轿车电磁与摩擦制动集成系统摩擦制动力分配优化方法

Optimization method of frictional braking force distribution for integrated system of electromagnetic and frictional braking of car

分析了轿车电磁与摩擦制动集成系统的结构与工作原理,推导了轿车前后轴利用附着系数的计算公式。以ECE R13制动法规与电磁制动器设计要求为约束条件,以轿车前后轴实际利用附着系数与理想状态制动强度差值的平方和最小为目标函数,以MATLAB优化工具箱为计算工具,建立了轿车电磁与摩擦制动集成系统摩擦制动力分配优化方法,计算了不同工况下的摩擦制动力分配最优值。计算结果表明:当制动强度分别为0.1、0.2、0.3、0.4、0.5、0.6、0.7、0.8时,优化前的目标函数值分别为0.03、0.05、0.07、0.07、0.08、0.07、0.06、0.04,优化后的的目标函数值分别为0.00、0.00、0.00、0.00、0.00、0.00、0.01、0.01,优化后,目标函数值明显减小,轿车前后轴利用附着系数曲线更靠近理想曲线,且均在ECE R13制动法规控制曲线的下方,因此,提出的优化方法满足ECE R13制动法规的要求,轿车制动稳定性得到提高。

The structure and working principle of integrated system of the electromagnetic and frictional braking for car were analyzed. The calculation formula of utilization adhesion coefficient for front and rear axles was derived. The ECE R13 braking regulation and the design requirement of electromagnetic braking were taken as constraint conditions, the minimum square sum of differences between the actual curve of utilization adhesion coefficient and the braking strength of ideal condition for front and rear axles was taken as objective function, MATLAB optimization toolbox was employed, the optimization method of frictional braking force distribution for the integrated system of electromagnetic and frictional braking was established, and the optimal values of frictional braking force distribution under different conditions were calculated. Calculation result indicates when the braking strength is 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0. 8 respectively, the value of objective function before optimization is 0.03, 0.05, 0.07, 0.07, 0.08, 0.07, 0.06, 0.04 respectively, while the value of objective function after optimization is 0.00, 0.00, 0.00, 0.00, 0.00, 0.00, 0.01, 0.01 respectively. After optimization, the values of objective function reduce obviously, the curve of utilization adhesion coefficient for front and rearaxles is close to the ideal curve and is below the control curve of ECE R13 braking regulation, so the proposed optimization method satisfies the requirement of ECE R13 braking regulation, and the braking stability of car also improves. 2 tabs, 6 figs, 33 refs.