后轮独立驱动电动汽车横摆稳定性控制研究

Research on Driving System Construction and Yaw Stability Control of Rear Axle Independent Drive Electric Vehicle

针对后轮独立驱动电动汽车高速稳定性控制难的问题,提川了基于模型预测控制的分层稳定性控制策略。在上层控制器中,考虑轮胎非线性侧佩特性,构建基于模型预测控制的广义控制力矩决策模型。为了实现对二自由度非线性动力学模型线性化,同时提高控制系统的实时性,建立轮胎非线性侧向力及其梯度在不同侧佩角和附着系数下的三维查找表;下层控制器中,以轮胎负荷率的加权平方和最小化为优化目标,以驱动力需求及附加横摆力矩需求为等式约束,以轮胎附着条件及电机特性为不等式约束,对控制力矩进行分配。最后基于Matlab/Simulink和Carsim联合仿真平台进行高速双移线和中高速蛇形工况的控制策略仿真验证。结果表明:所提川的控制策略有效提高了后轮独立驱动电动汽车的操纵稳定性和行驶安全性。

Aiming al the difficulty of high speed stdbhhy control for saswhel independenl drive electric ve-hicles,a layered stdbhity control stohgy l)ased on model predhtivv control was proposed.In the uppeo con-trolleo,consihering the nonlineae siheWip chdectestics of the tiro,a generalized contd torque decision­making model l)ased on model predictive contd was constructed.In addition,in ordeo to realiee the lineaa-ization of tlie two-dea^ee-of-freedom nonlineaa dynamics model and improve the real-time perfomiance of tlie contd system,a three-dimensional lookup rbie of Wc tiro nonlineae laterai force and Vs gradieni undeo dit-fereni slip angles and adhesion coefficients was estal)lished.In the lower conWoller,taking the minimum sum of tquares of the weighted tiro load rate as the optimization objetivv,taking the driving force demand and ad­ditional yaw moment as the equation constraint,and taking the tiro adhesion condition and motoe characteris­tics as the inequality constraint,the contwo torque was distributed.Findlly,based on the estal)lished Mdtldb/Simulink-Carsim co-simulation platform,simulation verification was carried out in hph・sped double lane chdnge and medium-high-speed snaking conditions.The results show that the proposed conWor strategy can ef­fectively improve the handling stability and driving safety of the oaewhea independent drive electac vehicle.