A Novel Integrated Stability Control Based on Differential Braking and Active Steering for Four-axle Trucks

Di erential braking and active steering have already been integrated to overcome their shortcomings. However, existing research mainly focuses on two-axle vehicles and controllers are mostly designed to use one control method to improve the other. Moreover, many experiments are needed to improve the robustness; therefore, these control methods are underutilized. This paper proposes an integrated control system specially designed for multi-axle vehicles, in which the desired lateral force and yaw moment of vehicles are determined by the sliding mode control algorithm. The output of the sliding mode control is distributed to the suitable wheels based on the abilities and potentials of the two control methods. Moreover, in this method, fewer experiments are needed, and the robustness and simultaneity are both guaranteed. To simplify the optimization system and to improve the computation speed, seven simple optimization subsystems are designed for the determination of control outputs on each wheel. The simulation results show that the proposed controller obviously enhances the stability of multi-axle trucks. The system improves 68% of the safe velocity, and its performance is much better than both di erential braking and active steering. This research proposes an integrated control system that can simultaneously invoke di erential braking and active steering of multi-axle vehicles to fully utilize the abilities and potentials of the two control methods.

An Adaptive Nonsingular Fast Terminal Sliding Mode Control for Yaw Stability Control of Bus Based on STI Tire Model

Due to the bus characteristics of large quality,high center of gravity and narrow wheelbase,the research of its yaw stability control(YSC)system has become the focus in the field of vehicle system dynamics.However,the tire nonlinear mechanical properties and the effectiveness of the YSC control system are not considered carefully in the current research.In this paper,a novel adaptive nonsingular fast terminal sliding mode(ANFTSM)control scheme for YSC is proposed to improve the bus curve driving stability and safety on slippery roads.Firstly,the STI(Systems Technologies Inc.)tire model,which can effectively reflect the nonlinear coupling relationship between the tire longitudinal force and lateral force,is established based on experimental data and firstly adopted in the bus YSC system design.On this basis,a more accurate bus lateral dynamics model is built and a novel YSC strategy based on ANFTSM,which has the merits of fast transient response,finite time convergence and high robustness against uncertainties and external disturbances,is designed.Thirdly,to solve the optimal allocation problem of the tire forces,whose objective is to achieve the desired direct yaw moment through the effective distribution of the brake force of each tire,the robust least-squares allocation method is adopted.To verify the feasibility,effectiveness and practicality of the proposed bus YSC approach,the TruckSim-Simulink co-simulation results are finally provided.The co-simulation results show that the lateral stability of bus under special driving conditions has been significantly improved.This research proposes a more effective design method for bus YSC system based on a more accurate tire model.

Vertical Tire Forces Estimation of Multi-Axle Trucks Based on an Adaptive Treble Extend Kalman Filter

Vertical tire forces are essential for vehicle modelling and dynamic control.However,an evaluation of the vertical tire forces on a multi-axle truck is difficult to accomplish.The current methods require a large amount of experimental data and many sensors owing to the wide variation of the parameters and the over-constraint.To simplify the design process and reduce the demand of the sensors,this paper presents a practical approach to estimating the vertical tire forces of a multi-axle truck for dynamic control.The estimation system is based on a novel vertical force model and a proposed adaptive treble extend Kalman filter(ATEKF).To adapt to the widely varying parameters,a sliding mode update is designed to make the ATEKF adaptive,and together with the use of an initial setting update and a vertical tire force adjustment,the overall system becomes more robust.In particular,the model aims to eliminate the effects of the over-constraint and the uneven weight distribution.The results show that the ATEKF method achieves an excellent performance in a vertical force evaluation,and its performance is better than that of the treble extend Kalman filter.

Global-Local Finite Element Analysis for Predicting Separation in Cord-Rubber Composites of Radial Truck Tires

A global-local finite element modeling technique is employed in this paper to predict the separation in steel cord-rubber composite materials of radial truck tires. The local model uses a finite element analysis in conjunction with a glob-al-local technique in ABAQUS. A 3-dimensional finite element local model calculates the maximum cyclic shear strain of an interface between steel cord and rubber materials at the carcass ply shoulder region. It is found that the maximum cyclic shear strain is reliable as a result of the analysis of carcass ply separation in radial truck tires. Using the analysis of the local model, a study of the cyclic shear strain is performed in the shoulder region and used to deter-mine the carcass ply separation. The effect of the change of carcass ply design on the separation in steel cord-rubber composite materials of radial truck tires is discussed.

Prediction of Burst Pressure of a Radial Truck Tire Using Finite Element Analysis

This paper is concerned with the numerical prediction of the burst pressure of a radial truck tire. Even though relatively rare, the tire fracture or failure brings up a big accident. Especially, the tire burst or rupture is a rapid loss of inflation pressure of a truck and bus tire leading to an explosion. The tire burst pressure, under this extreme loading condition, can be predicted by identifying the pressure at which the cord breaking force of the composite materials is attained. Recently, the use of finite element analysis in tire optimal design has become widely popular. In order to determine the burst pressure of a radial truck tire, an axisymmetric finite element model has been developed using a commercial finite element code with rebar element. The numerical result shows that the bead wire among the various layers modeled the rebar element breaks off first in the radial truck tire. The finite element modeling with the rebar element on the bead wire of a radial truck tire is able to well predict the tire burst pressure identifying the pressure at which the breaking force of steel bead wires is reached. The model predictions of tire burst pressure should be correlated with test data, in which case the tire is hydro-tested to destruction. The effect of the design change with the different bead structure on the tire burst pressure is discussed.

Computation of rolling resistance caused by rubber hysteresis of truck radial tire

Applying the results of stress and strain calculated by 3D finite element model of truck radial tire 11.00R20, a MATLAB program used to compute rolling resistance of the tire caused by hysteresis rolling resistance (HRR) is worked out. The HRR distribution on different part of tire section, and the effects of speed, load, internal pressure and the width of the rim on HRR are analyzed. The analysis results showed that energy loss produced by tread rubber contributes the most part to HRR of the whole tire, and that to decrease the HRR, the hysteresis factor of the tread rubber should be reduced, and the distribution of the stress and strain on the section be optimized.

Basic Properties of Pyrolysis Carbon Black of Waste Tyres and Application of Pyrolysis Carbon Black in Transition Layer Rubber of All Steel Radial Tire

The main chemical composition of pyrolysis carbon black of waste tires is C,O,Cu,Zn and so on.The content of ash and fine powder in pyrolysis carbon black is high,and the 300%elongation stress is high.The difference between pyrolysis carbon black and furnace black N326,which is commonly used in rubber,is obvious compared with chemical property.The pyrolysis carbon black was used to replace furnace black N326 in the transition layer of all steel load Radial tire rubber through experimental study.It was found that the compression heat generation and dynamic loss(Tanδ)of the blend rubber before and after aging were obviously reduced,the elongation at break and resilience increased,while the tensile stress and tear strength decreased by 100%and 300%,but the hardness and tensile strength changed little before and after aging.According to the latest raw material price calculation,15 used tire pyrolysis carbon black instead of furnace carbon black N326 used in all steel Radial tire transition layer rubber application,excluding labor costs,electricity and equipment depreciation,a ton of blended rubber saves about$22.86 in production costs.

生物基白炭黑和生物基油在全钢载重子午线轮胎胎面胶中的应用

研究生物基白炭黑和生物基油在全钢载重子午线轮胎胎面胶中的应用。结果表明:使用生物基油等量代替环烷油,胶料的硫化速度略加快,300%定伸应力降低,耐切割、耐低温和耐迁移性能提高,生热略增大,耐磨性能基本相当;在同样采用生物基油的情况下,使用生物基白炭黑等量代替沉淀法白炭黑,胶料的硫化特性、生热、耐磨和耐切割性能相当,但耐疲劳性能明显降低。

全钢载重子午线轮胎胎圈露线的原因分析及解决措施

从产品设计和工艺控制方面分析全钢载重子午线轮胎胎圈露线的原因,并提出相应的解决措施。通过适当增大成型平面宽和鼓肩宽,适当减小钢丝圈内侧胎侧厚度和胎趾角度,严格控制胎侧成型定位、胎坯存放、硫化机机械手精度、钢丝圈缠绕工艺及存放等措施,有效地解决了全钢载重子午线轮胎胎圈露线问题,提高了轮胎的安全性能,降低了生产成本。

矿用重载轮胎接地印痕的研究

以14.00R25宽体自卸车轮胎为例,通过轮胎使用情况调研,结合实验室测试和轮胎有限元仿真,研究矿用重载轮胎接地印痕及接地压力分布。结果表明:宽体自卸车轮胎接地印痕形状应接近矩形且接地压力分布均匀;影响轮胎接地印痕及接地压力分布的主要因素为断面高宽比、胎冠弧半径和弧度高、带束层角度和宽度、花纹沟壁角度和花纹沟宽度等。通过有限元仿真优化设计可避免轮胎出现花纹掉块和非均匀磨损等问题,提高设计效率。

双酰肼类材料CSC920在全钢载重子午线轮胎基部胶中的应用

研究双酰肼类材料CSC920(简称CSC920)对全钢载重子午线轮胎基部胶性能的影响。结果表明:CSC920对天然橡胶有较好的改性效果,能显著加快胶料的硫化反应速度,增大胶料的门尼粘度;加入CSC920后,基部胶的定伸应力、拉伸强度和弹性均有所提升,滚动阻力和生热明显降低;混炼过程中,CSC920在氧化锌之前加入,基部胶的物理性能较好,压缩生热明显降低,CSC920在氧化锌之后加入,可以起到抗硫化返原作用,基部胶的物理性能有所改善,但降低生热效果不明显。

高驱动性能315/80R22.5无内胎全钢载重子午线轮胎的设计

介绍高驱动性能315/80R22.5无内胎全钢载重子午线轮胎的设计。结构设计:外直径1093 mm,断面宽314 mm,行驶面宽度275 mm,行驶面弧度高7.5857 mm,胎圈着合直径570.5 mm,胎圈着合宽度240.8 mm,断面水平轴位置(H_(1)/H_(2))0.91,胎面采用泥地+雪地花纹,花纹深度24 mm,花纹饱和度66.41%,花纹周节数54。施工设计:采用双复合胎面,1^(#)和2^(#)带束层采用0.37+6×0.32ST钢丝帘线,0°带束层由3根3×0.7×0.20HE钢丝帘线压延成的冠带条围绕2#带束层缠绕而成,3#带束层采用5×5.30HI钢丝帘线,胎体采用0.22+6+11×0.205ST钢丝帘线,采用一次法成型机成型、双模蒸锅式硫化机硫化。成品轮胎性能试验结果表明,轮胎的充气外缘尺寸、强度性能、耐久性能和胎圈耐久性能均满足相应设计和标准要求。

全钢载重子午线轮胎氮气硫化工艺的有限元仿真优化

对全钢载重子午线轮胎氮气硫化工艺进行有限元仿真优化。结果表明:通高温蒸汽时间对轮胎整体硫化程度变化影响力不足,保证高温蒸汽足够支撑后期硫化后,不需要再延长通高温蒸汽时间;可以加强硫化设备的保温效果,减小氮气保压阶段温度降幅以降低能源耗散,增大氮气硫化工艺优化的空间,更有利于实现节能降耗和提质增效。

裂解炭黑G685在全钢载重子午线轮胎过渡层胶中的应用研究

研究裂解炭黑G685在全钢载重子午线轮胎过渡层胶中的应用。结果表明:与炭黑N660相比,裂解炭黑G685粒径小,结构度高,硫含量高,但其所含硫主要为结合硫;将裂解炭黑G685替代炭黑N660用于轮胎过渡层胶,胶料的t90延长,交联密度、定伸应力、拉伸强度和生热降低,拉断伸长率增大;在过渡层胶中用裂解炭黑G685替代50%的炭黑N660,成品轮胎的耐久性能和高速性能提高。

2+7×0.30ST钢丝帘线在轻型载重子午线轮胎带束层中的应用

研究以2+7×0.30ST钢丝帘线替代3×0.20+6×0.35HT钢丝帘线在7.50R16 14PR轻型载重子午线轮胎带束层中的应用。结果表明:与3×0.20+6×0.35HT钢丝帘线相比,2+7×0.30ST钢丝帘线整体呈椭圆形排布,帘线直径相同,强度更高;将2+7×0.30ST钢丝帘线应用于带束层中,成品轮胎的充气外缘尺寸符合国家标准要求,耐久性能相当,强度性能和高速性能略有提升,滚动阻力降低,单胎质量减小。

宽体自卸车轮胎失效原因分析及其正确选型

介绍宽体自卸车轮胎失效类型,分析轮胎的失效原因,并提出相应建议和轮胎正确选型方法。宽体自卸车轮胎因高负荷、高强度、使用环境复杂等特点导致胎面花纹利用率低,易早期失效,理赔率高。宽体车自卸车轮胎使用主要受到矿山开采类型、车型、载荷、运距、坡度、速度和气候等因素影响,结合使用场景合理选型是延长轮胎使用寿命、降低轮胎理赔率、提升矿山经济效益的重要途径。

60及以下系列超低断面宽基轮胎的结构设计方法

介绍60及以下系列超低断面宽基轮胎的结构设计方法。从宽基载重子午线轮胎半成品的结构、材料、宽度及各定位点等方面进行整体设计,重点介绍带束层、胎体、胎圈包布等钢丝帘布部件及胎面、胎侧、三角胶、垫胶等胶部件在材料分布图中的厚度及其端点在材料分布图中合理的分布位置。成品轮胎性能试验结果表明,该设计方法可降低轮胎关键部位的生热,有效提高轮胎的耐久性能,减少胎体帘布弯曲、胎圈漏钢丝等问题的发生,明显提升生产一次合格率。

12R22.5轻量化全钢载重子午线轮胎的设计

介绍12R22.5轻量化全钢载重子午线轮胎的设计。结构设计:外直径1074 mm,断面宽295 mm,行驶面宽度218 mm,行驶面弧度高7 mm,胎圈着合直径570.5 mm,胎圈着合宽度240 mm,断面水平轴位置(H_(1)/H_(1))0.919,胎面采用4条曲折主花纹沟,花纹沟底采用V形开放结构,花纹深度13 mm,花纹饱和度79.87%,花纹周节数67。施工设计:胎面采用两方三块结构,1^(#)和2^(#)带束层采用2+7×0.30ST钢丝帘线,3^(#)带束层采用5×0.35HI钢丝帘线,0°带束层采用3×7×0.20HE钢丝帘线,胎体采用3×0.24/9×0.225CCHT钢丝帘线,采用一次法成型机成型、硫化机硫化。成品轮胎性能试验结果表明,轮胎的充气外缘尺寸、强度性能和耐久性能符合国家标准要求,高速性能和轮胎接地印痕分布符合企业标准要求,且质量小于同规格产品。

18.00R25矿用宽体自卸车专用工程机械轮胎的设计

介绍18.00R25矿用宽体自卸车专用工程机械轮胎的设计。结构设计:外直径1644 mm,断面宽499 mm,行驶面宽度424 mm,行驶面弧度高26 mm,胎圈着合直径630 mm,胎圈着合宽度343 mm,断面水平轴位置(H_(1)/H_(2))1.05,胎面花纹采用横向花纹沟拉通设计,花纹深度47 mm,花纹饱和度65%,花纹周节数34。施工设计:胎面采用缠绕方式成型,采用4层带束层结构,1^(#)—3^(#)带束层采用7×7×0.22+0.15HT钢丝帘线,4^(#)带束层采用4×6×0.25NT钢丝帘线,胎体采用7×7×0.25+0.15HT钢丝帘线,采用四鼓一次法成型机成型、蒸锅硫化机硫化。成品性能试验结果表明,轮胎的外缘尺寸和耐久性能符合相应国家标准和设计要求,接地印痕合理,TKPH额定值满足实际工况作业需要。

硫化外温对全钢轻型载重轮胎性能的影响

研究硫化外温对全钢轻型载重轮胎性能的影响。结果表明,随着硫化外温的升高,轮胎的耐久性能和高速性能呈缓慢下降的趋势,虽然在一定温度范围内,提高硫化外温对轮胎性能的影响不明显,但可以缩短硫化时间,提高轮胎生产效率,进而提升产品的竞争力。