汽车主动悬架次优控制策略等效性研究

Equivalence of sub-optimal control strategy for vehicle active suspension

相比于全状态反馈的悬架最优控制,非全状态反馈的次优控制在减少输入变量数的同时保持了相近的控制效果。对比了两种获得次优控制的方法,即最小范数法和双阻尼控制法,在保持与最优控制的等效性上的能力;通过综合考虑舒适性,悬架动挠度和轮胎动载荷,在三种不同类型最优控制(I型LQR(linear quadratic regulator)控制、II型LQR控制和H∞控制)的合理参数范围内讨论次优控制策略的等效性,采用控制力相对差异来衡量次优控制对最优控制的等效程度。数值仿真结果表明,在合理控制参数范围内,双阻尼控制对LQR控制的等效程度更高,而最小优范数法获得的次优控制对H∞控制的等效程度更高。

Compared to the optimal control of suspension with full state feedback,the suboptimal control with non-full state feedback can reduce number of input variables and keep similar control effect.Here,2 methods for obtaining suboptimal control,i.e.,the minimum norm method and the dual-damping control method were compared in terms of their ability to maintain equivalence to the optimal control.By comprehensively considering comfort,suspension dynamic deflection and tire dynamic load,the equivalence of suboptimal control strategy was discussed within reasonable parametric ranges of optimal control’s 3 different types of I-type LQR control,II-type LQR control and H∞control.The relative difference between control forces was used to measure the equivalent degree of suboptimal control to optimal control.Numerical simulation results showed that within reasonable control parametric ranges,the dual-damping control has a higher degree of equivalence to LQR control,while the suboptimal control obtained with the minimum norm method has a higher degree of equivalence to H∞control.