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WIP Standard
2014-04-10
This SAE Recommended Practice provides performance and sampling requirements, test procedures, and marking requirements for aftermarket wheels intended for normal highway use on passenger cars, light trucks, and multipurpose passenger vehicles. For aftermarket wheels on trailers drawn by passenger cars, light trucks or multipurpose vehicles, see SAE J1204. These performance requirements apply only to wheels made of materials included in Table 1 and Table 2. New nomenclature and terms are added to clarify wheel constructions typically not used in OEM applications. The testing procedures and requirements are based on SAE standards listed in the references.
WIP Standard
2014-04-07
This SAE Standard covers performance requirements and methods of test for master cylinder reservoir diaphragm gaskets that will provide a functional seal and protection from outside dirt and water.
Technical Paper
2014-04-01
Quan Zhou, Gangfeng Tan, Xuexun Guo, Zhigang Fang, Bian Gong
Abstract Focusing the vehicle riding safety and global environmental problems, plenty of solutions on vehicle braking systems appeals during the recent period. Criteria and standards set up for commercial vehicles which should have equipped assisted braking systems were established by amounts of governments. Since eddy current retarders plays an important role in the area of assisted braking system, this article presents an energy-recuperation retarder, which is parallel connected with the driveline through a planet gear system. This paper offers a particular Energy-Recuperation Eddy Current Retarder (ERECR) system with a pedal control system and its characteristics is presented, either. Initially, the constitution of the energy-recuperation eddy current retarder system is established whereas the working principle of the energy-recuperation eddy current retarder is presented by modeling the system and simulation. According to the characteristics presented by simulation, the newly designed mechanical control system is established, and the characteristics of it is analysis.
Technical Paper
2014-04-01
Chen Lv, Junzhi Zhang, Yutong Li, Ye Yuan
Abstract Regenerative braking, which can effectively improve vehicle's fuel economy by recuperating the kinetic energy during deceleration processes, has been applied in various types of electrified vehicle as one of its key technologies. To achieve high regeneration efficiency and also guarantee vehicle's brake safety, the regenerative brake should be coordinated with the mechanical brake. Therefore, the regenerative braking control performance can be significantly affected by the structure of mechanical braking system and the brake blending control strategy. By-wire brake system, which mechanically decouples the brake pedal from the hydraulic brake circuits, can make the braking force modulation more flexible. Moreover, its inherent characteristic of ‘pedal-decouple’ makes it well suited for the implementation in the cooperative regenerative braking control of electrified vehicles. With the aims of regeneration efficiency and braking performance, a regenerative braking control algorithm for electrified vehicles equipped with a brake-by-wire system is researched in this paper.
Technical Paper
2014-04-01
James Gramling
Abstract It is very important to note that most present-day CVT's drive with a friction element. Unlike gears that can be produced with any size necessary for the torque load they must transfer, CVT's are limited in torque capacity and are only marginally suitable for small vehicle applications. A system is described using two variable-inertia flywheels to not only supply the heavy torque requirements during acceleration of a vehicle but also operate in reverse capturing the otherwise wasted decelerating torque (I.E. braking torque). This system (called Kinetic Energy Power Transmission System or KEPTS) provides all of the documented benefits of the use of an IVT for motor vehicle acceleration and also incorporates regenerative braking. The significance of the system is that besides providing a complete KERS (kinetic energy recovery and storage) system, all accelerating and braking torque is provided by the two variable-inertia flywheels, thus allowing the main motive engine (ICE, electric traction motor, gas turbine, etc.) to operate at a fixed angular velocity (rpm) isolated from large torque variances, and the CVT elements can be minimized in size (I.E. low-torque).
Technical Paper
2014-04-01
Robert Lloyd
Abstract A hydro-mechanical transmission is described that approximates the “gearing” performance of a continuously variable transmission and incorporates all functions required for hydraulic regenerative braking. Other characteristics such as efficiency, noise, and responsiveness, match or exceed that of present day conventional automatic transmissions. Performance and physical sizing are shown for passenger vehicle, bus and truck transmissions.
Technical Paper
2014-04-01
Yao Fu, Yulong Lei, Ke Liu, Yuanxia Zhang, Huabing Zeng
Abstract In a traditional shift control strategy, the gear range is selected based on the throttle opening and the vehicle speed. The disadvantage of two-parameter based system is that the shift map is lack of adaptability in certain special conditions. The driving environment and the true intentions of the drivers are not fully taken into account by the shift control system. Therefore, improving the feasibility of the shift control strategy for the true intentions of the driver and driving environment is of great significance. Under braking conditions, Automatic transmission shift map with two parameters is unable to use engine braking effectively, which affects the drivability and safety of vehicles greatly. This paper presents a newly developed shift control strategy under braking conditions. First of all, the necessity of engine braking was analyzed. Then, this paper proposed a shift control strategy based on fuzzy inference of braking duration, load, braking deceleration and the vehicle speed.
Technical Paper
2014-04-01
Jiageng Ruan, Paul Walker
Abstract Regenerative braking energy recovery bears significance in extending the driving mileage of electric vehicles (EVs) while fulfilling real-time braking demands. Braking energy strategy plays a significant role in improving the regenerative braking performance and ensuring braking safety. This paper presents a regenerative braking energy recovery strategy for an example EV with a two-speed Dual Clutch Transmission (DCT). The two-speed DCT, with simple structure, can effectively extend the active vehicle speed-range for regenerative braking. Meanwhile, a shifting strategy is proposed for the DCT, working with the presented braking energy recovery strategy, to optimize the brake force distribution between front and rear wheels, motor and friction brake force. The EVs' model with the proposed regenerative braking strategy and the optimal shifting schedule was established and implemented in Matlab/Simulink. A testing rig based on an example EV was then set up in our laboratory to experimentally validate the proposed strategy.
Technical Paper
2014-04-01
Yoshiharu Inaguma, Naohito Yoshida
Abstract This article describes the friction torque caused by pushing vanes on a cam contour and its influence on a variation of pump driving torque in a balanced vane pump. In the vane pump, the friction torque of the vane is significant to discuss a variation in the driving torque as well as an improvement in the mechanical efficiency. In this work, the influence of the thickness of a vane and the number of vanes on the friction torque of the vane and their additional effect on the variation in the pump driving torque are theoretically and experimentally investigated. The friction torque of the vane occupies a large part of the total friction torque in the vane pump and strongly depends on the number of vanes existing in a suction area as well as the thickness of the vane. The variation in the pump driving torque is composed of the variation of the ideal torque and that of the friction torque of the vane. The former is determined by vane arrangement in the suction area, and the latter is caused by a change in the number of vanes in the suction area.
Technical Paper
2014-04-01
Takao Suenaga, Takahiro Jo
Abstract The automotive industry is placing high importance on technologies that can reduce CO2, even in a highly fuel-efficient compact car. One major technology is Stop & Start(S&S) System, with a combined energy regeneration system. A key component of the system is a power supply storage device that has high-charge acceptance, light weight, and compact size. We believe a Lithium-ion (Li-ion) battery completely meets these requirements. For the battery, there are three key points: 1 Battery cell specification2 State Of Charge (SOC) detection method3 Temperature management for Li-ion battery. We have already proposed the battery cell and the SOC detection during SAE 2013, and now we are going to introduce “Temperature Management”. If the temperature of a Li-ion battery operates over 60 degrees Celsius, the battery could be severely damaged. Therefore, temperature management of the battery is very important. Conventionally, the temperature is managed by several thermistors and a cooling fan.
Technical Paper
2014-04-01
Rong He, Hongyu Zheng, Changfu Zong
Abstract In order to improve the braking energy recovery and ensure the braking comfort, a new type of regenerative braking coordinated control algorithm is designed in this paper. The hierarchical control theory is used to the regenerative braking control algorithm. First, the front axle braking force and rear axle braking force are distributed. Then the rear axle motor braking force and mechanical braking force are distributed. Finally, the dynamic coordinated control strategy is designed to control pneumatic braking system and motor braking system. Aimed at keeping the fluctuation of the total braking force of friction and the regenerative braking force small during braking modes switch, a coordinated controller was designed to control the pneumatic braking system to compensate the error of the motor braking force. Based on Matlab/Simulink platform, a parallel hybrid electric bus simulation model with electric braking system (EBS) was established. Then the simulation in different operating conditions was used to analyze the braking energy utilization and the braking performance based on the simulation model.
Technical Paper
2014-04-01
Youichi Kamiyama
Abstract Tire cavity noise has long been one of the main road noise issues. Various ideas for devices to reduce tire cavity noise have been patented or discussed in technical reports, but many issues remain for commercialization, and at present only some tires have appeared as products. Therefore, technology was developed for mounting Helmholtz resonators on the wheels, enabling reduction of tire cavity noise without placing restrictions on the tires. The advantage of this technology is that the cost and productivity targets needed for mass production can be satisfied without impairing the tire and wheel functions. The aim of this development was to construct low-cost device technology that is well-suited to mass production and enables reduction of tire cavity noise to an inaudible sound pressure without adversely affecting dynamic product marketability such as strength and durability performance and handling performance. In order to realize that aim, the device configuration employed a structure that assembles separate thin, lightweight plastic resonators in the wheel well.
Technical Paper
2014-04-01
Swapnil S. Kulkarni, Muragendra Magdum, Ravi B.
Abstract Automotive shock absorber shims are subjected to deformation while generating the pressure differential across the rebound and compression chambers. Considering the contact, large deflection, and material this shim stack deformation will be nonlinear throughout the working velocity of shock absorbers. The deformation of shim stack mainly depends on number and geometry of deflection disk, number and geometry of ports, and clamping disk geometry on which shims are rested. During the rebound and compression stroke of the shock absorber, the oil flows through the piston and base valve ports. High pressure oil developed during mid and high velocity of shock absorber results in deflection of shim stack in piston and base valve assembly. This deflection leads to oil leakage through the shim stack which results in change in damping force by the shock absorber. The fluid pressure from the flow passage (well) acting over surface area of shim differs while causing an elastic bending of the shims.
Technical Paper
2014-04-01
Manchi Venkateswara Rao, Jos Frank, Mohit Kohli
Abstract Brake groan noise is resolved without any major change in the design of brake system and vehicle sub-system components in the development phase of a utility vehicle. The groan noise is observed during the end of the stopping of the vehicle under moderate braking. The concerned NVH issue is perceived as unacceptable noise in the passenger compartment. Groan induced vibration is subjectively felt on steering and seat frame. A typical process is established to successfully reproduce the groan which helped in precisely evaluating the effect of modifications proposed. The temperature range of the disc which has the highest probability to produce the groan noise is found out experimentally. The transfer path analysis is carried out to find the path contributions from suspension. Acoustic transfer functions from considered paths are measured with the suspension removed from vehicle. Effects of addition of mass on various locations of suspension and stiffness change of suspension bushings are studied.
Technical Paper
2014-04-01
Gang Tang, Jinning Li, Chao Ding, Yunqing Zhang
Abstract This paper describes a simplified model to identify sprung mass using golden section method, the model treats the unsprung mass vertical acceleration as input and the sprung mass vertical acceleration as output, which can avoid the nonlinear influence of trye. Unsprung mass can be also calculated by axle load and the identified sprung mass. This study carries out road test on the vehicle ride comfort and takes a scheme that the group of 20 km/h is used to identify sprung mass and the group of 80 km/h is used to verify the identification result. The similarity of the results from the simulation and experiments performed are, for the sprung mass, 98.59%. A conclusion can be drawn that the simple method to measure the sprung mass in the suspension systems in used vehicles, such as the vehicle shown here, is useful, simple and has sufficient precision.
Technical Paper
2014-04-01
Yang Qi, Nenggen Ding, Feng Gao, Guoyan Xu
Abstract This paper develops a control strategy for tractor semi-trailers by active trailer steering, aiming at minimizing the sweep width of the vehicle at low speeds. The metric of sweep width is defined to evaluate the maneuverability of tractor semi-trailers under a circular motion with constant speeds. The active steering angle of the trailer for each given front wheel steering angle of the tractor is determined to minimize the sweep width, based on solution of equilibrium equations of both the tractor and the trailer in the yaw plane at a very low speed such as 5 km/h. The two steering angles of the tractor and the trailer are fitted to form an open-loop active-steering control algorithm. A nonlinear tractor semi-trailer system model is built for co-simulation purpose by using TruckSim and MATLAB/SIMULINK to evaluate the active trailer steering algorithm. Simulation results show that, under the low-speed roundabout and double lane change maneuvers, the active trailer steering controller can significantly reduce the sweep width and thus improve the low-speed maneuverability.
Technical Paper
2014-04-01
Mario Milanese, Ilario Gerlero, Carlo Novara
Abstract The vehicle sideslip angle is one of the most important variables for evaluating vehicle dynamics. The potential value of such a variable for obtaining significant improvements over current stability control systems is widely recognized. However, its direct measurement requires the use of complex and expensive devices which cannot be used in production cars. Large research efforts has been devoted to the problem of estimating the sideslip angle from other variables currently measured by standard Electronic Stability Control (ESC) sensors. However, at the best of author's knowledge, until now no application to production cars is known. In this paper, a new sideslip angle estimation technology is presented. Based on the innovative DVS methodology recently developed by the authors, a software algorithm, indicated as DVS/SA (Direct Virtual Sensor of Sideslip Angle), is designed, which estimates the sideslip angle from measurements of the yaw rate, lateral and longitudinal acceleration, wheel speed, steering angle, available from ESC sensors of most present production cars.
Technical Paper
2014-04-01
Ken Archibald, William Schnaidt, Rick Wallace, Kyle Archibald
Abstract SAE J2562 defines the background, apparatus and the directions for modifying the Scaled Base Load Sequence for a given a wheel rated load for a wheel design. This practice has been conducted on multiple wheel designs and over one hundred wheel specimens. All of the wheels were tested to fracture. Concurrently, some of the wheel designs were found to be unserviceable in prior or subsequent proving grounds on-vehicle testing. The remainder of the wheel designs have sufficient fatigue strength to sustain the intended service for the life of the vehicle. This is termed serviceable. Using the empirical data with industry accepted statistics a minimum requirement can be projected, below which a wheel design will likely have samples unserviceable in its intended service. The projections of serviceability result in a recommendation of a minimum cycle requirement for SAE J2562 Ballasted Passenger Vehicle Load Sequence.
Technical Paper
2014-04-01
Jongchol Han, Zong Changfu, Zhao Weiqiang
Abstract This article focuses on the research of control algorithm and control logic for the pneumatic EBS (Electronic Braking System) of commercial vehicle. An overall technical program was proposed which develops conventional braking and emergency braking for commercial vehicle EBS. According to the overall scheme, the methods of vehicle state estimation and driver's braking intention were determined, modeling and simulation for key components of commercial vehicle EBS were then carried out. This lead to the development of deceleration control, braking force distribution, brake assist and ABS control. Simulation models for key components of EBS and control strategy were validated through hardware-in-the-loop simulation tests. Simulation results show that the control strategy improves vehicle braking stability and vehicle active safety.
Technical Paper
2014-04-01
Ben Wen, Gregory Rogerson, Alan Hartke
Abstract Tire rolling resistance is one of tire performance indicator that represents a force needed to maintain the constant rolling of a tire. There are quite few methods and standards to measure tire rolling resistance, such as ISO-28585, ISO-18164, SAE-J1269, SAE-J2452, …. These tests have been used by tire companies, vehicle manufactures, and government agencies to evaluate tire rolling resistance performance. SAE-J1269 and SAE-J2452 are two popularly used multi-condition rolling resistance tests for passenger and light truck tires. Examining the test conditions and procedures of these two test standards showed that some key procedures and conditions from both standards are similar although there are many difference as well. The study presented here is to analyze test results from both tests and their correlation under certain conditions. If the correlation exists, one test may provide test results for both test conditions, therefore, test efficiency can be improved.
Technical Paper
2014-04-01
Hiroki Taniguchi, Takeshi Kimura, Yuya Takeda, Taku Suzuki, Akihiro Kaneko, Tomohiro Jinbo
Abstract This paper describes a control method to improve straight-line stability without sacrificing natural steering feel, utilizing a newly developed steering system controlling the steering force and the wheel angle independently. It cancels drifting by a road cant and suppresses the yaw angle induced by road surface irregularities or a side wind. Therefore drivers can keep the car straight with such a little steering input adjustment, thus reducing the driver's workload greatly. In this control method, a camera mounted behind the windshield recognizes the forward lane and calculate the discrepancy between the vehicle direction and the driving lane. This method has been applied to the test car, and the reduction of the driver's workload was confirmed. This paper presents an outline of the method and describes its advantages.
Technical Paper
2014-04-01
Ralph S. Shoberg, Jeff Drumheller
Abstract Reliable wheel attachment must start with proper tightening of the lug nuts in order to achieve the clamping force necessary to hold the vehicle's wheels securely for all operating conditions. It is the purpose of this paper to provide a complete overview of the theory and practice of using torque-angle signature analysis methods to examine the installation and audits of wheel lug nuts. An accurate estimate of clamp load can be determined without actually measuring the clamp load. The torque-angle signature analysis, known as “M-Alpha”, performed on tightening and loosening curves provides a powerful tool to understand the integrity of a bolted joint when clamp load data is not available. This analysis technique gives insight into the frictional effects, material properties, and geometric factors that can affect the clamp load attained during the installation process.
Technical Paper
2014-04-01
Andrew Nevin, Eric Daoud
Abstract Traditional tread depth measurements require manual utilization of a mechanical device to acquire measurements at each location of interest on a tire. Drive-over machine-vision sensors are becoming available as a means for measuring tread depth. These sensors typically consist of a laser and a camera contained in an environmentally-sealed sensor housing. Tires approach the sensor over the supporting surface, while a laser projects an illuminating line across the tread surface for capture in a digital image. This scan is evaluated to provide a single 2D contour of tread depth at the illuminated line. Advanced machine-vision sensors acquire a sequence of images, which results in a multitude of data points over a 3D region of the tread surface. Post-processing of the acquired images illustrates the observed tread pattern and establishes multiple tread depth measurements. Measurements determined by the advanced sensors from hundreds of tires were compared to manual measurements acquired with analog and digital mechanical gauges.
Technical Paper
2014-04-01
Akihito Yamamoto, Haruhiko Sugai, Ryo Kanda, Shuuichi Buma
Abstract This paper reports the results of a study into a preview control that uses the displacement of the road surface in front of the vehicle to improve for front and rear actuator responsiveness delays, as well as delays due to calculation, communication, and the like. This study also examined the effect of a preview control using the eActive3 electric active suspension system, which is capable of controlling the roll, pitch, and warp modes of vehicle motion.
Technical Paper
2014-04-01
Prashanth KR. Vaddi, Sandeep Vinjamuri, Kumar Cheruvu
Abstract Advanced research in ABS (Anti-lock Braking System), traction control, electronic LSD's (Limited Slip Differential) and electrical powertrains have led to an architecture development which can be used to provide a controlled yaw moment to stabilize a vehicle. A steer assistance mechanism that uses the same architecture and aims at improving the vehicle response to the driver steering inputs is proposed. In this paper a feed-forward approach where the steering wheel angle is used as the main input is developed. An optimal control system is designed to improve vehicle response to steering input while minimizing the H2 performance of the body slip angle. The control strategy developed was simulated on a 14 DOF full vehicle model to analyze the response and handling performance.
Technical Paper
2014-04-01
Anthony Barkman, Kelvin Tan, Arin McIntosh, Peter Hylton, Wendy Otoupal-Hylton
This paper discusses a project intended as a design study for a team of college students preparing for careers in motorsports. The project's objective was to conduct a design study on the possible redesign of the suspension for a dirt-track sprint car. The car examined was typical of those which race on one-quarter to one-half mile dirt oval tracks across the United States. The mission of this concept study was to develop a different configuration from the traditional torsion bar spring system, for the front end. The design included moving the dampers inboard with the addition of a rocker to relate the movement through the front suspension system. For the rear end, components were designed to allow the radius rod to be adjustable from the cockpit, thus providing the driver with adjustability to changing track conditions. The project goal was to design functional front end and rear end changes that could provide a positive impact on handling as well as keeping the system easy to replace in a short period of time.
Technical Paper
2014-04-01
Xiaomin Lin, Nenggen Ding, Guoyan Xu, Feng Gao
Abstract Most tractor-semitrailers are fitted with multi-axle trailers which cannot be actively steered, and such vehicles with an articulated configuration are inclined to exhibit instability such as trailer swing, jack-knifing, and rollover at high speed. Proposed in this paper is an optimal control of the yaw stability of tractor-semitrailers at high speed by applying an active trailer's steering angle. An optimal control algorithm is designed by employing a 3-DOF vehicle model in the yaw plane. The optimal linear quadratic regulator (LQR) approach is used with a cost function including sideslip angles, yaw rates of both tractor and trailer, and trailer's steering angle. The yaw stability at the high speed is also quantified by the dynamic performance measurements of lateral path deviation, hitch angle and rearward amplification (RA). The algorithm is evaluated by co-simulations using TruckSim and Matlab/Simulink softwares. Simulation results under double lane change maneuvers show that trailer swing and jack-knifing are suppressed with a small path-tracking error and it is concluded that the optimal control of semi-trailer steering can improve the yaw stability at high speed.
Technical Paper
2014-04-01
Shinhoon Kim, John McPhee, Nasser Lashgarian Azad
Abstract A compact sized vehicle that has a narrow track could solve problems caused by vehicle congestion and limited parking spaces in a mega city. Having a smaller footprint reduces the vehicle's total weight which would decrease overall vehicle power consumption. Also a smaller and narrower vehicle could travel easily through tight and congested roads that would speed up the traffic flow and hence decrease the overall traffic volume in urban areas. As an additional benefit of having a narrow track length, a driver can experience similar motorcycle riding experience without worrying about bad weather conditions since a driver sits in a weather protected cabin. However, reducing the vehicle's track causes instability in vehicle dynamics, which leads to higher possibility of rollovers if the vehicle is not controlled properly. A three wheel personal vehicle with an active tilting system is designed in MapleSim. The vehicle is driven by constant rotational input which is applied to the rear wheel.
Technical Paper
2014-04-01
Ibrahim A. Badiru
Abstract The automotive industry commonly uses two definitions of the suspension roll center, the Kinematic Roll Center (KRC) - of interest in studying suspension geometry, and the Force-based Roll Center (FRC) - of interest in studying steady-state vehicle dynamics. This paper introduces a third definition, the Dynamic Roll Axis (DRA) - of interest in studying transient vehicle dynamics. The location of each one of these roll centers has a unique application to vehicle design and development. Although the physical meaning of each roll center is significantly different, the generic term “roll center” is often used without proper specification. This can lead to confusion about how roll centers influence vehicle behavior. This paper hopes to clarify some of this confusion and is organized into three parts: (1) Describes calculation methods for each of the three vehicle roll centers (for independent suspensions) as well as their relevance to vehicle dynamics; (2) Explains the relationship between the kinematic and force-based roll centers; (3) Offers recommendations on considerations for choosing roll center(s) location during vehicle design.
Technical Paper
2014-04-01
Shreesha Y. Rao, JongYun Jeong, Ryan M. Ashby, Gary J. Heydinger, Dennis A. Guenther
Abstract A Software-in-the-Loop (SIL) simulation is presented here wherein control algorithms for the Anti-lock Braking System (ABS) and Roll Stability Control (RSC) system were developed in Simulink. Vehicle dynamics models of a 6×4 cab-over tractor and two trailer combinations were developed in TruckSim and were used for control system design. Model validation was performed by doing various dynamic maneuvers like J-Turn, double lane change, decreasing radius curve, high dynamic steer input and constant radius test with increasing speed and comparing the vehicle responses obtained from TruckSim against field test data. A commercial ESC ECU contains two modules: Roll Stability Control (RSC) and Yaw Stability Control (YSC). In this research, only the RSC has been modeled. The ABS system was developed based on the results obtained from a HIL setup that was developed as a part of this research. The RSC system was developed after a careful study of the field test data obtained from the vehicle manufacturer in which the ESC was activated.
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