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2017-10-23
Technical Paper
2017-01-7008
Yoshiharu Inaguma
This article describes cavitation in a hydraulic disk valve to control an inlet pressure by changing a valve opening at a constant flow rate and outlet pressure. A disk valve, which has a fundamental configuration of a poppet valve, is widely used in a hydraulic system such a power steering system in order to control flow and pressure in the system. The disk valve, which makes a large flow area with a small valve opening, has a simple construction and does not reqire its parts to be machined with severe torelances. The disk valve with a diverging flow, however, is apt to cause cavitation because the inlet pressure becomes lower than the outlet pressure in a gap between the nozzle seat and the disk. The cavitation affects the pressure control performance and thrust force and causes an unpleasant noise. Hence, the cavitation is a very important problem because the hydraulic system is used recently under a high pressure condition.
2017-10-16
WIP Standard
J3158
The scope of this new recommended practice should include, but not necessarily be limited to: 1. Define vehicle operating conditions used to drive MOC-EPB actuator design and selection 2. Define brake corner operating conditions (e.g. temperature and state of burnish) used to drive MOC-EPB actuator design and selection 3. Define actuator operating conditions (e.g. temperature, voltage, current limit, and state of wear) used to drive MOC-EPB actuator design and selection 4. Define methodology for addressing part to part variation in performance
2017-10-16
WIP Standard
J2115
This SAE Standard provides test procedures for air, air/hydraulic, and hydraulic drum and disc brakes used on highway commercial vehicles over 4536 kg (10,000 lb) GVWR.
2017-10-15
Article
Continental 's new electronically-controlled three chamber air suspension system it claims is lighter, more compact and energy efficient than rival systems, aimed at EVs and autonomous vehicles.
2017-10-13
Technical Paper
2017-01-7006
Gao Ke, Zhao Weiqiang, Xiaojian Han
As the main passenger and freight transport equipment,commercial vehicle’s safety and comfort has become particularly important.Due to the long traveled distance,commercial vehicle is equipped with more than one driver.Different drivers have their unique steering behavior and same driver have a large physical power change when driving for a long time.Therefore,the needs of drivers cannot be met by a single model of the steering characteristics.If the vehicle steering characteristics are not suitable for the drivers,the vehicle will always produce too much/ little of the steering angle when driver controls steering system.The steering angle need to be adjusted again by driver when this happens.The occurrence of such a situation will affect the road safety, and cause extra burden on driver. On the basis of the traditional hydraulic power, dynamic steering system adds an electric servo motor to the steering column.
2017-10-13
WIP Standard
J880
This code is intended for commercial vehicles over 4500 kg (10 000 lb) with brake systems having typical service pressure ranges 0 to 14.1 mPa (0 to 2050 psi) hydraulic or 0 to 830 kPa (0 to 130 psi) air and is not directly applicable to vehicles with other systems. Air over hydraulic systems are to be tested as air systems.
2017-10-13
WIP Standard
J2523
This SAE Standard is established for the following purpose: a. simplify the application of radial drive wheel tires to agricultural vehicles especially those with multiple drive axle having tires of different sizes; and b. provide a pattern to combine similar sized tires into Rolling Circumference Index groups with uniform spacing between groups.
CURRENT
2017-10-12
Standard
J1270_201710
The force, torque, and power methods of measurement are all in common use and should yield the same test results. Effects of steering, traction, surface texture, and non-steady-state tire operations are excluded from the recommended practice because they are still in the research stage.
CURRENT
2017-10-12
Standard
J1402_201710
This recommended practice covers minimum requirements for air brake hose assemblies made from reinforced elastomeric hose and suitable fittings for use in automotive air brake systems including flexible connections from frame to axle, tractor to trailer, trailer to trailer and other unshielded air lines with air pressures up to 1 MPa, that are exposed to potential pull or impact. This hose is not to be used where temperatures, external or internal, fall outside the range of 40 to +100 °C.
2017-10-08
Technical Paper
2017-01-2425
Ramit Verma, Ramdas R Ugale
Abstract On two wheelers, magneto/alternator generates either single/three phase AC power and Regulator Rectifier Unit (RRU) does regulated rectification to charge the battery. In order to face the requirements of 2-wheeler engine with respect to upcoming stringent regulations like electronic fuel injection (EFI), anti-lock braking system (ABS), automatic headlamp on (AHO) in emerging markets like India; vehicles demand more electrical power from batteries. This demands higher power from alternator and consequently from RRU. Requirement of higher output power presents challenges on regulator rectifier unit in terms of size, power dissipation management and reliability. In this paper, improved performance of MOSFET based RRU is discussed in comparison to Silicon Controlled Rectifier (SCR) based RRU. The motivation/benefits of MOSFET based design is described along with the thermal behavior and temperature coefficient performance of RRU with test results.
2017-10-08
Technical Paper
2017-01-2455
Vikram Chopra
Abstract This paper reports on the design of a synchronizer brake based on permanent magnets, capable of braking with an active zero-slip load. Eddy-current brakes are widely used in automation and transportation applications; however, their use is limited by the rotor speed. For low-speed and high-torque applications, designs based on permanent magnets are better suited. Zero-slip braking torque is increased by the use of permanent magnets but, consequently, so is the cogging torque. At first, the synchronizer brake was designed with 16 surface magnets on the rotor. However, in order to reduce the permanent magnet mass, the rotor was re-designed with half the number of surface magnets. This novel design helped lower cogging torque and fabrication costs. Simulation of the design, using the 3D transient with motion solver in commercial finite element software, showed promising results.
2017-10-08
Technical Paper
2017-01-2466
Graham Arnold
Abstract Regenerative braking is an important factor in improving hybrid electric vehicle efficiency. This paper proposes a new regenerative braking strategy that activates preemptively during a distracted driving scenario, before service brakes are utilized. The strategy uses onboard advanced driver assistance systems, such as forward facing radar, to detect when an object is approaching fast enough to enable regenerative braking in response. The proposed strategy is simulated on a full-vehicle model of a series plug-in hybrid electric vehicle. A driver model is developed to mimic the behavior of a distracted driver through delayed response time to the changing speed of a lead vehicle. Multiple trials are simulated using different combinations of existing regenerative braking strategies along with the proposed strategy. Results show that a preventative regenerative braking control strategy can recuperate significant amounts of energy while also improving vehicle safety.
2017-10-03
WIP Standard
J1015
This SAE Standard establishes the Tonne Kilometer Per Hour Test Procedure for off-the-road tires. This document is applicable to only those tires used on certain earthmoving machines referenced in SAE J1116.
CURRENT
2017-10-03
Standard
J1965_201710
This SAE Recommended Practice applies to fasteners/fixing nuts as specified in SAE J694 and SAE J1835 used for disc wheels and demountable rim attachment respectively. Only the test methods necessary to ensure proper wheel or rim assembly are specified. Fasteners for less common and special applications are not included.
CURRENT
2017-09-29
Standard
J2725_201709
This SAE Standard specifies a method for testing and measuring elastic constants in friction materials by precise ultrasonic velocity measurements. Measurement methods are also described for measurement of the out-of-plane modulus as a function of pre-load as well as the measurement of engineering constants as a function of temperature. Finally, methods are formulated to produce all engineering constants as a function of pre-load and temperature.
2017-09-28
WIP Standard
AS4833B
This SAE Aerospace Standard (AS) sets forth criteria for the selection and verification processes to be followed in providing tires that will be suitable for intended use on civil aircraft. This document encompasses new and requalified radial and bias aircraft tires.
2017-09-28
WIP Standard
J2686
This SAE Recommended Practice is intended for qualification testing for brake drums used on highway commercial vehicles with air brakes using an inertia-dynamometer procedure. This Recommended Practice consists of two distinct tests: Part A - durability and speed maintenance test, and Part B - heat check drag sequence test. Each test can be considered to be an independent evaluation of the brake drum which tests different properties.
2017-09-28
Magazine
Advances for off-highway engine design As manufacturers continue to drive out cost and meet a worldwide patchwork of regulatory frameworks, the tools for developing those engines are advancing. From showcase prototypes to advanced analytical techniques, suppliers are helping the cause. Military vehicles battle for autonomy at lower cost Engineers are adding sensors, more powerful micros and faster networks as they automate tasks and pave the way to autonomy. Heavy duty lightweighting Optimization of tractor-trailer systems and component design helps to reduce overall vehicle mass, a key strategy in improving fuel economy and meeting upcoming Phase 2 GHG regulations. Navistar's SuperTruck II explores composites, WiFi to cut weight Methane state of mind New Holland ramps up its focus on alternative fuels, showcasing a methane-powered concept tractor that trims emissions, operating costs.
2017-09-23
Technical Paper
2017-01-1954
Peng Hang, Xinbo Chen, Fengmei Luo
Abstract Path tracking is the rudimentary capability and primary task for autonomous ground vehicles (AGVs). In this paper, a novel four-wheel-independent-steering (4WIS) and four-wheel-independent-drive (4WID) electric vehicle (EV) is proposed which is equipped with steer-by-wire (SBW) system. For path-tracking controller design, the nonlinear vehicle model with 2 degrees of freedom (DOF) is built utilizing the nonlinear Dugoff tire model. The nonlinear dynamic model of SBW system is conducted as well considering the external disturbances. As to the path-tracking controller design, an integrated four-wheel steering (4WS) and direct yaw-moment control (DYC) system is designed based on the model predictive control (MPC) algorithm to track the target path described by desired yaw angle and lateral displacement. Then, the fast terminal sliding mode controller (FTSMC) is proposed for the SBW system to suppress disturbances.
2017-09-23
Technical Paper
2017-01-1952
ChengJun Ma, Fang Li, Chenglin Liao, Lifang Wang
Abstract With the load of urban traffic system becomes more serious, the Automatic Parking System (APS) plays an important role in alleviating the burden of drivers and improving vehicle safety. The APS is consisted of environmental perception, path planning and path following. The path following controls the lateral movement of vehicle during the parking process, and requires the trajectory tracking error to be as small as possible. At present, some control algorithms are used including PID control, pure pursuit control, etc. However, these algorithms relying heavily on parameters and environment, have some problems such as slow response and low precision. To solve this problem, a path following control method based on Model Predictive Control (MPC) algorithm is proposed in this paper. Firstly, Kinematic vehicle model and path tracker based on MPC algorithm are built. Secondly, a test bench that composed of CANoe hardware in the loop (HIL) system and steering wheel system is built.
2017-09-23
Technical Paper
2017-01-1962
Hongluo Li, Yutao Luo
Abstract The trajectory planning and the accurate path tracking are the two key technologies to realize the intelligent driving. The research of the steering wheel angle plays an important role in the path tracking. The purpose of this study is to optimize the steering wheel angle input during the automated lane changing. A dynamic programming approach to trajectory planning is proposed in this study, which is expected to not only achieve a quick reaction to the changing driving environment, but also optimize the balance between vehicle performance and driving efficiency. First of all, the lane changing trajectory is planned based on the positive and negative trapezoidal lateral acceleration method. In addition, the multi-objective optimization function is built which includes such indexes: lateral acceleration, lateral acceleration rate, yaw rate, lane changing time and lane changing distance.
2017-09-23
Technical Paper
2017-01-1964
Xiangkun He, Xuewu Ji, Kaiming Yang, Yulong Liu, Jian WU, Yahui Liu
Abstract Highway traffic safety has been the most serious problem in current society, statistics show that about 70% to 90% of accidents are caused by driver operational errors. The autonomous emergency braking (AEB) is one of important vehicle intelligent safety technologies to avoid or mitigate collision. The AEB system applies the vehicle brakes when a collision is eminent in spite of any reaction by the driver. In some technologies, the system forewarns the driver with an acoustic signal when a collision is still avoidable, but subsequently applies the brakes automatically if the driver fails to respond. This paper presents the development and implementation of a rear-end collision avoidance system based on hierarchical control framework which consists of threat assessment layer, wheel slip ratio control layer and integrated-electro-hydraulic brake (IEHB) actuator control layer.
2017-09-23
Technical Paper
2017-01-1991
Adit Joshi
The automotive industry is heading towards the path of autonomy with the development of autonomous vehicles. An autonomous vehicle consists of two main components. The first is the software which is responsible for the decision-making capabilities of the system. The second is the hardware which encompasses all aspects of the physical vehicle which are responsible for vehicle motion such as the engine, brakes and steering subsystems along with their corresponding controls. This component forms the basis of the autonomous vehicle platform. For SAE Level 4 autonomous vehicles, where an automated driving system is responsible for all the dynamics driving tasks including the fallback driving performance in case of system faults, redundant mechanical systems and controls are required as part of the autonomous vehicle platform since the driver is completely out of the loop with respect to driving.
2017-09-23
Technical Paper
2017-01-1993
Daoyuan Sun, Xiaofei Pei, Xu Hu, Hao Pan, Bo Yang
Abstract This paper presents a Driver-In-the-Loop (DIL) bench test system for development of ESC controller. The real-time platform is built-up based on NI/PXI system and the real steering/throttle/braking actuator. In addition, the CarSim provides the vehicle model and the animator for virtual driving environment. A hierarchical ESC controller is proposed in MATLAB/Simulink then download into PXI. In the upper motion controller, the sliding mode theory is adopted and the logic threshold algorithm is used in the lower slip controller. Finally, ESC test is implemented under typical conditions by DIL and Model-In-the-Loop (MIL). The results show that, DIL could make up the shortage of driver model which can’t accurately simulate the emergency response of real driver. Therefore, DIL test could verify the ESC controller more accurately and effectively with considering the human-vehicle-road environment.
2017-09-23
Technical Paper
2017-01-2002
Yang Yang Wang, Guangda Chen, Xuanjing Ao, Shuhao Fan, Han Mei, Wei Li
Abstract After obtaining the optimal trajectory through the lane change decision and trajectory planning, the last key technology for the automatic lane change assist system is to carry out the precise and rapid steering actuation according to the front wheel angle demand. Therefore, an automatic lane change system model including a BLDCM (brushless DC motor) model, a steering system model and a vehicle dynamics model is first established in this paper. Electromagnetic characteristics of the motor, the moment of the inertia and viscous friction etc. are considered in these models. Then, a SMC (Sliding Mode Control) algorithm for the steering system is designed to follow the steering angle input. The control torque of the steering motor is obtained through the system model according to steering angle demand. After that, the control current is calculated considering of electromagnetic characteristics of the BLDCM.
2017-09-23
Technical Paper
2017-01-2001
Xin Li, Lixin Situ, Yongqiang Yu, Feng Chen
Abstract Research and development of autonomous functions for a road vehicle become increasingly active in recent years. However, the vehicle driving dynamics performance and safety are the big challenge for the development of autonomous vehicles especially in severe environments. The optimum driving dynamics can only be achieved when the traction torque on all wheels can be influenced and controlled precisely. In this study, we present a novel approach to this problem by designing an advanced torque vectoring controller for an autonomous vehicle with four direct-drive in-wheel motors to generate and control the traction torque and speed quickly and precisely, thus to improve the stability and safety of the autonomous vehicle. A four in-wheel motored autonomous vehicle equipped with Radar and camera is modelled in PanoSim software environment. Vehicle-to-Vehicle (V2V) communication is used in this software platform to avoid collision.
2017-09-23
Technical Paper
2017-01-1996
Zhichao Lin, Xuexun Guo, Xiaofei Pei, Bo Yang, Yanggang Zhang
Abstract Dynamic modeling and state estimation are significant in the trajectory tracking and stability control of the intelligent vehicle. In order to meet the requirement of the stability control of the eight-in-wheel-motor-driven intelligent vehicle, a full vehicle dynamics model with 12 degrees of freedom, including the longitudinal, lateral, yaw and roll motion of the body, and rotational motion of 8 wheels, is established for the research of the intelligent vehicle in this paper. By simulation with MATLAB/SIMULINK and by comparison with the TruckSim software, the reliability and practicality of the dynamics model are verified. Based on the established dynamics model, an extended Kalman filter (EKF) state observer is proposed to estimate the vehicle sideslip angle, roll angle and yaw rate, which are the key parameters to the stability control of the intelligent vehicle.
2017-09-23
Journal Article
2017-01-1983
Bing Zhu, Shude Yan, Jian Zhao, Weiwen Deng, Ning Bian
Abstract Electric power steering (EPS) system is a kind of dynamic control system for vehicle steering, which can amplify the driver steering torque inputs to the vehicle to improve steering comfortable and performance, but the present EPS can’t cater to the driving habits of different people. In this paper, a personalized EPS controller is designed based on the driver behavior, which combines real-time driver behavior identification strategy with personalized assistance characteristic. Firstly, the driver behavior data acquisition system is designed and established, based on which, the input data of different kinds of drivers along with vehicle signals are collected under typical working conditions, then the identification of driver behavior online is realized using the BP neural network.
2017-09-23
Technical Paper
2017-01-2010
Junfeng Yang, Michael Ward, Jahangir Akhtar‎
Abstract The Connected and Autonomous Vehicles (CAVs) promise huge economic, social and environmental benefits. The autonomous vehicles supposed to be safer than human drivers. However, the advanced systems and complex levels of automation could also bring accidents by tiny faults of hardware or errors of software. To achieve complete safety, a safety case providing guidance on the identification and classification of hazardous events, and the minimization of these risks needs to be developed throughout the entire development lifecycle process of CAVs. A comprehensible and valid safety case has to employ appropriate safety approaches complying with the automotive functional safety requirements in ISO 26262.
2017-09-22
WIP Standard
J1098
This SAE Standard establishes the procedures for the application of Tonne Kilometer Per Hour (TKPH) rating values for off-the-road tires; utilizing empirical data formula, it describes the procedure for evaluating and predicting off-the-road tire TKPH requirements as determined by a work cycle analysis.
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