Browse Topic: Center of gravity (CG)

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Necessity of Body Torsional Rigidity of Personal Mobility Vehicles (PMVs) with an Inward Tilting Mechanism2024-32-001304/18/2025
In traditional four-wheeled automobiles, the imbalance between the roll moment, which is the product of the centrifugal force during a turn acting on the center of gravity and the height of the center of gravity, and roll stiffness, which is the product of the left-right difference in tire vertical load and the tread width and commonly used among automotive suspension engineers, of the front and rear sections necessitates body torsional rigidity. However, there is a lack of specific cases and guidelines for constructing the body structure of three-wheeled PMVs (Personal Mobility Vehicles) with a tilting mechanism from the perspective of vehicle dynamics characteristics. In this paper, the basic considerations related to the dynamics of such three-wheeled PMVs are investigated. We use the term “torsional rigidity” to refer to the stiffness as the torsional deformation of the body itself, and the term “roll stiffness” to refer to the moment that counteracts the roll moment during a turn
Haraguchi, Tetsunori, Kaneko, Tetsuya
Simulation methodology development for vibration test of Bus Body Structure code AIS 153:20182024-26-024901/16/2024
A bus is integral part of public transportation in both rural and urban areas. It is also used for scheduled transport, tourism, and school transport. Buses are common mode of transport all over the world. The growth in economy, the electrification of public transport, demand in shared transport, etc., is leading to a surge in the demand for buses and accelerating the overall growth of the bus industry. With increased number of buses, the issue of safety of passengers and the crew assumes special importance. The comfort of driver and passenger in the vehicle involves the vibration performance and therefore, the structural integrity of buses is critically important. The bus safety act depicts the safety and comfort of bus operations, management of safety risks, continuous improvement in bus safety management, and public confidence in the safety of bus transport, appropriate stakeholder involvement and the existence of a safety culture among bus service providers. In order to provide
Bijwe, Vilas B., Mahajan, Rahul, Vaidya, Rohit, Patel, Kaustubh, Hiwale, Diwakar, Walke, Abhijit Ashok
SUV Multi-Link Rigid Axle Control Links Optimization for Ride and Handling Improvement2024-26-004801/16/2024
In automotive world, role of suspension system is to absorb vibrations from the road, and to provide stability while vehicle is going over bumps or uneven roads, cornering, acceleration and braking etc. For body on frame SUVs which are typically characterized by high center of gravity, it is quite critical to find best balance in ensuring stability of the vehicle and having comfortable ride performance. Rigid axle rear suspension is quite typical choice in such vehicles, wherein lower and upper control links are two important components subjected to lateral, longitudinal, and vertical loads. These links allow the vehicle to move smoothly throughout the entire range of suspension travel. Kinematics and compliance optimization of these links is major factor in definition of ride-handling performance of the vehicle. The present study describes key challenges and methodology to define position as well as orientation of control links, where-in multiple inter-related handling and comfort
Hussain, Inzamam, Jani, Harshil, Rasal, Shraddhesh, Asthana, Shivam, ahire, Manoj, Jadhav, Prashant, Lenka, Visweswara, Vellandi, Vikraman
Impact of Toe and Thrust Angle Misalignment on Roll Behaviour of a Heavy Commercial Road Vehicle2024-26-005601/16/2024
Heavy Commercial Road Vehicles (HCRVs) may be more susceptible to rollover incidents due to their higher centre of gravity position than passenger vehicles, and rollover is one of the significant causes of HCRV accidents. Therefore, variation in vehicle roll behaviour becomes crucial to the safety of an HCRV. Toe misalignment is a commonly observed phenomenon in HCRVs, and studying its impact on roll behaviour is important. In this work, the impact of the symmetric toe and thrust misalignment on the roll behaviour of an HCRV is analysed using IPG TruckMaker®, a vehicle dynamics simulation software. A ramp steer manoeuvre was used for the simulations, and the toe misalignment on a wheel was chosen from the range [−0.21°, 0.21°]. Variation in roll behaviour was quantified using the steering wheel angle at which one-wheel lift-off (OWL) occurred (SWA_L). Additionally, an analytical model was formulated to predict OWL and the model predictions were compared with the results from IPG
Chandran, Amarchand, Grandhe, Roshan, Mukhopadhyay, Arko, Sharma, Mitanshu, Shankar Ram, C S
A novel approach for Combi Braking System design considering tire's nonlinear behavior2024-26-005801/16/2024
The standard usage of Combined Braking System (CBS) in lower cc/power 2-wheeler vehicles serves to reduce stopping distance and improve braking stability. The CBS system achieves this by engaging both the front and rear wheel brakes, taking advantage of the high load transfer characteristic during 2-wheeler braking. However, the current design of the CBS system relies on linear system analysis, based on vehicle geometry, load distribution, and tire-road friction. This approach overlooks the non-linearities inherent in braking dynamics, such as tire behavior and dynamic Center of Gravity (CoG) location. Consequently, the current CBS design methodology exhibits limitations, particularly in extreme scenarios where wheel lock-up may occur, such as on low friction surfaces or during panic braking. This paper proposes the incorporation of tire non-linearities into the design of CBS systems using Pacejka's tire model. Initially, calculations are performed to optimize the braking
Khandekar, Piyush, Badiger, Kartik, Gautam, Ashish, Soni, Lokesh
Assisted Steering Control for Distributed Drive Electric Vehicles Based on Combination of Driving and Braking2023-01-701210/30/2023
This paper presents a low-speed assisted steering control approach for distributed drive electric vehicles. When the vehicle is driven at low speed, the braking of the inner-rear wheel is combined with differential drive to reduce the turning radius. A hierarchical control structure has been designed to achieve comprehensive control. The upper-level controller tracks the expected yaw rate and vehicle side-slip angle through a Linear Quadratic Regulator (LQR) algorithm. The desired yaw rate and vehicle side-slip angle are obtained according to the reference vehicle model, which can be regulated by the driver through the accelerator pedal. The lower-level controller uses a quadratic programming algorithm to distribute the yaw moment and driving moment to each wheel, aiming to minimize tire load rate variance. Simulation and real vehicle tests compare three steering modes: front-wheel steering only, front-wheel steering + differential drive assisted steering, and front-wheel steering
Wu, Dongmei, Wang, Cheng, Du, Changqing, Zhang, Yichao
Effect of anti-dive suspension geometry on braking stability2022-01-117209/19/2022
Suspension plays a crucial role in stabilizing, comfort, and performance of a vehicle. During vehicle braking operation, load transfer happens from rear axle to front axle resulting in shifting of vehicle’s center of gravity towards vehicle front for a momentarily duration, this phenomenon is called diving. This leads to dropping of traction at rear wheel end, resulting in lifting of rear axle with front wheel as pivot causing increase in front to rear weight ratio of vehicle system and moreover, compromising driver safety due to skidding and locking of rear. To minimize this phenomenon’s affect, optimum anti-dive suspension geometry is used to have better rear wheel end traction resulting in improved braking stability. This paper provides methodology for establishing coherence between braking and suspension geometry by providing mathematical model with various suspension geometry and its reaction force on vehicle under braking condition for predicting traction lose at rear wheel end
Patel, Sahil, Pujari, Sachin, Nagrikar, Ravi, Umbare, Deepak
Investigation and Analysis of Brake Factor variation and its relation with Brake Pulling.2022-01-117109/19/2022
Vehicles pull during braking can be defined as the deviation of vehicle travel from intended path of the vehicle by a margin of half a wheel track or more. It is a dynamic phenomenon with very complex inter-dependencies among the combined functioning of various aggregates such as steering system, suspension system, axles, brakes. The problem is aggravated with shorter wheelbase & higher CG (Centre of Gravity) height, where the instantaneous load transfers are sudden and of relatively high magnitude which can lead to a combination of forces that are responsible for vehicle drifting or pulling to anyone side of center-line travel. Vehicle with shorter wheelbases, high GVW and high CG heights are more prone to this unstable behavior due to sudden change in dynamic forces acting on the tires while turning and braking. Although these vehicles have some disadvantages, they are required for important applications such as stage and intercity operations and hence cannot be stopped producing due
Pandey, Prashant, Pujari, Sachin, Nagrikar, Ravi
Creating an Instantaneous Center of Rotation Map to Determine the Influence of Yaw Rate on Occupant Kinematics and Injury Potential in Eccentric Planar Collisions2022-01-099303/29/2022
The reconstruction of planar vehicle-to-vehicle collisions often requires a kinematic analysis of post-impact occupant motion to assist with biomechanical injury assessment. When one vehicle imparts an eccentric force on the adverse vehicle, the resulting vehicle kinematics include both translation and rotation. The influence of vehicle yaw on occupant kinematics has been well established. The role that the vehicle yaw has with regard to occupant injury potential is dependent upon a number of factors, including delta-V, vehicle intrusion, occupant seating position, restraint use, and yaw rate. Assuming rotation about the vehicle center of gravity or trivializing post-impact rotation may overlook aspects of the collision dynamics that have important implications for post-impact occupant motion. This study examines the significance of vehicle yaw on occupant kinematics and the evaluation of injury potential in eccentric planar collisions. The paper describes the calculation of the
Rapp van Roden, Elizabeth, Zolock, John
Active control of Camber and Toe angles to improve vehicle Ride Comfort2022-01-112003/29/2022
This paper is part of the European OWHEEL project. It proposes a method to improve the comfort of a vehicle by adaptively controlling the Camber and Toe angles of a rear suspension. The purpose is achieved through two actuators for each wheel, one that allows to change the Camber angle and the other the Toe angle. The control action is dynamically determined based on the error between the reference angle and the actual angles. The reference angles are not fixed over time but dynamically vary during the manoeuvre. The references vary with the aim of maintaining a Camber angle close to zero and a Toe angle that follows the trajectory of the vehicle during the curve. This improves the contact of the tire with the road. This solution allows the control system to be used flexibly for the different types of manoeuvres that the vehicle could perform. An experimentally validated sports vehicle was used to carry out the simulations. The original rear suspension is a Trailing-arm suspension. It
Marotta, Raffaele, Strano, Salvatore, Terzo, Mario, Tordela, Ciro, Ivanov, Valentin
Validation of Utilizing a Self-Propelled Crash Sled to Simulate Occupant Accelerations in Minor Rear-End Impacts2022-01-104003/29/2022
A novel, electrically self-propelled, mobile, free-standing crash sled was constructed with a relatively minimal budget (i.e., ≤ $10,000). The crash sled was designed to simulate occupant driver or passenger seat movement in minor impacts at varying angles with minimal, if any, component replacement necessary between tests. Validation of the crash sled in a rear-end only configuration for determination of occupant accelerations was performed. Minor rear-end crash tests involving human occupants were conducted utilizing a 2007 Toyota Camry target vehicle and a 2005 Toyota Camry bullet vehicle with changes in velocity for the target vehicle ranging between 2.8 km/h and 7.7 km/h. Vehicle instrumentation consisted of tri-axial accelerometers affixed to the center tunnels near their respective center of gravities. Human occupant instrumentation occurred only in the target vehicle and involved tri-axial accelerometers at the head, thorax, and lumbar spine. Peak longitudinal head and lumbar
Vigil, Cole Mackenzie, Salboro, Conrad, Jones, Brian, Brink, Justin, Jorgensen, Michael, Swinford, Scott
An Autonomous Steering Control Scheme for Articulated Heavy Vehicles Using Non-Linear Model Predictive Control Technique2022-01-034403/29/2022
This article presents an autonomous steering control scheme for articulated heavy vehicles (AHVs). Despite efficient freight transportation in economic and environmental benefits, AHVs exhibits poor low-speed maneuverability and low high-speed lateral stability due to their multi-unit vehicle configurations, large sizes, high centers of gravity. In addition, North America’s harsh weather during winters makes the scenario more challenging. AHVs often experience amplified lateral motions of trailing vehicle units in transient curved path negotiations. Heavy goods vehicles represent a 7.5 times higher risk than passenger cars in highway operation. Moreover, human driver errors cause about 94% of traffic collisions. However, little attention has been paid to autonomous steering control of AHVs. To increase the safety of AHVs, an autonomous steering control scheme is designed for a tractor/semi-trailer using a non-linear model predictive control (NLMPC) technique. To this end, a 4 degrees
Sharma, Tarun, Huang, Wei, He, Yuping
AOC AIR-GROUND DATA AND MESSAGE EXCHANGE FORMATARINC633-4 (Current)11/30/2021
The purpose of ARNC 633 is to specify the format and exchange of Aeronautical Operational Control (AOC) communications. Examples of ARINC 633 AOC Structures/Messages include: Flight Plan, Load Planning (i.e., Weight and Balance and Cargo Planning Load Sheets), NOTAMs, Airport and Route Weather data, Minimum Equipment Lists (MEL) messages, etc. The standardization of AOC messages enable the development of applications shared by numerous airlines on different aircraft types. Benefits include improved dispatchability and reduce operator cost.
Airlines Electronic Engineering Committee
Steering Control Systems - Heavy TrucksJ2425_202111 (Current)11/09/2021
This SAE Recommended Practice describes a laboratory test procedure and requirements for evaluating the characteristics of heavy-truck steering control systems under simulated driver impact conditions, as well as driver entry/egress conditions. The test procedure employs a torso-shaped body block that is impacted against the steering wheel.
Truck Crashworthiness Committee
DESIGN AND FABRICATION OF VEHICLE ROLLOVER PREVENTION SYSTEM BY COUNTER STEERING MECHANISM IN AUTOMOBILE2021-28-015510/01/2021
Rollover prevention plays an important role in stability of the vehicle. About 35% percentage of accidents are caused due to rollover .Therefore this brings a need to prevent accidents caused by roll-over of vehicles. So this system prevents the eventual roll-over of the vehicle by a method of counter steering which turns or moves the vehicle in the direction where an eventual roll-over is occurring by applying a physical principle of neutral equilibrium which is displacing an object while not changing the position of its center of gravity .Counter steering brings the vehicle into a neutral equilibrium state thus avoiding the rollover. The rollover is sensed by the MPU-6050 accelerometer cum gyroscope sensor which detects the roll angle, roll acceleration of the vehicle. The programming is done for the ATMEGA controller using Arduino IDE software for continuous monitoring of roll angle and roll acceleration of the vehicle. When the roll acceleration or the roll angle exceeds the
Dhayaneethi, Sivaji, Deepan Kumar, Sadhasivam, S, Arulkumar, SUDHAN, V R, Vignesh, M, Boobalan, Saravanan
Suspension Components Calculation at Concept Stage to Evaluate the Ride and Handling Characteristics2021-26-008209/22/2021
Vehicle handing and ride are the critical attributes for customers while buying new passenger vehicle. Hence it is very important to design suspension which meets customer expectations. Often tuning of suspension parameters is very difficult at later stage like wheelbase, vehicle center of Gravity and other suspension parameters like roll center heights etc. A parametric mathematical model is built to study the effect of these parameters of vehicle handling and ride attributes at concept stage. These models are used to calculate the suspension ride rates, spring rates and Anti roll bar diameters for meeting target vehicle ride and handling performance. The model also calculates natural frequency of suspension and vehicle for understanding pitch and roll behaviours. The inhouse tool developed is used for calculating suspension damper characteristics and predicts ride attributes like Bounce damping, bounce stiffness, Isolation level, Flat ride and Impact Hardness categorized based on
Saifee, Aliakbar, Deshmukh, Chandrakant, deole, Subodh
Influence of Powertrain Mount Stiffness Progressivity on Buzz, Squeak & Rattle Noise for Electric Vehicle2021-01-108908/31/2021
For a modified electric vehicle on the same internal combustion engine (ICE) platform, the primary consideration is to have no change in long member and pendulum type conventional engine mounting system to save development cost and timeline. Electric vehicle (EV) powertrain is comparatively lighter w.r.t the ICE. As a result, the engine mount’s static preload setting point or powertrain centre of gravity under static powertrain load gets changed resulting in a change in stiffness for the same engine mount. As the static stiffness changes, the dynamic stiffness and modal frequency also change. The 6 degrees of freedom (DOF) modal frequency has almost no impact on powertrain modes as EV powertrain modes, mainly, the motor frequency, is much higher than engine mount Eigen modes. In this scenario, the gap management gets disturbed due to less static preload, and non-linearity gets affected. This paper will explain a case study on a modified EV, the change in modal map, its impact vis-a-vis
Hazra, Sandip, K, Janardhan Reddy
Design and Performance Criteria Aircraft Crash AxesAS5402A (Current)04/23/2021
This SAE Aerospace Standard (AS) provides design criteria and performance tests for crash axes intended for use by aircraft crew members to assist in evacuation, extrication, fire fighting, or other emergency activities.
S-9A Safety Equipment and Survival Systems Committee
Traction Control System of Electric Vehicle with 4 In-Wheel Motors using Lyapunov Stability Analysis Algorithm2021-01-012204/06/2021
A TCS strategy of electric vehicle with 4 in-wheel motors is proposed in this paper. The control method consists of three parts: target slip rate calculation, target torque calculation and coordination control. By using Lyapunov stability analysis algorithm, the target slip rate boundary which makes the system stable is obtained. The target torque of each wheel is calculated by PI controller. According to the engineering experience, the TCS coordinated control strategy under split friction coefficient (split-μ) road, and friction coefficient jump(μ jump) road is proposed. The test results show that this strategy can improve the acceleration comfort and yaw stability of vehicles on uniform low friction coefficient (low μ) , split-μ and μ jump road.
Zhao, Yongqiang, Hui, ZhouZehui, Cui, Jinlong
Standard Test Method for Measuring Forces During Normal Impact of a Soft Projectile on a Rigid Flat SurfaceAS6940 (Current)03/23/2021
This document describes a method for measuring forces during an impact between a soft or frangible projectile and a relatively rigid flat normal surface. The document describes the hardware and instrumentation required, as well as the processing and data reduction required to compute force. In this test, a projectile impacts one end of a long cylindrical bar with flat ends, called a Hopkinson bar. The impact occurs on the centerline of the bar in the axial direction. The diameter of the cylindrical bar is large compared to the lateral dimension of the projectile so that, during and after the impact, the projectile material moves radially or backward, rather than extruding around the perimeter of the impact surface. The bar is instrumented with strain gages at some distance from the impacted end to measure the longitudinal strain in the bar. The bar must be sufficiently long so that the duration of the impact is less than the time it takes for the transient stress wave generated by the
G-28 Simulants for Impact and Ingestion Testing Committee
Hyperspectral Cameras and Data QualityTBMG-3862903/01/2021
Hyperspectral imaging combines both imaging and spectroscopy. There are many different optical architectures that are used to make hyperspectral systems, but the end goal is the same – to make an image where each pixel in the image contains information from many spectral bands (many different colors or wavelengths).
Vehicle Transport Unit Load Device (ULD)ARP1554D (Current)11/30/2020
The tests are static in nature to minimize complexity and cost of required testing facilities. As far as practical, applied static loads should take into account the combined static and dynamic loads anticipated in service. It is intended that tests shall be non-destructive in nature and not result in damage unless ultimate load conditions are employed. Test equipment and methods of testing described are not meant to be restrictive. Alternate equivalent methods to accomplish the desired results may be employed. In selected cases, tests may be repeated under ultimate load conditions when required for substantiation of analytical data. If this becomes necessary, the parts deformed may be removed and replaced prior to the retest.
AGE-2 Air Cargo
Transitioning from IC Engine to Electric Vehicle: An Optimized Wheel End Solution2020-01-163210/05/2020
This paper discusses the change in vehicle parameters when moving from a conventional internal combustion engine (ICE) to an electric motor. In particular, the paper discusses the impact on the wheel end bearings, which must handle higher GAWRs (gross axle weight ratings) at lower center of gravity heights on electric vehicles. These changes require bearings to handle higher loads. Typically, larger loads increase the bearing size and with it, the mounting interface dimensions for auxiliary components. In this paper, The Timken Company demonstrates an alternative bearing design that can handle higher electric vehicle GAWRs but allows for continuity in the surrounding brake corner components - potentially saving OEMs significant design costs and delays. This solution focuses on the mid- and large-size SUV market where bearing capacity could be a limiting factor for electric vehicle variants - driving significant wheel end brake corner design changes to accommodate the larger bearings
Fernandes, Ryan, Parsons, Elizabeth, Gromosiak, Mike
Origami-Inspired Miniature ManipulatorTBMG-3783610/01/2020
Minimally invasive laparoscopic surgery, in which a surgeon uses tools and a tiny camera inserted into small incisions to perform operations, has made surgical procedures safer for both patients and doctors. Surgical robots further assist surgeons by allowing them to manipulate multiple tools at once with greater precision, flexibility, and control than is possible with traditional techniques. These robotic systems are extremely large, often taking up an entire room and their tools can be much larger than the delicate tissues and structures on which they operate.
Active roll stabilization introduced for Audi's large crossovers20AUTP10_0810/01/2020
Audi is fitting its largest crossover models with a new, active anti-roll system that the company said enhances cornering capability and reduces body roll without sacrificing ride comfort. Unlike other active anti-roll systems, Audi's electromechanical roll stabilization (eAWS) doesn't rely on hydraulics and is claimed to be “virtually maintenance-free.” Large crossovers and SUVs can be challenging to engineer with assertive vehicle dynamics because their weight and higher center of gravity typically mitigate against sporty cornering unless the suspension is uncomfortably stiff. But the powered anti-roll bars at each axle in the eAWS system permit a comparatively soft tune for the base suspension, firming cornering dynamics only when required.
Visnic, Bill
Air Cargo Unit Load Devices - Performance Requirements and Test ParametersAS36100C-TEST-REC (Historical)09/29/2020
This SAE Aerospace Standard (AS) defines the minimum performance requirements and test parameters for air cargo unit load devices requiring approval of airworthiness for installation in an approved aircraft cargo compartment and restraint system that complies with the cargo restraint requirements of Title 14 CFR Part 25, except for the 9.0-g forward ultimate inertia force of § 25.561 (b)(3)(ii).
AGE-2 Air Cargo
Air Cargo Unit Load Devices - Performance Requirements and Test ParametersAS36100C (Current)09/29/2020
This SAE Aerospace Standard (AS) defines the minimum performance requirements and test parameters for air cargo unit load devices requiring approval of airworthiness for installation in an approved aircraft cargo compartment and restraint system that complies with the cargo restraint requirements of Title 14 CFR Part 25, except for the 9.0-g forward ultimate inertia force of § 25.561 (b)(3)(ii).
AGE-2 Air Cargo
History of Commercial Aircraft New Tire Qualification TestingAIR5651 (Current)09/18/2020
This SAE Aerospace Information Report (AIR) is intended to provide a historical account of testing methods used during the years for Commercial Aircraft New Tire certification.
A-5C Aircraft Tires Committee
Aircraft Asset Lifecycle and Digital Data Standards OverviewAIR7501 (Current)09/18/2020
This SAE Aerospace Information Report (AIR) reviews technical, operational, and maintenance data being exchanged between key stakeholders in aerospace asset lifecycle and data standards available for such exchanges. It identifies gaps and non-availability of data standards in certain areas. The scope of the current document is limited to aircraft operations, maintenance and disposal stages post-build phase, and does not include the detailed interactions during the aircraft build phase.
G-31 Electronic Transactions for Aerospace Committee
Aircraft Asset Lifecycle and Digital Data Standards OverviewAIR7501-TEST-REC (Historical)09/18/2020
This SAE Aerospace Information Report (AIR) reviews technical, operational, and maintenance data being exchanged between key stakeholders in aerospace asset lifecycle and data standards available for such exchanges. It identifies gaps and non-availability of data standards in certain areas. The scope of the current document is limited to aircraft operations, maintenance and disposal stages post-build phase, and does not include the detailed interactions during the aircraft build phase.
G-31 Electronic Transactions for Aerospace Committee
Annual Product Guide20TOFHP06_1206/01/2020
Flexure Testing of Hydraulic Tubing Joints and Fittings by Planar Resonant Vibration (Free-Free Beam)AIR1529B (Current)05/06/2020
This Aerospace Information Report (AIR) establishes flexure test procedures to determine and classify the fatigue strengths of reconnectable or permanent hydraulic tube joints. The procedure is intended for conducting flexure tests of fittings and joints for hydraulic tubing materials such as AMS 5561 steel, AMS 4944 titanium and MIL-T-7081 aluminum alloy, mounted as free-free resonant beams. Of particular advantage are the inherent simplicity of test setup, minimum restraint from a test fixture, low power requirements, short test duration, and ease of varying stress level.
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Fire Containment Cover - Operation and UseARP6905-TEST-REC (Historical)04/23/2020
This SAE Aerospace Recommended Practice (ARP) provides guidelines for the effective operation and use of fire containment covers (FCCs). Technical Standard Orders (TSOs) C203 and C90e (and later revisions) incorporate AS6453, and provide the Minimum Performance Standards (MPS) for an FCC design. The net and pallet used with the FCC must be approved using the updated net and flammability requirements in TSO C90e and later revisions. However, fire containment performance also requires this equipment is properly used. Fire safety is compromised when FCCs are used in an inadequate manner.
AGE-2 Air Cargo
Fire Containment Cover - Operation and UseARP6905 (Current)04/23/2020
This SAE Aerospace Recommended Practice (ARP) provides guidelines for the effective operation and use of fire containment covers (FCCs). Technical Standard Orders (TSOs) C203 and C90e (and later revisions) incorporate AS6453, and provide the Minimum Performance Standards (MPS) for an FCC design. The net and pallet used with the FCC must be approved using the updated net and flammability requirements in TSO C90e and later revisions. However, fire containment performance also requires this equipment is properly used. Fire safety is compromised when FCCs are used in an inadequate manner.
AGE-2 Air Cargo
SUV Kinematics during a Steer-Induced Rollover Resolved Using Consumer-Grade Video, Laser Scans and Match-Moving Techniques2020-01-064204/14/2020
Rollover crashes are complex events that generate motions in all six degrees of freedom (6DOF). Directly quantifying the angular rotations from video can be difficult and vehicle orientation as a function of time is often not reported for staged rollover crashes. Our goal was to evaluate the ability of using a match-moving technique and consumer-grade video cameras to quantify the roll, pitch and yaw angles and angular velocities of a rollover crash. We staged a steer-induced rollover of an SUV at 106 km/h. The vehicle was fitted with tri-axial accelerometers and angular rate sensors, and five consumer-grade video cameras (2 on tripods, 2 on drones, 1 handheld, ~30 fps) captured the event. Roll, pitch and yaw angles were determined from the video using specialized software. We then compared the vehicle orientation angles from the video data to the integrated angular rate data measured by onboard sensors, and also compared the angular rates from the differentiated video data to the
Young, Cole R., King, David J., Siegmund, Gunter P.
Steering Behavior of an Articulated Amphibious All-Terrain Tracked Vehicle2020-01-099604/14/2020
This paper presents a study related to an Articulated Amphibious All-Terrain Tracked Vehicle (ATV) characterized by a modular architecture. The ATV is composed by two modules: the first one hosts mainly the vehicle engine and powertrain components, meanwhile the second one can be used for goods transportation, personnel carrier, crane and so on. The engine torque is transmitted to the front axle sprocket wheel of each module and finally distributed on the ground through a track mechanism. The two modules are connected through a multiaxial joint designed to guarantee four relative degrees of freedom. To steer the ATV, an Electro Hydraulic Power System (EHPS) is adopted, thus letting the vehicle steerable on any kind of terrain without a differential tracks speed. The paper aims to analyze the steady-state lateral behavior of the ATV on a flat road, through a non-linear mathematical vehicle model built in Matlab/Simulink environment. The model describes the vehicle main planar motion and
Tota, Antonio, Velardocchia, Mauro, Rota, Emanuele, Novara, Andrea
Optimal Yaw Rate Control for Over-Actuated Vehicles2020-01-100204/14/2020
As we are heading towards autonomous vehicles, additional driver assistance systems are being added. The vehicle motion is automated step by step to ensure passengers’ safety and comfort, while still preserving vehicle performance. However, simultaneous activations of concurrent systems may conflict, and non-suitable behavior may emerge. Our research work consists in proving that with the right coordination approach, simultaneous operation of different systems improve the vehicle’s performance and avoid the emergence of unwanted conflicts. To prove this, we gathered different control architectures implemented in commercial passenger cars, and we compared them with our control architecture using a unified reference vehicle model. The high-fidelity vehicle model is developed in Simcenter Amesim in a modular and extensible manner. This enables adding systems in a plug-and-play way. Not only different control architectures can be tested on the same vehicle, but also different systems
Kissai, Moad, Monsuez, Bruno, Mouton, Xavier, Martinez, Didier, Tapus, Adriana
A Smart Measuring System for Vehicle Dynamics Testing2020-01-106604/14/2020
A fast measurement of the car handling performance is highly desirable to easily compare and assess different car setup, e.g. tires size and supplier, suspension settings, etc. Instead of the expensive professional equipment normally used by car manufacturers for vehicle testing, the authors propose a low-cost solution that is nevertheless accurate enough for comparative evaluations. The paper presents a novel measuring system for vehicle dynamics analysis, which is based uniquely on the sensors embedded in a smartphone and therefore completely independent on the signals available through vehicle CAN bus. Data from tri-axial accelerometer, gyroscope, GPS and camera are jointly used to compute the typical quantities analyzed in vehicle dynamics applications. In addition to signals such as yaw rate, lateral and longitudinal acceleration, vehicle speed and trajectory, normally available when working with Inertial Measurement Units (IMU) equipped with GPS, in the presented application the
Galvagno, Enrico, Mauro, Stefano, Pastorelli, Stefano, Tota, Antonio
New Integrated Vehicle Dynamics Control System Based on the Coordination of AFS, DYC, and ED for Improvements in Vehicle Handling and Stability10-04-02-000901/27/2020
An integrated vehicle dynamics control system aiming to improve vehicle handling and stability by coordinating active front steering (AFS), direct yaw control (DYC), and electric differential system is developed in this article. First, an electric differential system for electric vehicle, composed of two sets of bi-PMS, in-wheel motors connected in parallel and supplied by a single five-leg inverter, one on the front axle and one on the rear axle, is designed. However, each set is controlled by a proposed sliding mode backstepping control, which has replaced the hysteresis controllers in the conventional direct torque control (DTC), can obviously reduce the torque ripple, and provide better speed tracking performance using sliding mode speed controllers. Second, an integrated control system which coordinates AFS and DYC braking system is designed by using a stability index, based on stability domain in the phase plane portrait, and a gain scheduling parameter to improve vehicle
Aouadj, Norediene, Hartani, Kada, Fatiha, Mekri
A Recommended Method of Analytically Determining the Competence of Hydraulic Telescopic Cantilevered Crane BoomsJ1078_202001 (Historical)01/15/2020
This analysis applies to crane types as covered by ASME B30.5.
Cranes and Lifting Devices Committee
Design of the Control Surfaces for an Aircraft Destined to the Competition SAE BRAZIL AERODESIGN2019-36-021401/13/2020
This work aims to present a methodology for the design of conventional control surfaces for light aircraft. Based on renowned aeronautical engineering references and standards, the theoretical framework presents the concepts of calculation for each flight phase particularity for each control surface in addition to a database with intervals of surfaces and their respective deflections of various aircraft. The methodology used takes into account the suggested steps for the aircraft design, where the dimensions are present in the preliminary design, according to the characteristics intended in the conceptual stage to develop conventional control surfaces aiming at the simplicity of design and the optimal response of control. The use of MATLAB and CFD software for data calculation and iterations are essential for the correct observance and evaluation of the obtained results. A comparative table and graphs will be elaborated for better visualization of the efficiency and behavior of each
Takano e Silva, Yoko Lucila, Kieling, Antonio Claudio, de Azevedo, Emile Diana Mendes, Vilaça, Neilson Luniere, Janzen, Renan Araújo, de Oliveira, Sanches Ismael
Numerical optimization of independent suspension hardpoint2019-36-015401/13/2020
The present work aims to use complex tools for the calculation of vehicle dynamics, using optimization analysis. The study was applied to a single seat off-road prototype that has independent suspension, Double A or WishBones type, both on the front and rear axles and whose main objective will be the analysis of the prototype suspension arms fixing points. A multi-body model was created by MotionView software and straight-line acceleration and deceleration analyzes were applied to obtain better longitudinal load transfer ratios for the axes, besides the force measurements for the arm connections during these events. After the creation of the multi-body model, some studies using optimization tools, through HyperStudy software, were performed in order to obtain the new positions of the attachment points in the chassis, achieving a better dynamic suspension design. The new points change the longitudinal load transfer design and generate controlled alteration between predefined parameters
Alvim, Olavo Fava Furtado, Silveira, Marcio Eduardo
Evaluating Effects of Roll Stiffness Change at Front and Rear Axles on Vehicle Maneuverability and Stability2019-28-240611/21/2019
To cater the push towards “Vehicle Light Weighting”, both sprung and unsprung mass are being reduced. This results in reduced stiffness and thus has a profound undesirable effect on the overall vehicle handling. To understand the effect of different reduction ratios of sprung to unsprung mass; it is desired to understand how changes in stiffness affect the overall vehicle handling characteristics. Therefore, the study was conducted to experiment with different values of roll stiffness, at both front and rear axles and comparing the frequency response and phase change of Yaw Gain observed through a Pulse Input test. The present work is further correlated with subjective feedback to predict the shift in vehicle balance and handling characteristics.
Reuben, Eric Pranesh, Budhiraja, Raghav, N, Sreeraj, K, Rakesh, Singh, Amardeep
Ride-Comfort Analysis for Commercial Truck Using MATLAB Simulink2019-28-242811/21/2019
Ride Comfort forms a core design aspect for suspension and is to be considered as primary requirement for vehicle performance in terms of drivability and uptime of passenger. Maintaining a balance between ride comfort and handling poses a major challenge to finalize the suspension specifications. The objective of this project it to perform ride- comfort analysis for a commercial truck using MATLAB Simulink. First, benchmarking was carried out on a 4x2 commercial truck and the physical parameters were obtained. Further, a mathematical model is developed using MATLAB Simulink R2015a and acceleration- time data is collected. An experimentation was carried out on the truck at speeds of 20 kmph, 30 kmph, 40 kmph and 50 kmph over a single hump to obtain actual acceleration time domain data. The model is then correlated with actual test over a single hump. This is followed by running the vehicle on Class A, B & C road profiles to account for random vibrations. Similarly, a simulation is done
Debnath, Sarnab, Bhanja, Subrat, Achanta, Krishna, Jain, Pranay, Bharti, Sumit, Agrewale, Mohammad Rafiq
A Comparative Study on ESC Drive and Brake Control Based on Hierarchical Structure for Four-Wheel Hub-Motor-Driven Vehicle2019-01-505111/04/2019
Electronic Stability Control (ESC) is an important measure to proactively guarantee vehicle safety. In this paper, the method of four-wheel hub-motor torque control is compared with the traditional single-wheel hydraulic brake control in ESC system. The control strategy adopts the hierarchical structure. In upper controller, the stability of the vehicle is identified by threshold method, the additional yaw moment control uses a way to get the moment including feedforward and feedback parts based on the linear quadratic regulator (LQR). The medium controller is tire slip rate control, in order to get the optimal target slip rate from the upper additional yaw moment, a method of quadratic programming to optimize the longitudinal force is proposed for each wheel. The inputs of tire state for the magic tire model is introduced so as to calculate the target slip rate from the target longitudinal force. The lower controller is wheel cylinder pressure control and motor torque control which is
Lin, Chen, Pei, Xiaofei, Guo, Xuexun
Axle Torque Distribution to Improve Vehicle Handling and Stability2019-01-503711/04/2019
The majority of the fully electric vehicles currently on the market have a basic drivetrain configuration, consisting of multiple electric motors, which promise considerable performance enhancements in terms of vehicle behavior and active safety. A significant advantage was achieving measurable benefits in terms of vehicle cornering response through controlling the individual drivetrains. This paper presents an axle torque distribution method to improve a 4WD vehicle steering performance. The method can automatically adjust the output drive torque of the front and rear motors of the vehicle to change the vehicle yaw rate before ESP intervention, and at the same time remain the driver torque demand unchanged. In this paper we present a feedback yaw rate controller. When the estimated yaw rate differs from the actual yaw rate with a pre-defined small threshold, a yaw rate control is active, the purpose of the controller is to reduce the vehicle understeer characteristic. The simulation
Wu, Aibin, Li, Chao, Zhao, Yongqiang, Cui, Jinlong
Performance Standard for Child Restraint Systems in Transport Category AirplanesAS5276/1 (Current)10/31/2019
This SAE Aerospace Standard (AS) defines minimum performance standards and related qualification criteria for add-on child restraint systems (CRS) which provide protection for small children in passenger seats of transport category airplanes. The AS is not intended to provide design criteria that could be met only by an aircraft-specific CRS. The goal of this standard is to achieve child-occupant protection by specifying a dynamic test method and evaluation criteria for the performance of CRS under emergency landing conditions.
Aircraft SEAT Committee
Setting Preload in Heavy-Duty Wheel BearingsJ2535_201910 (Current)10/07/2019
This SAE Recommended Practice applies to the four primary, large volume applications in the class 7-8 heavy-duty market place, as specified in SAE J1842: a “N” trailer axle b “R” powered rear axle c “FF / FG” nonpowered front axle d “P” trailer axle This document applies to on-highway applications. It is not applicable to those applications that exceed the GAWR ratings or the load line restrictions listed in columns “A,” “B,” and “C” of Table 1. Load lines are measured from the inboard bearing cup backface as shown in 3.4. This document establishes preload force values only. The methodology to obtain these force values must be determined by the fastener supplier and/or axle assembler. This document reviews the bearing system. It is NOT intended to prescribe (new or existing) axle and/or hub manufacturers’ ratings and/or specifications.
Truck and Bus Wheel Committee
Lightweight Exosuit Combines Robotics and Functional ApparelTBMG-3526310/01/2019
Between walking and running, human gaits can cover a wide range of speeds; for example, at low speeds, the metabolic rate of walking is lower than that of running in a slow jog. The opposite also is true: at high speeds, the metabolic cost of running is lower than that of speed-walking.
A Dictionary of Terms for the Dynamics and Handling of Single Track Vehicles (Motorcycles, Scooters, Mopeds, and Bicycles)J1451_201909 (Current)09/24/2019
Terminology within this document is limited to the dynamics and handling characteristics of single track, two-wheeled vehicles.
Motorcycle Technical Steering Committee
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