-flexible coupling relations. The system dynamic model of the actuating mechanism is established and the influence of the state variables and structure parameters on the structure performances are discussed by means of theoretical analysis and numerical simulation. The matching compatibility of power batteries and actuation mechanisms of different actuation mode are studied according to the control modes of on-off and continues actuation. The prototypes of SMA actuators and test benches are fabricated. The influences of mechanical and electrical parameters on the performances of driving force, actuation displacement, load characters and frequency response are investigated. The optimal matching relations of actuation mechanisms and movable components are obtained by the real vehicle tests and the effective actuations of movable components are achieved. This project provides an innovative research thinking of the electrification and lightweight of the intelligent electric vehicles.

针对未来智能电动汽车可动部件全部电机化过程中亟需解决的结构轻量化、空间布置柔性化等问题，提出利用丝式NiTiPd高温形状记忆合金(SMA)与外部支撑部件组成可弯曲多层管状复合结构，形成体积小、重量轻、易于集成的车用柔性执行机构，实现车内可动部件的电机化控制。研究SMA复合结构的力、电、热多场耦合作用机理，考虑柔性复合结构的耦合作用关系，运用解析和有限元法精确求解复合结构本构方程；建立执行机构系统动力学模型，通过理论分析与数值模拟研究状态、结构参量对机构性能的影响；以可动部件的开关式和连续式控制为目标，研究动力电池匹配相容性及不同驱动方式下的内在致动机理；对样机进行测试分析，研究系统参数对SMA执行机构的驱动力、驱动位移、负载特性、温度响应以及频率响应等性能的影响规律，获得执行机构与可动部件之间最优匹配关系，实现车内可动部件的有效驱动，为智能电动汽车电气化、轻量化技术发展提供创新性研究思路。

汽车电动化及智能化技术不断发展，汽车运动部件的电机化程度越来越高，未来智能电动汽车要求实现电机化的运动部件数量超过 200 个，汽车正在逐渐成为驱动电机的集合体，今后车用驱动电机的数量还在继续增加。针对未来智能电动汽车可动部件全部电机化过程中亟需解决的结构轻量化、空间布置柔性化等问题，在新型柔性驱动器理论分析、仿真建模与实验研究中，利用丝式温控形状记忆合金(SMA)与外部支撑部件组成了可弯曲多层管状复合结构，针对SMA复合结构的力、电、热多场耦合作用机理进行了理论建模、仿真分析和实验研究，获得了结构参量对复合驱动机构性能的影响规律；通过建立电载荷与输出特性之间的匹配模型，研究了电学参数与驱动器静动态输出的作用关系，揭示了SMA柔性驱动器的内在致动机理；试制了SMA柔性驱动器样机，并进行了测试分析，获得了系统参数对SMA执行机构的驱动力、驱动位移、负载特性、温度响应以及频率响应等性能的影响规律，验证了SMA柔性驱动器的致动效能，为实现车内可动部件的电机化高效致动进行了有益探索。同时也为新型 SMA 柔性执行器件在未来智能网联电动汽车领域的成功应用提供了理论方法和数据支撑。项目期间发表学术论文11篇，其中SCI/EI检索9篇，合计申请专利18项，其中获得美国发明专利授权1项，中国发明专利授权3项，参与国际国内重要学术会议5次。经过四年的研究，项目组顺利完成各项工作计划，实现了预期研究目标，为后续进一步的研究工作奠定了基础。