双前桥转向机构优化设计方法研究

双前桥转向机构包含两个独立的转向梯形机构和双前桥间的转向联动机构—双摇臂系统。文中分析了双前桥转向机构应实现的功能、运动规律和与其它系统可能造成的运动干涉,提出了同时保证双前桥汽车车轮转向时做纯滚动和杆系干涉造成的车轮异常磨损最小的多目标优化设计方法。     

汽车双前桥转向系统硬点优化

本文分析了汽车双前桥转向系统理想转角关系，利用Adams Car建立了双前桥多体动力学悬架模型，分别进行了平行轮跳及转向K特性分析，结果表明二轴跳动转向及阿克曼转角误差偏大，不满足设计目标。在动力学模型的基础上建立了硬点DOE分析模型，优化了轴跳动转向及阿克曼转角误差，优化效果在整车性能分析中得到验证。此优化方法具有实用性及便捷性，为后续车型开发奠定了理论基础，提升了开发效率及准确性。     

双前桥载货汽车第二前桥内轮转角优化设计

理论分析双前桥载货汽车第一前桥总成、第二前桥总成转向关系,确定双前桥内轮转角的总传动比的定义,然后计算各转向角理论状态下的总传动比,与车辆转向系统设计的总传动比进行比对,明确在各转向状态下的最优传动比。达到在任一转向状态下,第一前桥、第二前桥可最大限度绕同一旋转中心协调转向,避免了前桥总成拖磨吃胎,降低了油耗。     

实现快速调整某转向前桥转向角

转向前桥在汽车上一个非常重要的功能就是实现汽车转向,而转向角是决定转向前桥性能的一个非常重要的参数,本文解决了在桥总成装配线快速调整某转向前桥转向角问题。     

双前桥转向杆系的空间优化分析

应用动力学仿真软件ADAMS建立了双前桥转向系统的运动学模型。采用参数化分析方法,以基于双前桥转向理论建立的各转向车轮转角范围内所有转角的实际值与理想值之间的误差累积最小为目标函数,对转向杆系进行了仿真优化分析。仿真优化所得结构参数表明,该方法可以真实地反映转向机构的运动情况。     

客车前桥受力分析及设计

1前言 随着公路交通的发展和人民生活水平的提高，人们对乘用车的安全性、承载能力等方面提出了更高的要求。前桥做为汽车底盘的关键部件，其在实现汽车转向、制动以及支撑等诸方面起着至关重要的作用。因此，做好汽车前桥产品的设计开发，才能不断满足汽车底盘的要求。这里对前桥的主要功能、受力分析和设计计算等方面进行初步的探讨。     

红岩6×2双转向前桥汽车成功问世

既成功开发“红岩新大康——金刚”系列重卡后,近日,又一凝聚红岩人智慧的红岩6×2双转向前桥重卡在红岩公司完成试制,该车具有承载能力强、经济效益好、安全性高等特性。红岩6×2双转向前桥汽车成功问世,进一步丰富红岩系列产品型谱,将为红岩公司扩大市场     

基于汽车起重机双前桥转向机构的仿真研究

介绍汽车起重机双前桥转向系统的仿真研究,利用MSCADAMS软件对该转向梯形机构进行了运动仿真,对其转向性能进行了优化;道路试验结果表明,所设计的转向机构性能符合设计要求。     

转向沉重故障的诊断与排除

导致转向沉重的主要因素 引起汽车转向沉重的因素很多,主要受两大总成件影响。一是受转向器结构型式、安装位置以及转向器本身的故障影响;二是受转向前桥(包括横、纵拉杆)结构、参数及润滑情况影响。对于带有助力转向的汽车,液压系统的故障也是导致汽车转向沉重的原因之一。 转向沉重部位的诊断方法 1.支起前桥,转动转向盘,若感到转向灵活,则故障在前桥与车轮等部件。因为支起前桥后,转动转向盘时车轮与路面的接触阻力     

双前桥线控转向系统的应用研究

线控转向是一种先进的转向技术。文中介绍了线控转向系统的结构、工作原理及特点,以及线控转向技术在双前桥车辆领域的研究热点。展望了线控转向技术在双前桥车辆领域的应用前景。     

双前轴转向汽车车轮转角自动检测系统开发

现阶段汽车检测线对双前轴转向车辆的检测处于空白状况。本文在分析双前轴转向车辆的转向参数特征基础上,设计了双前轴转向车辆转角自动检测系统,并根据车辆检测数据对转向系的故障进行判定,为双前轴转向车辆检测和维修提供一种可靠、有效的方法。     

Role of steering wheel feedback on driver performance: driving simulator and modeling analysis

When driving in curves, how do drivers use the force appearing on the steering wheel? As it carries information related to lateral acceleration, this force could be necessary for drivers to tune their internal model of vehicle dynamics; alternatively, being opposed to the drivers' efforts, it could just help them stabilize the steering wheel position. To assess these two hypotheses, we designed an experiment on a motion-based driving simulator. The steering characteristics of the vehicle were modified in the course of driving, unknown to drivers. Results obtained with standard drivers showed a surprisingly wide range of adaptation, except for exaggerated modifications of the steering force feedback. A two-level driver model, combining a preview of vehicle dynamics and a neuromuscular steering control, reproduces these experimental results qualitatively and indicates that adaptation occurs at the haptic level rather than in the internal model of vehicle dynamics. This effect is related to other theories on the manual control of dynamics systems, wherein force feedback characteristics are abstracted at the position control level. This research also illustrates the use of driving simulation for the study of driver behavior and future intelligent steering assistance systems.     

Role of steering wheel feedback on driver performance: driving simulator and modeling analysis

When driving in curves, how do drivers use the force appearing on the steering wheel? As it carries information related to lateral acceleration, this force could be necessary for drivers to tune their internal model of vehicle dynamics; alternatively, being opposed to the drivers' efforts, it could just help them stabilize the steering wheel position. To assess these two hypotheses, we designed an experiment on a motion-based driving simulator. The steering characteristics of the vehicle were modified in the course of driving, unknown to drivers. Results obtained with standard drivers showed a surprisingly wide range of adaptation, except for exaggerated modifications of the steering force feedback. A two-level driver model, combining a preview of vehicle dynamics and a neuromuscular steering control, reproduces these experimental results qualitatively and indicates that adaptation occurs at the haptic level rather than in the internal model of vehicle dynamics. This effect is related to other theories on the manual control of dynamics systems, wherein force feedback characteristics are abstracted at the position control level. This research also illustrates the use of driving simulation for the study of driver behavior and future intelligent steering assistance systems.     

Modeling and control of an anti-lock brake and steering system for cooperative control on split-mu surfaces

The brake and steering systems in vehicles are the most effective actuators that directly affect the vehicle dynamics. In general, the brake system affects the longitudinal dynamics and the steering system affects the lateral dynamics; however, their effects are coupled when the vehicle is braking on a non-homogenous surface, such as a split-mu road. The yaw moment compensation of the steering control on a split-mu road is one of the basic functions of integrated or coordinated chassis control systems and has been demonstrated by several chassis suppliers. However, the disturbance yaw moment is generally compensated for using the yaw rate feedback or using wheel brake pressure measurement. Access to the wheel brake pressure through physical sensors is not cost effective; therefore, we modeled the hydraulic brake system to avoid using physical sensors and to estimate the brake pressure. The steering angle controller was designed to mitigate the non-symmetric braking force effect and to stabilize the yaw rate dynamics of the vehicle. An H-infinity design synthesis was used to take the system model and the estimation errors into account, and the designed controller was evaluated using vehicle tests.     

Sliding mode-based lateral vehicle dynamics control using tyre force measurements

In this work, a lateral vehicle dynamics control based on tyre force measurements is proposed. Most of the lateral vehicle dynamics control schemes are based on yaw rate whereas tyre forces are the most important variables in vehicle dynamics as tyres are the only contact points between the vehicle and road. In the proposed method, active front steering is employed to uniformly distribute the required lateral force among the front left and right tyres. The force distribution is quantified through the tyre utilisation coefficients. In order to address the nonlinearities and uncertainties of the vehicle model, a gain scheduling sliding-mode control technique is used. In addition to stabilising the lateral dynamics, the proposed controller is able to maintain maximum lateral acceleration. The proposed method is tested and validated on a multi-body vehicle simulator.     

Theory and experimental research on six-track steering vehicles

The structural characteristics and steering behaviour of a six-track vehicle are described in this paper. Kinematic analysis for skid steering of a six-track vehicle under steady-state conditions on firm ground is conducted, with the relationship between thrust force and speed instantaneous centre of the track–terrain interface taken into consideration. A mechanical model for steady steering of a six-track vehicle is also presented based on the kinematic analysis. In this model, the steering inaccuracy and efficiency are defined to evaluate steering performance. The steering performance of a six-track vehicle is numerically simulated to analyse the effect of the structural parameters and deflection angles on tracks. A virtual prototype model is established based on the multi-body dynamics software RecurDyn for steering simulation and the findings coincide well with theoretical results. The theory and the virtual prototype simulations presented are verified by a power test of a bucket-wheel excavator. The method for analysing the steering performance of a six-track vehicle proposed in this paper provides a basis for designing a six-track vehicle.     

Modelling and control of a new differential steering concept

This paper presents a new steer-by-wire concept using an all-wheel drive vehicle layout with in-wheel motors while completely omitting the application of any dedicated steering device. Steering is based on the so-called differential steering principle which generates the necessary steering moment about the kingpins by a traction force difference between left and right sides of the vehicle. In order to investigate the behaviour of the vehicle and to design the underlying control algorithms, a planar vehicle model is presented, where the vehicle is described as constrained non-holonomic system requiring a special treatment. A state feedback linear controller for controlling of the lateral dynamics of the vehicle at higher speeds and a simple PI angle controller for low-speed manoeuvring are developed. The resulting behaviour of the system is investigated by various simulation experiments demonstrating a comparable steering performance of the new steering concept as that of conventional passenger cars.     

分布式驱动电动汽车转向工况转矩分配控制研究

针对分布式驱动车辆转向工况在低速下期望提高转向机动性能，高速下期望保证行驶稳定性的需求，充分考虑转向行驶内外侧车轮的转向关系以及车辆动力学，制定了适应车速变化的四轮转矩分配策略，建立了四轮轮毂电机驱动模型以及二自由度参考模型。为了改善分布式驱动转向机动性能，建立自抗扰控制器调整内外侧车轮转矩，形成合理的转速差，减小转向半径，以提高转向机动性；对于高速转向行驶稳定性的需求，通过二次规划方法优化分配各车轮驱动力矩，分析轮胎纵横向附着裕度建立目标函数，并加入附加横摆力矩和路面附着力的限制，进行车轮驱动转矩的在线优化分配，提高车辆转向行驶的稳定性；另外为避免2种控制模式转换时驱动转矩突变，根据车速和稳定性参数制定模糊规则决策2种模式的协调系数，保证2种控制模式的平滑过渡。基于CarSim和MATLAB/Simulink进行联合仿真，并搭建硬件在环平台进行试验，对所提出的方法进行验证。结果表明：在低速转向工况下，提出的分配策略能够调节内外侧车轮产生差速效果，与转矩平均分配的策略相比，转向半径有所减小，提高车辆机动性；高速转向工况下，分配策略能够保证车辆稳定转向，与未考虑稳定性控制的分配策略相比，能更好地跟踪目标轨迹，且横摆角速度控制在参考横摆角速度附近，证明了所提控制策略的有效性。     

柴油机用动力转向泵的匹配

介绍柴油机转向泵的匹配设计方法,并以此为实例进行说明;通过实车转向力、压力损失和转向油温的测试来验证匹配效果;最后阐述系统管理对维护转向泵性能的重要性。     

汽车转向控制

本文研究侧偏角有约束条件下，汽车四轮转向控制系统的设计问题。根据汽车转向动力学的特点，建立了具有不确定的汽车转向模型，给出了车体质心处侧偏角有约束条件下，二自由度鲁棒四轮转向控制器的设计方法，最后基于ＬＭＩＴｏｏｌ给出了控制器的迭代算法，并给出了仿真计算实例。