一种动态抑制驱动电机转速波动的控制系统

根据驱动电机系统在纯电动轿车中的应用特性,在复杂工况下,对整车行驶过程中的转矩需求值、速度变化值等参数进行分析,基于模糊控制算法思想,模拟道路路况和驾驶员意愿,线性化调节扭矩补偿值,有效抑制车辆的低速抖动,提高车辆的行驶平稳性。     

克服无人机拍摄扰动的高精度车辆轨迹数据提取方法

受气流、机身震动等因素影响,无人机高空悬停拍摄过程中相机会出现不同程度的扰动,对车辆轨迹数据的精度造成了不可忽视的影响。鉴于此,首先采用YOLOv4和Deepsort算法,实现车辆目标的检测与跟踪,获取车辆图像坐标;其次采用Shi-Tomasi角点检测,完成图像锚点的自动检测与跟踪,获取锚点的图像坐标;再次,基于最大残差淘汰策略,对锚点进行甄别优选,采用单应性变换模型,构建图像坐标系与地面坐标系之间的动态映射关系;最后,根据坐标动态映射关系模型,实施坐标转换,并采用RTS平滑滤波,对车辆轨迹地面坐标实施平滑处理。通过抖动消除前、后的车辆轨迹对比,发现实施抖动去除后的车辆轨迹明显剔除了相机扰动造成的车辆“虚假位移”的影响,提取的车辆轨迹坐标能够达到10 cm级精度水平,表明提出的方法成功克服了无人机相机抖动带来的负面影响,对改善车辆轨迹数据的质量具有积极意义。     

制动盘对制动抖动的影响

制动抖动是汽车制动系统的重要故障之一,在各种类型的车辆中均有发生。制动抖动现象的出现不仅严重影响了车辆的驾乘舒适性和乘员安全感,同时也大大增加了车辆售后维修的费用和时间。本文主要针对目前乘用车使用较多的盘式制动器车辆,由于制动盘缺陷而引起的制动抖动现象的研究。     

悬架偏频对制动性能影响分析

制动性能是衡量车辆好坏的一个重要指标,世界上任何一个国家对此都有严格要求。本文着重介绍一款轻型载货车辆在设计验证过程中,车辆空载行驶速度超过40km／h时,在紧急制动情况下后桥出现抖动现象。通过对车辆制动系统、悬架系统全面分析,找到问题所在,最后在不影响车辆性能的前提下,通过适当调整后悬架板簧的刚度达到解决车辆制动抖动。     

磁力表座配合百分表在汽修中的应用

<正>车辆在一定车速范围内实施制动时常会引起方向盘、制动踏板、车身地板和座椅等的剧烈抖动,制动抖动一般发生在车辆高速行驶并实施中等强度制动时。制动抖动是汽车制动系统的重要故障之一,故障出现时严重影响车辆的舒适性且增加了驾驶     

多轮分布式电驱动车辆双重转向分层控制系统设计

为了提高多轮分布式电驱动车辆在复杂机动环境下的转向能力,设计了一种基于直接横摆力矩控制的双重转向系统。该控制系统采用分层结构,上层为横摆力矩决策层,下层为驱动力分配层。在控制系统上层,基于无迹卡尔曼滤波和递归最小二乘结合算法进行路面辨识;根据车辆状态信息和路面条件自适应调节滑移转向比,由车辆动力学模型和滑移转向比确定双重转向参考模型;针对滑模面附近非连续特性造成的控制信号抖动现象,将滑模控制算法进行改进,设计了滑模条件积分控制器,使车辆实际横摆角速度追踪双重转向参考模型计算出期望横摆角速度。系统下层在保证车辆总驱动力的前提下,基于控制分配规则将上层广义目标控制力需求分配至各执行器。最后,利用硬件在环实时仿真平台进行控制策略验证。结果表明,分层控制系统较好地实现了路面识别功能和车辆双重转向功能,针对不同路面工况对车辆进行了有效地行驶控制,减小了车辆在狭小弯曲地区的转弯半径,抑制了车辆状态参数及电机转矩的颤振和抖动,改善了车辆小半径行驶的转向机动性和高速行驶稳定性。     

复杂路面环境下前方车辆识别目标函数的选取

首先利用道路边界信息限定车辆的存在范围,以提高识别的实时性.接着根据灰度图像上车辆底部的灰度特征、方差特征和下边界梯度特征构造车辆检测目标函数,以指导在车辆存在区检测前方车辆.最后利用区域增长方法剔除由噪声引起的误判.实验验证表明,在复杂环境下该目标函数能够有效地消除大量无规则噪声的影响,并能准确地识别出车辆目标.     

后视镜振动抖动光学性能评价方法研究

在试验室环境下对汽车后视镜的振动抖动进行了分析研究,提出了后视镜镜面振动抖动的两种评价方法。结合图像分析法对后视镜镜面振动抖动形成机理进行了分析,并设计了一组镜面振动抖动标准图像。试验结果表明,利用图像分析法评价后视镜振动抖动结果与试车人员感觉相似,表明了该方法在评价后视镜振动抖动光学性能上的有效性。     

2009款伊兰特发动机故障灯亮,加速抖动

<正>故障现象:一辆2009款北京现代1.6L伊兰特,行驶了4562km,发动机配置CVVT(连续可变气门正时)系统。车辆正常行驶中发动机故障灯突然点亮,加速抖动,行驶无力,松开加速踏板后发动机有时自然熄火,再次启动车辆时怠速状态下发动机抖动很大,似乎有缸不工作。     

汽车在特定工况下抖动的技术分析及排除方法

汽车在行驶或制动过程中,有时会由于某些系统调整不当或个别机件技术状态不佳,引起方向盘或车身发生抖动,使车辆的安全性能急剧下降,甚至必须进行制动减速才能使车辆从抖动状态中摆脱出来,这种情况严重影响了车辆的正常使用。     

面向铲装作业场景的自动驾驶矿车路径规划方法研究

针对铲装作业场景复杂多变、矿车路径规划实时性及安全性要求高的特点，提出一种基于引导式变步长混合A*算法的路径规划方法。通过建立维诺图获取矿区路网并提取关键点作为方向引导，提升探索效率的同时避免车辆在U形障碍物处陷入局部最优；引入自适应变步长算法并改进启发函数，进一步提高规划效率及路径安全性；通过矿区实车场景试验验证算法有效性。试验结果表明，本路径规划方法满足矿车复杂场景要求，规划时间相比原引导式算法降低68%，路径到障碍物平均距离增加了11%，路径曲率变动次数减少45%，显著提高了计算效率与路径质量。     

以机动车“运行人”作为交通事故损害赔偿责任主体之探讨

各地人民法院审理机动车交通事故损害赔偿案件时,对损害赔偿责任主体把握不准是一个突出的问题。以机动车"运行人"作为损害赔偿责任主体,以运行支配和运行利益的扩大解释,作为衡量"运行人"的标准,有助于解决机动车雇佣驾驶,出借、出租,擅自驾驶,盗窃驾驶,送修、委托保管或者出质,分期付款买卖,挂靠,未履行转移登记手续,好意同乘,车辆故障等复杂情形下损害赔偿主体的确定。以保障受害人得到及时有效的救济。     

无人驾驶汽车路径规划算法研究综述

无人驾驶汽车是目前汽车发展的一个大方向,无人驾驶的实现依靠于汽车的感知、决策和控制功能。路径规划属于决策中重要的一环。目前,无人驾驶汽车的路径规划算法存在受环境影响较大,无法适用于复杂的道路环境的问题,基于此文章对无人驾驶汽车轨迹规划算法进行归纳。其在广义上可分成全局路径规划和局部路径规划两种,文章对上述两种规划进行细分并介绍了各种路径规划方法的原理,分析了各个方法的优劣,为无人驾驶汽车路径规划算法的研究提供参考。     

Automatic Cruise Control of a Mechatronically Steered Vehicle Convoy

In this paper a convoy of two vehicles is considered where the second one is mechatronically operated. The convoy model used for simulation and controller design is derived by the method of multibody systems. A nonlinear cruise controller based on the concept of flat outputs in connection with exact state linearization is derived. A nonlinear local observer is also implemented. It is shown that such a system responds properly to arbitrary maneuvers performed by the driver of the leading vehicle.     

Automatic Cruise Control of a Mechatronically Steered Vehicle Convoy

In this paper a convoy of two vehicles is considered where the second one is mechatronically operated. The convoy model used for simulation and controller design is derived by the method of multibody systems. A nonlinear cruise controller based on the concept of flat outputs in connection with exact state linearization is derived. A nonlinear local observer is also implemented. It is shown that such a system responds properly to arbitrary maneuvers performed by the driver of the leading vehicle.     

氢燃料电池汽车简易加氢站设计

为了面对能源与环境问题,国家与地方政府正在大力推动氢燃料电池汽车产业的发展,目前国内主流的汽车生产企业基本上都已经启动了氢燃料电池汽车的研发工作。然而,受限于我国加氢站建设周期长,成本高,流程复杂等问题,使得全国的加氢站数量十分稀少,许多汽车生产企业研发出来的氢燃料电池汽车面临着加氢的巨大挑战,一些偏远地方的汽车生产企业甚至到了无氢可加的境地。为了缓解氢燃料电池汽车的加氢问题,拓宽氢燃料电池汽车的使用场景,本文提出了一种简易加氢站的设计方法,期望该方法可为加氢困难的汽车生产企业提供借鉴,加速氢燃料电池汽车产业的发展。     

A design methodology for mechatronic vehicles: application of multidisciplinary optimization, multibody dynamics and genetic algorithms

A design methodology for mechatronic vehicles is presented. With multidisciplinary optimization (MDO) methods, strongly coupled mechanical, control and other subsystems are integrated as a synergistic vehicle system. With genetic algorithms (GAs) at the system level, the mechanical, control and other relevant parameters can be optimized simultaneously. To demonstrate the feasibility and efficacy of the proposed design methodology for mechatronic vehicles, it is used to resolve the conflicting requirements for ride comfort, suspension working spaces and unsprung mass dynamic loads in the optimization of half-vehicle models with active suspensions. Both deterministic and random road excitations, both rigid and flexible vehicle bodies and both perfect measurement of full state variables and estimated limited state variables are considered. Numerical results show that the optimized vehicle systems based on the methodology have better overall performance than those using the linear quadratic Gaussian (LQG) controller. It is shown that the methodology is suitable for complex design optimization problems where: (1) there is interaction between different disciplines or subsystems; (2) there are multiple design criteria; (3) there are multiple local optima; (4) there is no need for sensitivity analysis for the optimizer at the system level; and (5) there are multiple design variables.     

A design methodology for mechatronic vehicles: application of multidisciplinary optimization,multibody dynamics and genetic algorithms

A design methodology for mechatronic vehicles is presented. With multidisciplinary optimization (MDO) methods, strongly coupled mechanical, control and other subsystems are integrated as a synergistic vehicle system. With genetic algorithms (GAs) at the system level, the mechanical, control and other relevant parameters can be optimized simultaneously. To demonstrate the feasibility and efficacy of the proposed design methodology for mechatronic vehicles, it is used to resolve the conflicting requirements for ride comfort, suspension working spaces and unsprung mass dynamic loads in the optimization of half-vehicle models with active suspensions. Both deterministic and random road excitations, both rigid and flexible vehicle bodies and both perfect measurement of full state variables and estimated limited state variables are considered. Numerical results show that the optimized vehicle systems based on the methodology have better overall performance than those using the linear quadratic Gaussian (LQG) controller. It is shown that the methodology is suitable for complex design optimization problems where: (1) there is interaction between different disciplines or subsystems; (2) there are multiple design criteria; (3) there are multiple local optima; (4) there is no need for sensitivity analysis for the optimizer at the system level; and (5) there are multiple design variables.     

New approach for performing failure analysis of fuel cell-powered vehicles

Safety of hybrid-electric and fuel cell vehicles is a critical aspect of these new technologies, since any accident exposing occupants of such vehicles to unconventional hazards may result in significant setbacks to successful market penetration. Fuel cell and hybrid-electric drive systems are complex, and it is essential to perform a thorough analysis to determine critical failure conditions. There are several safety concerns for routine operation of such systems, particularly for hydrogen-fueled vehicles. A modified Failure Modes and Effect Analysis (FMEA) has been developed, along with a Criticality Analysis (CrA), to identify potentially hazardous conditions for crash and non-crash situations. A mathematical model of fuel cell operation has been developed and used here in conjunction with the FMEA. Component failures during the event modes are simulated using vehicle models developed with Matlab Simulink tools. Six simulation models were created using the software. In addition, a preliminary finite element model of a fuel cell vehicle, using a Ford Taurus (91′) model year sedan, has been developed and implemented. This finite element model is used as a demonstration of the crash simulation of the vehicle.