Vehicle dynamics control using an active third-axle system

This paper introduces the active third-axle system as an innovative vehicle dynamic control method. This method can be applicable for different kinds of three-axle vehicles such as buses, trucks, or even three-axle passenger cars. In this system, an actuator on the middle axle actively applies an independent force on the suspension to improve the handling characteristics, and hence, its technology is similar to slow-active suspension systems. This system can change the inherent vehicle dynamic characteristics, such as under/over steering behaviour, in the linear handling region, as well as vehicle stability in the nonlinear, limit handling region. In this paper, our main focus is to show the potential capabilities of this method in enhancing vehicle dynamic performance. For this purpose, as the first step, the proposed method in both linear and nonlinear vehicle handling regions is studied mathematically. Next, a comprehensive, nonlinear, 10 degrees of freedom vehicle model with a fuzzy control strategy is used to evaluate the effectiveness of this system. The dynamic behaviour of a vehicle, when either uncontrolled or equipped with the active third axle is then compared. Simulation results show that this active system can be considered as an innovative method for vehicle dynamic control.     

Integration of vehicle yaw stabilisation and rollover prevention through nonlinear hierarchical control allocation

This work presents an approach to rollover prevention that takes advantage of the modular structure and optimisation properties of the control allocation paradigm. It eliminates the need for a stabilising roll controller by introducing rollover prevention as a constraint on the control allocation problem. The major advantage of this approach is the control authority margin that remains with a high-level controller even during interventions for rollover prevention. In this work, the high-level control is assigned to a yaw stabilising controller. It could be replaced by any other controller. The constraint for rollover prevention could be replaced by or extended to different control objectives. This work uses differential braking for actuation. The use of additional or different actuators is possible. The developed control algorithm is computationally efficient and suitable for low-cost automotive electronic control units. The predictive design of the rollover prevention constraint does not require any sensor equipment in addition to the yaw controller. The method is validated using an industrial multi-body vehicle simulation environment.     

平动模式下挡土墙非极限状态主动土压力计算

改进了极限平衡理论,用于非极限状态主动土压力的研究。对挡土墙后滑动楔体的片体单元进行了分析,建立了关于非极限状态主动土压力强度的一阶微分方程,得到了平动变位模型下,非极限状态主动土压力强度、土压力合力和土压力合力作用点的理论公式,将计算所得结果与模型试验数据进行对比分析。结果表明:墙体平动变位模式下非极限状态主动土压力强度、土压力合力和土压力合力作用点理论公式的计算结果与已有模型试验结果基本吻合。     

纯电动汽车主动进气格栅策略开发及能耗贡献量研究

介绍了一套完整的主动进气格栅整车热管理控制策略平台架构和开发流程,基于多款纯电动汽车试验验证,充分利用大数据研究、理论分析、高低温环境舱试验匹配等手段,完成了对主动进气格栅整车热管理控制策略的正向开发,并结合纯电动车型热泵空调系统完成了整车能耗贡献量对比试验分析。研究表明,新开发的主动进气格栅整车热管理策略在常温、低温环境下均有较好的节能收益,高温环境下可及时响应整车热管理系统的散热需求,同时具备平台化应用的可行性。     

采用主动控制技术提高铁路车辆横向平稳性

建立了横向主动悬挂的１７个自由度计算模型，将主动控制铁路车辆的横向平稳性问题，归结为一性二次型最优问题（ＬＱ问题）求解。计算分析了铁路车辆在采用主动悬挂后横向平稳性改善的情况。计算结果表明，与被动悬挂相比，主动悬挂使车体横向加速度和轮轨作用力均方根值分别降低６０％和２０％左右。     

弯道上的桥台侧墙开裂原因分析

根据实桥状况,对桥台侧墙开裂的原因进行分析.考虑了弯道行车产生离心力作用,同时对墙后主动土压力计算公式进行比选,通过土压力和离心力共同作用的计算模式,运用有限元进行计算,找出了侧墙开裂的原因.     

基于分布式压电片的圆柱壳结构振动功率流主动控制研究

对基于压电片作用的圆柱壳结构振动功率流主动控制进行了研究,原始激励假设为周向余弦分布线力形式,使用压电片作为控制激振器。以输入壳体的总功率流为控制目标函数,利用导纳函数将其表示成外加电压的二次型函数形式求解最优控制电压。通过计算分析发现,压电片与原始激励间的轴向距离及压电片周向粘贴位置,都会对控制后输入壳体的总功率流产生较大影响,且影响形式不同。     

编队水声探测时抗同频干扰的空间分集法研究

编队水声探测是对潜搜索的常用手段和有效途径,同频干扰是编队水声探测时主动声纳的主要干扰之一。在对同频干扰分类研究的基础上,对几种常用的同频干扰抑制方法进行了研究和总结,并给出了空间分集法的实现方法以及抗同频干扰的效果。同时,通过两种编队队形对空间分集法的性能做了仿真分析。     

复杂电磁环境下一种新的航迹起始方法

针对复杂电磁环境下有源雷达所获得的量测数据不全,组网雷达中的有源雷达不能有效的进行航迹起始,提出一种有源与无源雷达协同的航迹起始方法。仿真结果表明该方法在干扰条件下的有效性。     

一种基于卡尔曼滤波的修正比例导引率

为分析雷达主动导引头抗干扰性能,建立所需数学模型,对导引头导引精度进行仿真分析。在模拟导引头进行导引所需的距离、速度以及角度信息的干扰噪声情况下,仿真分析了导引头在噪声干扰下的弹道轨迹和导引精度;为进一步提高导引头抗干扰性能,提出基于卡尔曼滤波的修正比例导引率。仿真结果证明此导引率提高了导弹的飞行稳定度和命中率,提高了导引头的抗干扰性能,为导引头试验提供理论支持和相应的试验依据。