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2015-04-14
Technical Paper
2015-01-0657
Binglu Tu, Kai Shen
This innovation is a Developed Anti-Lock Brake System (DABS for short) to automatically and precisely identify, correct and verify the peak-value slip ratio S0'' (i.e. braking force = adhesion force) when ε (namely the utilization ratio of adhesion coefficient, which is defined as the quotient of maximum braking strength divided by adhesion coefficient when ABS works) =1, and control S0'' to output continuously. It is a revision on the theory, method and algorithm of current ABS control that intermittently produces S0''. The objects are to eliminate the hidden unsafety of sideslip or ε<1 due to excessive or insufficient braking force, have more simplified structure and reduced costs than ABS, and improve the eligibility from ε≥0.75 to ε≥0.95.
2015-04-14
Technical Paper
2015-01-0654
Bing Zhu, Jiapeng Gong, Jian Zhao, Jian Wu, Weiwen Deng
The permanent-magnet DC motor, which directly connected to the hydraulic pump, is a significant component of hydraulic control unit (HCU) in an anti-lock braking system (ABS). It drives the pump to dump the brake fluid from the low-pressure accumulator back to master cylinder and make sure the pressure decrease of wheel cylinder in ABS control. Obviously, the motor should run fast enough to provide sufficient power and prevent the low-pressure accumulator from fully charging. However, the pump don’t need always run at full speed for the consideration of energy conservation and noise reduction. Therefore, it is necessary to accurately regulate the speed of the DC motor in order to improve quality of ABS control. In this paper, a DC motor model was established using Matlab/Simulink software at first. Then the ABS hydraulic brake system model was present in AMESim.
2015-04-14
Technical Paper
2015-01-0658
Min Zhou, Lifu Wang, Jie Zhang, Nong Zhang
Hydraulic suspensions with different interconnecting configurations can decouple suspension mode and improve performance of a particular mode. In this paper, two types of interconnected suspensions are compared for off-road vehicle trafficability. Traditionally, anti-roll bar, a mechanically interconnected suspension system, connecting left and right suspension, decouples roll mode from the bounce mode and results in a stiff roll mode and a soft bounce mode, which is desired. However, anti-roll bars fail to connect the front wheel motions with the rear’s, thus the wheels’ motions in the warp mode are affected by anti-roll bars and it results an undesired stiffened warp mode. A stiffened warp mode limits the wheel-ground contact and may cause one wheel lift up especially during off-road drive. In contrast to anti-roll bars, two types of hydraulic suspensions which interconnect four wheels (for two-axis vehicles) can further decouple warp mode from other modes.
2015-04-14
Technical Paper
2015-01-1405
Guanjun Zhang, Feng Yu, Zhigao OuYang, Huiqin Chen, Zhonghao Bai, Libo Cao
Abstract: The combination of passive and active vehicle safety technology can effectively improve vehicle safety. Most of them predict vehicle crashes using radar or video, but it can’t be applied extensively currently due to high cost. Another collision forecasting method is more economic which base on driver behavior and vehicle status, such as acceleration, angular velocity of the brake pedal and so on. But acceleration and angular velocity of the brake pedal will change with drive and vehicle change. In order to study the effect of different drives and vehicle types on braking acceleration and angular velocity of the brake pedal, six volunteers were asked to drive five vehicles for simulating the working conditions of emergency braking, normal braking, inching braking and passing barricades under different velocities. All the tests were conducted on asphalt road, and comprehensive experimental design was used to arrange test content.
2015-04-14
Technical Paper
2015-01-1497
Hideaki Shibue, Devesh Srivastava
Torsion beam suspensions are lightweight and low-cost, and they are therefore frequently used for the rear of small front-wheel drive vehicles. The configuration of the suspension is simple and it comparatively consists of fewer components. However, it is difficult to predict their characteristics and satisfy the target of the performance in the early stages of development in particular, because it should realize the various performance elements demanded of a suspension in a single part. A great deal of research has been conducted on the cross-sectional shape of the beam section, but up to the present there has been almost no discussion of the effect of property of the trailing arms on suspension characteristics. This paper discusses tests conducted to study the effect of the rigidity of the trailing arms, and considers the mechanism of that effect.
2015-04-14
Technical Paper
2015-01-1499
Tadatsugu Takada, Kazuki Tomioka
Honda developed the right and left independent toe-angle control system (first-generation P-AWS) in the Acura RLX in 2013 and announced it as the first in the world. As indicated in a previous paper, “Independent Left and Right Rear Toe Control System,” with this system Honda has realized an excellent balance between the fun of handling that is at the driver’s will (INOMAMA) and driving performance with a sense of stability. This first-generation P-AWS is designed to be optimal to the vehicle specifications (suspension axial force, steering gear ratio, etc.) of the Acura RLX. Honda is due to widely adapt P-AWS to other models from now on. Following this, we developed the next-generation P-AWS system (second-generation P-AWS) in order to reconcile system performance and low cost wherever possible, in order to be adaptable for all ACURA models.
2015-04-14
Technical Paper
2015-01-1498
Yuyao Jiang, Weiwen Deng, Sumin Zhang, Shanshan Wang, Qingrong Zhao, Bakhtiar Litkouhi
Driver steering torque feedback is one of the critically important factors in the consideration and measurement both on vehicle design and performance, and on model accuracy of vehicle dynamics. On the one hand, driver steering torque feedback is one of the key measures on human-machine interface for drivers’ comfort and intuitive road feel, such as return-to-center capability, on-center feel and ease of steering effort, etc. This mainly involves the design of vehicle dynamics as a whole, but in particular, vehicle steering system. On the other hand, it is also the most determining factor to the quality of drivers’ interaction with or driver-in-loop simulation of vehicle dynamics models, such as driver simulator, etc.
2015-04-14
Technical Paper
2015-01-1501
Ryusuke Hirao, Kentaro Kasuya, Nobuyuki Ichimaru
Many electronic control components have been introduced into vehicles with the aims of improving their safety and comfort, and saving energy. Various suspension systems have been developed, to reconcile ride feeling with control stability at a high level. Development efforts have been particularly active in the field of semi-active suspension, prompted by its superior energy-saving and cost performance. Algorithm which is based on skyhook control has been applied mostly to the ride comfort control of semi-active suspension system of vehicle. Also, at the time of steering, control for enhancing damping force are commonly used as handling control to restrain transitional roll angle. Therefore, in this development we developed new ride comfort control and new handling control, and constructed a system which uses only vehicle height sensor as dedicated sensor and uses damping force variable damper of pressure control type.
2015-04-14
Technical Paper
2015-01-1504
WeiNing Bao
A ball screw regenerative shock absorber was designed for the relief of the vehicle vibration and the energy recovery of the vehicle vibration. The effect of its main parameters on the suspension system was numerically analyzed. According to the principle of the ball screw regenerative suspension system, a mathematical model of the ball screw regenerative shock absorber was established regarding the ball screw rotational inertia, the motor rotational inertia, the screw lead and the radius of the screw nut. A suspension dynamic model based on the ball screw regenerative shock absorber was developed combining the road model and the two-degrees-of-freedom suspension dynamic model.
2015-04-14
Technical Paper
2015-01-1502
Liangyao Yu, Wenwei Xuan, Liangxu Ma, Jian Song, Xianmin Zhu, Shuai Cheng
Energy saving is one of the most popular and significant motifs of contemporary and future vehicles. A relatively large amount of concern is concentrated on the power steering system as over 70% of the fuel consumed by conventional HPS system is unnecessary and avoidable, so the application of advance power steering systems like EPS and EHPS can help a lot on saving energy. Although the EHPS system has been widely used among passenger cars, SUV, Pickup trucks and Vans, it is now still infeasible on the conventional heavy duty vehicles because of the contradiction between the limitation of the 24V electric power system and the power demand of the electric motor of the general EHPS system. As a solution for this problem, a new type of EHPS system was investigated, which can decrease the demand of the motor power significantly, so that it can be applied to heavy duty vehicles.
2015-04-14
Technical Paper
2015-01-1410
Shotaro Odate, Kazuhiro Daido, Yosuke Mizutani
According to the National Automotive Sampling System (NASS) Crashworthiness Data System (CDS), which is a North American automobile accident database, collision events referred to as multiple-collision accidents, in which multiple collisions occur during travel, account for 55% of all accidents. In addition, multiple-collision accidents in which collision events following the first collision event are more severe than the first event account for 20% of all accidents. In a first collision, the system had simultaneously operated to restrain and protect the vehicle occupant. If the multiple-collision accidents occurs, because the system for restraining and protecting vehicle occupants will have already deployed, the performance of the system can be limited from subsequent collisions.
2015-04-14
Technical Paper
2015-01-1414
Jitendra Shah, Mohamed Benmimoun
In the framework of large scale project interactIVe co-funded by the European Commission Ford has developed an active safety system for the supported and autonomous avoidance of rear end collisions by intervention of braking and steering systems. This paper focuses on the assessment of threat perceived by drivers in collision avoidance situation. The decision making related to the initiation of the interventions by driver is crucial to understand how much threat is the driver can hold. The study has helped to understand how driver feels a threat arising from environment. It is a step towards autonomous driving where the system interventions have to be initiated as early as possible in order to avoid the collision and avoid unstable vehicle dynamics situations. In parallel the reaction has to be delayed long enough until it is likely that the driver will no longer intervene or respectively he is no longer able to intervene. For this reason an experiment is conducted with 26 subjects.
2015-04-14
Technical Paper
2015-01-1495
Qiushi Wang, Shenjin Zhu, Yuping He
Articulated heavy vehicles (AHVs) exhibit poor directional performance that is attributed to the high accident rate of these vehicles. Many control strategies have been proposed to increase the safety of AHVs. Optimal controllers based on the Linear Quadratic Regulator (LQR) technique have been explored to enhance the lateral stability of AHVs; these controllers are designed under the assumption that the vehicle model parameters and operating conditions are given and they remain as constants. However, in reality, the vehicle system parameters and operating conditions may vary. For example, the payload of trailer may vary within a huge range. To address the vehicle model parametric variation issue, this paper proposes a model reference adaptive controller for active trailer steering of AHVs. The adaptive controller is designed based on a tractor-semitrailer model with three degrees of freedom; to ensure the convergence of the controller, Lyapunov theory is applied.
2015-04-14
Technical Paper
2015-01-1494
Quan Zhou, Xuexun Guo, Lin Xu, Guoling Wang, Jibing Zhang
Nowadays, off-highway vehicles enjoyed a significant status in the national defense and civil construction. There is no doubt that the working condition of off-highways are quite different from the conventional passenger cars, hence, their suspensions are particularly designed. Since the hydro-pneumatic suspension technology was maturely applied in engineering machinery, this paper present a novel energy-harvesting device which was applied in off-highway vehicles based on hydro-pneumatic suspension, namely, electro-hydraulic energy-harvesting suspension (EHEHS). The EHEHS took the fundamental of mechanism-electronic-hydraulic system which consisted the following elements: a cylinder, 2 check valves, a hydro-pneumatic spring, a hydraulic motor, a DC motor, a processing circuit and a battery. In the EHEHS system, the cylinder is used to transmit the vibration energy into hydraulic energy, which is stored in hydro-pneumatic spring.
2015-04-14
Technical Paper
2015-01-1508
Lijiao Yu, Hongyu Zheng
As the electric technique develops fast, steering systems change from conventional mechanic steering systems to electrically controlled steering (ECS) systems, including electric power (EPS) system, active front steering (AFS) system and steer-by-wire (SBW) system. ECS could improve vehicles’ steering portability at a low speed and handing stability at a high speed. The study of ECS involves mechanic design, detection of electric components, software design and so on, which need a lot of trials and errors. By now, the development of ECS mostly depends on experiments on hard-ware-in-the-loop (HIL) and real vehicles. Because tests on real vehicles have many short cuts, such as a higher cost, a longer period, etc. HIL is gradually taking the place of real vehicles to carry out kinds of experiments in order to reduce test times, cycles and cost, which has been a main means to research and develop ECS.
2015-04-14
Technical Paper
2015-01-0613
Donghong Ning, James Coyte, Hai Huang, Haiping Du, Weihua Li
Heavy duty vehicles suffer from detrimental vibrations which have significant influence to the operator’s comfort, health and safety. Especially, long term exposures to vibration with a frequency range between 0.5 and 10Hz will severely damage the driver’s backbone. Tires, chassis suspension and seat suspension are three traditional methods to isolate vehicles vibration, but it is generally difficult to modify the parameters of tires and chassis suspension, even many approaches are proposed for the performance of chassis suspension. On the other hand, the seat suspension system is easy to modify and optimize. Therefore, seat suspension has been employed as a simple and effective method to isolate vehicle vibration transmitted to the driver’s body. Studying the vibration characteristics of seat suspension is one important step for seat suspension design.
2015-04-14
Technical Paper
2015-01-1096
Robert Lloyd
Abstract The frequent occurrence of stops and starts on the typical postal delivery route makes it an attractive application for regenerative braking. The transmission described in SAE paper 2014-01-1717 contains all the functions necessary to implement hydraulic regenerative braking including the accumulator and reservoir. This paper describes the substitution of the hydro-mechanical transmission for the present transmission and estimates the performance benefits. The result in a low impact path for the US Postal Service to conform to the congressional mandate to improve the mpg of the vehicles and extend their useful life.
2015-04-14
Technical Paper
2015-01-1203
Subhashree Rajagopal, Sebastien Desharnais, Balamurugan Rathinam, Upendra Naithani
Eddy-current brakes are contactless magnetic brakes that allow decelerating a vehicle without friction and wear. Electromagnetic brakes are found in variety of applications. However they suffer from a decreasing torque at low and high speed. In this study a novel concept of permanent magnet eddy-current brake is proposed that maintains a flat braking torque profile over a broad speed range. The principle is analytically investigated and numerically validated through finite element simulations using MAXWELL. It is demonstrated that a useably flat braking torque profile can be achieved by altering the path of eddy-currents by magnetic field orientation, thereby, affecting the apparent rotor resistance. Keywords: Eddy-currents, eddy-current brakes, electromagnetic brakes, permanent magnet brakes, MAXWELL
2015-04-14
Technical Paper
2015-01-1210
Bharat Singh, Naveen Kumar, Amaya Kak, Satya Kaul
In the present, vast numbers of problems are triggered due to growing global energy crisis and rising energy costs. Since, on-road vehicles constitute the majority share of transportation; any energy losses in them will have a direct effect on the overall global energy scenario. Most of the energy lost is dissipated from the exhaust, cooling, and lubrication systems, and, most importantly, in the braking system. About 6% of the total energy produced is lost with the airstream in form of heat energy when brakes are applied. Thus, various technological systems need to be developed to conserve energy by minimize energy losses while application of brakes. Regenerative Braking is one such system or an energy recovery mechanism causing the vehicle to decelerate by converting its kinetic energy into another form (usually electricity), which further can be used either immediately or stored until needed.
2015-04-14
Technical Paper
2015-01-1211
Zhuoping Yu, Caitao Jian, Songyun Xu, Lu Xiong
This paper is to research the dynamic response of active power source (APS) of electro hydraulic brake (EHB) system, which is a new design system. The dynamic response of APS could impact the effectiveness of brake system, the reason is that the slow-response of APS will cause the slow speed of building pressure and increasing the braking distance. So researching the dynamic response of active power source is very important for brake system. First of all, the part is about the components and working principle of EHB system and some parameters of active power source. EHB systemconsists of active power source (APS), pedal feel emulator (PFE), electro control unit (ECU) and hydraulic control unit (HCU). APS includes motor, master cylinder and retarding mechanism consisting of warm, gear and gear rack. Secondly, this paper proposes a restricted distribution control strategy——the control strategy of restricted distribution (CSRD).
2015-04-14
Technical Paper
2015-01-1516
Mohammed K Billal, Rizwan Basha, Anilkumar Nesarikar, Abdul Haiyum, Thomas Oery
Damages (fracture) in metals are caused by material degradation due to crack initiation and growth due to fatigue or dynamic loadings. The accurate and realistic modeling of an inelastic behavior of metals is essential for the solution of various problems occurring in engineering fields. Currently, various theories and failure models are available to predict the damage initiation and the growth in metals. In this paper, the failure of aluminum alloy is studied using progressive damage and failure material model using Abaqus explicit solver. This material model has the capability to predict the damage initiation due to the ductile and shear failure. After damage initiation, the material stiffness is degraded progressively according to the specified damage evolution response. The progressive damage models allow a smooth degradation of the material stiffness, in both quasi-static and dynamic situations.
2015-04-14
Technical Paper
2015-01-1515
Kwangwon Kim, Hyeonu Heo, Md Salah Uddin, Jaehyung Ju, Doo-Man Kim
Due to the relatively high freedom of selection of materials associated with a simple manufacturing method, a nonpneumatic tire (NPT) can be manufactured with a low viscoelastic energy loss material. A highly increasing demand to reduce greenhouse gases drives engineers to explore NPTs. NPTs consisting of flexible spokes and the shear band are still at an early stage of research and development. An optimization study of geometry of NPTs needs to be conducted, which is the objective of this paper. Parametric studies, design of experiments (DOE), and sensitivity analyses are conducted with a hyper-viscoelastic finite element (FE) model to determine the effects of three design variables on rolling resistance; the thickness of cellular spokes, the cell angle, and the shear band thickness.
2015-04-14
Technical Paper
2015-01-1513
Anudeep K. Bhoopalam, Kevin Kefauver
Indoor laboratory tire testing on flat belt machines and tire testing on the actual road yield different results. Testing on the machine offers the advantage of repeatability of test conditions, control of the environmental condition, and performance evaluation at extreme conditions. However, certain aspects of the road cannot be reproduced in the laboratory. It is thus essential to understand the connection between the machine and the road, as tires spend all their life on the road. This research, investigates the reasons for differences in tire performance on the test machine and the road. The first part of the paper presents a review on the differences between tire testing in the lab and on the road, and existing methods to account for differences in test surfaces.
2015-04-14
Technical Paper
2015-01-1514
Deepak Tiwari, Japveer Arora, Rakesh Khanger
A typical wheel development process involves designing a wheel based on a defined set of criteria and parameters followed by verification on CAE. The virtual testing is followed by bench level and vehicle level testing post which the design is finalized for the wheel. This paper aims to establish the learnings which were accomplished for one such development processes. The entire wheel development process had to be analyzed from scratch to arrive at a countermeasure for the problem. This paper will not only establish the detailed analysis employed to determine the countermeasure but also highlight its significance for the future development proposals. The paper first establishes the failure which is followed by the detailed analysis to determine the type of failure, impact levels and the basic underlying conditions. This leads to a systematic approach of verification which encompasses the manufacturing process as well as the test methodology.
2015-04-14
Technical Paper
2015-01-1512
Sairom Yoo, Md Salah Uddin, Hyeonu Heo, Jaehyung Ju, Doo Man Kim, Seok-Ju Choi
In an effort to develop tires with low rolling resistance, nonpneumatic tires (NPTs) with low viscoelastic energy loss materials are receiving more attention. For better design of NPTs for better fuel efficiency, one may need to analyze rolling energy loss of NPTs at a component level. The objective of this study is to develop a tool to quantify rolling energy loss and thermal dissipation of NPTs at a component level. For varying vehicle loads and rolling speeds, we suggest a thermo-mechanical model of an NPT with hexagonal cellular spokes to investigate temperature distribution of the NPT caused by hysteresis and convection loss into air. Using a hyper-viscoelastic model developed from a uniaxial (tensile and compression) testing and dynamic mechanical analysis (DMA), a thermo-mechanical model is developed by combining longitudinal shear deformation induced hysteresis and cooling to air.
2015-04-14
Technical Paper
2015-01-1510
Edoardo Sabbioni, Davide Ivone, Francesco Braghin, Federico Cheli
Estimation of friction coefficient and sideslip angle represents a key-point for improving control systems for vehicle safety, e.g. ESP (Electronic Stability Control), VDC (Vehicle Dynamics Control), etc. A model-based approach (state observer or Kalman filter) is generally used on purpose. Benefits induced by in-tyre sensors on sideslip angle and friction coefficient estimation are investigated in this paper. Thus tyre cornering force measurements are added to the ones usually present on-board vehicle (steer angle, lateral acceleration and yaw rate) and used to implement an Extended Kalman Filter (EKF) based on a single-track vehicle model. Tyre-road contact forces are assumed to be provided once per wheel turn by a smart tyre constituted of two tri-axial accelerometers glued on the tyre inner liner. Performance of the proposed observer is evaluated on a series of handling maneuvers and its robustness to road bank angle and tyre/vehicle parameters variation is discussed.
2015-04-14
Technical Paper
2015-01-1518
Emmanuel O. Bolarinwa, Oluremi Olatunbosun
Three-dimensional (3D) Finite element (FE) tyre models have been widely used for tyre design, vehicle design and dynamic investigations. Such tyre models have the inherent advantage of covering a wide range of tyre modelling issues such as the detailed tyre geometry and material composition, in addition to an extensive coverage of tyre operational conditions such as the static preload, inflation pressure and driving speed. Although tyre vibration behaviour, in different frequency ranges are of general interest, both for the vehicle interior and exterior noise, the present study is limited to a frequency of 100 Hz which is prevalent in most road induced NVH ride and handling problems. This study investigates tyre vibration behaviour using a propriety FE code. Such investigation plays an important role in the study of vehicle dynamics.
2015-04-14
Technical Paper
2015-01-1522
Takahiro Yokoyama, Koji Hiratsuka, Shinya Notomi
Users drive at relatively high speeds during the winter season, and maneuvering on snow-covered roads is a key performance for drivers. Demands are increasing for tires with lower rolling resistance. Tire patterns were developed similar to summer tires with reduced grooving and tire patterns with shallower grooves. This required techniques that predict maneuverability on snow-covered roads. This study treated maneuverability on snow-covered roads as maneuverability in the grip region, and verified the correlation between subjective evaluation using vehicles and tire stand-alone characteristics. Indexes were clarified for the tire contact patch and the physical properties of the tread rubber, which are prerequisites for securing grip in the normal-use. Typical index values for indexes were investigated using the surface pressure distribution obtained by a tire contact and surface pressure measuring system.
2015-04-14
Technical Paper
2015-01-1524
Ping Chen, Nan Xu, Konghui Guo, Rongsheng Liu
Tire lateral force is essential to vehicle handling and stability under cornering. However, it is difficult for engineers to get tire lateral force under high loading condition due to the loading ability limitation of most tire test machine in the world. Widely used semi-empirical tire lateral force models are obtained by curve-fitting experiments data and don’t possess load prediction ability. The objective of this paper is to predict the tire lateral force model under high-load condition based on low-load tire data. The nonlinear characteristic of tire cornering stiffness vary with load is greatly affected by tire carcass compliance. In this paper, a theoretical tire lateral model was built by considering carcass complex deformation. Combined with the relationship between half-length of tire contact patch and load, the non-linear characteristic of tire cornering stiffness vary with load was obtained.
2015-04-14
Technical Paper
2015-01-0614
Ye Zhao, Liangmo Wang, Xiangli Yang, Liukai Yuan, Zunzhi Zhang
Abstract: In most cases, researches on the ride performance of air suspension system are based on simplified mathematical models which could be too theoretical or not be able to consider the coupling relationship between the various components so that they behave far away from the actual vehicle system. This paper represents the study on the ride performance of an air suspension vehicle based on the complex whole vehicle model which was established though ADAMS and Matlab. The applying of flexible components helped to improve the model accuracy and the tensile and compression tests of the air spring were used to establish the interconnected four-gasbag air suspension system. The vehicle ride performance was studied through the co-simulation between ADAMS and Matlab. The accuracy of the results were verified by the vehicle test results, which demonstrated the reliability of the whole model.
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