共查询到18条相似文献,搜索用时 312 毫秒
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基于汽车系统动力学和随机振动理论,建立了简化的人体-座椅、车身及车轮3-DOF车辆振动模型,采用线性滤波白噪声法建立了路面激励模型,并仿真分析了常见C级路面的不平度特性。以C级随机路面激励为车辆振动系统输入,运用变步长四阶Runge-Kutta法求解了车辆系统数学模型。在时域和频域两方面,仿真分析了座椅刚度、阻尼,悬架刚度、阻尼及轮胎刚度对座椅、悬架性能的影响,以及路面不平度和车速对座椅垂向加权加速度的影响。得出了座椅加速度、悬架动挠度、轮胎动载荷功率谱密度随座椅刚度、阻尼系数,悬架刚度、阻尼系数及轮胎刚度变化的规律。 相似文献
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针对国产某微型轿车,在建立汽车悬架系统5自由度模型和时域路面模型基础上,对悬架系统的线性弹簧和非线性阻尼参数进行了优化。根据优化结果,对悬架系统的刚度和阻尼进行了匹配设计。经试验表明:座椅加速度自谱峰值减小7.4%,加速度均方根值减小19.4%,有效地改善了该车的行驶平顺性,证明时域优化方法对于悬架系统非线性参数优化是可行的。 相似文献
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基于区间分析的汽车平顺性优化 总被引:1,自引:0,他引:1
基于区间分析方法,建立了一种汽车悬架平顺性的不确定性优化模型。以悬架弹簧刚度和减振器阻尼为设计参数,车身加速度均方根值最小化为目标,悬架刚度和固有频率等为约束,并使用区间描述设计变量的制造和测量误差。利用公差指标和区间可能度,将该不确定性优化模型转化为确定性优化问题,并利用序列二次规划法和非支配排序遗传算法进行求解;在保证平顺性目标的前提下,使设计变量的对称公差最大化,以降低制造成本。最后,该方法被应用于两自由度1/4车身和7自由度整车车身悬架振动系统的平顺性优化。 相似文献
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<正>(接上期)1/4车辆2自由度的主动悬架系统数学模型如图34所示。以上给出的车辆各被动、主动或半主动悬架系统模型均为线性悬架系统的振动模型,悬架和车轮弹簧刚度是定值,悬架的阻尼系数也是常数。然而,事实上车辆悬架中的弹性元件和阻尼元件均存在不同程度的非线性,并且由于车辆悬架材料的变形老化以及使用环境等不确定因素影响,使得实际的车辆悬架系统是一个复杂的非线性不确定系统。主动悬架系统的非线性控制主要由其所采用的控制策略来体现。依据控制策略不同所采用的控制理论也不同。通过对主动悬架系统施加一定的控制规则或策略, 相似文献
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汽车非线性半主动悬架的模糊神经网络控制 总被引:8,自引:0,他引:8
考虑磁流变减振器阻尼力和悬架弹性元件非线性特性,建立车辆6自由度的半主动悬架非线性动力学模型。提出了一种基于模糊神经网络系统结构的模型参考自适应控制方法来研究汽车半主动悬架的非线性控制问题,并考虑半车模型前后悬架的输入时滞,对其进行了仿真研究。研究结果表明:运用模糊神经网络非线性控制方法能够使人体和车身垂直加速度、俯仰角加速度都得到很大的衰减,证实这种模糊神经网络控制方法可大大减少路面对车身的振动冲击,提高汽车行驶平顺性。 相似文献
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附加气室空气悬架是通过在空气弹簧气室上增加一个气室,从而进一步降低空气弹簧刚度和提高阻尼的悬架。建立了附加气室空气悬架1/4二自由度系统动力学模型和数学模型,并对其进行了计算机仿真实验。通过观察仿真结果,分析了附加气室空气悬架对汽车行驶平顺性的影响因素。 相似文献
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带反压气室油气弹簧悬架的研究 总被引:1,自引:0,他引:1
介绍了带反压气室油气弹簧悬架的结构、工作原理、弹性特性、刚度特性、自由振动频率特性及阻尼特性等,并通过台架性能试验、装车性能试验及振动加速度测试,证明了这种油气弹簧性能稳定可靠,寿命长,减振性能好. 相似文献
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为提高车辆行驶平顺性,建立某四轴重型商用车悬架动力学模型,并对悬架参数进行优化。模型中,在车辆结构上考虑了平衡悬架和驾驶室,在悬架力学特性上考虑了阻尼非线性。采用遗传算法对车辆悬架的刚度特性和阻尼特性进行优化,优化综合考虑了车辆在不同路面等级下以不同车速行驶的平顺性。对优化前后驾驶室处垂直加速度均方值进行仿真对比,结果显示,优化后车辆行驶平顺性得到有效提高。 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(12):1830-1849
In this paper, a roll and pitch independently tuned hydraulically interconnected passive suspension is presented. Due to decoupling of vibration modes and the improved lateral and longitudinal stability, the stiffness of individual suspension spring can be reduced for improving ride comfort and road grip. A generalised 14 degree-of-freedom nonlinear vehicle model with anti-roll bars is established to investigate the vehicle ride and handling dynamic responses. The nonlinear fluidic model of the hydraulically interconnected suspension is developed and integrated with the full vehicle model to investigate the anti-roll and anti-pitch characteristics. Time domain analysis of the vehicle model with the proposed suspension is conducted under different road excitations and steering/braking manoeuvres. The dynamic responses are compared with conventional suspensions to demonstrate the potential of enhanced ride and handling performance. The results illustrate the model-decoupling property of the hydraulically interconnected system. The anti-roll and anti-pitch performance could be tuned independently by the interconnected systems. With the improved anti-roll and anti-pitch characteristics, the bounce stiffness and ride damping can be optimised for better ride comfort and tyre grip. 相似文献
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Leilei Zhao Yuewei Yu Fuxing Yang 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2017,55(9):1283-1296
In this paper, a 3-DOF (degree-of-freedom) model of quarter-car coupled with driver and cushion is used to derive an analytical formula, which can describe the driver RMS (root-mean-square) acceleration response with cars under random excitation generated by road irregularities. The study starts with the 3-DOF model. Based on the vehicle random vibration theory, using the residue theorem, the analytical formula of driver RMS acceleration considering cushion effects is obtained. Then, the driver RMS acceleration values calculated from the measured data and from the analytical formulae of the 3-DOF and the classical 2-DOF model are compared. The results show the analytical formula for the 3-DOF model provides a more reasonable approximation of the real response of the test car. Having obtained the analytical formula, the effects of vehicle parameters on driver RMS acceleration are studied. Finally, to provide critical foundations for the selection of the cushion damping, the optimal damping ratio of driver-cushion system is deciphered from the analytical formula. To uncover how each dynamic parameter effects the optimal damping ratio, the analysis of influencing factors is performed and some important conclusions are obtained. The derived analytical formula can be also conveniently used either during preliminary design or for other special purposes. 相似文献
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Reza Kashani Joseph E. Strelow 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1999,32(4):409-420
For off-road vehicles, minimizing the absorbed power is the main objective of suspension control. The primary cause of increase in the absorbed power in off-road vehicles driven at high speeds on harsh courses is the exhaustion of the suspension travel. Fuzzy-logic approach to active and semi-active off-road vehicle suspension control, with the goal of improving the speed of the vehicle over rough terrains are developed. The ride metric used for quantifying improvements is the absorbed power of the sprung mass. Particular attention is paid to the proper modeling of the suspension using both the full kinematic constraints and the more convenient two degree of freedom linear model of the quarter vehicle suspension. The nonlinearities due to the kinematic constraints on motion are accounted for by modifying the stiffness and damping coefficients of the suspension spring and dashpot in the linear model. The control laws are developed using the less complex model and demonstrated in the fully constrained environment. Nonlinearities of the suspension, including tire stiffness/damping and bumpstops are included at all stages of controller development. 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(4-5):409-420
For off-road vehicles, minimizing the absorbed power is the main objective of suspension control. The primary cause of increase in the absorbed power in off-road vehicles driven at high speeds on harsh courses is the exhaustion of the suspension travel. Fuzzy-logic approach to active and semi-active off-road vehicle suspension control, with the goal of improving the speed of the vehicle over rough terrains are developed. The ride metric used for quantifying improvements is the absorbed power of the sprung mass. Particular attention is paid to the proper modeling of the suspension using both the full kinematic constraints and the more convenient two degree of freedom linear model of the quarter vehicle suspension. The nonlinearities due to the kinematic constraints on motion are accounted for by modifying the stiffness and damping coefficients of the suspension spring and dashpot in the linear model. The control laws are developed using the less complex model and demonstrated in the fully constrained environment. Nonlinearities of the suspension, including tire stiffness/damping and bumpstops are included at all stages of controller development. 相似文献
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运用虚功原理导出了悬架受力、弹簧刚度与悬架刚度之间、阻尼器参数与系统阻尼之间的非线性函数关系。开发了简单实用的双横臂-螺旋弹簧独立悬架仿真分析与设计软件,应用于某微型电动汽车的悬架系统设计。利用ADAMS建立双横臂悬架模型,通过仿真验证了公式及其结论的正确性。 相似文献