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2017-03-28
Technical Paper
2017-01-0112
Mingming Zhao, Hongyan Wang, Xiao Xu, Yutong He
Rear-end accident is one of the most important collision modes in China, which often leads to severe accident consequences due to the high collision velocity. Autonomous Emergency Braking (AEB) System could perform emergency brake automatically in dangerous situation and mitigate the consequence. This study focused on the analysis of the rear-end accidents in China in order to discuss about the parameters of Time-to-Collision (TTC) of AEB and the potential effectiveness. A sample of 84 accidents was in-depth investigated and reconstructed, providing a comprehensive set of data describing the pre-crash matrix. Each accident in this sample is reconstructed and modeled numerically by the simulation tool PC-Crash. In parallel, a model representing the function of an AEB system has been established. This AEB system applies partial braking when the TTC ≤ TTC1 and full braking when the TTC ≤ TTC2.
2017-03-28
Technical Paper
2017-01-1575
Andrei Keller, Sergei Aliukov, Vladislav Anchukov
Trucks are one of the most common modes of transport and they are operated in various road conditions. As a rule, all-wheel drive trucks are equipped with special systems and mechanisms to improve their cross-country capability and overall efficiency. The usage of blocked mechanisms for power distribution is one of the most popular and effective ways to improve the off-road vehicle performance. However, the lock of differential may adversely affect the stability and control of vehicle because of the unobvious redistribution of reactions acting on wheels, which consequently leads to poor performance and safety properties. Problems of rational distribution of power in transmissions of all-wheel drive vehicles, as well as research in the field of improving directional stability and active safety systems are among the priorities in modern automotive industry.
2017-03-28
Technical Paper
2017-01-0408
Sergei Viktorovich Aliukov
Currently, a group of scientists consisting of six doctors of technical sciences, professors of South Ural State University (Chelyabinsk, Russia) has completed a cycle of scientific research for creation of adaptive suspensions of vehicles. We have developed design solutions of the suspensions. These solutions allow us to adjust the performance of the suspensions directly during movement of a vehicle, depending on road conditions - either in automatic mode or in manual mode. We have developed, researched, designed, manufactured, and tested experimentally the following main components of the adaptive suspensions of vehicles: 1) blocked adaptive dampers and 2) elastic elements with nonlinear characteristic and with improved performance.
2017-03-28
Technical Paper
2017-01-1504
Zachary Carpenter, Aaron Gholston, Benjamin James Cobb, Sam Kennedy, Ethan Blankenship, Peter Tkacik, Mesbah Uddin, Jerry Dahlberg
Wind tunnel aerodynamic testing involving rolling road tire conditions can be expensive and complex to set up. Low cost rolling road testing can be implemented in a 0.3m2 Eiffel wind tunnel by modifying a horizontal belt sander to function as a moving road. This sander is equipped with steel supports to hold a steel plate against the bottom of the wind tunnel to stabilize the entire test section. These supports are bolted directly into the cast iron sander frame to ensure minimal vibrational losses or errors during testing. The wind tunnel design at the beginning of the project was encased in a wooden box which was removed to allow easier access to the test section for installation of the rolling road assembly. The tunnel was also modified to allow observers to view the testing process from various angles.
2017-03-28
Technical Paper
2017-01-1503
Jared Johan Engelbrecht, Peter Thomas Tkacik
Most commercial heavy-duty truck trailers are equipped with either a two sensor, one modulator (2S1M) or four sensor, two modulator (4S2M) anti-lock braking system (ABS). Previous research has been performed comparing the performance of different ABS modules, in areas such as longitudinal and lateral stability, and stopping distance. This study focuses on relating ABS module type, and wheel speed sensor placement to trailer wheel lock-up and subsequent impact to tire wear for tandem axle trailers with the nationally common Hendrickson air-ride suspension. Prior to tire wear inspection, functionality of the ABS system was tested electronically using a scan tool communicating with the SAE J560 plug access port on the trailer. Observations were documented on trailers using the 2S1M system with the wheel speed sensor placed on either the front or rear axle of a tandem pair.
2017-03-28
Technical Paper
2017-01-1479
Wei Wang, Xinbo Chen
Electrified chassis system featuring distributed wheel drive and independent steering has become a research focus of EVs considering the increasing demand of maneuverability for intelligent driving. The concept of multi-function chassis corner presents new challenges also revolution opportunity of traditional suspension mechanism. The question is how to increase the system compactness with different actuators in limited wheel side space as well as keeping dynamic performance of chassis. Rather than providing isolated structures, the primary focus of the research is to present a general design method of independent suspension topological structures suitable for function integration. This paper suggested that the distributed drive-line can be part of suspension and constrain the knuckle motion together with other suspension links, thus the system could be synthesized integrally in terms of mechanisms in order to obtain more compact solutions.
2017-03-28
Technical Paper
2017-01-1480
Zhenfeng Wang, Mingming Dong, Yechen Qin, Feng Zhao, Liang Gu
Abstract: The study of controllable suspension properties special in the characteristics of improving ride comfort and road handling is a challenging task for vehicle industry. Currently, since most suspension control requires the observation of unmeasurable states, how to accurately acquire the states of a suspension system attracts more attention. To solve this problem, a novel approach interacting multiple mode Kalman Filter (IMMKF) is proposed in this paper. Suspension system parameters are crucial for the performance of state observers. Uncertain suspension system parameters in various conditions, e.g. due to additional load, have significant effect on state estimation. Simultaneously, state transition among different models may be happened on the condition of varying system parameters.
2017-03-28
Technical Paper
2017-01-1486
Shashikant Sharma, Thomas Mathai, Megan Wooley, Daniel Moore
Decoupler in a hydraulic engine mount (HEM) acts as a binary gate, an ON/OFF switch. Depending on operating condition it either floats or sinks. This study was focused on studying decoupler as a gradual gate rather than binary sub-system. Major objectives of this study involved designing decoupler for a tunable and optimum stiffness response that could deliver desired low and high frequency dynamic response for HEM as a system. A simplified lumped parameter dynamic model was developed for HEM, capable of predicting low and high frequency resonance. Measured characteristics of decoupler and physical linear/non-linear parameters of rubber element along with fluid column were utilized to provide quantitative validation of experimental dynamic response of HEM as a system. Preliminary work shows highly encouraging correlation between analytical model and experimental data.
2017-03-28
Technical Paper
2017-01-1487
Russ Norton, Ben Bulat, Ahmed Mohamed
The RLM algorithm seeks to resolve the tradeoff of high damping rates required to control the loads and the need for lower damping forces to improve secondary ride. As the base active damping forces are increased to control the loads, ride benefits of the system are diminished. To ensure the best possible outcome, the team sought to reduce the tradeoffs by looking for a way to switch the damping force fast enough to manage the loads without affecting secondary ride. The RLM algorithm is designed to manage the road loads when driving through potholes. The algorithm detects the presence of a pothole based on individual suspension velocity and direction. When the wheel enters the pothole, the suspension velocity increases quickly while traveling downward (suspension rebound travel) into the pothole.
2017-03-28
Technical Paper
2017-01-1488
Srinivas Kurna, Ruchik Tank, Riddhish Pathak
The job of a suspension system is to maximize the friction between the tires and the road surface, to provide steering stability with good handling and to act as a cushioning device ensuring the comfort of the driver & passengers. The suspension also protects the vehicle itself and any cargo or luggage from damage and wear. Almost all heavy duty vehicles use inverted type suspension system which is also called as bogie type suspension system. The design of this type of suspension is a complex and difficult science which has evolved over many years. It was recognized very early in the development of suspensions that the interface between vehicle body and wheel needed some sort of cushioning system to reduce the vibration felt as the vehicle moved along. This was already part of road coach design and took the form of leaf (laminated) steel springs mounted on the axles, upon which the vehicle body rested.
2017-03-28
Technical Paper
2017-01-1491
Manish Kumar Seth, Jens Glorer, Ralf schellhaas
This paper outlines the invention, patented under patent number US 9,315,087 B2, on how a twist beam can be efficiently designed for a given roll stiffness by using the sectional properties of the beam section in combination with a long reinforcement and curved flanges. This helps in reducing the weight and cost in addition to improve the durability performance and camber compliance of the twist beam structure while using conventional stamping and welding technologies. As against the conventional method of changing the roll stiffness only with the thickness of the torsion beam, the invention detailed in this paper uses the shape and the thickness of the torsion profile to control the roll stiffness.The paper details the work done to develop the design concept and the validation using rig and vehicle level testing. This invention has been successfully patented with USPTO in 20166 (Patent number US 9,315,087 B2)
2017-03-28
Technical Paper
2017-01-1483
Jia Mi
This paper presents a novel application of hydraulic electromagnetic energy-regenerative shock absorber (HESA) into bogie system of railway vehicles. In order to find out the relationship and differences between first suspension system and second suspension system when installed it, HESA is built in AMESim to make comparison studies on the different department suspensions caused by the nonlinear damping behaviors of the HESA. The simulation results show that the system can effectively reduce the impact between wheel and rail tracks, while maintaining good potential to recycle vibratory energy. And the relationships as well as differences between the first suspensions and second suspensions have been concluded, which are useful for the design of HESA-Bogie.
2017-03-28
Technical Paper
2017-01-1478
Srinivas Kurna, Sajal Jain
In automobile, steering system's main function is to allow driver to guide vehicle on desired course. Steering system consists of various components & linkages. Using these linkages, the torque from steering wheel got transferred to Tyre which results in turning of vehicle. The steering components are subjected to various loading conditions over the life of vehicle. As steering components are safety critical elements in vehicle therefore it should not failure in any load condition because failure of any of these component causes vehicle failure. In commercial vehicle segment, vehicle failure means delay in freight delivery & results in huge loss to costumer. Therefore, while designing steering components one should consider all the possible loading which is not possible through theoretical calculation. Therefore, Physical tests has to be done to validate design of steering system which is very costly & time consuming process.
2017-03-28
Technical Paper
2017-01-1490
Silvia Faria Iombriller
The air suspension development and application has becoming increasingly applied also in commercial vehicles, offering to the driver more dynamic comfort as well as contributing to the reduction of impact loads on highways. Through this project pursuit show the analysis and application of an air suspension system for commercial tractor vehicles application. A special focus was given to pneumatic actuation system, responsible for leveling and control of suspension´s stiffness under different conditions of usage, laden and unladen. The project was conducted starting with the vehicle dynamic performance analysis, evaluating the pneumatic suspension circuit modifications in order to obtain the vehicle dynamic behavior improvement, ensuring directional stability under different maneuvering conditions. For entire development were also used quality tools, considering the possible failure modes and effects as well as virtual simulation tools (Adams) and bench validations.
2017-03-28
Technical Paper
2017-01-1495
Srinivas Kurna, Ruchik Tank
At the time of invention of road coaches, the vehicle consisted only of an axle with wheels & a body attached. Smooth roads were built for a better ride comfort however they were not consistent. The road coaches were too bumpy & uncomfortable for the passenger along with the driver who was not able to control the vehicle. That's why the engineers had to turn their attention to the suspension system for a better ride comfort & handling. The technology has advanced with the time so has the suspension system. Weveller type leaf spring is one of the many type of suspension systems available in the industry. The job of a suspension system is to maximize the friction between the tires and the road surface, to provide steering stability with good handling and to act as a cushioning device ensuring the comfort of the driver & passengers. The suspension also protects the vehicle itself and any cargo or luggage from damage and wear.
2017-03-28
Technical Paper
2017-01-1509
L. Daniel Metz
We examine some characteristics, physical properties and idealized delamination and rupture failure modes of pneumatic tires. After measurement of some typical tire properties, calculations regarding stresses resulting from various tire failure and rupture scenarios are developed.
2017-03-28
Technical Paper
2017-01-0406
Jindong Ren, Xiaoming Du, Tao Liu, Honghao Liu, Meng Hua, Qun Liu
This paper presented an integrated method for rapid modeling, simulation and virtual evaluation of the interface pressure between driver human body and seat. For the simulation of the body-seat interaction and the calculation of the interface pressure, in addition to body dimensions and material characteristics, an important aspect was the posture and position of the driver body with respect to the seat. The correct simulation results could be acquired only by realistic setting of the body posture, by introducing posture prediction models. To ensure accommodation of the results to the target population, usually several individuals were simulated, whose body anthropometries covered the scope of the whole population. The multivariate distribution of the body anthropometry and the sampling techniques were adopted to generate the individuals and to predict the detailed body dimensions.
2017-03-28
Technical Paper
2017-01-0454
Colin Young
Contacts between different meshed components in a finite element model frequently present modeling challenges. Tracking the progress of contact and separation is computationally expensive and may result in non-convergence of the model. In many contact problems of practical interest, such as bolted assemblies or in a shaft bearing where the shaft is constrained against rotation, it is clear that the components are in essentially constant contact and relative motion between them is negligible. In these cases, we can reduce the computational burden by defining an interface between the bodies using modeling devices other than the contact commands. Some approaches in common use, such as tying the meshed surfaces together, while they resolve convergence issue, can result in non-physical stress distributions and un-conservative results in some cases.
2017-03-28
Technical Paper
2017-01-0404
Sergei Viktorovich Aliukov
Currently, a group of scientists consisting of six doctors of technical sciences, professors of South Ural State University (Chelyabinsk, Russia) has completed a cycle of scientific research for creation of adaptive suspensions of vehicles. We have developed design solutions of the suspensions. These solutions allow us to adjust the performance of the suspensions directly during movement of a vehicle, depending on road conditions - either in automatic mode or in manual mode. We have developed, researched, designed, manufactured, and tested experimentally the following main components of the adaptive suspensions of vehicles: 1) blocked adaptive dampers and 2) elastic elements with nonlinear characteristic and with improved performance.
2017-03-28
Technical Paper
2017-01-0401
Ye Yuan, Junzhi Zhang, Yutong Li, Chen Lv
Autonomous vehicle is considered as the future of vehicle industry and transportation due to its nominal intelligence and safety. The demand for low energy consumption and environment protection has pushed electrified vehicle into an inexorable trend. Therefore, autonomous electrified vehicle has become research focus of research organizations. The development of by-wire control systems such as hub motor propulsion and brake-by-wire system are the foundation of intelligent vehicle. Due to direct concerning safety and being core of ACC (Adaptive Cruise Control) and AB (Active Brake), brake system and its control algorithm are the key of all by-wire systems. A novel type of brake-by-wire system is proposed in this article, which is composed of four direct-current-control valves, one relief valves, eleven ordinary switch valves and one pump.
2017-03-28
Technical Paper
2017-01-1506
Johannes Wiessalla, Yiqin Mao, Frank Esser
Stability control systems like the ESC (Electronic Stability Control) are triggered when the vehicle extends the thresholds controllable by an average driver. This happens more probable on slippery surfaces, e.g. snow, ice and wet roads. Testing of stability systems on dry asphalt can be done almost any time of the year. Testing on slippery surfaces however is more restricted by weather and proving grounds. Another drawback in testing is the reproducibility of the measurements, since the surface condition changes during the tests and the vehicle behaviour gets more sensitive on low surface. Therefore, simulation enables a good pre-assessment of the stability systems independent from testing conditions. Essential for this is a good knowledge about the contact between road and surface, meaning a good tyre model and a reasonable set of tyre model parameters. Getting these parameters for snow and ice was described in two papers of the authors published before.
2017-03-28
Technical Paper
2017-01-0347
Yat Sheng Kong, Dieter Schramm PhD, Zaidi Omar PhD, Sallehuddin Mohd. Haris, Shahrum Abdullah PhD
This paper presents the development of a relationship between objective vehicle ride level and coil spring durability life using road data to shorten suspension design process. Current development processes of vehicle suspension systems which include vehicle ride and suspension spring durability are categorized into different stages of analysis and therefore, consumes lots of time. Through the developed predictive model, the ISO weighted accelerations were used to describe durability of spring components or vice versa. This model has led to immediate solution of suspension design with reduced number of testing. In order to construct the model, strain and acceleration data from various roads were measured using data acquisition which was involving car movements. Prior to the strain measurement, a finite element model of the spring was measured to identify the critical region of the spring and strain gauges were applied on the particular spot.
2017-03-28
Technical Paper
2017-01-0418
Gregory McCann, Prashant Khapane
An increase in data measurement and recording within vehicles has allowed Anti-lock Braking Systems (ABS) to monitor a vehicles dynamic behavior in far more detail. This increased monitoring helps to improve vehicle response in scenarios such as braking whilst cornering and braking on uneven surfaces. Durability and Robustness (D&R) CAE department within Jaguar Land Rover discovered that the lack of a complex ABS system in virtual vehicle models was contributing to poor lateral and longitudinal loads correlation throughout the suspension and mounting systems. Last year the team started a project to incorporate Continentals ABS system, provided by '©Continental AG' for physical JLR vehicles, into SIMPACK virtual vehicles by means of a co-simulation. The work involved collaboration between 3 departments in Jaguar Land Rover and ultimately led to implementation of the ABS into the JLR wide virtual database.
2017-03-28
Technical Paper
2017-01-0421
Xiang Liu, Wei Chen, Ying Chen, Jing Zhao
The leaf spring has significant hysteresis characteristics due to the interleaf friction. The traditional three-link model could not simulate the hysteresis characteristics at all. According to the dynamic load test results one can find that the dynamic stiffness of leaf spring has a nonlinear relationship with the travel distance and the load frequency has a tiny influence on it. Based on the traditional three-link model, this paper proposed a simulation modeling method by introducing torsional friction on the revelute joint. The key parameters including torsional spring stiffness, friction torque preload, stiction transition velocity and max stiction deformation are optimized by combining the ADAMS, OPTIMUS and MATLAB. The comparsion analysis between the simulation and test results of front and rear leaf springs have revealed that the simulation precision is up to 92%.
2017-03-28
Technical Paper
2017-01-1590
Jyotishman Ghosh, Stéphane Foulard, Rafael Fietzek
The knowledge of vehicle mass is very important for the proper functioning of various vehicle stability control systems and vehicle state observers. A method for estimating the vehicle mass in real time is presented. Traditional mass estimation methods suffer due the lack of the knowledge of vehicle parameters, road surface conditions and most importantly the effect of the vehicle transmission. To resolve these issues, a vehicle model independent method is utilized in conjunction with a drivetrain torque output observer to obtain the estimate of the vehicle mass. Simulations and experimental track tests indicate that the method is able to accurately estimate the vehicle mass with a relatively fast rate of convergence compared to traditional methods.
2017-03-28
Technical Paper
2017-01-1485
Mikihiro Hiramine, Yoshitaka Hayashi, Takashi Suzuki
In recent years, Power steering system has been replaced to electric power steering (EPS), in order to achieve better fuel consumption and reduce exhaust emissions and now EPS also plays important roles in driving assistance such as active safety and automated parking, so its number is expected to increase more and more. EPS is one of many automotive applications that requires a high level of safety. Since installation of EPS system started from light weight vehicles, fail-safe concept of the EPS system is reverting to manual steering mode if a failure occurs by any chances in order to maintain steering control. Now, EPS is expanding to heavier vehicles such as SUVs and Pickup Trucks, which require higher output motor power, with the advance in the power electronics technology. As the weight of the vehicle with the EPS increases, there is increase in the importance of an argument about avoidance of a sudden loss of electric power steering.
2017-03-28
Technical Paper
2017-01-0416
Vishal BARDE, Baskar Anthonysamy, Ganeshan Reddy, Senthil S, Visweswara lenka, Gurdeep Singh Pahwa
Power steering pump is vital component of hydraulic power steering system. Failure of steering pump can lead to loss of power assistance. Prediction of hub load on pump shaft is an important design input for pump manufacturer. Higher hub loads than design load of pump bearing can lead to seizure of pump. Pump manufacturer has safe limits for hub load. Simulations can assist for optimization of belt layout and placement of accessories to reduce the hub load. Lower hub load can have direct effect on improvement of pump durability. This paper deals with dynamic simulation of belt drive system in MSC.ADAMS as well as vehicle level measurement of hub load on power steering pump. Hub load is measured with two different belt layout as well as in different maneuver related to cranking and high speed conditions at which the worst load cases are seen.
2017-03-28
Technical Paper
2017-01-1584
Peng Hang, Xinbo Chen, Fengmei Luo, Shude Fang
Compared with the traditional front-wheel- steering (FWS) vehicles, four-wheel-independent-steering (4WIS) vehicles have better handing stability and path tracking performance. In view of this, a novel 4WIS electric vehicle (EV) with steer-by-wire (SBW) system is proposed in this paper. As to the 4WIS EV, a linear quadratic regulator (LQR) optimal controller is designed to make the vehicle track the desired path based on the linear dynamic model. Taking the effect of uncertainties in vehicle parameters into consideration, a robust controller utilizing μ synthesis approach is designed and the controller order reduction is implemented based on Hankel-Norm approximation. In order to evaluate the performance of the designed controllers, numerical simulations of two maneuvers are carried out using the nonlinear vehicle model in MATLAB/Simulink.
2017-03-28
Technical Paper
2017-01-1494
Weinan Tao, Bingzhao Gao, Hongqing Chu, Mengjian Tian, Hong Chen
Steer-by-wire technology is considered as a next step in steering system evolution. The substitution of electronic systems in place of mechanical components simplifies the car interior design and saves larger space for driver cabin. But the absence of the force coming from the road directly challenges us to model an optimal steering feel. Referring to the structure of the conventional steering systems, the forces transmitted to the driver through handwheel consist of steering system friction and aligning torque. In the paper, the steering system friction is simulated by the Stribeck friction model. The accurate friction model is important for simulating feedback torque during stand-still, low speed and low lateral acceleration conditions. Besides that, the elasticity of steering column should be taken into consideration, which helps to improve the dynamic response performance of the system especially in the condition that the steering angle changes rapidly.
2017-03-28
Technical Paper
2017-01-1371
Hao Pan, Xuexun Guo, Xiaofei Pei, Xingzhi Dong
Brake pedal feel plays an important role in the driver's comprehensive subjective feeling when braking, which directly affects the active safety and riding comfort of passenger car. In this paper, a systematical mathematical model of the vehicle brake system is built in according with the structure and system characteristics of hydraulic servo brake system. A complete hydraulic servo brake system simulation model composed of brake pedal, vacuum booster, brake master cylinder, brake pipe, brake wheel cylinders, brake calipers is established in AMESim. The effects of rubber reaction plate stiffness, rubber valve opening, brake master cylinder piston, brake caliper, brake pipe deformation and friction liner deformation on brake pedal feel are considered in this model. The accuracy of this model is verified by real road vehicle tests under static and dynamic two different conditions.
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