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Viewing 121 to 150 of 10607
2016-04-05
Technical Paper
2016-01-1309
Yingping Lv, Yongchang Du, Yujian Wang
Abstract In this paper, analysis methods for brake squeal including substructure modal composition analysis and substructure modal parameters sensitivity analysis are presented. These methods are based on a new closed-loop coupling disc brake model, where the coupled nodal pairs in each coupling interface are connected tightly. This assumption is different from other existing models in literatures, where the interface nodes are coupled through assumed springs. Based on this new model, two analysis methods are derived: Substructure modal composition analysis indicates the contribution of modes of each substructure to the noise mode; Substructure modal parameters sensitivity analysis indicates the sensitivity of the real part of system’s eigenvalue to component’s modal frequency and shape. Finally, the presented analysis methods are applied to analyse a high frequency squeal problem of a squealing disc brake.
2016-04-05
Technical Paper
2016-01-0014
Shun Yang, Weiwen Deng, Haizhen Liu, Rui He, Lei Qian, Wenlong Sun, Ji Gao
Abstract Nowadays, the vehicle market puts forward urgent requirement for new kinds of braking booster because the traditional vacuum booster cannot meet the demands of new energy vehicles anymore. However, one problem that all the new plans should face is how to guarantee an ideal pedal feeling. In this paper, a novel mechatronics braking booster is proposed, and servo motor introduced into the booster makes the assist rate can be adjusted under a great degrees of freedom, so the structural parameters and control parameters of the booster should be determined elaborately to get an optimal pedal feeling. The pedal feeling is always represented by the pedal stoke-force curve which is influenced by different parameters.
2016-04-05
Technical Paper
2016-01-0029
Chuanliangzi Liu, Bo Chen, Ming Cheng, Anthony Champagne, Keyur Patel
Abstract The Electronic Control Unit (ECU) of an Electric Power Steering (EPS) system is a core device to decide how much assistance an electric motor applies on a steering wheel. The EPS ECU plays an important role in EPS systems. The effectiveness of an ECU needs to be thoroughly tested before mass production. Hardware-in-the-loop simulation provides an efficient way for the development and testing of embedded controllers. This paper focuses on the development of a HiL system for testing EPS controllers. The hardware of the HiL system employs a dSPACE HiL simulator. The EPS plant model is an integrated model consisting of a Vehicle Dynamics model of the dSPACE Automotive Simulation Model (ASM) and the Nexteer Steering model. The paper presents the design of an EPS HiL system, the simulation of sensors and actuators, the functions of the ASM Vehicle Dynamics model, and the integration method of the ASM Vehicle Dynamics model with a Steering model.
2016-04-05
Technical Paper
2016-01-0051
Hongyu Zheng, Mingxin Zhao
Abstract Electric power steering (EPS), active front wheel steering (AFS) and steer by wire systems (SBW) can enhance the handling stability and safety of the vehicle, even in dangerous working conditions. Now, the development of the electric control steering system (ECS) is mainly based on the way that combines the test of the electric steering hardware-in-loop (HIL) test bench with real vehicle tests. However, the real vehicle tests with higher cost, long cycle and vulnerable to space weather have the potential safety problems at early development. On contrast, electronic control steering HIL test bench can replace real vehicle tests under various working conditions and make previous preparations for real vehicle road tests, so as to reduce the number of real vehicle test, shorten the development cycle, lower development costs, which has gradually become the important link of research and development of electronic steering system.
2016-04-05
Journal Article
2016-01-0387
Yunkai Gao, Jingpeng Han, Jianguang Fang, Shihui Wang
Abstract A compiled method of the programmed load spectrum, which can simplify and accelerate the fatigue bench test of a car body, is proposed and its effectiveness is checked by the fatigue simulation. By using the multi-body dynamics model with a satisfactory accuracy, the virtual iteration is applied to cascade body loads from the wheel hubs. Based on the rain-flow counting method and statistics theory, the distributions of the body loads are analyzed, and then the programmed load spectrum is compiled and simplified. Through comparative study, the simulation results of random and programmed load spectrum are found to agree well with each other in terms of the damage distribution and fatigue life, which demonstrates the effectiveness of the presented method.
2016-04-05
Technical Paper
2016-01-0378
John George, Daniel Gross, Hamid Jahed, Ali Roostaei
Abstract The choice of an appropriate material model with parameters derived from testing and proper modeling of stress-strain response during cyclic loading are the critical steps for accurate fatigue-life prediction of complex automotive subsystems. Most materials used in an automotive substructure, like a chassis system, exhibit combined hardening behavior and it is essential to capture this behavior in the CAE model in order to accurately predict the fatigue life. This study illustrates, with examples, the strain-controlled testing of material coupons, and the calculations of material parameters from test data for the combined hardening material model used in the Abaqus solver. Stress-strain response curves and fatigue results from other simpler material models like the isotropic hardening model and the linear material model with Neuber correction are also discussed in light of the respective fatigue theories.
2016-04-05
Technical Paper
2016-01-0381
Moorthy Senniappan, Rajendra More, Shreyas Bhide, Siddesh Gowda
Abstract In the present scenario, automobile manufacturers are forced to reduce the weight of each components through design optimization. In a bid to enhance the fuel efficiency and load carrying capacity of the vehicle; however this approach may not be practical for all the parts in real life, and the engineer will end up adding further mass to the component. This is carried out to enhance the strength of the component, since considerable over load application in real world usage condition which can damage the component drastically. In this paper, steering tie rod arm of a heavy commercial vehicle was taken as a case study. The Steering tie rod arm is a part which connects the wheel spindle with steering system linkage i.e. Track rod. Track rod transfers the steered force from one wheel to another wheel and steering tie rod arm transfers the force from track rod to wheel spindle to steer both the wheels in same direction.
2016-04-05
Journal Article
2016-01-0420
Frank Anthony Cuccia, James Pineault, Mohammed Belassel, Michael Brauss
Abstract It is well known that manufacturing operations produce material conditions that can either enhance or debit the fatigue life of production components. One of the most critical aspects of material condition that can have a significant impact on fatigue life is residual stress (RS) [1, 2]. When springs are manufactured, the spring stock may undergo several operations during production. Additional operations may also be introduced for the purpose of imparting the spring with beneficial surface RS to extend its fatigue life and increase its ability to execute the task it was designed to perform. The resultant RS present in production springs as a result of the various fabrication and processing operations applied can be predicted and modeled, however, RS measurements must be performed in order to quantify the RS state with precision.
2016-04-05
Technical Paper
2016-01-0411
Yosuke Akita, Kenji Abe, Yoshihiro Osawa, Yoshitsugu Goto, Yuji Nagasawa, Noboru Sugiura, Satoshi Wakamatsu, Kyoko Kosaka
Abstract If a vehicle is left in a humid environment, the coefficient of friction between the brake pads and discs increases, generating a discomforting noise during braking called brake squeal. It is assumed that this increase in the coefficient of friction in a humid environment is the effect of moisture penetrating between the brake friction surfaces. Therefore, this paper analyzes the factors causing coefficient of friction variation with moisture between the friction surfaces by dynamic observation of these surfaces. The observation was achieved by changing the disc materials from cast iron to borosilicate glass. One side of the glass brake disc was pushed onto the brake pad and the sliding surface was observed from the opposite side by a charge coupled device (CCD) camera. First, a preliminary test was carried out in a dry state using two pad materials with different wear properties to select the appropriate pad for observing the friction surfaces.
2016-04-05
Journal Article
2016-01-0426
Francisco C. Cione, Armando Souza, Luiz Martinez, Jesualdo Rossi, Evandro Giuseppe Betini, Fabio Rola, Marco A. Colosio
Abstract Studying the formation and distribution of residual stress fields will improve the wheel safety operational criteria among other gains. Many engineering specifications, manufacturing procedures, inspection and quality control have begun to require that the residual stress of a particular component to be evaluated. It is known that these residual stress fields could be added to the effects of a system load (tare weight plus occupation of vehicle, traction, braking and torque combined). The mathematical tools for modeling and simulations using finite elements had evolved following the increasing computing power and hardware cost reduction. On the other hand, the experimental testing, offers specific physical component behavior and with the use of statistical tools, it is possible to predict the real behavior of the component when in operation. The experiments undertaken used the X-ray diffraction technique and the drilling method with rosette type strain gages.
2016-04-05
Technical Paper
2016-01-0408
Sagar Polisetti, Siddesh Gowda, Nitin Kumar Khanna, Manjul Jyoti
Abstract Suspension system is one of the most important systems in an automobile and the failure in the sub systems or parts would prove catastrophic. A semi-trailing arm (STA) suspension is an independent rear suspension system for automobiles where each wheel hub is located only by a large, roughly triangular arm that pivots at two points onto the chassis or the body. STA usually is subjected to three directional loads viz. vertical, longitudinal and lateral in service. The conventional methodology of validating the system is by applying multi-axial loads or by road load simulation consuming significant amount of time. In this paper an attempt is being made to validate the damper mounting pins by reproducing the damper loads locally instead of validating the entire system. STA was strain gauged at the critical locations and was mounted onto the vehicle.
2016-04-05
Journal Article
2016-01-0462
Chunlei Wang, Xinjie Zhang, Konghui Guo, Fangwu Ma, Dong Chen
Abstract With the development of the advanced driver assistance system and autonomous vehicle techniques, a precise description of the driver’s steering behavior with mathematical models has attracted a great attention. However, the driver’s steering maneuver demonstrates the stochastic characteristic due to a series of complex and uncertain factors, such as the weather, road, and driver’s physiological and psychological limits, generating negative effects on the performance of the vehicle or the driver assistance system. Hence, this paper explores the stochastic characteristic of driver’s steering behavior and a novel steering controller considering this stochastic characteristic is proposed based on stochastic model predictive control (SMPC). Firstly, a search algorithm is derived to describe the driver’s road preview behavior.
2016-04-05
Technical Paper
2016-01-0463
Juan Sierra, Camilo Cruz, Luis Munoz, Santiago Avila, Elkin Espitia, Jaime Rodriguez
Abstract Brake systems are strongly related with safety of vehicles. Therefore a reliable design of the brake system is critical as vehicles operate in a wide range of environmental conditions, fulfilling different security requirements. Particularly, countries with mountainous geography expose vehicles to aggressive variations in altitude and road grade. These variations affect the performance of the brake system. In order to study how these changes affect the brake system, two approaches were considered. The first approach was centered on the development of an analytical model for the longitudinal dynamics of the vehicle during braking maneuvers. This model was developed at system-level, considering the whole vehicle. This allowed the understanding of the relation between the braking force and the altitude and road grade, for different fixed deceleration requirement scenarios. The second approach was focused on the characterization of the vacuum servo operation.
2016-04-05
Journal Article
2016-01-0461
Wenfei Li, Haiping Du, Weihua Li
Abstract This paper proposes a new braking torque distribution strategy for electric vehicles equipped with a hybrid hydraulic braking and regenerative braking system. The braking torque distribution strategy is proposed based on the required braking torque and the regenerative braking system’s status. To get the required braking torque, a new strategy is designed based on the road conditions and driver's braking intentions. Through the estimated road surface, a robust wheel slip controller is designed to calculate the overall maximum braking torque required for the anti-lock braking system (ABS) under this road condition. Driver's braking intentions are classified as the emergency braking and the normal braking. In the case of emergency braking, the required braking torque is to be equal to the overall maximum braking torque. In the case of normal braking, the command braking torque is proportional to the pedal stroke.
2016-04-05
Technical Paper
2016-01-0460
Salem A. Haggag, Abraham Mansouri
Abstract The control of automotive braking systems performance and wheel slip is a challenging problem due to the nonlinear of the braking process, vehicle body dynamics during braking and the tire-road interaction. When the wheel slip is not between the optimal limits during braking, the desired tire-friction force cannot be achieved, which influences the braking distance, the loss in steerability and maneuverability of the vehicle. A simple and at the same time realistic vehicle longitudinal braking model is essential for such challenging problem. In this paper, a new longitudinal rolling/braking lumped-vehicle model that takes vehicle aerodynamic forces in consideration is presented. The proposed model takes the rolling resistance force, the braking force and the aerodynamic lift and drag forces in consideration and investigates their impact on the vehicle longitudinal dynamics especially vehicle braking distance and time.
2016-04-05
Technical Paper
2016-01-0458
Jiawei Li, Gangfeng Tan, Yangjie Ji, Yongchi Zhou, Ziang Liu, Yingxiao Xu
Abstract Vehicle auxiliary braking system is very significant to the brake safety. The eddy current retarder (ECR) has a good braking performance, but the braking torque would fade under high speed domain. In the contrary, the regenerative brake (RGB) could provide a satisfied braking performance in high speed domain. However, the braking torque in low speed domain is insufficient. This paper proposed a novel concept of the integrated energy-recuperation retarder (IEER), which would take advantage of the merits of both the ECR and the RGB to have a steady braking performance in all-speed domain. The IEER integrates the structures of rotary eddy current retarder (RECR) and the RGB, both of which share a stator. Braking torque of the IEER produced by stator core and armature-windings can stack together, and therefore the IEER can provide greater braking torque than the RECR. Besides, the IEER can recover electric energy from armature-windings.
2016-04-05
Technical Paper
2016-01-0456
Zhaozhong Zhang, Dongpu Cao
Abstract One main objective is to find out how these parameters interact and optimal driver control gain and driver preview time are obtained. Some steps further, neuromuscular dynamics is considered and the system becomes different from the simplified driver-vehicle system studied before. New optimal driver control gain and driver preview time could be obtained for both tensed and relaxed muscle state. Final step aims at analysing the full system considering driver, neuromuscular, steer-by-wire and vehicle models. The steer-by-wire system could potentially have a significant influence on the vehicle when the driver is at impaired state, which could be represented by setting higher response delay time or smaller preview time. Vehicle's stability and active safety could also be improved by introducing the steer-by-wire system.
2016-04-05
Journal Article
2016-01-0457
Yutong Li, Junzhi Zhang, Chen Lv, Ye Yuan
Abstract This paper presents a coordinated controller for comprehensive optimization of vehicle dynamics performance and energy consumption for a full drive-by-wire electric vehicle, which is driven by a four in-wheel motor actuated (FIWMA) system and steered by a steer-by-wire (SBW) system. In order to coordinate the FIWMA and SBW systems, the mechanisms influencing the vehicle dynamics control performance and the energy consumption of the two systems are first derived. Second, the controllers for each subsystem are developed. For the SBW system, a triple-step control technique is implemented to decouple the yaw rate and sideslip angle controls. The FIWMA system controller is designed with a hierarchical control scheme, which is able not only to satisfy the yaw rate and sideslip angle tracking demands, but also to deal with actuation redundancy and constraints.
2016-04-05
Technical Paper
2016-01-0455
Hongyu Zheng, Jinghuan Hu, Shuo Yang
Abstract Steering-by-wire(SBW) system makes the vehicle not constrained by the steering wheel control. Joystick, button and touch screen can all be used for automobile steering control. Using joystick to achieve steering operations has its unique advantages and many problems which are needed to be resolved at the same time. This paper firstly introduced the components of traditional steering wheel steer-by-wire system, then came up with the difference between joystick steer-by-wire system and traditional steer-by-wire system about transmission ratio, transmission ratio control strategy of joystick steer-by-wire system is proposed at the same time. At last, this paper studied driver’s busy degree when the vehicle running with a big turning radius at low speed and the effect of different angle transmission ratio on vehicle handing stability when the vehicle running at intermediate speed.
2016-04-05
Technical Paper
2016-01-0454
Hongyu Zheng, Shenao Ma
Abstract As a new braking system, EHB can significantly improve the braking performance and vehicle handling and stability. In this paper the structure of high-speed on-off valve and the valve core principle are discussed, the paper also analysis the response of the valve core under different modulation frequency, duty cycle and the change of wheel cylinder pressure. Set a proper modulation frequency to make sure that electromagnetic valve can be worked in a greater linear range.
2016-04-05
Technical Paper
2016-01-0453
Yingxiao Xu, Xuexun Guo, Gangfeng Tan, Jiawei Li, Yongchi Zhou, Yangjie Ji, LiWen Yu
Abstract Eddy current retarder (ECR) shares a large market of auxiliary brakes in China, but shortcomings of the short continuous braking time and the high additional energy consumption are also obvious. The propose of combined braking partakes the braking torque of ECR. However, the existed serial-parallel braking strategy could hardly balance well the relationship between the braking stability and the energy recovery efficiency. This research puts forward an energy management strategy of combined braking system which aims to maximize energy recovery while ensure the brake stability. The motor speed, the braking request and the state of charge (SoC) of the storage module are analyzed synthetically to calculate the reasonable braking torque distribution proportion. And the recovered energy is priority for using in the braking unit to reduce the additional energy consumption in this strategy.
2016-04-05
Technical Paper
2016-01-0452
Tingyou Ming, Weiwen Deng, Sumin Zhang, Bing Zhu
Abstract In this paper, a model predictive control (MPC) based trajectory tracking scheme utilizing steering wheel and braking or acceleration pedal is proposed for intelligent vehicles. The control objective is to track a desired trajectory which is obtained from the trajectory planner. The proposed control is based on a simplified third-order vehicle model, which consists of longitudinal vehicle dynamics along with a commonly used bicycle model. A nonlinear model predictive control (NMPC) is adopted in order to follow a given path by controlling front steering, braking and traction, while fulfilling various physical and design constraints. In order to reduce the computational burden, the NMPC is converted to a linear time-varying (LTV) MPC based on successive online linearization of the nonlinear system model. Two different test conditions have been used to verify the effectiveness of the proposed approaches through simulations using Matlab and CarSim.
2016-04-05
Technical Paper
2016-01-0451
Fu Wenkui, Liu Ligang, Shu Jin, Wang Dawei, Xu Long
Abstract Virtual Road Load Data Acquisition (vRLDA) is to replace traditional Road Load Data Acquisition (RLDA) thus becomes the important method to obtain the load for the fatigue analysis of the vehicle components. Pothole event, which is a typical loadcase among vehicle durability test in the development process, is simulated based on Adams/Car in this paper. Flex-body is adopted in the full vehicle model in order to improve the simulation accuracy. Flexible ring tire model, FTire, is used for the benefit of validity in higher frequency domain. The result shows that simulation result correlated well both in wheel center travel and load of tire and suspension parts. Consequently, it is available to predict the max effective jounce travel and body max load in the early phase of vehicle development thus decrease the potential risk in the later phase and the total research cost. vRLDA is also proven as a reliable and effective method to obtain the load.
2016-04-05
Technical Paper
2016-01-0447
Manfred Baecker, Axel Gallrein, Francesco Calabrese, Remco Mansvelders
Abstract Sudden pressure loss can lead to vehicle instability and - without aid of systems such as e.g. Electronic Stability Control (ESC) - to an emergency situation, possibly resulting in an accident. But also with an ESC system such a situation is an unusual (unstandardized) application case, because the vehicle system (car+tires) properties change very rapidly during the sudden pressure loss, which leads to a very high dynamic response in the system and moreover to a very fuzzy and unclear description of the vehicle system. From this point of view, a proper validation and verification of an ESC system for such an application seems to have a high safety relevancy. The authors have set up a simulation case to simulate a sudden tire inflation pressure loss and its consequences to the car stability. Using this simulation setup enables a CAE engineer to pre-develop ESC systems and/or to validate and test these for a realistic and relevant use case.
2016-04-05
Technical Paper
2016-01-0446
Chen Liang, Guolin Wang, Zhou Zheng
Abstract A 3D finite element (FE) model of a radial tire 205/55R16, established using ABAQUS software, is utilized to simulate tire force and moment properties. Drum tests are designed to validate the FE model’s reliability. To investigate the impacts of PCR contour design theory on tire force and moment, a modified string balance contour theory is presented. Based on string balance contour theory, it simplifies the shape of belt pressure share ratio as a trapezium. Besides, a program for calculating tire contour curve is compiled using MATLAB software. Applying different belt pressure share ratios, diverse tire contours are designed. One of the contours is selected according to its positive effect on cornering stiffness in simulation.
2016-04-05
Technical Paper
2016-01-0445
Brian Paul Wiegand
Abstract Evaluation of the performance potential of an automotive conceptual design requires some initial quantitative estimate of numerous relevant parameters. Such parameters include the vehicle mass properties, frontal and plan areas, aero drag and lift coefficients, available horsepower and torque, and various tire characteristics such as the rolling resistance coefficient(s)… A number of rolling resistance models have been advanced since Robert William Thomson first patented the pneumatic rubber tire in 1845, most of them developed in the twentieth century. Most early models only crudely approximate tire rolling resistance behavior over a limited range of operation, while the latest models overcome those limitations but often at the expense of extreme complexity requiring significant computer resources.
2016-04-05
Journal Article
2016-01-0444
Kemal Çalışkan, Mina M.S. Kaldas, Roman Henze, Ferit Küçükay
Abstract This paper presents a performance analysis study for the Rule-Optimized controller of a semi-active suspension system. The Rule-Optimized controller is based on a Fuzzy Logic control scheme which offers new opportunities in the improvement of vehicle ride performance. An eleven degree of freedom full vehicle ride dynamics model is developed and validated through laboratory tests performed on a hydraulic four-poster shaker. An optimization process is applied to obtain the optimum Fuzzy Logic membership functions and the optimum rule-base of the semi-active suspension controller. The global optima of the cost function which considers the ride comfort and road holding performance of the full vehicle is determined through discrete optimization with Genetic Algorithm (GA).
2016-04-05
Technical Paper
2016-01-0443
Han Zhang, Gang Li, Yu Wang, Yuchuan Gu, Xiang Wang, Xuexun Guo
Abstract A vehicular hydraulic electrical energy regenerative semi-active suspension(HEERSS) was presented, and its working principle and performance were analyzed. Firstly, configuration and working principle of the HEERSS were described; Secondly, kinetic equation of HEERSS was deduced, and a skyhook controller was designed for HEERSS. The traditional skyhook control strategy should be changed for the characteristic of HEERSS, because the damping force during extension stroke could be controlled, but not in compression stroke. Thirdly, the performance of HEERSS was compared with passive suspension(PS), traditional semi-active suspension(TSS). The simulation results indicated that the performance of HEERSS would be compromise between TSS and PS, but the HEERSS could harvest vibration energy which was advanced than TSS and PS.
2016-04-05
Technical Paper
2016-01-0442
Xing Xu, Zou Nannan
Interconnected air suspension system can change a vehicle’s operation characteristics by exchanging gas between air springs. In this paper, we analyze the structure and working principle of interconnected air suspension based on thermodynamics and vehicle dynamics. Then air suspension’s mathematical model including interconnected characteristics is established to study gas exchange principle of air suspension system. Interconnected pipeline parameters and excitation phase differences’ influence on characteristics of air suspension system in whole vehicle are calculated and analyzed. Simulation results show that the stiffness of air suspension is reduced when air springs of the suspension system are interconnected, as well as it decreases gradually with the increase of interconnected pipeline diameter; the stiffness of air springs is minimum if the excitation phase difference between both sides of air springs is 180 degrees.
2016-04-05
Technical Paper
2016-01-0441
Aref M. A. Soliman
Abstract An active suspension system has better performance than a passive suspension. However, it requires a significant amount of energy and is constructed from high cost components. To solve the problem of the power required, a switchable damper suspension system has been studied. In this paper, control strategies for the switchable damper suspension system and passive are compared in terms of their relative ride performance capabilities. Practical limitations involving switching time delay and threshold delay values are modeled and their effect on the ride performance are evaluated. The four setting switchable damper is compared with the two and three setting switchable dampers. The control strategies are used to maintain suspension working space level within design limit and to minimize body acceleration level. The results showed that the four setting switchable damper gives better ride improvements compared with the two and three setting switchable dampers.
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