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2017-03-28
Technical Paper
2017-01-0414
Bin Li, Xiaobo Yang, James Yang, Yunqing Zhang, Zeyu Ma
In this paper, a detailed 3D tire model is first proposed which includes a rigid rim with thickness, different layers of discretized belt points and a number of tread blocks attached on the area formatted by the neighboring belt points. The parameters of the proposed 3D tire model can be divided into two parts: the stiffness and damping values which only involve the in-plane motion and the stiffness and damping values which involve the out-of-plane motion, i.e. the lateral direction. In this paper, the relations between the in-plane parameters of the 3D tire model and the 2D tire model are given. Based on this relation, it is shown that the 3D tire model can generate exactly the same prediction results as the 2D tire model for tire straight line driving dynamics.
2017-03-28
Technical Paper
2017-01-1579
Liang-kuang Chen, Chien-An Chen
The electric buses have gained more popularity aiming to reduce pollutions due to transportation. Equipping the electric buses with four independent driving motors leads to the utilizations of smaller motors, which generally implies lower cost. Additionally, it also opens up the possibility of implementing direct yaw moment control (DYC) for the electric buses. While DYC has been widely used to improve yaw plane stability, its usage has to be limited since the differential torque inevitably increases the loadings on the lateral tire force which may increase the risk of instability. Four wheel steering (4WS), on the other hand, has the capability to mitigate the vehicle understeer or oversteer situations. However, since the yaw rate response is immediately affected by the additional rear wheel steering, it is usually used only in critical situations with limited amount of control so that the yaw rate will not quickly deviate from the desired value based on the roadway curvature.
2017-03-28
Technical Paper
2017-01-0402
Zhigang Zhang, Shi Xiaohui, Ye Bin
Based on the formation mechanism of engaging force of clutch, the engagement was divided into four stages: idle travel stage, cushion spring stage, diaphragm spring stage and locking stage, and mechanism of transmitted torque in each stage was analyzed and the transmitted torque model of clutch was deduced. Multi-load step analysis method based on finite element was used to analyze the coupling load-deformation characteristics of diaphragm spring and cushion spring in engagement, and the change laws of engaging force, diaphragm spring force and release bearing force were achieved and their coupling interaction were studied. And then change of friction coefficient of clutch with oscillating temperature was measured on friction test rig, and effect of temperature on transmitted torque was further discussed. Finally, simulation results of transmitted torque were validated by the experiment. Results indicate that the transmitted torque in clutch engagement has a nonlinear characteristic.
2017-03-28
Technical Paper
2017-01-1595
Mustafa Ali Arat, Hans-Martin Duringhof, Johan Hagnander, Eduardo L. Simoes
This paper presents a brake control strategy with a novel approach to the allocation of actuator effort in an electric vehicle. The proposed strategy relies on a combination of the conventional hydraulic braking system and the electric machine in order to improve braking performance. The higher response frequency of the electric machine is paired with the additional braking torque employed by the hydraulic brakes using an integrated control allocation strategy, which allows for a constant availability of a faster and more accurate modulation of both wheel torque and wheel speed. Therefore, the availability of an electric machine as a fast longitudinal actuator yields to an improved tracking of the desired wheel slip, especially when compared to the hydraulic actuators used in traditional braking applications.
2017-03-28
Technical Paper
2017-01-1111
Marcello Canova, Luca D'Avico, Cristian Rostiti, Stephanie Stockar, Gang Chen, Michael Prucka, Hussein Dourra
]To improve torque management algorithms for drivability, the powertrain controller must be able to compensate for the nonlinear dynamics of the driveline. In particular, the presence of backlash in the transmission and drive shafts excites sharp torque fluctuations during tip-in or tip-out transients, leading to a deterioration of the vehicle drivability and NVH. This paper proposes a model-based estimator that predicts the wheel torque in an automotive drivetrain, accounting for the effects of backlash and drive shaft flexibility. The starting point of this work is a control-oriented model of the transmission and vehicle drivetrain dynamics that predicts the wheel torque during tip-in and tip-out transients at fixed gear. The estimator is based upon a switching structure that combines a Kalman Filter and an open-loop prediction based on the developed model.
2017-03-28
Technical Paper
2017-01-0436
Tianjun Zhu, Bin Li
A new extending planar model for multi-axles articulated vehicle with nonlinear tire model is presented. This nonlinear multi-axles articulated vehicle model is specifically intended for improving the model performance in operating regimes where tire lateral force is near the point of saturation, and it has the potential to be applied to extend the specific axles model to any representative configuration of articulated vehicles model. At the same time, the extending nonlinear vehicle model can reduce the model's sensitivity to the tire cornering coefficients. Firstly A nonlinear tire model is used in conjunction with the 6-axle planar articulated vehicle model to extend the ranges of the original linear model into the nonlinear regimes of operation. Secondly the performance analysis of proposed nonlinear vehicle model is verified through the double lane change maneuver on different road adhesion coefficient using Trucksim software.
2017-03-28
Technical Paper
2017-01-1399
Bin Wu, Xichan Zhu, Lin li, xuejun cang, jianping shen
A driver steering model for emergency lane change based on the China naturalistic driving data is proposed in this paper. The steering characteristic of three phases is analyzed. Using the steering primitive fitting by Gaussian function, the steering behaviors in collision avoidance and lateral movement phases can be described, and the stabilization steering principle of yaw rate null is found. Based on the steering characteristic, the near and far aim point used in steering phases is analyzed. Using the near and far aim point correction model, a driver steering model for emergency lane change is established. The research results show that the driver emergency steering model proposed in this paper performs well when explaining realistic steering behavior, and this model can be used in developing the ADAS system.
2017-03-28
Technical Paper
2017-01-1408
Satoshi Kozai
The goal of both automakers and vehicle users is to minimize the negative impacts of vehicles on society, such as traffic accidents, not only on the road but parking area, optimizing the enjoyment of using a car, comfort, and usability. To realize this, we have already provided automatic brake system (ICS) for static obstacles in parking area. We have also developed the Rear Cross Traffic Auto Brake (RCTAB) system, which detects a vehicle approaching from the sides when backing out of a parking area. We decided RCTAB system specifications based on two information “Approaching vehicle speed in parking area” and “Maximum backing speed”. RCTAB system structure consists of Radar which shared with “Blind Spot Monitor” and ECU which shared with “ICS Computer”. The radar detects the approaching vehicle. The ICS Computer judge Collision prediction and request “Braking Force” and “Driving Force” to Brake and Engine Computer.
2017-03-28
Technical Paper
2017-01-1556
Jianbo Lu, Li Xu, Daniel Eisele, Stephen Samuel, Matthew Rupp, Levasseur Tellis
The paper presents an advanced yaw stability control (AYSC) system that uses a centralized inertial measurement unit (IMU) to measure the 6 DOF motions of a vehicle and uses the enhanced vehicle states to improve the effectiveness of the traditional electronic stability control (ESC) systems. The MEMS based IMU has nowadays been widely used in consumer electronics, such as smart phones, and its cost has been significantly reduced, which makes it feasible to roll out IMU for ESC type of systems. The additional info from an IMU helps improve the sensing capability of a vehicle, which in turn leads to refined stability control commands for AYSC such that the better control performance than the traditional ESC can be achieved (w.r.t. the real world driving scenarios). Vehicle tests will be used to show the improved control performance.
2017-03-28
Technical Paper
2017-01-1561
Anton A. Tkachev, Nong Zhang
Rollover prevention is one of the prominent priorities in vehicle safety and handling control. A promising alternative for roll angle cancellation is the active hydraulically interconnected suspension. This paper represents the analytical model of active hydraulically interconnected suspension system followed by the general simulation. Passive hydraulically interconnected suspension systems have been widely discussed and studied up to now. This work specifically focuses on the active hydraulically interconnected suspension system. Equations of motion of the system are formalised first. The entire system consists of two separate systems that can be modelled independently and further combined together for simulation. One of the two systems is 4 degrees of freedom half-car model which simulates vehicle lateral dynamics and vehicle roll angle response to lateral acceleration in particular.
2017-03-28
Technical Paper
2017-01-1571
Kevin McLaughlin, HyungJu Kwon, Jonah Shapiro
An approach to electric steering control is provided that uses vehicle dynamics and quantitative steering objectives to tune the steering system. The steering objective chosen is a torque vs. lateral acceleration target for the driver. The commanded torque vs. lateral acceleration gain is termed the “steering gain”. The steering gain is achieved independently of the ability of the controller to reject unwanted effects such as friction. Two parameters are computed using vehicle dynamics that substantially determine driver feel: the vehicle’s “manual gain” (total steering torque divided by lateral acceleration) and the vehicle’s lateral acceleration gain (lateral acceleration divided by steering angle). Lateral acceleration gain is a well known quantity in the literature but the concept of manual gain is new for steering control.
2017-03-28
Technical Paper
2017-01-0066
Shogo nakao, Akihiko Hyodo, Masaki ITABASHI, Tomio Sakashita, Shingo Obara, Mitsuo Sasaki, Tetsuya Uno, Yasuo Sugure, Yoshinobu Fukano, Yoshihiro Miyazaki
This paper presents a high-fidelity electrical-failure simulation environment of belt drive electric power steering (BEPS) system based on our proposed “Virtual Failure Mode and Effects Analysis (vFMEA)” method. The vFMEA system is able to dynamically inject an analog fault into a circuit model of electrical control unit (ECU) of BEPS system, and analyze system-level failure effects and verify software-implemented safety mechanisms, which consequently reduces both cost and time of development. It consists of a cycle-accurate microcontroller model with mass-production software components in binary format implemented, analog and digital circuit models, mechanical models, and a dynamic fault –injection mechanism. In this paper, the vFMEA method was applied to the verification of the safety mechanisms implemented on the ECU of BEPS system, and accuracy of the simulation was evaluated.
2017-03-28
Technical Paper
2017-01-0084
Jiantao Wang, Bo Yang, Jialiang Liu, Kangping Ji, Qilu Wang
Studies show that driving in foggy environment is a security risk, and when driving in foggy environment, the drivers are easy to accelerate unconsciously. The safety information prompted to the driver is mainly from fog lights, road warning signs and the traffic radio. In order to increase the quality of the safety tips to prevent drivers from unintended acceleration and ensure the security of driving in foggy environment, the study proposes a safety speed assessment method for driving in foggy environment, combining the information of driving environment, vehicle’s speed and the multimedia system.The method uses camera which is installed on the front windshield pillar to collect the image about the environment, and uses the dark channel prior theory to calculate the visibility. And by using the environment visibility, the safety speed can be calculated based on the kinematics theory. And it is appropriate for vehicles which have different braking performance.
2017-03-28
Technical Paper
2017-01-1563
Abhijeet Behera, Murugan Sivalingam
Two and three wheeler vehicles are largely used in many developing and under developing countries because of its lower cost, better fuel economy and easy to handle. Although, the construction of them is simpler than the four wheeler vehicle, they pose some problems related to instability. Wobble is the main cause of instabilities in two wheeler and three wheeler vehicles. In this study, a mathematical model was proposed and developed to determine wobble instability of a two wheeler. Nonlinear equations were formulated by using kinematics and d’Alembert’s principle with the help of multi body formalism. The non-linear equations found above were linearized with respect to rectilinear and upright motion, considering no rolling. It led to formation of matrix. The real part of Eigen value of the matrix was found to be negative, implication of whose was an asymptotic stable motion.
2017-03-28
Technical Paper
2017-01-1569
Amro Elhefnawy, Alhossein sharaf, Hossam Ragheb, Shawky Hegazy
This paper presents an advanced control system, which integrates three fuzzy logic controllers namely; Direct Yaw-moment Control (DYC), Active Roll-moment Control (ARC) and Active Front Steering (AFS) to enhance vehicle cornering and overturning stability. Based on a well-developed and validated fourteen degree of freedom (DOF) full vehicle model with non-linear tyre characteristics, a reference 3-DOF yaw-roll plane vehicle model is introduced to control yaw rate, sideslip angle, and roll angle of the vehicle body. The control actions of both direct yaw and active roll moments are performed by generating differential braking moments across the front wheels, while the control action of the active steering is performed by modifying the steering wheel angle. Different standard cornering tests are conducted in MATLAB / Simulink environment such as J-turn, fishhook and lane change manoeuvres.
2017-03-28
Technical Paper
2017-01-1567
Jaepoong Lee, Sehyun Chang, Kwangil Kim, Bongchoon Jang, Dongpil Lee, Byungrim Lee, Kyongsu Yi
This paper proposes a reference steering wheel torque map and a torque tracking algorithm via steer-by-wire to design the targeted steering feel. The reference steering wheel torque map is designed using the measurement data of rack force and steering characteristic of a target performance of the vehicle at sinusoidal and transition steering test. Since the target performance of the vehicle is only tested in nominal road condition, various road conditions such as disturbances and tire-road friction are not considered. Hence, the measurement data of the rack force of reflecting the road conditions in the reference steering wheel torque map have been used. The rack force is the net force which consists of tire aligning moment, road friction force and normal force on the tire kingpin axis. A motor and a magnetorheological damper are used as actuators to generate the desired steering feel using the torque tracking algorithm.
2017-03-28
Technical Paper
2017-01-1591
Haotian Cao, Xiaolin Song, Zhi Huang PhD
Generally, lateral steering control which ensures good performance of the tracking quality and handling quality simultaneously for autonomous vehicle in high speed is a changeling task. In order to keep the vehicle safe when faces a situation with an emergency lane change, a switched MPC lateral steering controller which is on the basis of the stability characteristic of the vehicle is presented in this paper. First, a MPC steering controller based on the 3DOF nonlinear vehicle model is derived, a comparative study of different vehicle models for MPC control are conducted to prove that the presented MPC steering controller with 3DOF nonlinear vehicle model possesses an advantage of balancing the conflicts between the tracking quality and handling quality. Further, a performance evaluation system which assesses the vehicle handling quality and tracking quality is established.
2017-03-28
Technical Paper
2017-01-1481
Kyung-bok Lee, Sanghyuk lee, Namyoung Kim, Tae soo Chi, Do young kim
Conventional EPS systems are operated by one type of steering tuning map set by steering test drivers before releasing to customers. That is, steering feeling can't change by other conditions such as road condions(low mu, high mu, unpaved roads) or some specific driving condtions(emergency braking/EPS fail modes/full gasing start). Those conditiions can't afford the drivers consistent steering feel and vehicle driving. This paper approached the techonology detecting those conditions by using vehicle sensors such as wheel speed/vehicle speed/steering angle/steering torque/steering speed and so on. After detecting those conditions and judging which one is the best steering feel and safe vehicle driving, EPS system automatically can be changed with the steering friction level and selection of steering opitmized mapping on several conditions. I believe that this technology can afford the customer "Joy of driving and fun to drive".
2017-03-28
Technical Paper
2017-01-1537
Ananya Bhardwaj
Improving brake cooling has commanded substantial research in the automotive sector, as safety remains paramount in vehicles of which brakes are a crucial component. To prevent problems like brake fade and brake judder, heat dissipation should be maximized from the brakes to limit increasing temperatures. This research is a CFD investigation into the impact of existing wheel center designs on brake cooling through increased cross flow through the wheel. The novel study brings together the complete wheel and disc geometries in a single CFD study and directly measures the effect on brake cooling, by implementing more accurately modelled boundary conditions like moving ground to exactly replicate true conditions. It also quantifies the improvement in cooling rate of the brake disc with change in wheel design unlike previous studies. The axial flow discharge was found to be increased to 0.47 m3/min for the suggested design in comparison to 0.04 m3/min for traditional design.
2017-03-28
Technical Paper
2017-01-1466
Claudia De La Torre, Ravi Tangirala, Michael Guerrero, Andreas Sprick
Studies in the EU and the USA found higher deformation and occupant injuries in frontal crashes when the vehicle was loaded outboard (frontal crashes with a small overlap). Due to that, in 2012 the IIHS began to evaluate the small overlap front crashworthiness In order to solve this problem. A set of small overlap tests were carried out at IDIADA’S passive safety laboratory and the importance of identifying the forces applied in each structural element involved in small overlap crash were determined. One of the most important structural elements in the small overlap test is the wheel. Its interaction in a small overlap crash can modify the vehicle interaction at the crash, which at the laboratory the interaction is with a barrier. That interaction has a big influence at the vehicle development and design strategy. In order to study and understand in a better way the wheel kinematics and separation strategy, IDIADA developed with HATCI a small overlap sled test.
CURRENT
2017-01-12
Standard
ARP5429A
This SAE Aerospace Recommended Practice (ARP) applies to fatigue testing of landing gear and landing gear components.
2017-01-10
Technical Paper
2017-26-0194
Ramkumar Rajamanickam, Shriniwas Chivate, Gaurav Shinde, Nagesh Voderahobli Karanth, Shalil Akre, Kishor Desale
Abstract Sound Quality (SQ) of brake and clutch pedal assembly plays an important role in contributing to vehicle interior noise and perception of sound. Quiet operation of brake and clutch units also reflects the vehicle built and material quality. Noise emitted from these sub-assemblies has to meet certain acceptance criteria as per different OEM requirements. Not much work has been carried on this over the years to characterize and quantify the same. An attempt has been made in this paper to study the sound quality of brake and clutch pedal assemblies at component level and validate the same by identifying the parameters affecting SQ. Effect on noise at different environmental conditions was studied with typical operating cycles in a hemi-anechoic chamber. The effect of sensor switches integrated within the clutch and brake pedal on sound quality is analyzed. It is found that the operating characteristics of switches drives the noise and SQ.
2017-01-10
Technical Paper
2017-26-0299
Mahesh Kishore Patekar, Jeevan Patil, Sivakumar Palanivelu, Bhupendra Bhat
Abstract Brake system is the most important system in the vehicle considering the overall vehicle safety and speed control. Brake applications are repetitive during a city traffic and hilly terrain on downhill gradient. Frequent braking gives rise to an overheating of the brake drum and its components. Braking operations at high temperature gives rise to problems like reduced deceleration due to loss of brake pad friction characteristics, pad softening and sticking to drum, pad distortion and wear etc. All these factors collectively result in deterioration of the braking performance and reduction of brake pad durability with time. Till date most of the thermal analysis performed for brake drum heating are through physical testing using brake system prototypes and by means of CFD tools. These methods are time consuming and expensive. There is a need for an alternative method to reduce physical trials and prototype building and reduce dependency on CFD analysis.
2017-01-10
Technical Paper
2017-26-0310
Vyankatesh Madane, Sameer Shivalkar, Chandrakant Patil, Sanjeev Annigeri
Abstract In rubber industry, different techniques are used to enhance durability. This paper gives complete design, development and testing methodology of rubber bush in which pre-compression of rubber is used to enhance rubber bush life. In bogie suspension, axle to torque rod join is critical as it has to transfer lateral and longitudinal load with flexibility. This makes challenging to design joint which need to carry more than 6 ton load and having flexibility of more than 10 degree articulation. In this torque rod to axle joint called as End bush, compressed rubber is used to carry high load with flexibility. Other possible material for bush can be brass bush which able to carry high load however not able to give high flexibility Design and finite element calculations are done to design pre-compression and rubber volume to get desired strength and stiffness to carry required load with flexibility.
2017-01-10
Technical Paper
2017-26-0312
Sagar Polisetti, Ganeshan Reddy
Abstract Twist beam is a type of suspension system that is based on an H or C shaped member typically used as a rear suspension system in small and medium sized cars. The front of the H member is connected to the body through rubber bushings and the rear portion carries the stub axle assembly. Suspension systems are usually subjected to multi-axial loads in service viz. vertical, longitudinal and lateral in the descending order of magnitude. Lab tests primarily include the roll durability of the twist beam wherein both the trailing arms are in out of phase and a lateral load test. Other tests involve testing the twist beam at the vehicle level either in multi-channel road simulators or driving the vehicle on the test tracks. This is highly time consuming and requires a full vehicle and longer product development time. Limited information is available in the fatigue life comparison of multi-axial loading vs pure roll or lateral load tests.
2017-01-10
Technical Paper
2017-26-0313
Manoj Kumar Rajendran, Srinivasa Chandra V, Manikandan Rajaraman, Dinesh Kumar Rajappan, Agathaman Selvaraj
Abstract In today competitive world, gaining customer delight is the most vital part of an automotive business. Customers’ expectations are high which need to be satisfied limitless, to stay in the business. The major expectation of a commercial vehicle customer is a vehicle without failures which involves lower spares cost and downtime. The significance of a suspension system in the new age automobiles is getting advanced. There have been many improvements in the suspension system especially in leaf springs to provide a better ride comfort, and one such modern era implementation is the Parabolic Spring which comprises of fewer leaves with varying thickness from the center to the ends without inter-leaf friction. Study reveals that parabolic spring exhibits better ride comfort, but less life compared to a conventional leaf spring which leads to the increase in downtime of the vehicle.
2017-01-10
Technical Paper
2017-26-0315
Jyoti Kale, Satish Kumar, Pravin Lavangare, Anand Subramaniam
Abstract The Steering system is one of the most safety critical systems in an automobile. With time the durability, reliability and the fine-tuning of the parameters involved in this subsystem have increased along with the competitiveness of the market. In a competitive market, accelerated testing is the key to shorter development cycles. It is observed that the majority of component manufacturers have a preference on vehicle level testing to achieve their development goals. The vehicle level trials are time consuming and lack the control and repeat-ability of a laboratory environment. This paper describes the development of a steering test rig designed to simulate the disturbances experienced on road within a controlled laboratory environment. The five axis steering rig would allow simulation of individual road wheel displacement along with steering wheel angle input and lateral steering rack displacements. The rig also is designed to be adaptable to a range of vehicle categories.
2017-01-10
Technical Paper
2017-26-0339
Jagankumar Mari, Egalaivan Srinivasan
Abstract In heavy commercial vehicle segment in India, driver comfort and feel was largely ignored. Fierce competition in the recent years and buyer’s market trend is compelling the designers of heavy truck to focus more on the finer aspects of attribute refinements. Steering is one driver-Vehicle interface which the driver is engaged throughout. Comfort and feel in steering wheel is defined by parameters like steering effort, manoeuvrability, on-center feel & response, cornering feel & response, Torque dead band, return-ability etc. and is influenced by a long list of components and systems in the truck. This study focuses on the influences of jacking torque and steering system friction on the on-center driving performance. Experiments to measure the Jacking torque and steering system friction were conducted in the lab and subjective and objective assessments of on-center driving performance were later conducted at test track in two similar 12 Ton truck to correlate their effects.
2017-01-10
Technical Paper
2017-26-0341
Chaitanya Ashok Vichare, Sivakumar Palanivelu
Abstract The fuel economy of heavy commercial vehicles can be significantly improved by reducing the rolling resistance of tires. To reduce the rolling resistance of 6×4 tractor, the super single tires instead of rear dual wheel tires are tried. Though the field trials showed a significant increase in fuel economy by using super single tires, it posed a concern of road safety when these tires blowout during operation. Physical testing of tire blowout on vehicle is very unsafe, time consuming and expensive. Hence, a full vehicle simulation of super single tire blowout is carried out. The mechanical properties of tires such as cornering stiffness, radial stiffness and rolling resistance changes during the tire blowout; this change is incorporated in simulation using series of events that apply different gains to these mechanical properties.
2017-01-10
Technical Paper
2017-26-0340
Sarang Bire, Prashant R Pawar, M Saraf
Abstract Air suspension systems had been introduced in automobiles since 1950s. These systems are being explored to improve the ride comfort, handling stability and also serve as a medium for better cargo protection. These system are well developed for buses and high end passenger sedans, also have feasibility for adapting for wide range of configurations of suspension system and axle. Passenger cars and Sports Utility Vehicle (SUV) pickup category of vehicle offers different challenges such as space availability, spring selection and characterization that need to be addressed for successful implementation of air suspension in these category vehicles. This work defines methodology to implement air suspension system in SUV Pickup category vehicle. Paper work includes concept study, mathematical co-relation, and prediction of air spring characteristics and integration of experimental and analytical tool for development of air suspension system.
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