Criteria

Text:
Topic:
Display:

Results

Viewing 1 to 30 of 7451
2015-01-14
Technical Paper
2015-26-0086
Prakhar Srivastava, Manish Laxman Karle, Ujjwala Shailesh Karle, Anand A Deshpande
Electric Power Assist Steering (EPAS) is a safety critical system because it affects vehicle stability and dynamics. Therefore, this system should be very reliable. To ensure safety and reliability ISO 26262 standards are adapted which is derived from IEC 61508. This standard regulates product development on system, hardware and software level and manages functional safety for electrical and electronics components. This paper discusses the applicability of the ISO 26262 standard to the development of EPAS ECU w.r.t its hardware and software design. For the hardware safety and reliability, the paper describes the hardware design safety analysis methods like Fault Tree Analysis (FTA), Failure mode and effect analysis (FMEA) and Hazard analysis. The paper discusses the use of these techniques used for improvement of reliability and safety of EPAS at component and system level.
2015-01-14
Technical Paper
2015-26-0085
Boris Belousov, Tatiana I. Ksenevich, Sergei Naumov
A distributed structure of the automated control system (ACS) was used in designing the wheel open-link locomotion module (OLLM). It has allowed splitting the system into subsystems and studying the automatic control over each individual function. The paper considers the results of the experimental studies of the ACSs, which regulate the rigidity and damping parameters of axle suspensions (the control system of the pressure in wheel suspensions), and the vertical displacements of the left and right wheels of the axle (the control systems of the vertical wheel displacements), in response of the signals that arrive to the input of the complex from the main or backup system of automated control of the vehicle. A similar method was used to study the ACS of the wheel springing system as a component of the ACS of the OLLM.
2015-01-14
Technical Paper
2015-26-0082
Jeevan N. Patil, Sivakumar Palanivelu, Vaibhav Aswar, Vipin Sharma
Air brake system is widely used in heavy truck and intercity buses for its great superiority and braking performance over other brake systems. Pneumatic brake system consists of various valves such as Dual Brake Valve (DBV), Quick release Valve (QRV), Relay Valve, Brake chambers. Dynamics of each valve is playing crucial role in overall dynamic performance of braking system. Also, it is very difficult to find the contribution of each valve in overall braking performance. In addition to this, there are various pipe diameters, which can be used between various valves. Hence, it is very difficult to find the best possible pipe diameter combination between various valves as well as contribution of each valve in overall performance through experiment as we cannot try all possible combinations on the actual vehicle.
2015-01-14
Technical Paper
2015-26-0084
Ishwar Patil, Kiran P Wani
With the increasing competition in automotive sector, the customer is available with more options when it comes to buying a vehicle. So it has become necessary to improve the vehicle’s characteristics which affect its impression on the customer. Handling and ride comfort are very important characteristics that influence the quality of the vehicle. These characteristics depend on the suspension system of the vehicle. The three main objectives that a suspension system of an automobile must satisfy are ride comfort, vehicle handling and suspension working space. Ride comfort is directly related to the vehicle acceleration experienced by the driver and the passengers. Higher vertical acceleration, lesser is the level of comfort. The aim of this paper is to design and analyze the semi active suspension system models using skyhook, ground hook and hybrid control method.
2015-01-14
Technical Paper
2015-26-0079
Ram Ranjan Sahu, Jayant Sinha
Brake drum is an important component in automotive, which is a link between axle and wheel. It performance is of utmost importance as it is related to the safety of the car as well to the passengers. Many design parameters are taken into consideration while designing the brake drum. The sensitivity of these parameters is studied for optimum design of brake drum. The critical parameters in terms of reliability, safety & durability could be the cross section, thickness of hub, interference & surface roughness between bearing and hub, wheel loading, heat generation on drum, manufacturing and assembly process. The brake drum design is derived by considering these parameters. Hence the sensitivity of these parameters is studied both virtually & physically, in detail. The optimum value of each parameter could be chosen complying each other's values.
2015-01-14
Technical Paper
2015-26-0080
Wen Zhang, Bo Yang
Commercial vehicle plays an important role during transportation process under the demand of high speed, convenience and efficiency. So improving active safety of commercial vehicles has become a research topic. Due to the fact that braking characteristic is the basic and most closely related to safe driving of vehicles’ performances, this paper aimed to improve the braking performance by researching into an integrated control method based on the mature ABS products. Firstly, a control strategy which gave priority to ABS and differential yawing moment control, complementary with the hydraulic active suspension system control was proposed. In comparison with the single ABS system, the combined control of brake system and suspension system was designed not only for preventing wheels lock. But the directional control to avoid roll or spin was more focused on and the tires’ cornering characteristic was much better because of the invention of active suspension system.
2015-01-14
Technical Paper
2015-26-0077
Deepak Sharma, Abhishek Atal, Abhay shah
Background: Anti-Roll bar (ARB) bushes are used for mounting Anti-Roll bar on the vehicle chassis or the sub frame. Function of ARB bushes typically made from Natural Rubber, is to provide support and take the twist loads coming from ARB articulation and provide NVH isolation from road inputs. But for this particular application of ARB involving higher articulation, Since couple of decades in all around globe a typical problem of "Creaking" noise from ARB bushes during ARB articulation had been noticed in passenger cars. Several means have been tried across the globe to control or eliminate this typical noise, such as greasing to inner surface of rubber bush, using thermo plastic polyurethane material, using Self-lubricating waxed rubber, using Teflon coating in rubber inner surface and so on. But no appreciable results, leading to customer discomfort.
2015-01-14
Technical Paper
2015-26-0078
Parth Lunia, Mrigendra Prajapati, V Jayashankar, Varun Parakh, Samir Rawte
A parking brake or hand brake is the mechanical hand or foot operated secondary braking system that prevents the vehicle from rolling or slipping when parked on the gradient or leveled surface and provides assistance to stop/slowdown the vehicle in case of service brake failure. This paper is an attempt to compile a systematic approach which can be easily incorporated in a product development system to design and develop parking brake system for passenger cars having rear drum brakes which in turn can effectively reduce the lead time and give a better performance. Vehicle GVW, percentage gradient and maximum effort limits (As per IS 11852-Part 3), Tire and drum brake specifications were taken as front loading. This data is further used for target setting of functional and engineering parameters, such as Lever Pull Effort, Lever Ratio and angular travel of lever. Design calculations were performed to obtain theoretical value of critical parameters like lever effort and travel.
2014-11-11
Technical Paper
2014-32-0088
Claudio Annicchiarico, Renzo Capitani
Abstract In a Formula SAE car, as for almost all racecars, suppressing or limiting the action of the differential mechanism is the technique mostly adopted to improve the traction exiting the high lateral acceleration corners. The common Limited Slip Differentials (LSDs) unbalance the traction torque distribution, generating as a secondary effect a yaw torque on the vehicle. If this feature is electronically controlled, these devices can be used to manage the attitude of the car. The yaw torque introduced by an electronically controlled LSD (which can also be called SAD, “Semi-Active Differential”) could suddenly change from oversteering (i.e. pro-yaw) to understeering (i.e. anti-yaw), depending on the driving conditions. Therefore, controlling the vehicle attitude with a SAD could be challenging, and its effectiveness could be low if compared with the common torque vectoring systems, which act on the brake system of the car.
2014-11-11
Technical Paper
2014-32-0017
R Varunprabhu, Himadri Bushan Das, S Jabez Dhinagar
Abstract The steering system of a 3-wheeler vehicle comprises a single column steering tube. The steering inclination at handle bar end is converted to wheel slip or inclination by the steering column. A compromise in either ride or handling is considered in the functional requirement of the 3-wheeler vehicle. The 3- wheeler vehicle under study is designed for ride comfort and the handling levels are compromised. Variants of the vehicle under study are meant for public passenger transport requirements. Drivers' ride comfort is considered as the primary functional requirement during design and driver's steering fatigue is not given importance. For the comfort of driver, steering effort has to be less without compromise in handling characteristics. The driver of this type of vehicle drives the vehicle for 15-18 hours a day. Driver's feedback suggests high steering effort as a human fatigue failure mode and also a cause of shoulder pain.
2014-11-11
Journal Article
2014-32-0053
Yoshihiro Nakagawa, Shinya Takahashi, Mikihito Masaki, Ranju Imao
Abstract In brake squeal analyses using FE models, minimizing the discrepancies in vibration characteristics between the measurement and the simulation is a key issue for improving its reproducibility. The discrepancies are generally adjusted by the shape parameters and/or material properties applied to the model. However, the discrepancy cannot be easily adjusted, especially, for the vibration characteristic of the disc model of a motorcycle. One of the factors that give a large impact on this discrepancy is a thermal history of the disc. That thermal history includes the one experienced in manufacturing process. In this paper, we examine the effects of residual stress on the natural frequency of motorcycle discs. The residual stress on the disc surface was measured by X-ray stress measurement method. It was followed by an eigenvalue analysis. In this analysis, we developed a unique method in which the residual stress was substituted by thermal stress.
2014-10-01
Journal Article
2014-01-9028
Theodoros Kosmanis, Georgios Koretsis, Athanasios Manolas
Abstract The implementation of an electronic differential system in a delta-type, electrically assisted, three wheel Human Powered Vehicle is the subject of this paper. The electronic differential algorithm is based on the turning angle of the vehicle and its geometrical characteristics. The theoretical analysis is applied in a realistic human powered tricycle constructed in the premises of the Alexander Technological Educational Institute of Thessaloniki. The system's efficiency is validated through test measurements performed on the rear wheels during vehicle's operation in appropriately selected routes. The measurements are performed for both typical cornering and oversteering.
2014-10-01
Journal Article
2014-01-9026
Christopher Gill, Christopher Knight, Scott McGarry
Vehicle shock absorbers are designed to dissipate kinetic energy through frictional viscous forces. In some circumstances, this can be in the order of kilowatts of instantaneous power dissipation. This study quantitatively assesses the vehicle damper system energy dissipation of a low-mass utility vehicle and a high-mass hauling vehicle, using empirically derived regression models of the working dampers and custom data logging equipment. The damper force and power is derived from post-processing of the measurement of critical damper metrics, including linear velocity and temperature. Under typical operating conditions, the low-mass utility vehicle showed an average power dissipation of 39 W for a single shock absorber, and approximately 150 W for a complete vehicle-damper model. The high-mass hauling vehicle demonstrated an average power dissipation of 102 W for a single shock absorber, and approximately 600 W for a complete vehicle-damper model under laden operating conditions.
2014-09-30
Technical Paper
2014-01-2425
L. Joseph Bachman, Anthony Erb, Jeffry Sellers
Abstract Road tests of class 8 tractor trailers were conducted by the US Environmental Protection Agency (EPA) on a new and retreaded tires of varying rolling resistance in order to provide estimates of the quantitative relation between rolling resistance and fuel consumption. Reductions in fuel consumption were measured using the SAE J1231 (reaffirmation of 1986) test method. Vehicle rolling resistance was calculated as a load-weighted average of the rolling resistance (as measured by ISO28580) of the tires in each axle position. Both new and retreaded tires were tested in different combinations to obtain a range of vehicle coefficient of rolling resistance from a baseline of 7.7 kg/ton to 5.3 kg/ton. Reductions in fuel consumption displayed a strong linear relationship with coefficient of rolling resistance, with a maximum reduction of fuel consumption of 10 percent relative to the baseline.
2014-09-30
Journal Article
2014-01-2358
Marius-Dorin Surcel, Yves Provencher
Abstract The objective of this project was to compare the fuel consumption and traction performances of 6 × 2 and 6 × 4 Class 8 tractors. Two approaches have been considered: evaluation of 6 × 2 tractors, modified from 6 × 4 tractors, and evaluation of OEM 6 × 2 tractors. Compared to the 6 × 4 tractors, which are equipped with a rear tandem with both drive axles, the 6 × 2 tractors have a rear tandem axle with one drive axle, and one non-drive axle, also called dead axle. The 6 × 2 tractor configurations are available from the majority of Class 8 tractor manufacturers. The SAE Fuel Consumption Test Procedures Type II (J1321) and Type III (J1526) were used for fuel consumption track test evaluations. Traction performances were assessed using pull sled tests to compare pulling distance, maximum speed, and acceleration when pulling the same set sled on similar surface.
2014-09-30
Journal Article
2014-01-2387
Hongyu Zheng, Linlin Wang
Abstract The active safety and stability of tractor and trailer (heavy-duty vehicle) have becoming big concern among the road transportation industry. The purpose of this paper is to specify the research differential braking force distribution control algorithm to improve braking safety of heavy-duty vehicle. The ideal braking force of each wheel axle should be proportional to vertical load of vehicle that is also related to the road adhesion coefficient, the load and the braking intensity. Reasonable braking force distribution can enhance its braking stability and shorten the braking distance by making full use of the road adhesion condition of each wheel. A braking force distribution algorithm is proposed, in which the objective braking force change with the axle load of vehicle.
2014-09-30
Technical Paper
2014-01-2386
Takahiko Yoshino, Hiromichi Nozaki
Abstract It has been reported that steering systems with derivative terms have a heightened lateral acceleration and yaw rate response in the normal driving range. However, in ranges where the lateral acceleration is high, the cornering force of the front wheels decreases and hence becomes less effective. Therefore, we applied traction control for the inner and outer wheels based on the steering angle velocity to improve the steering effectiveness at high lateral accelerations. An experiment using a driving simulator showed that the vehicle's yaw rate response improved for a double lane change to avoid a hazard; this improves hazard avoidance performance. Regarding improved vehicle control in the cornering margins, traction control for the inner and outer wheels is being developed further, and much research and development has been reported. However, in the total skid margin, where few margin remains in the forward and reverse drive forces on the tires, spinout is unavoidable.
2014-09-30
Technical Paper
2014-01-2385
Linlin Wang, Hongyu Zheng
The paper focus on enhancing the braking safety and improving the braking performance of the tractor/trailer vehicle. A slip-rate-based braking force distribution algorithm is proposed for the electronic braking system of tractor/trailer combination vehicle. The algorithm controls the slip-rates of the tractor's rear wheels and the semi-trailer's wheels changing with the slip-rate of tractor's front wheels, making tractor's front wheels lock up ahead of the tractor's rear wheels and the semi-trailer's wheels. The algorithm protects the combination vehicle from jackknifing and swing, guaranteeing that the combination vehicle has better driving stability and steering capability. The algorithm can be tested by co-simulation with MATLAB/Simulink and TruckSim software both on high adhesion and low adhesion roads.
2014-09-30
Journal Article
2014-01-2382
Hongyu Zheng, Linlin Wang
Abstract At present, the active safety and stability of heavy vehicles have becoming big concern among the road transportation industry. The purpose of this paper is to specify the research stability and safety of heavy vehicles those set up the accurate and reliable dynamic vehicle reference model and search the method to improve the stability and safety of tractor and semitrailer. A Multi-objective control algorithm was studied to differential braking based on linear quadratic regulator (LQR) control method. Simulation results show that the multi-objective control algorithm can effectively improve the vehicle driving stability and safety.
2014-09-30
Technical Paper
2014-01-2383
Takahiko Yoshino, Hiromichi Nozaki
Abstract In recent years, the conversion of vehicles to electric power has been accelerating, and if a full conversion to electric power is achieved, further advancements in vehicle kinematic control technology are expected. Therefore, it is thought that kinematic performance in the critical cornering range could be further improved by significantly controlling not only the steering angle but also the camber angle of the tires through the use of electromagnetic actuators. This research focused on a method of ground negative camber angle control that is proportional to the steering angle as a technique to improve maneuverability and stability to support the new era of electric vehicles, and the effectiveness thereof was clarified. As a result, it was found that in the critical cornering range as well, camber angle control can control both the yaw moment and lateral acceleration at the turning limit.
2014-09-30
Journal Article
2014-01-2380
Joshua L. Every, M. Kamel Salaani, Frank S. Barickman, Devin H. Elsasser, Dennis A. Guenther, Gary J. Heydinger, Sughosh J. Rao
Dynamic Brake Support (DBS) is a safety system that has been applied to various passenger cars and has been shown to be effective at assisting drivers in avoiding or mitigating rear-end collisions. The objective of a DBS system is to ensure that the brake system is applied quickly and at sufficient pressure when a driver responds to a collision imminent situation. DBS is capable of improving braking response due to a passenger car driver's tendency to utilize multi-stage braking. Interest is developing in using DBS on commercial vehicles. In order to evaluate the possible improvement in safety that could be realized through the use of DBS, driver braking behavior must first be analyzed to confirm that improvement is possible and necessary. To determine if this is the case, a study of the response of truck drivers' braking behavior in collision imminent situations is conducted. This paper presents the method of evaluation and results.
2014-09-30
Technical Paper
2014-01-2379
Yang Li, JianWei Zhang, Konghui Guo, Dongmei Wu
Abstract This paper presents an ideal force distribution control method for the electric vehicle, which is equipped with four independently in-wheel motors, in order to improve the lateral stability of the vehicle. According to the friction circle of tyre force, the ideal distribution control method can be obtained to make the front and rear wheels reach the adhesion limit at the same time in different conditions. Based on this, the force re-distributed control is applied to enhance the security of vehicle when the in-wheel motor is in the failure mode. The simulation result shows that: the force distributed method can not only improves the lateral stability of the vehicle but also enhances the vehicle safety.
2014-09-30
Journal Article
2014-01-2330
Matt Zwick
Abstract The base design of commercial vehicle wheel end systems has changed very little over the past 50 years. Current bearings for R-drive and trailer wheel end systems were designed between the 1920's and the 1960's and designs have essentially remained the same. Over the same period of time, considerable gains have been made in bearing design, manufacturing capabilities and materials science. These gains allow for the opportunity to significantly increase bearing load capacity and improve efficiency. Government emissions regulations and the need for fuel efficiency improvements in truck fleets are driving the opportunity for redesigned wheel end systems. The EPA and NHTSA standard requires up to 23% reduction in emissions and fuel consumption by 2017 relative to the 2010 baseline for heavy-duty tractor combinations.
2014-09-30
Journal Article
2014-01-2320
Yiting Kang, Subhash Rakheja, Wenming Zhang
Abstract A range of axle suspensions, comprising hydro-pneumatic struts and diverse linkage configurations, have evolved in recent years for large size mining trucks to achieve improved ride and higher operating speeds. This paper presents a comprehensive analysis of different independent front suspension linkages that have been implemented in various off-road vehicles, including a composite linkage (CL), a candle (CA), a trailing arm (TA), and a double Wishbone (DW) suspension applied to a 190 tons mining truck. Four different suspension linkages are modeled in MapleSim platform to evaluate their kinematic properties. The relative kinematic properties of the suspensions are evaluated in terms of variations in the kingpin inclination, caster, camber, toe-in and horizontal wheel center displacements considering the motion of a hydro-pneumatic strut. The results revealed the CL and DW suspensions yield superior kinematic response characteristics compared to the CA and TA suspensions.
2014-09-30
Technical Paper
2014-01-2321
Xianjian Jin, Guodong Yin, Youyu Lin
Abstract Knowledge of vehicle dynamics variables is very important for vehicle control systems that aim to improve handling characteristics and passenger safety. However for both technical and economical reasons some fundamental data (e.g., Lateral tire-road forces and vehicle sideslip angle) are difficult to measure in a standard car. This paper proposes a novel Interacting Multiple Model Filter-Based method to estimate lateral tire-road forces by utilizing real-time measurements. The estimation method of lateral tire-road forces is based on an interacting multiple model (IMM) filter that integrates in-vehicle sensors of in-wheel-motor-driven electric vehicles to adaptively adjusted multiple vehicle-road system models to match variable driving conditions. A four-wheel nonlinear vehicle dynamics model (NVDM) is built considering extended roll dynamics and load transfer.
2014-09-30
Technical Paper
2014-01-2283
Can Wang, Gangfeng Tan, Bo Yang, Ming Chen, Fudong Wei, Yabei Ni
Abstract The hydraulic retarder, which is an auxiliary brake device for enhancing traffic safety, has been widely used in kinds of heavy commercial vehicles. When the vehicle equipped with the retarder is traveling in non-braking state, the transmission loss would be caused because of the stirring air between working wheels of the rotor and the stator no matter if the retarder connects in parallel or in series with the transmission [1]. This paper introduces an elaborate hydraulic retarder air-friction reduction system (AFRS) which consists of a vacuum generating module and pneumatic control module. AFRS works to reduce the air friction by decreasing the gas density between working wheels when the retarder is in non-braking state. The pneumatic control model of hydraulic retarder is built first. Then various driving conditions are considered to verify the performance of the AFRS. The stability of the AFRS is analyzed based on the complete driveline model.
2014-09-30
Technical Paper
2014-01-2284
Sunil Raj, S Ravi Shankar
Abstract Automotive component light weighing is one of the major goals for original equipment manufacturers (OEM's) globally. Significant advances are being made in developing light-weight high performance components. In order to achieve weight savings in vehicles, the OEM's and component suppliers are increasingly using ultra-high-strength steel, aluminum, magnesium, plastics and composites. One way is to develop a light weight high performance component through multi material concept. In this present study, a bimetal brake drum of inner ring cast iron and outer shell of aluminum has been made in two different design configurations. In two different designs, 40 and 26% weight saving has been achieved as compared to conventional gray cast iron brake drum. The component level performance has been evaluated by dynamometer test. The heat dissipation and wear behavior has been analyzed.
2014-09-30
Technical Paper
2014-01-2282
Dhiraj Dashrat Salvi
Braking system is having a key importance in vehicle safety & handling stability. In this research paper I had developed a circuit model of Antilock braking system where the operating medium is hydro-pneumatic. A solenoid operated modulator valve consisting of two 2/2 valves is connected in line with the air cylinder & hydraulic master cylinder assembly. Using methodology of response time calibration time taken to modulate hydraulic pressure against pneumatic pressure is evaluated. The signal input to the modulator valve is given by the Electronic controlled unit (ECU). All results obtained is exported to an excel file using Data Acquisition software with pressure myograph system. It gives easy and intuitive readings based on the signal program from ECU for various inputs (i.e. ramp, step). The signals are program for various inputs in order to check the fidelity of the circuit. These readings are easily customized to get the optimum graphs.
2014-09-30
Technical Paper
2014-01-2287
Hongyu Zheng, Linlin Wang
Abstract A brake pad wear control algorithm used under non-emergency braking conditions is proposed to reduce the difference in brake pad wear between the front and rear axles caused by the difference in brakes and braking force. According to the adhesion state of the pad wear, the control algorithm adjusted the braking force distribution ratio of front and rear wheel that balanced adhesion pad wear value. Computer co-simulations of braking with Trucksim and Matlab/Simulink using vehicle models with equal brake pad wear, greater wear on the front axle and greater wear on the rear axle respectively is performed. The computation simulation results show that meet the brake force distribution system regulatory requirements and total vehicle braking force unchanged.
2014-09-30
Technical Paper
2014-01-2285
Dong Zhang, Changfu Zong, Ying Wan, Hongyu Zheng, Wei-qiang Zhao
Abstract Electronic braking system (EBS) of commercial vehicle is developed based on Anti-lock Braking System (ABS), for the purpose of enhancing the braking performance. Based on the previous study, this paper aims at the development and research on the control strategy of advanced electronic braking system for commercial vehicle, which mainly includes braking force distribution and multiple targets control strategy. In the study of braking force distribution control strategy, the mass of vehicle and the axle loads will be calculated dynamically and the braking force of each wheel will be distributed regarding to the axle loads. The braking intention recognition takes the brake pad wear into account when braking uncritically, so it can detect a difference in the pads between the front and the rear axles. The brake assist strategy supports the driver during emergency braking and the braking distance is shortened by the reduction of the braking system response time.
Viewing 1 to 30 of 7451