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Simulation of cavitation in rotary valve of hydraulic power steering gear

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Science China(Technological Sciences) 2009年第11期52卷 3142-3148页

作者： LIU YaHui ji xuewu Department of Automotive Engineering Tsinghua UniversityBeijing 100084

Hydraulic power steering gear supplies assistant power by liquid stream. The stream will be changed greatly for the flow field formed by the rotary valve will vary during steering. And the change of the stream in this narrow field will (be big enough to) cause the fluctuation of the assistance power and noise of the steering gear. 3-D meshes of the flow field between the sleeve and the rotor of the valve with different structure parameters such as entry caliber and groove depth were set up and a general CFD code-Fluent was used to analyze the stream performance. The results including pressure and gas-phase's volume fraction were analyzed under certain operation flow rate. It was found that the entry caliber did not affect the operation pressure of the valve under the same flow rate but affected the gas-phase's volume fraction of the flow field, and so did the groove depth of the valve' sleeve and rotor. Many researches have pointed that the noise of steering valve is almost cavitation noise, that is, the gas-phase in the flow field has great correlation with rotary valve noise. Based on these analyses of the stream in the rotary steering valve, this paper gave suggestion that increasing entry caliber of the rotary valve and choosing appropriate groove depth will reduce the valve noise.

关键词： rotary valve computational fluid dynamic cavitation noise

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商用车电控转向系统的发展现状与趋势

汽车工程 2024年第5期46卷 816-829页

作者：董梒季学武陶书鑫蒋体通何祥坤王恒刘亚辉北京科技大学自动化学院北京100083 清华大学车辆与运载学院北京100084 南洋理工大学机械与航空航天工程学院新加坡639798

商用车转向系统的电控化是实现商用车节能化和智能化的必由之路,为此商用车转向系统从传统的液压助力转向系统发展到以电液耦合助力转向系统为代表的电控转向系统。本文将对商用车电控转向技术进行综述,从电控转向系统的典型构型、智能... 详细信息

商用车转向系统的电控化是实现商用车节能化和智能化的必由之路,为此商用车转向系统从传统的液压助力转向系统发展到以电液耦合助力转向系统为代表的电控转向系统。本文将对商用车电控转向技术进行综述,从电控转向系统的典型构型、智能转向控制和功能安全设计3个方面对商用车电控转向技术的研究进行梳理,总结电控转向技术的重点研究领域和未来发展方向。梳理总结发现:(1)在系统构型方面,商用车电控转向系统以电液耦合转向助力技术为主,着重于实现商用车智能转向功能,同时兼顾节能化需求;商用车电动助力转向系统是未来理想的电控转向技术方案。(2)在智能控制方面,为了适应商用车智能化的发展,转向执行控制着重于解决液压系统所造成的非线性与时滞性问题以及轨迹跟随过程中的横向动力学控制难题;辅助驾驶功能着重于克服液压系统的非线性导致的转向力矩不连续以及人机控制权的分配;自动驾驶功能着重于提升安全性与燃油经济性。(3)在系统功能安全设计方面,商用车电控转向系统着重于设计符合功能安全标准的故障诊断与容错控制策略。

关键词：商用车电控转向系统智能转向控制功能安全容错控制策略

Objective Evaluation Method of Steering Comfort Based on Movement Quality Evaluation of Driver Steering Maneuver

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Chinese Journal of Mechanical Engineering 2014年第5期27卷 1027-1037页

作者： YANG Yiyong LIU Yahui WANG Man ji Run ji xuewu School of Engineering and Technology China University of Geosciences(Beijing) State Key Laboratory of Automotive Safety and Energy Tsinghua University National Research Center for Rehabilitation Technical Aids

The existing research of steering comfort mainly focuses on the subjective evaluation,aiming at designing and optimizing the steering *** the development of steering system,especially the evaluation of steering comfort,the objective evaluation methods considered the kinematic characteristics of driver steering maneuver are not proposed,which means that the objective evaluation of steering cannot be conducted with the evaluation of kinematic characteristics of driver in steering *** order to propose the objective evaluation methods of steering comfort,the evaluation of steering movement quality of driver is developed on the basis of the study of the kinematic characteristics of steering ***,the steering motion trajectories of the driver in both comfortable and certain extreme uncomfortable operation conditions are detected using the Vicon motion capture *** operation conditions are under the restrictions of the vertical height and horizontal distance between steering wheel center and the H-point of driver,and the steering resisting torque ***,the movement quality evaluation of driver steering maneuver is assessed using twelve kinds of evaluation indices based on the kinematic analyses of the steering motion trajectories to propose an objective evaluation ***,an integrated discomfort index of steering maneuver is proposed on the basis of the regression analysis of subjective evaluation rating and the movement quality evaluation indices,including the Jerk,Discomfort and Joint Torque *** test results show that the proposed integrated discomfort index gives a good fitting with the subjective evaluation of discomfort,which means it can be used to evaluate or predict the discomfort level of steering *** paper proposes an objective evaluation method of steering comfort based on the movement quality evaluation of driver steering maneuver.

关键词： steering maneuver movement quality evaluation driver discomfort

A Novel Estimating Method for Steering Efficiency of the Driver with Electromyography Signals

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Chinese Journal of Mechanical Engineering 2014年第3期27卷 460-467页

作者： LIU Yahui ji xuewu HAYAMA Ryouhei MIZUNO Takahiro State Key Laboratory of Automotive Safety and Energy Tsinghua University Research and Development Center jtekt co.ltd.

The existing research of steering efficiency mainly focuses on the mechanism efficiency of steering system, aiming at designing and optimizing the mechanism of steering system. In the development of assist steering system especially the evaluation of its comfort, the steering efficiency of driver physiological output usually are not considered, because this physiological output is difficult to measure or to estimate, and the objective evaluation of steering comfort therefore cannot be conducted with movement efficiency perspective. In order to take a further step to the objective evaluation of steering comfort, an estimating method for the steering efficiency of the driver was developed based on the research of the relationship between the steering force and muscle activity. First, the steering forces in the steering wheel plane and the electromyography （EMG） signals of the primary muscles were measured. These primary muscles are the muscles in shoulder and upper ann which mainly produced the steering torque, and their functions in steering maneuver were identified previously. Next, based on the multiple regressions of the steering force and EMG signals, both the effective steering force and the total force capacity of driver in steering maneuver were calculated. Finally, the steering efficiency of driver was estimated by means of the estimated effective force and the total force capacity, which represented the information of driver physiological output of the primary muscles. This research develops a novel estimating method for driver steering efficiency of driver physiological output, including the estimation of both steering force and the force capacity of primary muscles with EMG signals, and will benefit to evaluate the steering comfort with an objective perspective.

关键词： electromyography muscle activity steering efficiency estimating

A modified structure internal model robust control method for the integration of active front steering and direct yaw moment control

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Science China(Technological Sciences) 2015年第1期58卷 75-85页

作者： WU jian ZHAO YouQun ji xuewu LIU YaHui YIN ChengQiang Department of Automotive Engineering College of Energy and Power Engineering Nanjing University of Aeronautics and Astronautics School of Mechanical and Automotive Engineering Liaocheng University State Key Laboratory of Automotive Safety and Energy Tsinghua University

Taking into account the nonlinearity of vehicle dynamics and the variations of vehicle parameters,the integrated control strategy for active front steering(AFS)and direct yaw control(DYC)that can maintain the performance and robustness is a key issue to be ***,the H∞method is widely applied to the integrated control of chassis dynamics,but it always sacrifices the performance in order to enhance the *** modified structure internal model robust control(MSIMC)obtained by modifying internal model control(IMC)structure is proposed for the integrated control of AFS and DYC to surmount the conflict between performance and *** lane change(DLC)simulation is developed to compare the performance and the stability of the MSIMC strategy,the PID controller based on the reference vehicle model and the H∞*** results show that the PID controller may oscillate and go into instability in severe driving conditions because of large variations of tire parameters,the H∞controller sacrifices the performance in order to enhance the stability,and only the MSIMC controller can both ensure the robustness and the high performance of the integrated control of AFS and DYC.

关键词： modified structure internal model control robust control chassis integrated control double lane change

Generalized Internal Model Robust Control for Active Front Steering Intervention

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Chinese Journal of Mechanical Engineering 2015年第2期28卷 285-293页

作者： WU jian ZHAO Youqun ji xuewu LIU Yahui ZHANG Lipeng College of Energy and Power Engineering Nanjing University of Aeronautics and Astronautics School of Mechanical and Automotive Engineering Liaocheng University State Key Laboratory of Automotive Safety and Energy Tsinghua University

Because of the tire nonlinearity and vehicle＇s parameters＇uncertainties,robust control methods based on the worst cases,such as H_∞,μsynthesis,have been widely used in active front steering control,however,in order to guarantee the stability of active front steering system（AFS）controller,the robust control is at the cost of performance so that the robust controller is a little conservative and has low performance for AFS *** this paper,a generalized internal model robust control（GIMC）that can overcome the contradiction between performance and stability is used in the AFS *** GIMC,the Youla parameterization is used in an improved *** GIMC controller includes two sections：a high performance controller designed for the nominal vehicle model and a robust controller compensating the vehicle parameters＇uncertainties and some external *** of double lane change（DLC）maneuver and that of braking on split-μroad are conducted to compare the performance and stability of the GIMC control,the nominal performance PID controller and the H_∞*** results show that the high nominal performance PID controller will be unstable under some extreme situations because of large vehicle＇s parameters variations,H_∞controller is conservative so that the performance is a little low,and only the GIMC controller overcomes the contradiction between performance and robustness,which can both ensure the stability of the AFS controller and guarantee the high performance of the AFS ***,the GIMC method proposed for AFS can overcome some disadvantages of control methods used by current AFS system,that is,can solve the instability of PID or LQP control methods and the low performance of the standard H_∞controller.

关键词： active front steering system generalized internal model robust control H_∞ optimization PID split-μ road

Function of shoulder muscles of driver in vehicle steering maneuver

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Science China(Technological Sciences) 2012年第12期55卷 3445-3454页

作者： LIU YaHui ji xuewu RYOUHEI Hayama TAKAHIRO Mizuno LOU LiMing State Key Laboratory of Automotive Safety and Energy Tsinghua UniversityBeijing 100084China Research and Development Center JTEKT Co.Ltd.Nara 634-8555Japan

In order to study the function of muscles of driver shoulder during vehicle steering, identification of relations between electromyograph (EMG) activity of 10 shoulder muscles and steering force was performed. The procedure was to perform controlled steering maneuver by right hand in a driving simulator, and based on analyzing the EMG data with steering force in the steering wheel plane, the function was identified. It was found that muscle function depends strongly on both steering rotation and steering torque directions. In clockwise steering, the long head of triceps brachii was the prime mover and an important contributor to clockwise moment, while the sternocostal portion of the pectoralis major, the lateral head of triceps brachii, biceps brachii and teres major were the important stabilizers or fixators. In contrast, in counterclockwise steering, the anterior, middle and posterior deltoid, the clavicular portion of the pectoralis major and infraspinatus were the prime movers and also the important contributors to counterclockwise moment, while the sternocostal portion of the pectoralis major, the lateral head of triceps brachii, biceps brachii and teres major were the important stabilizers or fixators. We conclude that the prime movers are primarily a consequence of steering direction, while the stabilizers or fixators are primarily constant. These results can be used to improve the neuromuscular model and estimate the steering comfort of driver.

关键词： electromyograph muscle function steering maneuver

蜀南自贡地区茅口组岩溶储层成因及地震预测方法

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石油物探 2024年第2期63卷 437-448,471页

作者：王雷纪学武屈卫华孙增玖柯钦孙国翔查小军陈迎楠李瑞珍东方地球物理勘探有限责任公司研究院地质研究中心河北涿州072751 中国石油天然气股份有限公司吉林油田分公司吉林松原138000 成都理工大学四川成都610059

近年来,四川盆地下二叠统茅口组大量非构造圈闭钻井获得高产,证实了岩溶储层是茅口组岩性气藏的一个重要控制因素。但岩溶储层的成因及地震响应特征尚不明确,不同地区的岩溶储层预测方法不尽相同。通过对蜀南自贡地区茅口组构造特征、... 详细信息

近年来,四川盆地下二叠统茅口组大量非构造圈闭钻井获得高产,证实了岩溶储层是茅口组岩性气藏的一个重要控制因素。但岩溶储层的成因及地震响应特征尚不明确,不同地区的岩溶储层预测方法不尽相同。通过对蜀南自贡地区茅口组构造特征、地层特征和岩溶储层地震响应特征研究,得出以下5方面认识:①台内滩相是岩溶储层发育的物质基础,自贡地区茅口组台内滩相主要在茅三段和茅二b段发育;②东吴运动差异抬升是研究区岩溶储层的主控因素;③断层形成于茅口组沉积之后,茅口组顶部岩溶储层受后期局部持续风化控制,茅口组内部岩溶储层受后期断层改造控制;④距茅口组顶距离不同,岩溶储层地震响应特征不同,茅三段表层型岩溶储层物性与茅口组顶部波峰振幅呈负相关,茅二b段内幕型岩溶储层物性则与茅口组内部波峰振幅呈正相关;⑤表层型岩溶储层在平面上不依赖断层且具有一定规模。

关键词：蜀南自贡地区茅口组岩溶储层成因岩溶储层地震预测方法东吴运动内幕型岩溶表层型岩溶

Exploration prospect and resolution of foreland thrust faulting belts in Corridor Basin

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Exploration prospect and resolution of foreland thrust fault...