应用模拟退火算法进行电动汽车转向传动比的设计研究  

Application of Simulated Annealing Algorithm in the Design and Research of Electric Vehicle Steering Transmission Ratio

作　　者：牛晶 Niu Jing(Mechatronics and Automotive Engineering School,Tianshui Normal University,Gansu Tianshui 741001)

机构地区：[1]天水师范学院机电与汽车工程学院,甘肃天水741001

出　　处：《汽车实用技术》2021年第9期4-8,共5页Automobile Applied Technology

基　　金：甘肃省高等学校创新能力提升资助项目(2019A-098)。

摘　　要：为了提高四轮独立驱动电动汽车的操纵稳定性,建立了三自由度非线性车辆转向动力学模型,基于实车模型应用CarSim/Simulink联合仿真分析的方法,文章对其前轮转向系统设计了一种基于模拟退火算法(SA)的变角传动比传动规律。其中,根据不同车速进行了分段研究,低速区间采用定增益法,将车辆横摆角速度增益和侧向加速度增益都设为定值;中高速区间采用可变权重系数的设计方法,其中权重系数根据SA算法动态进行优化,优化目标函数依据转向灵敏度最高的原则取传动比的最小值,应用MATLAB曲线拟合工具箱cftool分别对两个权重系数进行了函数拟合。仿真实验结果表明,在转向盘角阶跃输入和正弦角输入两种典型工况下,采用这种新型的传动比设计规律可以明显减小车辆的横摆角速度和侧向加速度,转向盘角阶跃输入工况下横摆角速度减小了13.6%,侧向加速度减小了23.1%;尤其是正弦角输入工况下,驾驶员转向盘转角减小了53.5%。可见,用这种方法设计的转向传动比规律可以明显减轻驾驶员的转向驾驶负担,提高车辆的操纵稳定性,从而为今后基于四轮独立驱动电动汽车前轮转向系统的设计奠定一定的理论基础和实验依据。In order to improve the steering stability of 4WD EV,A three-degree-of-freedom nonlinear vehicle steering dynamics model is established,by the joint simulation analysis of the real vehicle model on CarSim/Simulink,a variable angle transmission ratio of SBW system based on SA simulation is designed.Then,segmentation research is carried out according to different vehicle speeds.The low-speed interval adopts,the vehicle yaw rate gain and the lateral acceleration gain are fixed;the medium-high speed interval adopts the design method of variable weight coefficient.The weight coefficient is dynamically optimized according to the SA algorithm.The optimization objective function takes the mini-mum value of the gear ratio according to the principle of the highest steering sensitivity.The MATLAB curve fitting toolbox cftool is used to fit the two weight coefficients.The simulation results show that under the typical conditions of steering angle step input and sinusoidal input,the new transmission ratio design can significantly reduce the yaw rate and lateral acceleration of the vehicle.Under the steering wheel angle step input condition,the yaw rate decreased by 13.6%and the lateral acceleration decreased by 23.1%.Especially in the sine angle input condition,the driver's steering wheel angle decreased by 53.5%.It can be seen that the steering gear ratio law designed by this method can significantly reduce the driver's steering driving burden and improve the steering stability of the vehicle,thus laying a theoretical foundation and experimental basis for the design of the 4WD EV SBW system in the future.

关 键 词：电动汽车主动前轮转向 转向传动比 模拟退火算法 横摆角速度增益 

分 类 号：U469.72[机械工程—车辆工程]