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结合卡尔曼滤波器的车辆主动悬架轴距预瞄控制研究 总被引:8,自引:2,他引:8
利用轴距预瞄信息,即前后轮路面输入之关系,同时结合卡尔曼滤波器作为状态估计器,本文提出了一种算法用于车辆悬架控制律的设计,根据模拟结果,研究了算法的可行性,分析了卡尔曼滤波器对状态变量的估计精度,以及轴距预瞄控制对进一步改进车辆性能的潜力。 相似文献
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主动悬架最优控制整车模型的研究 总被引:17,自引:5,他引:17
以一个车辆的整车模型为研究对象,通过利用轴距预瞄信息,应用最优控制理论设计了一个车辆的悬架控制策略,通过模拟和仿真的结果,验证了该模型和算法的可行性,并分析了轴距预瞄控制对于改进车辆性能的能力,检验了所建立的整车模型。 相似文献
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智能车主要分为路径规划、路径跟踪、自动泊车三大部分。路径规划主要研究车辆的避障问题,路径跟踪主要研究车辆跟随期望路径的有效性,自动泊车主要分析车辆在有限的几何空间内将车辆泊到指定的空间位置。其中路径跟踪是其核心部分,根据研究方法的不同,主要分为"预瞄跟随模型"和"智能控制模型"。文章根据预瞄点的不同,主要分析单点预瞄模型、两点预瞄模型、路程预瞄模型。根据智能控制方法的不同,主要分析模糊逻辑控制驾驶员模型、神经网络控制驾驶员模型、模型预测控制驾驶员模型。 相似文献
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基于横向预瞄偏差的驾驶员前视轨迹控制模型 总被引:5,自引:0,他引:5
文章给出了横向预瞄偏差的概念,提出了一种基于横向预瞄偏差的驾驶员前视轨迹控制模型。通过计算机仿真,验证了该控制模型的正确性。该模型与现行的预瞄驾驶员模型相比,具有理解容易,分析计算简单,实用性强的优点。 相似文献
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应用模糊控制和神经网络控制理论,构建了1/2车辆的半主动悬架模型,设计了基于轴距预瞄的半主动悬架模糊神经网络控制系统.对前轮半主动悬架采用以对应处车身垂向加速度为目标的模糊控制,对后轮半主动悬架采用轴距预瞄模糊控制,并利用神经网络来调整模糊控制器的控制规则和隶属度函数.在不同车速下对所建的控制系统分别进行了白噪声和路面脉冲输入的仿真.结果表明,与传统的被动系统相比,轴距预瞄模糊神经网络控制的半主动悬架系统能有效降低车辆振动;与模糊控制的半主动悬架系统相比,质心垂向加速度和后轮对应处车身加速度均有显著减小,较好地改善了车辆的行驶平顺性. 相似文献
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汽车主动悬架的最优预见控制 总被引:1,自引:0,他引:1
本文针对1/2车辆模型,应用最优预见控制理论对汽车主动悬架进行控制系统的设计和研究。计算机仿真结果表明,所提出的系统能有效改善汽车乘坐舒适性。 相似文献
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针对智能车辆横向运动控制中驾驶员和辅助系统的控制权限冲突问题,本文中提出一种人机权值分配策略。采用车辆在预瞄点处的预期偏移距离(PDLC)衡量车道偏离危险度,预期偏移距离通过对预瞄偏差修正获取。权值分配函数设计时以PDLC为自变量,以保证驾驶员的权值为优先控制目标,以一定的横向运动控制精度为先决条件。在CarSim/Simulink联合仿真平台和CarSim/Labview RT硬件在环实验台上对提出的控制策略进行了实验验证和数据分析。结果表明,采用权值分配策略协调驾驶员和辅助系统的控制,可在有效跟踪理想道路中心线的前提下保证驾驶员的控制权值,降低其工作负荷以及纠正驾驶员的误操作行为。 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(12):1923-1948
Both ride quality and roadholding of actively suspended vehicles can be improved by sensing the road ahead of the vehicle and using this information in a preview controller. Previous applications have used look-ahead sensors mounted on the front bumper to measure terrain beneath. Such sensors are vulnerable, potentially confused by water, snow, or other soft obstacles and offer a fixed preview time. For convoy vehicle applications, this paper proposes using the overall response of the preceding vehicle(s) to generate preview controller information for follower vehicles. A robust observer is used to estimate the states of a quarter-car vehicle model, from which road profile is estimated and passed on to the follower vehicle(s) to generate a preview function. The preview-active suspension, implemented in discrete time using a shift register approach to improve simulation time, reduces sprung mass acceleration and dynamic tyre deflection peaks by more than 50% and 40%, respectively. Terrain can change from one vehicle to the next if a loose obstacle is dislodged, or if the vehicle paths are sufficiently different so that one vehicle misses a discrete road event. The resulting spurious preview information can give suspension performance worse than that of a passive or conventional active system. In this paper, each vehicle can effectively estimate the road profile based on its own state trajectory. By comparing its own road estimate with the preview information, preview errors can be detected and suspension control quickly switched from preview to conventional active control to preserve performance improvements compared to passive suspensions. 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(12):1475-1494
This study concerns with multi-objective H ∞/GH 2 preview control of active vehicle suspensions. This control scheme has two main aspects: first, it allows constrained outputs of the system to vary freely as long as they remain within their given bounds, in order that the best possible performance could be delivered. Secondly, the optimisation as well as constraint fulfilment is done for the worst-case road disturbances to cover all road types. To design a system to perform satisfactorily for a wide range of road irregularities, H ∞-norm is used wherever minimisation is required, and generalised H 2-norm is used to care for the constraints on suspension working space. Moreover, to ensure desired stability margins for the system, pole location constraints are considered in the design. The proposed approach is evaluated on a quarter-car model and compared with the state-of-the-art preview control algorithm in the literature, namely, Linear quadratic Gaussian preview. Simulation results demonstrate the effectiveness of the proposed approach. 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(4):429-456
The response of a motorcycle is heavily dependent on the rider’s control actions, and consequently a means of replicating the rider’s behaviour provides an important extension to motorcycle dynamics. The primary objective here is to develop effective path-following simulations and to understand how riders control motorcycles. Optimal control theory is applied to the tracking of roadway by a motorcycle, using a non-linear motorcycle model operating in free control by steering torque input. A path-following controller with road preview is designed by minimising tracking errors and control effort. Tight controls with high weightings on performance and loose controls with high weightings on control power are defined. Special attention is paid to the modelling of multipoint preview in local and global coordinate systems. The controller model is simulated over a standard single lane-change manoeuvre. It is argued that the local coordinates point of view is more representative of the way that a human rider operates and interprets information. The simulations suggest that for accurate path following, using optimal control, the problem must be solved by the local coordinates approach in order to achieve accurate results with short preview horizons. Furthermore, some weaknesses of the optimal control approach are highlighted here. 相似文献
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紧急避障工况下的驾驶人操作具有响应快且动作幅值较大的特点,传统预瞄驾驶人模型已不能适应紧急避障工况的需求,故考虑实际避撞场景开发相应的驾驶人模型就显得尤为必要。针对此种状况,基于驾驶模拟器,结合紧急避撞工况实际驾驶人操纵数据,提出了一种融合预瞄与势场栅格法的紧急避撞驾驶人模型。首先针对紧急避撞工况下车辆运动特点,建立车辆横、纵向耦合非线性动力学模型,并给出其状态空间方程描述;其次,离线仿真分析紧急避撞系统特征,并结合线性二次型最优控制,建立最优曲率预瞄+跟踪误差反馈驾驶人模型;再者,基于紧急避撞工况下真实驾驶人经验转向行为数据,开发基于势场栅格法的驾驶人模型,为进一步提高驾驶人模型对避障行驶工况的适应性,将基于势场栅格法的驾驶人模型与最优曲率预瞄+跟踪误差反馈驾驶人模型进行融合,并基于Sigmoid函数实现两者输出的权重分配;最后,针对所提出的融合预瞄与势场栅格法的驾驶人模型,开展基于避撞台架的驾驶人在环仿真试验以及实车试验。研究结果表明:在紧急避撞工况下,对比最优曲率预瞄+跟踪误差反馈驾驶人模型,融合预瞄与势场栅格法的驾驶人模型输出的转向动作与实际驾驶人行为较为接近,可在保证避障安全性的前提下,兼顾避障路径跟踪精度与车辆行驶的稳定性。 相似文献
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针对固定时长的预瞄时间无法真实反映驾驶人预瞄行为的问题,首先对自由流条件下的驾驶人视觉特性进行研究,得到直行路段驾驶人注视点多分布在车道中央、弯道路段驾驶人注视点多分布在内侧边缘线附近且视线近似与内侧边缘线相切的结论;在此基础上,探究直行和弯道路段驾驶人预瞄时间的求解方法,并借助驾驶模拟器进行试验,获得了17位驾驶人的预瞄时间。由于预瞄时间的原始数据分布离散程度高,难以直观地体现其随道路线形的变化规律,因而对预瞄时间随道路线形的分布特征进行研究,利用分组求中位数的方法进行数据处理,最终构建预瞄时间关于道路线形的分段线性函数和非线性指数函数。最后,通过数值仿真研究不同类型的预瞄时间(固定时长的预瞄时间、分段线性函数预瞄时间及指数函数预瞄时间)对人-车-路闭环系统动力学特性的影响。研究结果表明:驾驶人预瞄特性会对车辆的轨迹跟随和车道保持绩效产生重要影响;在闭环系统中使用随道路线形变化的预瞄时间可以显著提高车辆的轨迹跟随绩效,确保车辆在指定车道内行驶;驾驶人对道路环境的感知具有自适应性,通过其视觉特性可准确感知环境变化,并据此调整决策目标及其操纵特性。 相似文献
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A robust H
∞ preview control is investigated for an active suspension system with look-ahead sensors. The uncertain system is described
by a state-space model with linear nominal parts and additional nonlinear time-varying norm-bounded uncertainties. Proof of
robust stability and a feedback-type robust H
∞ preview controller are derived by augmenting the dynamics of the original system and previewed road input. As, however, the
augmented previewed road input gives the system a much larger dimension than the original system, much more computation time
is required for solving of Riccati equations. To resolve this problem, a decomposed robust H
∞ preview controller is proposed. Robust stability and performance variations for system uncertainties are shown using a numerical
example of a quarter-car model. 相似文献