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Vehicle side-slip angle estimation based on Uni-Tire model
基于Uni-Tire轮胎模型的车辆质心侧偏角估计

GUO Hong-yan,CHEN Hong,DING Hai-tao,HU Yun-feng,
郭洪艳
,陈虹,丁海涛,胡云峰

控制理论与应用 , 2010,
Abstract: A nonlinear full-order observer is proposed for vehicle side-slip angle estimation to improve the accuracy and the real-time performance of the side-slip angle estimation. The longitudinal velocity, lateral velocity and yaw rate of the vehicle are estimated by the observer using the information of vehicle states which are measured by on-board sensors based on the vehicle dynamic model and Uni-Tire model for longitudinal slip and lateral slip, and then, the estimates of the side-slip angle are determined based on the above results. The stability of the observer is analyzed using the theory of input-to-state stability(ISS). The offline estimation result is validated using the vehicle simulation software veDYNA with the parameters of Hongqi CA7180A3E in critical condition; the real-time performance of the full-order nonlinear observer is tested on the simulation platform using the xPC-Target simulation environment and dSPACE real-time system. The simulation results show that the nonlinear estimation method has high estimation precision, good real-time performance and satisfies the requirements of engineering application.
Model Reference Variable Structure Control for Improving Vehicle Active Safety
提高车辆主动安全性的模型参考变结构控制方法

LI Jian-feng,GAO Li,
李剑峰
,高利

系统工程理论与实践 , 2007,
Abstract: A model reference variable structure controller based on Lyapunov function was designed to generate additional yaw moment of the vehicle for improving active safety.This controller was expected to make the actual vehicle response tracking the reference model.The proposed simulation model was employed to calculate the yaw rate and slip angle response characteristics of a vehicle under sine steering angle and J-turn input.It shows that the handling and stability of the vehicle is significantly improved as compared to the uncontrolled one.The control strategy is robust to vehicle speed and road condition variations,and uncertainties.
带碰撞角约束的高速飞行器小速度比交会制导律
Guidance Law of Small Velocity Ratio Interception Against High-Speed Vehicle with Impact Angle Constraint
 [PDF]

熊俊辉,唐胜景,郭杰,高峰
- , 2015, DOI: 10.15918/j.tbit1001-0645.2015.02.010
Abstract: 针对目标飞行器速度较大引起的拦截器与目标速度比小于1的空间交会问题,建立拦截器与目标交会的三维运动模型,分析共面运动的碰撞角对相对速度及有效碰撞面积的影响并讨论交会的速度比条件. 基于初始预测的目标速度信息,根据准平行接近原则将碰撞角约束转化为交会过程中的视线角约束,应用变结构控制设计带视线角约束的三维制导律并分析其稳定性. 结果显示,设计的制导律不仅使视线角速率逼近于0,还可以实现以期望的碰撞角实施交会,并且对预测的目标速度偏差具有较强的鲁棒性.
Tail chase, head-on interception and head pursuit guidance methods were described by impact angle. To solve small velocity ratio intersection problem caused by developing high-speed vehicle, a kinematics model of interceptor and target was established. The effect of coplanar impact angle on approaching velocity and allowed impact area was analyzed and the velocity ratio requirement of three-dimensional intersection was studied. Based on predicted initial target velocity and moving direction, the impact angle constraint was diverted into expected line-of-sight angle via quasi parallel approach. An improved guidance law with line-of-sight angle constraint was proposed via variable structure control. The results show that the proposed guidance law achieves to guiding the line-of-sight to converge to zero as well as reaching the expected impact angle; what's more, the robustness of guidance to evaluated error of target velocity is satisfied.
Helix Angle Effect on the Helical Gear Load Carrying Capacity  [PDF]
Mehmet Bozca
World Journal of Engineering and Technology (WJET) , 2018, DOI: 10.4236/wjet.2018.64055
Abstract: The aim of this study is to investigate the helix angle effect on the helical gear load carrying capacity, including the bending and contact load carrying capacity. During the simulation, the transverse contact ratio is calculated with respect to the constant pressure angle. By changing the helix angle, both the overlap contact ratio and total contact ratio are calculated and simulated. The bending stress and contact stress of a helical gear are calculated and simulated with respect to the helix angle. Solid (CAD) modelling of a pinion gear was obtained using SOLIDWORKS software. The analytically obtained results and finite elements method results are compared. It is observed that increasing the helix angle causes an increase of the contact ratio of the helical gear. Furthermore, increasing the contact ratio reduces the bending stress and contact stress of the helical gear. However, with a constant transverse contact ratio, it is possible to improve the total contact ratio depending on the helix angle. It is concluded that a higher helix angle increases the helical gear bending and contact load carrying capacity.
Experimental analysis of the slip sinkage effectbased on real vehicle test  [PDF]
Yang Fan, , Lin Guoyu, Zhang Weigong, Wang Ningbo
- , 2016, DOI: 10.3969/j.issn.1003-7985.2016.02.012
Abstract: To improve the semi-empirical model, the slip sinkage effect is analyzed based on the real vehicle test. A dynamic testing system is used to gain the dynamic responses of wheel-soil interactions. The Gauss-Newton algorithm is adopted to estimate the undetermined parameters involved in the slip sinkage models. Wong’s original model is compared with three typical slip sinkage models on the prediction performance of a drawbar pull. The maximum error rate, root mean squared error and correlation coefficient are utilized to evaluate the performance. The results indicate that the slip sinkage models outperform Wong’s model and greatly improve the prediction accuracy. Lyasko’s model is confirmed as an outstanding one for its comprehensive performance. Hence, the existence of the slip sinkage effect is validated. Lyasko’s model is selected as an optimal one for the practical evaluation of military vehicle trafficability.
Slip-line metal cutting model with negative rake angle
Ozturk, Sabri;Altan, Erhan;
Journal of the Brazilian Society of Mechanical Sciences and Engineering , 2012, DOI: 10.1590/S1678-58782012000300004
Abstract: a small dead region is seen in front of the rake face of the tool during cutting with negative rake. the lack of knowledge about the stagnant region in the cutting with negative rake requires researching new models. in this work, cutting mechanism of the metal cutting with negative rake angle tools and the stagnation zone formation were studied. a model was generated from the experimental work by usage of the dewhurst and collins' matrix technique for solving the slip-line problem numerically. this model was applied at negative rake angles from 0o to -70o. all slip line angles in the slip line model that consist of three regions were resolved with the help of the experimental data. variation of the dead metal zone and slip line regions with negative rake angle was determined. effects of the negative rake angle on the cutting and thrust forces were investigated according to the cutting speed.
Kinetic Slip Condition, van der Waals Forces, and Dynamic Contact Angle  [PDF]
Len M. Pismen,Boris Y. Rubinstein
Physics , 2000,
Abstract: The profiles of a spreading wetting film are computed taking into account intermolecular forces and introducing a kinetic slip condition at a molecular cut-off distance. This eliminates the stress singularity, so that both "true" and "visible" contact angles are defined unequivocally. The "true" contact angle at the cut-off distance depends on the slip length as well as on the edge propagation speed, but not on gravity or asymptotic inclination angle. These macroscopic factors influence, however, the "visible" contact angle observed in the interval where the actual film profile departs from the intermediate asymptotic curve.
电驱动高地隙车辆滑转率滑模控制研究
Research on sliding mode control of slip rate for electric high-clearance vehicle
 [PDF]

毛家稳,周俊,梁洋洋
- , 2017,
Abstract: 为实现四轮独立驱动高地隙车辆在田间路况下正常工作,防止车轮过度滑转,设计一种滑转率控制器,该控制器通过反馈数据计算出各轮的实际滑转率,再结合滑模变结构算法对4个驱动轮力矩进行分配,从而控制滑转率到目标值。试验结果表明:1)该滑转率控制器能够有效的控制车轮的滑转;2)使用该控制器时,车辆在1 s内达到稳定状态;而未使用时,车辆需要3~4 s达到稳定状态;3)使用该控制器能够有效减小路面变化对车辆速度的影响;4)当车辆遇到障碍时,车轮的滑转率能在1~2 s内恢复至目标值,表明该控制器具有鲁棒和快速响应的特性。
In order to realize the operating regularly of four wheel independent drive vehicle and prevent excessive wheel slip under the field condition,a slip ratio controller,which can be used to calculate the real slip rate of each wheel through feedback data was constructed.The torque allocation value of each wheel can be gained by combing with sliding mode variable structure algorithm so that the slip ratio would be controlled to reach the target value.Experimental results indicate that:1) The wheel slip can be controlled effectively by the slip rate controller;2) The vehicle can reach to the steady state within 1 second by using the system,while it need 3-4 seconds to reach the steady state without using the controller;3) The controller can minimize the effects of road surface changes for the vehicle speed effectively;4) When the vehicle encounter obstacles,the wheel slip ratio can recover to the target value in 1-2 seconds which verifies the robustness and fast response of the controller.
Gear Ratios Strategy of PROTON Waja CNG-DI Vehicle for Improved Performance  [cached]
B. B. Sahari,Hamzah Adlan,S. V. Wong,A. M. Hamouda
Modern Applied Science , 2009, DOI: 10.5539/mas.v3n8p63
Abstract: A 1597cc gasoline CamPro engine was modified to adapt a Direct Injection (DI) technology that uses Compressed Natural Gas (CNG) as a fuel to form Compressed Natural Gas Direct Injection (CNGDI) engine. The modification includes increasing the compression ratio, redesigning the piston crown and cylinder head and a new engine control systems. These changes resulted in engine performance characteristics which is very different from its gasoline origin. This CNGDI engine is to be used with PROTON Waja vehicle body. Due to this change in the characteristics, the transmission systems utilizing an existing gear ratio combination, appears to be unsuitable, particularly for use in automatic transmission. Therefore, new gearbox with appropriate transmission matching needs to be developed. A computer based algorithm was developed for the purpose of predicting the PROTON Waja’s vehicle dynamic performance when CNGDI engine is used. The parameters being considered are maximum speed, acceleration, and elapsed time and these were optimized depending on the engine characteristics such as power, torque, gear ratios, and vehicle design parameters. The results recommended that the gear ratios of 3.58, 1.95, 1.34, 0.98, 0.8 and 4.33 for first, second, third, fourth, fifth and Final Drive (FD) respectively were the most suitable.
Investigation of the optimum differential gear ratio for real driving cycles by experiment design and genetic algorithm
Investigation of the optimum differential gear ratio for real driving cycles by experiment design and genetic algorithm
 [PDF]

AHMED Aboud,赵长禄,张付军
- , 2015, DOI: 10.15918/j.jbit1004-0579.201524.0110
Abstract: Experiment statistical method and genetic algorithms based optimization method are used to obtain the optimum differential gear ratio for heavy truck that provides best fuel consumption when changing the working condition that affects its torque and speed range. The aim of the study is to obtain the optimum differential gear ratio with fast and accurate optimization calculation without affecting drivability characteristics of the vehicle according to certain driving cycles that represent the new working conditions of the truck. The study is carried on a mining dump truck YT3621 with 9 forward shift manual transmission. Two loading conditions, no load and 40 t, and four on road real driving cycles have been discussed. The truck powertrain is modeled using GT-drive, and DOE -post processing tool of the GT-suite is used for DOE analysis and genetic algorithm optimization.
Experiment statistical method and genetic algorithms based optimization method are used to obtain the optimum differential gear ratio for heavy truck that provides best fuel consumption when changing the working condition that affects its torque and speed range. The aim of the study is to obtain the optimum differential gear ratio with fast and accurate optimization calculation without affecting drivability characteristics of the vehicle according to certain driving cycles that represent the new working conditions of the truck. The study is carried on a mining dump truck YT3621 with 9 forward shift manual transmission. Two loading conditions, no load and 40 t, and four on road real driving cycles have been discussed. The truck powertrain is modeled using GT-drive, and DOE -post processing tool of the GT-suite is used for DOE analysis and genetic algorithm optimization.
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