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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. In addition, unlike common ESC (“Electronic Stability Control”) systems do, a SAD can modify the vehicle attitude without limiting its traction performance, which is a crucial factor for racecars.
2014-11-11
Technical Paper
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. Using this method, the discrepancy between measurement and calculation of the natural frequency was reduced from ±5.2% to ±1.3%.
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. In the present work, a DC motor assisted steering mechanism with an electronic control module has been designed.
2014-10-23
Article
To debut in 2016 on a front-drive-based vehicle, the lightweight Flex4 features new axle-disconnect clutch technologies.
2014-10-22
Article
WABCO Holdings Inc. recently opened its fifth manufacturing facility in India, located in Lucknow. The new plant will supply advanced braking technologies, including antilock braking systems (ABS), actuators, and a range of braking valves, for multiple global heavy-truck and bus manufacturers operating in India.
2014-10-21
Standard
J3006_201410
This Recommended Practice is derived from OEM and tier-1 laboratory tests and applies to two-axle multipurpose passenger vehicles, or trucks with a GVWR above 4536 kg (10 000 pounds) equipped with hydraulic disc or drum service brakes. Before conducting testing for a specific brake sizes or under specific test conditions, review, agree upon, and document with the test requestor any deviations from the test procedure. Also, the applicable criteria for the final test results and wear rates deemed as significantly different require definition, assessment, and proper documentation; especially as this will determine whether or not Method B testing is needed. This Recommended Practice does not evaluate or quantify other brake system characteristics such as performance, noise, judder, ABS performance, or braking under extreme temperatures or speeds. Minimum performance requirements are not part of this recommended practice. Consistency and margin of pass/fail of the minimum requirements related to wear rates and wear behavior can be assessed as part of the project in coordination with the test requestor.
2014-10-10
WIP Standard
J1939DA
The J1939 Digital Annex The J1939 Digital Annex, introduced in August 2013, offers key J1939 technical data in an Electronic Spreadsheet that can be easily searched, sorted, and adapted to other formats. J1939DA contains all of the SPNs (parameters), PGNs (messages), and other J1939 data previously published in the SAE J1939 top level document. J1939DA also contains all of the SLOTs, Manufacturer ID Codes, NAME Functions, and Preferred Addresses previously published in the SAE J1939 top level and the J1939-71 document. J1939DA contains the complete technical details for all of the SPNs and PGNs previously published in the SAE J1939-71 document. For all other SPNs and PGNs which are published in a document other than SAE J1939-71, J1939DA lists only basic details along with a reference to the document that contains the complete technical details. J1939DA replaces, and expands upon, the 1939 Companion Spreadsheet (CS1939), which was last published through November 2012. The data fields included in J1939DA for PGNs are: PGN Parameter Group Label Acronyn EDP DP PF PGN Length PS PGN Description Multipacket Transmission Rate PGN Data Length Default Priority PGN Reference PGN Document The data fields included in J1939DA for SPNs are: SPN SPN Name SPN Description SPN Length Resolution Offset Data Range Operational Range Units SLOT Identifier SPN Type SPN Reference SPN Document The J1939 Digital Annex is current through Second Quarter 2014 and can be purchased separately or as part of the SAE J1939 Standards Collection on the Web.
2014-10-09
Standard
J1609_201410
This SAE Recommended Practice establishes performance guidelines of the air reservoir systems used on trucks, towing trucks, truck-tractors, trailers, and converter dollies, with GVWRs over 10 000 lb, designed to be used on the highway. NOTE: Compliance with this document does not guarantee compliance with the air reservoir requirements of FMVSS 121.
2014-10-08
Article
Among the new products WABCO displayed at the IAA Hanover CV Show was an electrically driven compressor for heavy duty air-braking systems and a new energy saving engine driven compressor.
2014-10-06
WIP Standard
J1404
This SAE Recommended Practice presents requirements for the structural integrity of the brake system of all new trucks, buses, and combinations of vehicles designed for roadway use and falling into the following classifications: a. Truck and Bus: Over 4500 kg (10 000 lb) GVWR b. Combination of Vehicles: Towing vehicle over 4500 kg (10 000 lb) GVWR The requirements are based on data obtained from SAE J294.
2014-10-05
WIP Standard
J1476
This SAE Recommended Practice establishes a method of evaluating the structural integrity of the parking brake system of all new trucks, buses, and combination vehicles designed for roadway use in the following classifications: TRACTOR, TRAILER, TRUCK, AND BUS: over 4500 kg (10 000 lb) GVWR.
2014-10-03
Article
Polymer composites reinforced with the "wonder material" graphene could cut structural weight by a third or more, researchers claim.
2014-10-03
WIP Standard
J3080
This Recommended Practice applies to air disc brakes fitted in commercial vehicles with a Gross Axle Weight Rating of 4536.0 kg or above.
2014-10-01
Standard
J2902_201410
This SAE recommended practice provides procedures and methods for testing service, spring applied parking and combination brake actuators for air disc brake applications. Methods and recommended samples for testing durability, function and environmental performance are listed in 1.1 and 1.2.
2014-10-01
Technical Paper
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. Our results provide evidence of the amount of energy available for harvesting from a vehicles' damper system using a kinetic energy recovery device.
2014-10-01
Technical Paper
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.
2014-09-30
Article
The industry outlook for 2021 underscores engineering efficiency and flexible, modular architectures, according to industry forecasters IHS Automotive.
2014-09-30
WIP Standard
J3081
This document is written to address acceleration and deceleration contol issues related to Heavy Duty Trucks and Bueses greater than 10,000 GVW.
2014-09-30
WIP Standard
J2377
This SAE Recommended Practice (RP) provides test procedures for air braked trucks and truck-tractors used to tow single and multiple trailer combinations on highways. This RP is not intended for off-highway applications.
2014-09-30
Technical Paper
2014-01-2409
C Venkatesan, R DeepaLakshmi
Abstract The automotive industry is constantly looking for new alternate material and cost is one of the major driving factors for selecting the right material. ABT is a safety critical part and care has to be taken while selecting the appropriate material. Polyamide (PA12) [1] is the commonly available material which is currently used for ABT applications. Availability and material cost is always a major concern for commercial vehicle industries. This paper presents the development of ABT with an alternative material which has superior heat resistance. Thermoplastic Elastomer Ether Ester Block Copolymer (TEEE) [3] materials were tried in place Polyamide 12 for many good reasons. The newly employed material has better elastic memory and improved resistance to battery acid, paints and solvents. It doesn't require plasticizer for extrusion process because of which it has got excellent long term flexibility and superior kink resistance over a period of time. Also it has got better heat ageing properties and higher burst pressure at elevated temperature.
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
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. The simulation results shows that the algorithm can control the wheels' slip-rate changing in the settled range and shorten the braking time, thus improves braking performance of tractor/trailer combination vehicle.
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. It was also confirmed that both stability and the steering effect in the critical cornering range are improved by implementing ground negative camber angle control that is proportional to the steering angle using actuators.
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. Therefore, we applied tire camber angle control to improve vehicle maneuverability in the total skid margin.
2014-09-30
Technical Paper
2014-01-2288
Boris Belousov, Tatiana I. Ksenevich, Vladimir Vantsevich, Sergei Naumov
An open-link locomotion module (OLLM) is an autonomous energy self-sufficient locomotion setup for designing ground wheeled vehicles of a given configuration that includes drive/driven and steered/non-steered wheels with individual suspension and brake systems. Off-road applications include both trucks and trailers. The paper concentrates on the module's electro-hydraulic suspension design and presents results of analytical and experimental studies of a trailer with four driven (no wheel torque applied) open-link locomotion modules. On highly non-even terrain, the suspension design provides the sprung mass with sufficient vibration protection at low level of normal oscillations, enhanced damping and stabilized angular movements. This is achieved by the introduction of two control loops: (i) a fast-acting loop to control the damping of the normal displacements; and (ii) a slow-acting control loop for varying the pressure and counter-pressure in the suspension system. Thus, two separate but coordinated controls were designed for both loops to act under small (less than ±7 degrees) and big (larger than ±7 degrees) pitch and roll angles of a vehicle designed with a set of the modules.
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
2014-01-2286
Ying Wan, Dong Zhang, Zhao Weiqiang, Changfu Zong, Jongchol Han
Pneumatic Electric Braking System (EBS) is getting widely spread for commercial vehicles. Pneumatic EBS improves the problem of slow response of traditional pneumatic braking system by implementing brake-by-wire. However, the time-delay response and hysteresis of some electro-pneumatic components and some other issues decrease the response and control accuracy of the pneumatic EBS. Therefore, this paper does the following work for this problem: (1) the structure of proportional relay valve is introduced and the response time and hysteresis characteristics of proportional relay valves are analyzed, (2) the dynamic characteristic of pressure response time and the steady-state characteristic of hysteresis curve are tested with open-loop test bench, (3) a hysteresis compensation control method which integrates PID closed loop control and the feed-forward compensation control is presented for mitigating the hysteresis characteristic of proportional relay valve and improving the pressure response character of the front wheels, (4) a vehicle dynamic simulation platform of commercial vehicle consists of EBS is developed with the co-simulation of MATLAB/Simulink and AMESim for the purpose of EBS control strategy development and validation, (5) the effect of the hysteresis compensation control strategy on vehicle braking performance is validated and analyzed offline.
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. In the multiple targets stability control algorithm, a simplified vehicle model, a Kalman filter estimator and an Adaptive Kalman filter estimator of heavy duty vehicles are built, by which the parameters and states can be estimated successfully.
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. And the vacuum power of AFRS and the air-friction of retarder are analyzed comprehensively.
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