考虑人体坐姿模型的乘坐舒适性自适应控制研究
【摘要】为了研究振动对乘坐舒适性的影响,根据 ISO5982:2001(E)推荐的人体坐姿低频振动模型,建立了 1/2路面-车辆-座椅8自由度动力学模型。针对传统滤波-X最小均方( FxLMS)算法收敛速度慢的缺点,提出了一种基于小波包变换的多通道FxLMS 算法( WP-MFxLMS),并将其应用于座椅振动主动控制。利用MATLAB/Simulink 对传统FxLMS、小波包变换 FxLMS(WPFxLMS)和WP-MFxLMS进行了仿真,结果表明,系统与人体产生共振的频率范围主要集中在 0~20 Hz,采用振动主动控制可以有效抑制共振峰值,提高乘坐舒适性,步长因子和滤波器阶数对主动控制算法影响的对比结果表明, WPMFxLMS具有较好的收敛性和稳定性。主题词:路面-车辆-座椅模型 FxLMS 小波包 振动主动控制U461.4;TH113;TB533+.2 A中图分类号: 文献标识码: 10.19620/j.cnki.1000-3703.20181178 DOI: Research on Adaptive Control of Ride Comfort in Consideration of Human Sitting Posture Model Hu Qiguo, Lu Wei Chongqing Jiaotong University, Chongqing 400074) ( Abstract In order to study the influence of vibration on ride comfort, an eight DOF dynamic model of one-half road【 】vehicle- seat is established according to the low- frequency vibration model recommended by ISO 5982: 2001(E). To address the disadvantage of slow convergence speed of traditional FxLMS, a multi- channel FxLMS algorithm (WP- MFxLMS) based on wavelet packet transform is proposed and applied to active control of seat vibration. The simulation of traditional FxLMS, WPFxLMS and WP- MFxLMS in Matlab/Simulink shows that the frequency range of resonance generated by human body is mainly 0~20 Hz. Active vibration control can effectively inhibit the resonance peak value and improve ride comfort. The effect of step factor and filter order on active control algorithm is compared, the results show that WP- MFxLMS has good convergence and stability. Key words: Road-vehicle-seat model, FxLMS, Wavelet packet, Active vibration control
1 前言
传统的被动减振隔振技术已经成熟并广泛应用,但在激励振幅较大或低频振动情况下无法达到满意的效
-X果,而主动减振恰好弥补了这一不足[1]。滤波 最小均
Filtered- x Least Mean Square,FxLMS)
方( 算法因其结构简单和计算复杂度低而被广泛应用于振动主动控制领域,配合压电智能材料的使用,能够对振动进行实时控
FxLMS
制。传统的 算法收敛速度较慢,为此,许多学者针对其结构和特性提出了相应的改进方法[2- 6]。这些改进算法虽然在一定程度上提高了收敛速度,减小了稳态误差,但是在处理频率变化范围较大,即带宽较宽的信
Qiu Z[
号时,其性能会受到一定的限制。针对上述问题, 7]
等采用离散小波变换对参考输入信号进行分解,得到低频和高频信号,并对不同频率成分的信号采用独立的滤波器进行调整,提高了系统的稳定性和收敛速度。但是小波变换仅对低频成分进行细分,当面对微弱、非平稳高频振动信号时,小波变换的分解重构能力受限。为了
Lei Luo[ FxLMS解决上述问题, 8]等采用小波包变换
Wavelet Packet FxLMS,WPFxLMS)
( 算法,通过小波包变