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1.提高电极使用寿命的必要性点焊工艺,由于其具有高效、低耗及机械化、自动化程度高等优点,所以被广泛用来焊接轿车、客车、商用车等的薄板金属结构件。以高档旅游大客车为例,每个车身上约有5500个焊点,可见确保点焊接头质量,是提高汽车整车质量的关键之一。 相似文献
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将拓扑优化方法扩展至离散空间,采用板件优化后的某轻型商用车车身模型进行焊点拓扑优化和联合拓扑优化,并采用优化后的焊点分布进行车身静、动态分析.结果表明,在焊点数量不变的情况下,拓扑优化可提高车身刚度10%以上;通过板件厚度与焊点拓扑联合优化,可减轻车身质量29%. 相似文献
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针对电控空气悬架在车高调节过程中存在的过充,过放以及震荡等不良现象和加速、减速、转弯以及路面随机干扰对整车姿态的影响,根据变质量充放气系统热力学理论,提出一种能够对气体质量流量进行自适应快速调节的单神经元PID控制方法。根据车辆动力学理论,建立了加速、减速、转弯以及路面随机干扰下的空气悬架车身高度调节系统整车模型。基于神经网络控制算法,设计了车身高度调节的单神经元PID控制器和整车姿态控制的BP神经网络PID控制器。为检验所设计控制器的性能,搭建了Matlab/Simulink车身高度控制仿真模型和整车姿态控制仿真模型。仿真结果表明所设计的控制系统不仅能够实现车身高度的有效调节,同时还能抑制车身高度调节中的整车姿态变化。 相似文献
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为降低车人碰撞事故中人与地面撞击所致损伤,提出一种车辆制动控制策略。该策略在检测到人体头部与车辆首次接触后松开车辆制动,之后依据若干准则再次完全制动车辆直到车辆停止。选择10种车型、两种制动方法(完全制动和控制制动)和一个虚拟仿真系统(包含3种车速×4种行人尺寸×2种行人步态)设计了共480次MADYMO仿真试验。结果发现控制制动能降低人-地撞击所致损伤但不会加重车辆的损伤,且能将83.75%案例中车辆与人体主要部位首次触地点位置之间的距离缩短至1 m内。进一步讨论了车型和车速对制动控制策略防护效果的影响、人车首次接触与再次完全制动车辆的时间间隔取值规律和控制制动中损伤加重案例的原因等问题,为今后开发更实用且高效的制动控制策略提供技术支持。 相似文献
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汽车车身装焊误差产生的原因分析及控制 总被引:3,自引:0,他引:3
汽车车身的装焊质量直接决定产品质量及整车性能。分析了汽车装焊的内在规律,并指出要保证良好的车身装焊质量,应从产品开发设计、工装的设计和制造、工艺的制定到工装的使用和维护、现场技术问题的处理、工人的操作以及零组件的尺寸保证等第一系列环节和过程进行综合的控制。 相似文献
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汽车车门总成的装配、焊接及合成质量,在一定程度上反映了汽车车身总成的制造水平。较全面地介绍了车门总成压合的4种通用方法的具体实施情况,评价了它们各自的性能质量及适用性。 相似文献
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R. G. Langlois R. J. Anderson 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1995,24(1):65-97
The potential performance improvement using preview control for active vehicle suspension was first recognized in the late nineteen sixties. All work done since that time has been based on optimal control theory using simple vehicle models.
In this article, the performance of quarter vehicle preview controllers when applied to a real off-road vehicle is simulated using both two degree of freedom quarter and ten degree of freedom full vehicle models. The results, which are compared with non-preview active and conventional passive suspensions, confirm that preview control reduces vertical acceleration of the body centre of gravity, which results in improved ride quality. Further, reductions in pitch and roll motion result from smaller vertical displacements of the vehicle quarters. Coupling between quarters, through the vehicle body, appears to have a smoothing effect on the control.
As an alternative to optimal control theory based controllers, a simple ad hoc preview controller based on isolating the vehicle body from dynamic loads transmitted through the suspension is proposed. Simulation results show that such a controller outperforms the optimal control theory based controllers over small discrete disturbances but responds poorly to disturbances encountered from other than steady state. 相似文献
In this article, the performance of quarter vehicle preview controllers when applied to a real off-road vehicle is simulated using both two degree of freedom quarter and ten degree of freedom full vehicle models. The results, which are compared with non-preview active and conventional passive suspensions, confirm that preview control reduces vertical acceleration of the body centre of gravity, which results in improved ride quality. Further, reductions in pitch and roll motion result from smaller vertical displacements of the vehicle quarters. Coupling between quarters, through the vehicle body, appears to have a smoothing effect on the control.
As an alternative to optimal control theory based controllers, a simple ad hoc preview controller based on isolating the vehicle body from dynamic loads transmitted through the suspension is proposed. Simulation results show that such a controller outperforms the optimal control theory based controllers over small discrete disturbances but responds poorly to disturbances encountered from other than steady state. 相似文献