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Viewing 151 to 180 of 10326
2015-04-14
Technical Paper
2015-01-1600
Tong Zou, Lu Xiong, Pengfei Yang, Chi Jin
Abstract Distributed drive electric vehicle (EV) is driven by four independent hub motors mounted directly in wheels and retains traditional hydraulic brake system. So it can quickly produce driving/braking motor torque and large stable hydraulic braking force. In this paper a new control allocation strategy for distributed drive electric vehicle is proposed to improve vehicle's lateral stability performance. It exploits the quick response of motor torque and controllable hydraulic pressure of the hydraulic brake system. The allocation strategy consists of two sections. The first section uses an optimal allocation controller to calculate the total longitudinal force of each wheel. In the controller, a dynamic efficiency matrix is designed via local linearization to improve lateral stability control performance, as it considers the influence of tire coupling characteristics over yaw moment control in extreme situations.
2015-04-14
Technical Paper
2015-01-1601
Long Chen, Mingyuan Bian, Yugong Luo, Keqiang Li
Abstract This paper proposes an estimation method of road-tire friction coefficient for the 4WID EV(4-wheel-independent-drive electric vehicle) in the pure longitudinal wheel slip, lateral sideslip and combined slip situations, which fuses both estimated longitudinal and lateral friction coefficients together, compared with existing methods based on a tire model in one single direction. Unscented Kalman filter (UKF) is introduced to estimate one-directional friction coefficient based on a modified Dugoff tire model. Considering the output results for each direction as a signal for the same target with different noise, MSE-weighted fusion method is proposed to fuse these two results together in order to reach a higher accuracy. The tire forces are estimated with the benefits of the 4WID EV that the driving torque and rolling speed of each wheel can be accurately known. The sideslip angles and slip ratios of each tire are calculated with a vehicle kinematic model.
2015-04-14
Technical Paper
2015-01-1494
Quan Zhou, Xuexun Guo, Lin Xu, Guoling Wang, Jibing Zhang
Abstract Nowadays, off-highway vehicles enjoyed a significant status in the national defense and civil construction. There is no doubt that the working conditions of off-highways are quite different from the conventional passenger cars, hence, their suspensions are particularly designed. Since the hydro-pneumatic suspension technology is maturely applied in engineering machinery, this paper presents a concept for a novel energy-harvesting device, which is 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
2015-01-1495
Qiushi Wang, Shenjin Zhu, Yuping He
Abstract This paper proposes a model reference adaptive control (MRAC) strategy for active trailer steering (ATS) in order to improve the lateral stability of articulated heavy vehicles (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. To address the variable payloads of trailer(s), the controller based on MRAC technique is adopted. A three degrees of freedom (DOF) linear yaw-plane tractor-semitrailer model is generated to design the control law. The reference model is also developed using the linear yaw-plane model with the LQR technique.
2015-04-14
Technical Paper
2015-01-1502
Liangyao Yu, Wenwei Xuan, Liangxu Ma, Jian Song, Xianmin Zhu, Shuai Cheng
Abstract The earth's fossil energy is not limitless, and we should be taking advantage of the highly developed fields of science and technology to utilize it more efficiently and to create a fully environmentally friendly life. Considering the prodigious amount of vehicles in the world today, even a small improvement in their energy-saving performance could have a significant impact. In this paper, a new type of electro-hydraulic power steering (EHPS) system is described. It has two main advantages. First, it can significantly decrease the demand on the motor so that it can be used for a wider range of vehicles. Second, its pressure-flow characteristic can be programmed and is more flexible than hydraulic power steering (HPS) system. A prototype with a 500 W motor was applied to a truck with a front load of 2,700 kg, and static steer sweep tests were conducted to validate its feasibility.
2015-04-14
Technical Paper
2015-01-1504
WeiNing Bao
Abstract 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
2015-01-1497
Hideaki Shibue, Devesh Srivastava
Abstract Torsion beam suspensions are lightweight and low in cost, and they are therefore frequently used as the rear suspensions of small front-wheel drive vehicles. However, it is difficult to predict their characteristics and to satisfy performance targets in the early stages of development in particular, because the various aspects of performance required of a suspension must be achieved by a single structure. A great deal of research has been conducted into the cross-sectional shape of the beam section; however, this paper focuses on the effect of the properties of the trailing arms on suspension characteristics. Two similar test torsion beam suspensions differing only in the rigidity of the trailing arms were fabricated, and kinematics and compliance (K&C) tests were conducted using a 3D measurement system. The lateral compliance test showed the anticipated result that change in toe and camber is greater in the suspension with lower rigidity trailing arms.
2015-04-14
Technical Paper
2015-01-1499
Tadatsugu Takada, Kazuki Tomioka
Abstract Honda announced an independent right and left rear toe control system (first generation) in 2013 and presented it as the world's first. As stated in a previous paper, “Independent Left and Right Rear Toe Control System,” with this system Honda has achieved a balance between an enjoyable driving experience in which handling is performed at the driver's will (“INOMAMA” handling) and stable driving performance.(1) This first generation is optimally designed to the vehicle specifications such as suspension axial force and steering gear ratio of the vehicle to which the system is applied. For more widespread application of independent rear toe control technology, a next generation system (second generation) has been developed, which achieves both cost reduction and flexible system performance which can be adapted to a variety of vehicles. The system development began by setting the required target performance with consideration for adaptation to various car models.
2015-04-14
Technical Paper
2015-01-1512
Sairom Yoo, Md Salah Uddin, Hyeonu Heo, Jaehyung Ju, Doo Man Kim, Seok-Ju Choi
Abstract 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 on fuel efficiency, one may need to analyze rolling energy loss of NPT at a component level. The objective of this study is to develop a tool to quantify rolling energy loss and the corresponding internal heat generation 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 and investigate temperature distribution of the NPT generated by hysteresis and convection loss into air. Using a hyper-viscoelastic material model developed from uniaxial (tensile and compression) tests and dynamic mechanical analysis (DMA), a thermo-mechanical model is developed by combining a longitudinal shear deformation induced hysteresis and a cooling procedure exposed to air.
2015-04-14
Technical Paper
2015-01-0159
Zhihui Tan, Zhenfu Chen, Xiaofei Pei, Jie Zhang, Xuexun Guo
Abstract Analogous to a vacuum boosted system, Electro-Hydraulic Braking System (EHB) is free from engine vacuum and supplies a braking force proportional to driver input. The independence of engine vacuum makes it especially suitable to be used in electric vehicles (EVs) and hybrid electric vehicles (HEVs). As a key component of EHB, master cylinder is driven by the pump rather than the vacuum booster. Even if the pump fails, the cylinder can also build proper pressure. Meanwhile, in order to maintain the pedal feeling, a pedal stroke simulator is applied in the system. In this paper, aiming at decreasing the size and cost of master cylinder and providing an ideal pedal feeling without compromise of performance, a new integrated master cylinder of EHB system is designed including two parts: master cylinder and pedal stroke simulator. The key components of the integrated master cylinder are motor pump, solenoid valves and composite springs.
2015-04-14
Technical Paper
2015-01-0492
Gaurav Paliwal, Naveen Sukumar, Umashanker Gupta, Ashutosh Dubey, Nitin Chopra
Abstract The need to develop products faster and to have designs which are first time right have put enormous pressure on the product development timelines, thus making computer aided optimization one of the most important tool in achieving these targets. In this paper, a design of experiments (DOE) study is used, to gain an insight as to, how changes to different parameters of front suspension and steering of a passenger bus affect its kinematic properties and thus to obtain an optimized design in terms of handling parameters such as bump steer, percent ackermann error and lock to lock rotation angle of steering wheel. The conventional hit and trial method is time consuming and monotonous and still is an approximate method, whereas in design of experiments (DOE), a model is repeatedly run through simulations in a single setup, for various combinations of parameter settings.
2015-04-14
Technical Paper
2015-01-0316
Kazuto Yokoyama, Masahiro Iezawa, Yohei Akashi, Toshihide Satake, Yukiyasu Akemi, Satoru Inoue, Ryotaro Suzuki
Abstract Parking assist systems which relieve burden of drivers have been put into practice in the world. Mitsubishi Electric has also been developing several technologies to realize the system, where our products such as sonar (ultrasonic sensor), electric power steering (EPS), a motor, and an inverter are used. In the parking assist system, peripheral environment of the vehicle in a parking lot is detected with our sonar sensors and determine whether or not there is a parking space available. Estimation of the position and the attitude of the vehicle is also carried out. On the basis of the detection and the estimation, a smooth and efficient path to drive and park the vehicle is generated with an optimization technique. In particular, this paper focuses on a drive control for electrified vehicles to track the reference trajectory at a desired speed given from the assist system.
2015-04-14
Technical Paper
2015-01-0724
Liangxu Ma, Liangyao Yu, Jian Song, WenWei Xuan, Xuhui Liu
Abstract This paper presents a new magnetorheological braking which can be used in vehicles. Magneto-rheological (MR) fluid is a novel material which can be used in different components of vehicle. Magneto-rheological fluids (MRF) are suspensions of micron size whose yield stress varies rapidly as the change of magnetic field. The use of MRF in vehicles has been gaining popular recently due to its strong rheological effect, fast response and low energy consumption. Besides, these performances give designers more choice in automotive designs. However, most of the related research of MRF brake is about the construction of small prototype to verify its rheological performance. As a result, research progress is limited to calculation and simulation which make the braking force of prototype can hardly meet the requirement of vehicle due to a lack of optimal design and the understanding of MRF in the situation of high sheer stress and magnetic field.
2015-04-14
Technical Paper
2015-01-0658
Min Zhou, Lifu Wang, Jie Zhang, Nong Zhang
Abstract Hydraulic suspension systems with different interconnected 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 wheels', 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.
2015-04-14
Technical Paper
2015-01-0654
Bing Zhu, Jiapeng Gong, Jian Zhao, Jian Wu, Weiwen Deng
Abstract The permanent-magnet DC motor, which is 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 makes sure the pressure decreases 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, an accurate speed control algorithm was developed for the permanent-magnet DC motor of the ABS to implement the performance of the system, reduce the noise and save the energy in the meanwhile.
2015-04-14
Technical Paper
2015-01-0657
Binglu Tu, Kai Shen
Abstract 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 aim is to eliminate the security risks of sideslip or ε<1 due to excessive or insufficient braking force, simplify structure, reduce cost, and improve the eligibility from ε≥0.75 to ε≥0.95.
2015-04-14
Technical Paper
2015-01-1410
Shotaro Odate, Kazuhiro Daido, Yosuke Mizutani
Abstract According to the North American National Automotive Sampling System Crashworthiness Data System (NASS/CDS), approximately one-half of all accidents during driving are of the secondary collision pattern in which the collision event involves the occurrence of secondary collision. Accidents involving impact to a stopped vehicle (chain-reaction collisions) have increased to approximately 3% of all accidents in North America, and although the rate of serious injury is low, cases have been reported of accidents in which cervical sprain occurs as an after-effect[1]. In order to mitigate these circumstances, research has been conducted on systems of automatic braking for collisions. These systems apply brakes automatically when a first collision has been detected in order to avoid or lessen a second collision. Research on automatic collision braking systems, however, has not examined the multiple collisions parked [1, 2].
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 technologies can effectively improve vehicle safety. Most of them predict vehicle crashes using radar or video, but they can't be applied extensively currently due to the high cost. Another collision forecasting method is more economic which is based on the driver behavior and vehicle status, such as the acceleration, angular velocity of the brake pedal and so on. However, the acceleration and angular velocity of the brake pedal will change with the driver and the vehicle type. In order to study the effect of different drivers and vehicle types on the 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 tests.
2015-04-14
Technical Paper
2015-01-1328
Da-Wei Gao, Xing-Xing Huang, Jun Xu, Song-Lin Zheng
Abstract Taking a domestic brand car as example, this paper is about how to find out a three-point nonlinear stiffness characteristic curve which can meet the requirements of variable stiffness and three-load condition. The new coil spring gives the passive suspension a lot of improvements in riding and safety, changing the nonlinear stiffness characteristic from weak to strong. This paper summarizes the optimization design method for the rear suspension coil spring, which includes the fitting of ideal stiffness characteristic curve, quantitative method for figuring out how the change of vehicle load influences the load on rear suspension axle, the design method of variable stiffness coil spring which corresponds to the change of vehicle load. A new kind of modified ideal point solution for building the objective function was also put forward.
2015-04-14
Technical Paper
2015-01-1237
Xiaoming Chen, Jeff L. Conklin, Robert M. Carpenter, Jeff Wallace, Cynthia Flanigan, David A. Wagner, Vijitha Kiridena, Stephane Betrancourt, Jason Logsdon
Abstract The Multi Material Lightweight Vehicle (MMLV) developed by Magna International and Ford Motor Company is a result of a US Department of Energy project DE-EE0005574. The project demonstrates the lightweighting potential of a five passenger sedan, while maintaining vehicle performance and occupant safety. Prototype vehicles were manufactured and limited full vehicle testing was conducted. The Mach-I vehicle design, comprised of commercially available materials and production processes, achieved a 364kg (23.5%) full vehicle mass reduction, enabling the application of a 1.0-liter three-cylinder engine resulting in a significant environmental benefits and fuel consumption reduction. As part of this project, several automotive chassis components were selected for development and evaluation on the MMLV C/D segment passenger sedan.
2015-04-14
Technical Paper
2015-01-1127
Wenbin Liu, Gangfeng Tan, Xiaoqing Tian, Zhiqiang Hu, Yuanqi Gao, Zhi Li, Junyi Yuan, Wei Liu
Abstract The hydraulic retarder is an important auxiliary braking device for the heavy vehicle, which has some characteristics, such as the big brake torque and long duration braking, when the vehicle is traveling in braking state. However, the transmission power loss will be produced when the vehicle is traveling in non-braking state. This transmission power loss is called Air-friction. Firstly, the air flow distribution characteristics of retarder cavity are studied by computational fluid mechanics, and the Air-friction characteristic in different conditions is analyzed. Then, according to the Air-friction characteristics for the condition of different filling density, a set of vacuum air loss reduction system is designed. Meanwhile, the test bench for retarder Air-friction is set up, the test data of the revolution speed, pressure in cavity and air loss resistance is obtained according to the test bench for hydraulic retarder.
2015-04-14
Technical Paper
2015-01-1118
Fengyu Liu, Li Chen, Jian Yao, Jianlong Zhang, Chengliang Yin, Dongxu Li, Chunhao Lee, Ying Huang
Abstract Dry dual clutch transmission (DCT) has played an important role in the high performance applications as well as low-cost market sectors in Asia, with a potential as the future mainstream transmission technology due to its high mechanical efficiency and driving comfort. Control system simplification and cost reduction has been critical in making dry DCT more competitive against other transmission technologies. Specifically, DCT clutch actuation system is a key component with a great potential for cost-saving as well as performance improvement. In this paper, a new motor driven clutch actuator with a force-aid lever has been proposed. A spring is added to assist clutch apply that can effectively reduce the motor size and energy consumption. The goal of this paper is to investigate the feasibility of this new clutch actuator, and the force-aid lever actuator's principle, physical structure design, and validation results are discussed in details.
2015-04-14
Technical Paper
2015-01-1211
Zhuoping Yu, Caitao Jian, Songyun Xu, Lu Xiong
Abstract To research the dynamic response of active power source of electronic hydraulic brake system, the paper proposes a restricted distribution control strategy. Building control strategy model and active power source model to simulation with Matlab/Simulink and AMEsim, and bench test is conducted on different driving cycles, which proves that the dynamic response of active power source is fit and controllable by adjusting PID parameters.
2015-04-14
Technical Paper
2015-01-1356
Atishay Jain
Abstract Conventional motorcycle swingarm design includes steel tubing and sheet metal structures. Conventional swingarm are inherently over-designed as their design comprises of tubular structures of same cross section through the entire length of the swingarm, whereas the stress induced varies along the length (maximum near the frame pivot). An aluminum alloy swingarm design even when subjected to casting manufacturing constraints, has the potential for better material layout and weight minimization. But obtaining an ideal material layout for maximum performance can be a challenge as it requires a number of time consuming design iteration cycles. This paper aims to use concept based design methodology for design of aluminum alloy swing arm by application of topology optimization techniques to meet styling and structural targets and thus, obtain an end user product.
2015-04-14
Technical Paper
2015-01-1347
Fiona Ruel, Pierre-Olivier Santacreu, Saghi Saedlou, Guillaume Badinier, Jean Herbelin
Abstract In order to meet new environmental regulations (i.e. mass of CO2 rejected in the atmosphere per km), car manufacturers are looking for new solutions to lighten chassis and structural parts in cars. High strength steels formed by hot stamping have proved to be good candidates for achieving better in-use performances together with a lighter structure. In particular, the martensitic stainless steel MaX fulfils the industrial targets for chassis parts in terms of mechanical and fatigue properties. For instance, from a cold formed baseline made of 600 MPa carbon steel, a 50 % mass reduction can be expected with a hot stamped suspension arm made of MaX and included a new clamshell design. However, those parts are often made of a complex assembly of different materials (high strength steels, aluminium and cast iron among others) which are subjected to aggressive environments in service. Therefore galvanic corrosion of those complex assemblies has to be evaluated.
2015-04-14
Technical Paper
2015-01-1345
Srinivas Kurna, Arpit Mathur, Sandeep Sharma
Abstract In commercial vehicle, Leaf Spring design is an important milestone during product design and development. Leaf springs are the most popular designs having multiple leaves in contact with each other and show hysteresis behavior when loaded and unloaded. Commonly used methods for evaluation of leaf spring strength like endurance trials on field and Rig testing are time consuming and costly. On the other hand, virtual testing methods for strength and stiffness evaluation give useful information early in the design cycle and save considerable time and cost. They give flexibility to evaluate multiple design options and accommodate any design change early in development cycle. A study has been done in Volvo-Eicher to correlate Rig result with Finite Element Analysis (FEA) simulation result of Multi-stage Suspension Leaf Spring, entirely through Finite Element Analysis route.
2015-04-14
Technical Paper
2015-01-1373
Yulong Lei, Hui Tang, Xingjun Hu, Ge Lin, Bin Song
Abstract With the continuous improvement of the road condition, commercial vehicles get to be faster and more overloaded than before, which puts higher pressure on the vehicle braking system. Conventional friction braking has been difficult to meet the needs of high-power commercial vehicle. The auxiliary braking equipment will become the future trend for commercial vehicle. Hydraulic retarder is superior to secondary braking equipment. Previously hydraulic retarder research mainly focus on flow field analysis, the braking torque calculation, cascade system optimization and control methods for hydraulic retarder. The gas-liquid two-phase flow in working chamber is less researched. Based on this, this article discusses on the hydraulic retarder from two aspects. Firstly, this paper presents a block modeling method for hydraulic retarder system.
2015-04-14
Technical Paper
2015-01-1371
Samuel T. Bartlett
Abstract With the many model variations produced on the same production line because of increasing power train options, fuel efficiency targets, performance and customer demands we saw limitations with our existing suspension mount equipment. Layout options were limited due to guided shifts and transfers. Large supporting frame work took up valuable floor space. Model wheelbase sizes and suspension pallets were limited to the model requirements of the original equipment. We needed an adaptable system to install the engine/front suspension assemblies and the rear suspension assemblies. We found a solution by utilizing the capabilities of 6-axis industrial robots to make the core components of the equipment simpler; many of the functions of a traditional machine can now be accomplished by the robot. We were able to vary install position to optimize handling characteristics and accommodate the model-to-model varieties on the same production line.
2015-04-14
Technical Paper
2015-01-1363
Charles Yuan, Niat Mahmud Rahman
Abstract For a CAE model of the park pawl dynamic system, the engagement speed calculation is done by controlling the input rotational velocity of the vehicle. Usually, it requires multiple adjustment of the input rotational velocity to get the engagement speed and that demands time, effort and file management skill of an analyst. The current objective of this paper is to demonstrate how software Isight, working with ABAQUS Explicit as the solver, can be used to automate the engagement speed calculation procedure and thus reduce the time and effort required of a CAE analyst. The automated system is developed in a way such that the accuracy of the results can be controlled by the end user. It is observed that the automated system significantly saves an analyst's effort. The system design can be optimized easily for modifiable design features such as the torsional spring and the actuator spring stiffness values using the proposed procedure.
2015-04-14
Technical Paper
2015-01-0634
Adebola Ogunoiki, Oluremi Olatunbosun
Abstract This paper presents a statistical characterisation of the effects of variations in vehicle parameters on vehicle road load data using a quarter vehicle as a case study. A model of a quarter vehicle test rig constructed from a commercial SUV is created in a multi-body dynamics (MBD) simulation environment to reproduce the real-life behaviour of the SUV. The model is thereafter validated by correlating the response data collected from both the model and laboratory test rig to the same road input. In order to ensure that only the effects of the variation of the vehicle parameters are captured, a time domain drive signal for a kerb strike road event on the physical vehicle is generated from the proving ground data collected during durability testing of the vehicle.
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