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基于纵向频响特性的整车质量估计方法
作者 胡满江,罗禹贡,陈 龙,李克强
出版年份 2018 引用
摘要
为了能够实现对不同车辆质量的通用型估计,提出了一种基于纵向频响特性的整车质量估计方法。该方法通过智能网联汽车普遍获取的纵向加速度和车轮转速信息,基于车辆纵向动力学模型,推导出加速度与轮速信号间的幅频函数关系,并求取在不同频率下车辆质心处加速度与...展开全文
为了能够实现对不同车辆质量的通用型估计,提出了一种基于纵向频响特性的整车质量估计方法。该方法通过智能网联汽车普遍获取的纵向加速度和车轮转速信息,基于车辆纵向动力学模型,推导出加速度与轮速信号间的幅频函数关系,并求取在不同频率下车辆质心处加速度与轮速之间的幅值比,进而通过最小二乘法拟合得到整车质量。CarSim-Simulink联合仿真结果表明:本文的整车质量估计方法精度在93.9%以上,可满足多车协同避撞系统车辆控制的要求。收起全文

基于序列Kriging-GA的薄板件定位点优化方法研究
作者 杨泽宇,邓乾旺,胡满江,周华健,钟志华
出版年份 2018 引用
摘要
为降低车身薄板焊接装夹时的重力以及夹具定位点偏差对柔性薄板件定位精度的影响,提高薄板定位方案的稳健性,基于有限元分析方法对薄板件第一基准面的定位点布置进行了优化。为了建立能反映薄板定位精度对定位点偏差敏感度的定位方案评价指标,引入影响系数法,建...展开全文
为降低车身薄板焊接装夹时的重力以及夹具定位点偏差对柔性薄板件定位精度的影响,提高薄板定位方案的稳健性,基于有限元分析方法对薄板件第一基准面的定位点布置进行了优化。为了建立能反映薄板定位精度对定位点偏差敏感度的定位方案评价指标,引入影响系数法,建立了定位点偏差对薄板件定位精度的影响系数矩阵。基于影响系数平方矩阵的迹,并考虑重力对薄板定位精度的影响建立了多目标优化模型。采用Kriging代理模型构造出优化模型的目标函数,为了解决代理模型预测精度较差的问题,提出了基于序列Kriging-GA的薄板件定位点优化方法,将最优点选点准则和期望改善准则融合使用,反复在兴趣域增加样本点,更新代理模型,提高了代理模型的预测精度并保证了算法的全局搜索能力。结果表明:序列Kriging模型在兴趣域的预测误差可低至1%,具有很高的预测精度;与采用遗传算法相比,所提出的方法能减少75%仿真次数,显著提高设计效率;在不同定位点偏差组合下,零件各关键点位移量的均值与方差都显著减小,定位精度对定位点偏差的敏感度降低,优化后的定位方案具有较高的稳健性。收起全文

Design and Occupant-Protection Performance Analysis of a New Tubular Driver Airbag
作者 Huajian Zhou , Zhihua Zhong, Manjiang Hu
出版年份 2018 引用
摘要
An airbag is an effective protective device for vehicle occupant safety, but may cause unexpected injury from the excessive energy of ignition when it is deployed. This paper focuses on the design of a new tubular driver airbag from ...展开全文
An airbag is an effective protective device for vehicle occupant safety, but may cause unexpected injury from the excessive energy of ignition when it is deployed. This paper focuses on the design of a new tubular driver airbag from the perspective of reducing the dosage of gas generant. Three different dummies were selected for computer simulation to investigate the stiffness and protection performance of the new airbag. Next, a multi-objective optimization of the 50th percentile dummy was conducted. The results show that the static volume of the new airbag is only about 1/3 of the volume of an ordinary one, and the injury value of each type of dummy can meet legal requirements while reducing the gas dosage by at least 30%. The combined injury index (Pcomb) decreases by 22% and the gas dosage is reduced by 32% after optimization. This study demonstrates that the new tubular driver airbag has great potential for protection in terms of reducing the gas dosage.收起全文

Cooperative control of heterogeneous connected vehicles with directed acyclic interactions
作者 Yang Zheng, Yougang Bian, Shen Li, and Shengbo Eben Li
出版年份 2018 引用
摘要
Cooperation of multiple connected vehicles has the potential to benefit the road traffic greatly. In this paper, we consider analysis and synthesis problems of the cooperative control of a platoon of ...展开全文
Cooperation of multiple connected vehicles has the potential to benefit the road traffic greatly. In this paper, we consider analysis and synthesis problems of the cooperative control of a platoon of heterogeneous connected vehicles with directed acyclic interactions (characterized by directed acyclic graphs). In contrast to previous works that view heterogeneity as a type of uncertainty, this paper directly takes heterogeneity into account in the problem formulation, allowing us to develop a deeper understanding of the influence of heterogeneity on the collective behavior of a platoon of connected vehicles. Our major strategies include an application of the celebrated internal model principle and an exploitation of lower-triangular structures for platoons with directed acyclic interactions. The major findings include: 1) we explicitly highlight the tracking ability of heterogeneous platoons, showing that the followers can only track the leader’s spacing and velocity; 2) we analytically derive a stability region of feedback gains for platoons with directed acyclic interactions; 3) and consequently we propose a synthesis method based on the solution to an algebraic Riccati equation that shares the dimension of single vehicle dynamics. Numerical experiments are carried out to validate the effectiveness of our results.
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Behavioral cooperation of multiple connected vehicles with directed acyclic interactions using feedforward-feedback control
作者 Yougang Bian, Yang Zheng, Shengbo Eben Li, Qing Xu, Jianqiang Wang, Keqiang Li
出版年份 2018 引用
摘要
This paper presents a behavioral cooperation method for multiple connected vehicles with directed acyclic interactions. Our main idea is based on a novel feedforward-feedback control scheme, in w...展开全文
This paper presents a behavioral cooperation method for multiple connected vehicles with directed acyclic interactions. Our main idea is based on a novel feedforward-feedback control scheme, in which each vehicle takes the average of neighbors’ control inputs as a feedforward term and the average of neighbors’ state errors as a feedback term. In this way, the control inputs are mutually dependent in a group of connected vehicles. We show taht the control inputs can be calculated sequentially according to the topological ordering of the directed acyclic communication topology. Further, we prove that the proposed controller guarantees the asymptotic stability and is optimal with respect to a specific quadratic performance index, since it implicitly uses the leader’s information. Simulation results demonstrate the advantage of the proposed control method.
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Reducing time headway for platoons of connected vehicles via multiple-predecessor following
作者 Yougang Bian, Yang Zheng, Shengbo Eben Li, Zhitao Wang, Qing Xu, Jianqiang Wang, and Keqiang Li
出版年份 2018 引用
摘要
In a platoon of connected vehicles, a lower time headway can reduce the inter-vehicle distance, thus leading to higher traffic capacity. This paper discusses an approach to reduce time headway for s...展开全文
In a platoon of connected vehicles, a lower time headway can reduce the inter-vehicle distance, thus leading to higher traffic capacity. This paper discusses an approach to reduce time headway for string stable platoons via multiplepredecessor following (MPF). First, the platoon system is formulated using a third-order linear model and a linear feedback controller under the MPF topology. Then, we introduce a new definition of desired inter-vehicle distances using the constant time headway (CTH) policy, which avoids inconsistency in intervehicle distances. Under the proposed definition, we present a sufficient condition to guarantee string stability by analyzing the feasible region of feedback gains. It is proved that there exist string stable feedback gains if the time headway is lower bounded. The result indicates that increasing the number of predecessors can reduce the time headway for string stability,which in turn increases the road capacity. Numerical simulations validate the theoretical results.

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Car-following method based on inverse reinforcement learning for autonomous vehicle decision-making
作者 Hongbo Gao,Guanya Shi,Guotao Xie,Bo Cheng
出版年份 2018 引用
摘要
There are still some problems need to be solved though there are a lot of achievements in the fields of automatic driving. One of those problems is the difficulty of designing a car-following d...展开全文
There are still some problems need to be solved though there are a lot of achievements in the fields of automatic driving. One of those problems is the difficulty of designing a car-following decision-making system for complex traffic conditions. In recent years, reinforcement learning shows the potential in solving sequential decision optimization problems. In this article, we establish the reward function R of each driver data based on the inverse reinforcement learning algorithm, and r visualization is carried out, and then driving characteristics and following strategies are analyzed. At last, we show the efficiency of the proposed method by simulation in a highway environment.
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基于行星传动的双模混合动力履带车辆传动系统结构设计
作者 秦兆博,罗禹贡,解来卿,陈文强,李克强
出版年份 2018 引用
摘要
该文提出了一种具有双输出的混联式混合动力履带车辆的传动系统结构设计。该结构具有双输出轴分别连接左、右履带,通过与3排行星齿轮结构连接,可以实现两侧履带的精确独立控制,通过控制发动机工作状态,使车辆的运行效...展开全文
该文提出了一种具有双输出的混联式混合动力履带车辆的传动系统结构设计。该结构具有双输出轴分别连接左、右履带,通过与3排行星齿轮结构连接,可以实现两侧履带的精确独立控制,通过控制发动机工作状态,使车辆的运行效率最优,在充分保证直线行驶性能的同时,增强行进中转向能力。相比于现有的复杂混合动力履带车辆传动系统,该设计可以省去转向机构,并提升系统综合运行能力。采用自动建模的方法对所有可行结构进行动力学分析,结合不同结构类型的特点确定双模结构组合方式。通过系统特性初筛、性能精细筛选得到满足设计要求的结构。通过动态规划算法对所选结构进行典型工况下的燃油经济性分析。仿真结果表明,得到的最优方案比目前常用的串联式混合动力履带推土机具有更优的直线行驶、转向行驶和燃油经济性能。
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