Criteria

Text:
Topic:
Display:

Results

Viewing 271 to 300 of 8253
2016-09-27
Technical Paper
2016-01-8102
Rıfat Kohen Yanarocak, Yavuz Can Ozkaptan
Abstract The intake and exhaust valve spring of a 12.7L heavy duty diesel engine was instrumented with torque/shear rosette type strain gages to measure torsional stresses applied on the springs under different engine operating conditions. The engine was tested with no load, partial load and full load conditions and the effect of engine brake switch loading operation on the springs is investigated. Additional measurement of the valve lift motion and the peak fire pressure values from exactly the same cylinder were conducted to better understand the exact timing of the forces applied on the spring. This study gave an insight to the design engineer to determine the dynamic safety margin of the spring under permissible torsional stress values and optimize the material type of the spring accordingly. Another achievement is to measure any possible unpredictable torsional stress values occurred during engine operation when the engine brake is turned on/off and correlate the CAE model.
2016-09-27
Technical Paper
2016-01-8121
Riccardo Bianchi, Addison Alexander, Andrea Vacca
Abstract Typically, earthmoving machines do not have wheel suspensions. This lack of components often causes uncomfortable driving, and in some cases reduces machine productivity and safety. Several solutions to this problem have been proposed in the last decades, and particularly successful is the passive solution based on the introduction of accumulators in the hydraulic circuit connecting the machine boom. The extra capacitance effect created by the accumulator causes a magnification of the boom oscillations, in such a way that these oscillations counter-react the machine oscillation caused by the driving on uneven ground. This principle of counter-reacting machine oscillations through the boom motion can be achieved also with electro-hydraulic solutions, properly actuating the flow supply to the boom actuators on the basis of a feedback sensors and a proper control strategy.
2016-09-27
Journal Article
2016-01-8104
Ryo Yamaguchi, Hiromichi Nozaki
Abstract In this study, we report on the development of a steering assistance control system that feeds back information on the outside environment collected by laser sensors to the vehicle driver. The system consists of an emergency avoidance assistance control program that performs obstacle detection and avoidance, as well as a cornering assistance control program that operates by detecting the white lines painted on roadways. Driving simulator experiments were conducted in order to confirm the effectiveness of these functions, as well as to improve understanding of the synergistic effects of the steering assistance and chassis control functions: camber angle control and derivative steering assistance (DSA) control.
2016-09-27
Journal Article
2016-01-8029
Chrysostomos-Alexandros Bekakos, George Papazafeiropoulos, Dan J. O'Boy, Jan Prins, George Mavros
Abstract A novel semi-analytical solution has been developed for the calculation of the static and dynamic response of an off road tire interacting with a deformable terrain, which utilizes soil parameters independent of the size of the contact patch (size-independent). The models involved in the solution presented, can be categorized in rigid and/or pneumatic tires, with or without tread pattern. After a concise literature review of related methods, a detailed presentation of the semi-analytical solution is presented, along with assumptions and limitations. A flowchart is provided, showing the main steps of the numerical implementation, and various test cases have been examined, characterized in terms of vertical load, tire dimensions, soil properties, deformability of the tire, and tread pattern. It has been found that the proposed model can qualitatively capture the response of a rolling wheel on deformable terrain.
2016-09-27
Journal Article
2016-01-8030
Dai Quoc Vo, Hormoz Marzbani, Mohammad Fard, Reza N. Jazar
Abstract As long as a tire steers about a titled kingpin pivot, the point coming in contact with the road moves along its perimeter. This movement affects the determination of kingpin moments caused by the tire forces, especially for large steering angles. The movement, however, has been neglected in the literature on the steerable-tire-kinematics-related topics. In this investigation, the homogeneous transformation is employed to develop a kinematic model of a steering tire in which the instantaneous ground-contact point on the tire is considered. The moments about the kingpin axis caused by tire forces are then computed based on the kinematics. A four-wheel-car model is constructed for determining the kingpin moment of steering system during the low-speed cornering maneuver. The result shows that the displacement of the ground-contact point along the tire perimeter is significant for large steering angles.
2016-09-27
Journal Article
2016-01-8039
Rui He, Emilio Jimenez, Dzmitry Savitski, Corina Sandu, Valentin Ivanov
Abstract Tire modeling plays an important role in the development of an Active Vehicle Safety System. As part of a larger project that aims at developing an integrated chassis control system, this study investigates the performance of a 19” all-season tire on ice for a sport utility vehicle. A design of experiment has been formulated to quantify the effect of operational parameters, specifically: wheel slip, normal load, and inflation pressure on the tire tractive performance. The experimental work was conducted on the Terramechanics Rig in the Advanced Vehicle Dynamics Laboratory at Virginia Tech. The paper investigates an approach for the parameterization of the Dugoff tire model based on the experimental data collected. Compared to other models, this model is attractive in terms of its simplicity, low number of parameters, and easy implementation for real-time applications.
2016-09-27
Journal Article
2016-01-8106
Sameer Kolte, Ananth Kumar Srinivasan, Akilla Srikrishna
Abstract As we move towards the world of autonomous vehicles it becomes increasingly important to integrate several chassis control systems to provide the desired vehicle stability without mutual interference. The principles for integration proposed in existing technical literature are majorly centralized which are not only computationally expensive but does not fit the current supplier based OEM business model. An Automotive OEM brings multiple suppliers on-board for developing the Active Safety systems considering several factors such as cost, quality, time, ease of business etc. When these systems are put together in the vehicle they may interfere with each other’s function. Decoupling their function results in a need of heavy calibration causing performance trade-offs and loss in development time.
2016-09-27
Technical Paper
2016-01-8006
John Reid, Stewart Moorehead, Alex Foessel, Julian Sanchez
Abstract A transformation of agriculture reached commercial reality at the beginning of this century as automated steering of agricultural machine systems increased the productivity and convenience in crop production systems. Following guidance, additional technologies have resulted in increasing optimized machine productivity. Today, integrated worksite solutions through machine and information management continues to transform agriculture. This is the precursor to autonomous worksite solutions that lead to the optimization of the worksite ecosystem. This paper will review the progress from the perspective of the customer value provided by increasing automated systems and the industry execution of autonomous driving technologies and will enable the pathways to autonomous worksites.
2016-09-27
Technical Paper
2016-01-8031
Nicholas Atanasov, Evan Chenoweth
Abstract Since the introduction of electronically controlled air suspension (ECAS) systems in the nineties, no major improvements have been made in the realm of controlling air suspensions in the heavy duty truck market. Despite the lack of improvement, a need exists for intelligently controlled air suspension systems, specifically systems which can be applied to 6x2 axle configurations in the North American market. This study outlines a concept proposal for a novel suspension control concept which encompasses traction control capabilities in addition to suspension control for improved fuel efficiency benefit. The major novelty of the concept is that, by utilizing specific axle configurations and tires, a shift in pressure from the driven to the non-driven axles may result in improvements in the overall fuel economy of the vehicle.
2016-09-27
Journal Article
2016-01-8010
M. Kamel Salaani, David Mikesell, Chris Boday, Devin Elsasser
Abstract Field testing of Automatic Emergency Braking (AEB) systems using real actual heavy trucks and buses is unavoidably limited by the dangers and expenses inherent in crash-imminent scenarios. For this paper, a heavy vehicle is defined as having a gross vehicle weight rating (GVWR) that exceeds 4536 kg (10,000 lbs.). High fidelity Hardware-in-the-Loop (HiL) simulation systems have the potential to enable safe and accurate laboratory testing and evaluation of heavy vehicle AEB systems. This paper describes the setup and experimental validation of such a HiL simulation system. An instrumented Volvo tractor-trailer equipped with a Bendix Wingman Advanced System, including the FLR20 forward looking radar and AEB system, was put through a battery of different types of track tests to benchmark the AEB performance.
2016-09-18
Technical Paper
2016-01-1936
Ashesh Anil Shah, Kshitiz Raj
Abstract Brake system for any vehicle plays an important role, as safety comes at highest level, also domestic and international safety norms for commercial vehicles are getting stringent. In current scenario of highly competitive commercial market, Payload advantage comes at peak level in customer demand list, also maintainability plays an important role to make sure least vehicle downtime, linked to customer profitability. Finally, if product has less complexity (reducing no. of parts), then it will provide add on benefit to any organization. Considering these customer oriented perspectives, mainly payload & maintenance, along with regulation compliance. We have proposed new Disc brake system for heavy duty commercial vehicle providing maximum payload benefit, along with enhancement in maintainability. It has also enhanced performance and meeting all legislative criteria at vehicle level.
2016-09-18
Technical Paper
2016-01-1934
Arun Kumar Prasad, Baskar Anthonysamy, V.A. Gopalakrishn, Gurdeep Singh Pahwa
Abstract Fierce competition in India’s automotive industry has led to constant production innovation among manufactures. This has resulted in the reduction of the life cycle of the design philosophies and design tools. One of the performance factors that have continues to challenge automotive designer is to design and fine tune the braking performance with low cost and short life cycle. Braking performance of automotive vehicle is facilitated by the adhesion between the tyre and the ground. Braking force generated at the wheels of a vehicle have to appropriately match to the adhesion. Antilock braking system (ABS) is used for this purpose. ABS is a modern braking system which could significantly improve directional stability and reduce stopping distance of a vehicle. However this system still too complicated and expensive to use in low end compact car and pickup truck.
2016-09-18
Technical Paper
2016-01-1918
Yusuke Aoki, Yasuyuki Kanehira, Yukio Nishizawa
Abstract Brake squeal is an uncomfortable noise that occurs while braking. It is an important issue in automobile quality to prevent brake products from squealing. Brake shims are widely used to reduce squeal occurrence rate. The anti-squeal effect of shims is quantified as damping properties measured with a bending mode tester, instead of repeating many dynamometer tests. However, there are cases where measurement results have less correlation to actual squeal suppression rate. Therefore, the evaluation of the anti-squeal effect with a dynamometer or on an actual car is needed until the best shim can be selected. To improve the predicted accuracy of the anti-squeal effect, the difference between measurement conditions and actual braking conditions of shims, was focused on. The bending mode tester measures loss factor under pressure-free conditions, even though shims are compressed by pistons or cylinders towards the backplate of the pad.
2016-09-18
Technical Paper
2016-01-1922
Yongchang Du, Yujian Wang
Abstract Modelling of disc is crucial in analyzing brake squeal since the disc rotates past the non-rotating pads and the pads are coupled with different areas of the disc at different times. However, in most of the complex eigenvalue analysis of brake squeal, the effect of disc rotation was ignored. This paper proposes a closed-loop coupling model for brake squeal analysis. A modal parameter-based rotating disc model, whose dynamic behavior is represented by rotation speed-dependent equivalent modal parameters, is built through space and time-frequency transformation between reference and moving coordinate systems. The orthogonality of the equivalent modal parameters in state-space is derived. By performing modal synthesis in state-space, the rotating disc is incorporated into brake squeal closed-loop coupling model with other stationary components. Dynamic instability of the system is solved through complex eigenvalue analysis in state-space.
2016-09-18
Technical Paper
2016-01-1951
Björn Dingwerth
Abstract Caused by a number of beneficial properties inherently from the zinc-nickel material, this electrodeposited alloy is used more and more for cathodically protecting layers on ferrous components like cast iron brake calipers. Direct plating from acidic solutions is the state-of-the-art solution for zinc-nickel surface finishing of these components. To contribute to the continuous improvement of the final component and reduce the finishing cost, areas for improvement have been scrutinized in a current finishing system. Areas for improvement have been identified in the uniformity of the nickel distribution within different current densities and in the handling and economy of the metallic zinc anodes used for zinc metal replenishment. While today’s acidic zinc-nickel electrolytes suit and usually exceed the requirements for an alloy containing 10-15% nickel, nickel incorporation may drop just below 12% incorporation rate in areas which are plated at high current densities.
2016-09-18
Technical Paper
2016-01-1953
Michael Herbert Putz, Harald Seifert, Maximilian Zach, Jure Peternel
Abstract Since more than eight years Vienna Engineering (VE) is working on an electro-mechanical brake (EMB) actuated by eccentrics and a highly non-linear actuation mechanism. The principle allows full braking in approx. 70 milliseconds (including air gap) and only approx. 3 A RMS actuator current at 12 V for classical ABS with oscillations. This EMB reached an elaborated state. Versions for passenger cars, elevators, railway and commercial vehicles (CVs) were derived. Now, as the EMB is going to road tests, it is necessary to fulfill safety requirements closely. What are these safety requirements and how can they be fulfilled? The properties of the overall system, of the mechanics and electronics of the single brake are discussed in this paper. The overall brake system for EMBs needs a truly redundant power supply, a safe control bus and a safe brake pedal. The mechanics of a single brake can be required to release when power is off and it must not get mechanically stuck.
2016-09-18
Technical Paper
2016-01-1957
Seonho Lee, Heejae Kang, Ohchul Kwon, Chirl Soo Shin
Abstract A trend in automotive parts development is the pursuit of long life, high quality and reliability. The increase in service life of automotive wheel bearings, by improving the rolling contact fatigue (RCF) life of bearing steels, was investigated. Conventional studies of bearing steels and heat treatments have dealt with quenching and tempering (Q/T) in 52100 steel. This study is a new trial to increase the strength of bearing steels by special austempering in phases after general Q/T heat treatments.
2016-09-18
Technical Paper
2016-01-1955
Liangyao Yu, Xiaohui Liu, Xiaoxue Liu
Abstract The traditional vacuum booster is gradually replaced by Brake-by-Wire system (BBW) in modern passenger car, especially Electric Vehicle (EV). Some mechanical and hydraulic components are replaced by electronic components in Brake-by-Wire system. Using BBW system in modern passenger vehicles can not only improve the automotive safety performance, reliability and stability, but also promote vehicle maneuverability, comfort, fuel economy and environmental protection. Although vehicle's braking performance is greatly improved by using BBW, the system will inevitably consume some energy of the vehicle power supply, thus introducing unexpected drawback in comparison with the traditional vacuum assist braking system, since it doesn't need any electric power. Therefore, the analysis of energy consumption on typical main cylinder booster based BBW system under typical driving cycles will contribute to advanced design of current advanced braking system.
2016-09-18
Technical Paper
2016-01-1935
Binyu Mei, Xuexun Guo, Gangfeng Tan, Ming Chen, Bo Huang, Longjie Xiao
Abstract With the continuous increasing requirements of commercial vehicle weight and speed on highway transportation, conventional friction brake is difficult to meet the braking performance. To ensure the driving safety of the vehicle in the hilly region, the eddy current retarder (ECR) has been widely used due to its fast response, lower prices and convenient installation. ECR brakes the vehicle through the electromagnetic force generated by the current, and converted vehicle mechanical energy into heat through magnetic field. Air cooling structure is often used in the traditional ECR and cooling performance is limited, which causes low braking torque, thermal recession, and low reliability and so on. The water jacket has been equipped outside the eddy current region in this study, and the electric ECR is cooled through the water circulating in the circuit, which prolongs its working time.
2016-09-18
Technical Paper
2016-01-1941
Tie Wang, Gangfeng Tan, Xuexun Guo, Shengguang Xiong, Zhiwei Zhang, Xin Gao
Abstract Vehicle hydraulic retarders are applied in heavy-duty trucks and buses as an auxiliary braking device. In traditional cooling systems of hydraulic retarders, the working fluid is introduced into the heat exchanger to transfer heat to the cooling liquid in circulation, whose heat is then dissipated by the engine cooling system. This prevents the waste heat of the working fluid from being used effectively. In hydraulic retarder cooling system based on the Organic Rankine Cycle, the organic working fluid first transfers heat with the hydraulic retarder working fluid in Rankine cycle, and then outputs power through expansion machine. It can both reduce heat load of the engine cooling system, and enhance thermal stability of the hydraulic retarder while recovering and utilizing braking energy. First of all, according to the target vehicle model, hydraulic retarder cooling system model based on Rankine cycle is established.
2016-09-18
Technical Paper
2016-01-1947
Albert Boretti, Sarim Al-Zubaidy
Abstract The operation of a conventional passenger car is characterised by increasing or maintaining the kinetic energy, when accelerating or cruising the vehicle, and reducing the kinetic energy by using the brakes. While the energy taken by the friction brakes to slow the vehicle is dissipated into heat, the introduction of Kinetic Energy Recovery Systems (KERS) has permitted the recovery of part of the braking energy. This reduces the amount of energy needed from the internal combustion engine (ICE). The contribution reviews the latest developments in electric KERS (E-KERS), with emphasis to round trip efficiency wheels to wheels and electrification of the powertrain. The contribution considers the opportunity to connect the E-KERS traction battery to other electric machines, such as an electrically assisted turbocharger (E-TC) connected to a motor/generator unit, or an electric water pump (EWP), to further optimise the vehicle operation.
2016-09-18
Technical Paper
2016-01-1920
Deaglan O'Meachair, Stamatis Angelinas, Matthew Crumpton, Antonio Rubio Flores, Juan Garcia, Pablo Barles
Abstract Bentley Motors Ltd. has developed a Carbon Silicon Carbide (CSiC) brake system for its Mulsanne product, introduced at 17MY. The CSiC brake system is conceived as a performance brake system, and as such offers notable improvements in brake performance. In developing the brake system, particular focus was placed on meeting the refinement levels required for a premium product, and indeed as the flagship model for Bentley Motors, NVH refinement of the brake system was of particular concern. This paper intends to discuss the technical performance of the brake system and review the NVH performance of the brakes. Particular attention is given to the methodology employed by Bentley Motors Ltd. and IDIADA Automotive Technology S.A. in identifying NVH concerns, and proposing and validating solutions in the field, through extensive NVH endurance runs. The performance of the system is benchmarked against similar systems offered by Bentley Motors.
2016-09-18
Technical Paper
2016-01-1932
Niclas Strömberg
Abstract During several years a toolbox for performing virtual rig tests of disc brake systems has been developed by the author. A thermo-flexible multi-body model of a test rig is derived and implemented by coupling two types of models: a finite element model and a multi-body model. The finite element model is a thermo-mechanical model of the pad-disc system that is formulated including thermo-elasticity, frictional contact and wear. The energy balance of the contact interface is governed by contact conductance that depends linearly on the contact pressure and the frictional heat depends on a temperature dependent coefficient of friction. Instead of adopting a standard Lagrangian approach, the disc is formulated in an Eulerian frame like a fluid. This is then coupled to the pad most accurately by using Signorini’s contact conditions, Coulomb’s law of friction and Archard’s law of wear.
2016-09-18
Technical Paper
2016-01-1950
Guirong Zhuo, Subin Zhang, Kun Xiong
Abstract As is known to all, the structure of the chassis has been greatly simplified as the application of in-wheel motor in electric vehicle (EV) and distributed control is allowed. The micro EV can alleviate traffic jams, reduce the demand for motor and battery capacity due to its small size and light weight and accordingly solve the problem that in-wheel motor is limited by inner space of the wheel hub. As a result, this type of micro EV is easier to be recognized by the market. In the micro EV above, two seats are side by side and the battery is placed in the middle of the chassis. Besides, in-wheel motors are mounted on the rear axle and only front axle retains traditional hydraulic braking system. Based on this driving/braking system, distribution of braking torque, system reliability and braking intensity is analyzed in this paper.
2016-09-18
Journal Article
2016-01-1948
Axel Freiwald, Gunn Hwang
Abstract Vehicle manufacturers are suffering from increasing expenses for fixing software issues. This fact is mainly driving their desire to use mobile communication channels for doing Software Updates Over The Air (SOTA). Software updates today are typically done at vehicle service stations by connecting the vehicles’ electronic network via the On Board Diagnostic (OBD) interface to a service computer. These operations are done under the control of trained technicians. SOTA means that the update process must get handled by the driver. Two critical aspects need to get considered when doing SOTA at Electronic Brake Control (EBC) systems. Both will determine the acceptance of SOTA by legal authorities and by the passengers: The safety and security of the vehicle The availability of the vehicle for the passengers The security aspect includes the necessity to protect the vehicle and the manufacturers IP from unwanted attacks.
2016-09-18
Technical Paper
2016-01-1954
Zhe Xiong, Xiaofei Pei, Xuexun Guo, Chengcai Zhang
Abstract In this paper a new pressure control method of a modified accumulator-type Electro-hydraulic Braking System (EHB) is proposed. The system is composed of a hydraulic motor pump, an accumulator, an integrated master cylinder, a pedal feel simulator, valves and pipelines. Two pressurizing modes are switched between by-motor and by-accumulator to adapt different pressure boost demands. A differentiator filtering raw sensor signal and calculating pedal speed is designed. By using the pedal feel simulator, the relationship between wheel pressures and brake force is decoupled. The relationships among pedal displacement, pedal force and wheel pressure are calibrated by experiments. A model-based PI controller with predictor is designed to lower the influences caused by delay. Moreover, a self-tuning regulator is introduced to deal with the parameter’s time-varying caused by temperature, brake pads wearing and delay variation.
2016-09-18
Technical Paper
2016-01-1938
Xin Gao, Gangfeng Tan, Binyu Mei, Mengzuo Han, Tie Wang
Abstract The hydraulic retarder is an auxiliary braking device used for commercial vehicle in a long slope brake, and its transmission oil generates a lot of heat in its working process. If the heat of transmission doesn’t go through a reasonable management, it will seriously affect the braking performance of hydraulic retarder. To cool down the transmission oil, it will aggravates the load of the engine cooling system, and the long cooling path sometimes causes heat exchange not timely. When the Rankine cycle is used for cooling the hydraulic retarder transmission oil in virtue of its good heat transfer performance in phase change process, it can make the transmission oil temperature controlled more stable. In this new system, the setting parameters of the Evaporate-condensate system will affect the stability of the transmission oil temperature in the hydraulic retarder inlet and the energy recovery efficiency of the system.
2016-09-18
Technical Paper
2016-01-1933
Mingzhuo Li, Dejian Meng, Lijun Zhang
Abstract Brake judder severely affects the riding comfort and safety of vehicle. For the brake corner system, a rigid-flexible coupling model is established based on ADAMS. In the model, brake pads, caliper, anchor and knuckle are flexible bodies, and the contacts between pads and disc and the contacts between pads and caliper are defined in detail. Meanwhile, the vibration acceleration of the brake corner components and the contact forces between disc and pads are used as evaluation index and the evaluation system of brake judder are improved. The analysis results show that the novel model and evaluation system can be used to predict brake judder effectively.
2016-09-18
Technical Paper
2016-01-1942
Sarah Chen, Steve Hoxie
Abstract Developing a brake system with high overall customer satisfaction rating is a constant challenge for OEMs as well as their brake suppliers. Brake system performance is directly linked to the engagement between the rotors and pads. The materials for the rotors and pads play a key role in the nature of the engagement. Therefore, to meet the performance targets, it is critical to have a good understanding of the brake rotor materials and their impacts. Gray iron is the most widely used brake rotor material in the industry owing to its superior thermal handling capacity, damping characteristics, and wear and cost advantages. G30 per ASTM A48 is generally specified for most brake rotors with minimum tensile strength of 200 MPa and Brinell hardness of 187∼241. G20 is also widely used for brake rotors, especially for brake smoothness and optimal lining life.
2016-09-18
Technical Paper
2016-01-1921
Yusuke Sunagawa, Tsuyoshi Kondo
Abstract Brake squeal noise is generally classified into two vibration modes of disc. One is called “out-of plane mode” which vibrates in disc’s out-of-plane direction. The other is “In-plane mode” which vibrates in disc’s in-plane direction, it means the disc is contracted partially or is extended. There are few “In-plane noise” analysis reports from Disc pad standpoint, so it has been unclear how disc pad contributes to “In-plane mode” until now. This paper confirms that we successfully analyzed direct pad vibration mode by laser scanning under in-plane mode condition. Based on these results, we assume that pad stiffness affected in-plane mode and carried out validation tests.
Viewing 271 to 300 of 8253