Browse Topic: Suspension systems

Items (3,579)
The SAE Formula prototypes are developed by students, where in the competition, various aspects of project definitions are evaluated. Among the factors evaluated for scoring is the braking system, in which the present work aims to present the development and design of the braking system of a vehicle, prototype of Formula SAE student competition. As it is a project manufactured mostly by students, where the chassis, suspension system, electrical, transmission and powertrain are developed, it is important to first pass the static and safety tests, where the brakes of the four wheels are tested during deceleration at a certain distance from the track. To enable such approval and also to demonstrate, for the competition judges, the veracity of the system’s sizing, all the parameters and assumptions of the choice of the vehicle’s braking system are presented, thus ensuring their reliability, efficiency and safety. Using drawing and simulation software such as SolidWorks and Excel for
Gomes, Lucas OlenskiGrandinetti, Francisco JoséMartins, Marcelo SampaioSouza Soares, Alvaro ManoelReis de Faria Neto, AntônioCastro, Thais SantosAlmeida, Luís Fernando
The fuel economy performance of road vehicles is one of the most important factors for a successful project in the current automotive industry due to greenhouse effect gases reduction goals. Aerodynamics and vehicle dynamics play key roles on leading the automaker fulfill those factors. The drag coefficient and frontal area of the vehicle are affected by several conditions, where the ground height and pitch angle are very relevant, especially for pickup trucks. In this work, we present a combined study of suspension trim heights and aerodynamics performance of a production pickup truck, where three different loading conditions are considered. The three weight configurations are evaluated both in terms of ground height and pitch angle change considering the suspension and tires deflection and these changes are evaluated in terms of drag coefficient performance, using a Lattice-Boltzmann transient solver. Results are compared with the baseline vehicle at road speed condition, where both
Buscariolo, Filipe FabianTerra, Rafael Tedim
A serious problem of public healthcare around the world is the number of road vehicle accidents, every year almost 1,3 million people die and approximately 20 to 50 million people suffer a non-fatal accident because of a road vehicle accident [1]. As a result of that, in 2021 the World Health Organization stated the “The Second Decade of Action for Road Safety”, which the goal is to prevent at least 50% of deaths and injuries due traffic by 2030. To achieve this goal, the automobile companies have invested in technology and products that can enhance vehicle safety. Despite exist some control systems able to reduce roll, and consequently the roll over, such as active suspension, semi-active suspension, and stability control systems, none of them have as main purpose reduce the number of rollovers. The following study aims to examine the effects of an active anti roll bar, to improve the vehicle dynamics during corners and reduce the risk of a rollover by reducing the roll of the sprung
Gomes, Pedro CarvalhoTeixeira, Evandro Leonardo SilvaMorais, Marcus Vinicius GirãoFortaleza, Eugenio Liborio FeitoraSantos Gioria, Gustavo
This paper aims to describe a quarter-car suspension test bench automation process to be utilized in an academic environment. The project is made up of pneumatic system modeling and control system design. An analysis of the bench’s pneumatic system is carried out. This pneumatic system is composed of a pneumatic actuator and a proportional directional control valve, which are responsible for generating the road profile. It is proposed a model to compensate the non-linearities present in the pneumatic system measurement process and the disturbances caused by the under test suspension system, as well as a control strategy for small displacements of the load through linear control approaches, which provide the necessary flexibility to directly influence the parameters affecting the dynamics of the excitation system platform’s displacement, thereby reducing the complexity of the controller design to be adopted. Furthermore, analyses are conducted on the effectiveness of the control in
Siqueira, Matheus AmaralGomes, Pedro CarvalhoTeixeira, Evandro Leonardo SilvaFortaleza, Eugênio Libório FeitosaMorais, Marcus Vinicius Girão
Autonomous vehicles for mining operations offer increased productivity, reduced total cost of ownership, decreased maintenance costs, improved reliability, and reduced operator exposure to harsh mining environments. A large flow of data exists between the remote operation and the ore haul vehicle, and part of the data becomes information for the maintenance sector which it monitors the operating conditions of various systems. One of the systems deserving attention is the suspension system, responsible for keeping the vehicle running and within a certain vibration condition to keep the asset operational and productive. Thus, this work aims to develop a digital twin-assisted system to evaluate the harmonic response of the vehicle’s body. Two representations were created based on equations of motion that modeled the oscillatory behavior of a mass-damper system. One of the representations indicates a quarter of the ore transport truck’s hydraulic system in a healthy state, called a virtual
Rosa, Leonardo OlimpioBranco, César Tadeu Nasser Medeiros
The SAE Formula, a national stage of the international competition, consists of a student project at universities in Brazil that seeks to encourage engineering students to apply the theoretical knowledge obtained in the classroom to practice, dealing with real problems and difficulties in order to prepare them for the job market. The SAE Formula prototype is developed with the intention of competing in the SAE national competition, where teams from various universities in Brazil meet to compete and demonstrate the projects developed during the year. Focusing on the vehicle dynamics subsystem, which can be divided into the braking, suspension, and steering systems of a prototype, the steering system includes main mechanical components such as the front axle sleeves, wheel hub, steering arm, steering column, rack, wheel, and tire. All these components work together with the suspension systems, including suspension arms, “bell crank,” and spring/shock absorber assembly. These components
Rigo, Cristiano Shuji ShimadaNeto, Antonio Dos Reis De FariaGrandinetti, Francisco JoseCastro, Thais SantosDias, Erica XimenesMartins, Marcelo Sampaio
This research addresses the pivotal role of active anti-roll bars in mitigating vehicle body roll during cornering, thereby enhancing overall stability, maneuverability, and comfort. The proposed approach integrates two distinct control methodologies—a straightforward error proportional controller and a reinforcement learning (RL)-based controller. Each front and rear active anti-roll bar applies a roll-reducing torque computed by the proportional controller during cornering. However, this torque alone proves insufficient in effectively damping roll oscillations induced by road irregularities. The RL-based controller leverages observations encompassing inertial measurement unit data (roll rate, pitch rate, and vertical acceleration), and wheel vertical displacements and employs the roll as a reward signal. This controller calculates two additional corrective torques. These torques are seamlessly incorporated by both front and rear anti-roll bars alongside the proportional controller
Marotta, RaffaeleStrano, SalvatoreTerzo, MarioTordela , Ciro
Throughout the vehicles industry and electrification, vehicle ride comfort, road holding, and fuel/charge economy have always been important considerations for the design and development of shock absorbers. Vehicle suspension is one of the oscillating power dissipation sources in which the undesired mechanical energy is dissipated into heat waste. Therefore, in this study a regenerative MacPherson strut is modeled and validated to investigate the vehicle vertical dynamics performance as well as the harvestable power that can be used to charge batteries or power vehicle electrical loads. The optimal design parameters of the regenerative MacPherson strut (RE.M.S) is obtained by using multi-object genetic algorithm (MOGA) optimization for a better trade-off between regenerated power, ride comfort, and road holding. The results showed that RE.M.S can function as a semi-active shock absorber as change of duty cycle of charging circuit. Furthermore, the optimal selection of the design
Hegazy, Ahmed H.A.Kaldas, Mina M.Soliman, Aref M.A.Huzayyin, A.S.
As a part of an automobile suspension structure, fatigue durability performance of the automotive stabilizer bar linkage is crucial to the safety and reliability of the suspension system. In this study, the modeling and simulation analysis methods of the stabilizer bar linkage were described in detail, especially for the welded positions between the connecting rod and the spherical shells (or sleeves). Based on the equivalent structural stress method and the theory of critical distances, damage values of welded positions in the stabilizer bar linkage were solved. For the spherical shell end, the simulation reproduced the bench test; and for the sleeve end, the analysis approach was determined by comparing in several different modeling ways. Mooney-Rivlin model was adopted to fit the constitutive relationship of rubber material in the bushing. The above methods were applied to predict the fatigue durability performance of the stabilizer bar linkage product, and the effectiveness was
Wang, XuHan, ChaoDeng, Jianjiao
The parametrized twist beam suspension is a pivotal component in the automotive industry, profoundly influencing the ride comfort and handling characteristics of vehicles. This study presents a novel approach to optimizing twist beam suspension systems by leveraging parametric design principles. By introducing a parameter-driven framework, this research empowers engineers to systematically iterate and fine-tune twist beam designs, ultimately enhancing both ride quality and handling performance. The paper outlines the theoretical foundation of parametrized suspension design, emphasizing its significance in addressing the intricate balance between ride comfort and dynamic stability. Through a comprehensive examination of key suspension parameters, such as twist beam profile, material properties, and attachment points, the study demonstrates the versatility of the parametric approach in tailoring suspension characteristics to meet specific performance objectives. To validate the
Pakala, Pradeep KumarGanesh, Lingadalu
Sports Utility Vehicles (SUVs) Braking performance is a critical parameter, and it is described by the measure of stopping distance & stability of the vehicle at a specified speed. When it comes to electric vehicles, balancing tyre performance parameters like RRc, traction, wear, ride and handling, weight and NVH is challenging due to higher axle weights, higher moment of inertia and high instant torque delivery. This study presents the braking performances of EV-intended tyres at various contact surfaces in both dry & wet conditions. Impact of tyre design attributes like tyre tread pattern, contact patch, tread compound, tyre carcass construction & characteristics studied on 3 different tyres including ultra-high-performance tyres on braking performances. This paper contains the study & analysis of 1) Footprint analysis concerning the shape of the contact patch, pressure distribution, land-sea ratio, and contact area 2)Tyre tread design such as NSD, grooves, ribs & sipes design and
V, PadmasriVellandi, VikramanSundaram, RaghupathiSingh, Ram KrishnanP, PraveenChittibabu, Santhosh
Hydro-pneumatic suspension is widely used because of its desirable nonlinear stiffness and damping characteristics. However, the presence of parameter uncertainties and high nonlinearities in the system, lead to unsatisfactory control performance of the traditional controller in practical applications. In response to this challenge, this paper proposes a novel stability control method for active hydro-pneumatic suspension (AHPS). Firstly, a nonlinear mathematical model of the hydro-pneumatic suspension, considering the seal friction, is established based on the hydraulic principle and the knowledge of Fluid dynamics. On the basis of the established hydro-pneumatic suspension nonlinear model, a vehicle dynamics model is established. Secondly, an active disturbance rejection sliding mode controller (ADRSMC) is designed for the vertical, roll, and pitch motions of the sprung mass. The lumped disturbance caused by the model nonlinearities and uncertainties is estimated by the extended
Niu, ChangshengLiu, XiaoangJia, XingGong, BoXu, Bo
In the fast growing automotive sector, reliability & durability are two terms of utmost importance along with weight and cost optimization. Therefore it is important to explore new technology which has less weight, low manufacturing cost and better strength. It also seek for a quick, cost effective and reliable methodology for its design validation so that any modification can be made by identifying the failures. This paper presents the rig level real world usage pattern simulation methodology to validate and correlate the vehicle level targets for micro strain, wheel forces and displacement on suspension components like optimized Z spring, torque rods, pan hard rod & mounting brackets of newly developed air suspension for buses
Tangade, Atul BanduBabar, SunilBankar, Milind AchyutraoMehendale, RavindraDhumal, KailasBhusari, DeepakSonawane, RavindraShinde, Saurabh
December is a good time to reflect on the past year - to celebrate successes and consider opportunities for improvement - but it is also an opportune time to look to the future. As I think about the year ahead and appraise the tradeshow landscape that'll provide significant content for this magazine, mobilityengineeringtech.com, our e-newsletters and other multimedia products, none is bigger than Bauma in Munich, Germany, particularly in terms of the global construction and mining vehicle industries. The triennial event will cover an area that's equivalent to 86 soccer fields, according to Stefan Rummel, CEO of Messe München GmbH. Speaking to the press during an October virtual preview of Bauma 2025, which takes place from April 7-13, Rummel said that the number of exhibitors - expected to be about 3,600 - will be closer to the 2019 event versus the post-COVID-19 edition that was pushed back from its usual spring timeslot to the fall of 2022
Gehm, Ryan
ABSTRACT A unique laboratory suspension testing capability has been developed which, for the first time, enables rapid evaluation of tracked vehicle suspension components. The testing capability was stood up in the Durability Test Lab (DTL) in conjunction with the materials division, both organizations within GVSC. Testing has been ongoing, and the results of that testing are presented, current to the time of publication. Historically, laboratory component testing has been very limited due to the lack of a capability to provide relevant loading conditions. Previous testing capabilities not only were deficient in their vertical speed capability, but more importantly, lacked the ability to apply the corning forces. Further reasoning and details associated with the development of this test system are presented. This capability was developed as part of an ongoing campaign in the materials division of GVSC. The purpose of this campaign is to demonstrate and establish design standards, and
Allen, SamuelOstberg, David
ABSTRACT Damper models used in Multi Body Dynamics simulations of tracked vehicles are commonly defined solely by damper curves, that is stabilized damper reaction torque as a function of steady state velocity. In reality, the achievement of the stable reaction torque lags behind damper curve torque upon attainment of a given velocity. As detailed in this paper, the idealization to reduce damper performance to a “damper curve” cannot produce an accurate representation of the two primary terrains military vehicles are designed against: half-round and ride quality courses. By introducing “compliance” and “lash”, the damper performance can be accurately represented. With the slight extension of this model to a fully physics based one, future dampers can be designed to expand the operating performance envelope of tracked vehicles. Citation: D. Ostberg, K. Redner, S. Allen, “Transient Torque Response Modeling of Tracked Vehicle Suspension Rotary Dampers,” In Proceedings of the Ground
Ostberg, DavidRedner, KennethAllen, Samuel
ABSTRACT Conceptual design of automotive structures has received substantial research attention in recent years in order to speed up vehicle development and innovation. Although several structural optimization methods have been employed in concept design, there still exists lack of efficient design tools to produce initial design shapes with less problem dependency, less computation-intensive analysis and more design flexibility. In this paper, an innovative Computer Aided Engineering (CAE) approach based on an integrated Genetic Algorithms(GA) and Finite Element (FE) optimization system has been studied and implemented for efficient conceptual design of automotive suspension system related structural part. Integration of GA provides the method a great amount of design flexibility and robustness that increases possibility of finding more efficient and innovative design shapes of the structure
Islam, Mohammad RefatulMotoyama, Keiichi
ABSTRACT We compared performance of a lightweighted and baseline vehicle and demonstrated how performance is affected by adjusting the spring and shocks using 2-D and 3-D simulations. 2-D lump-parameter model was constructed from physical vehicle parameters by transforming displacements and loads from the springs and dampers into wheel motion and spindle forces. For the 3-D model, a detailed model for each suspension was used including rotational inertia of moving parts. Ride quality was assessed for 16 ride-courses with varying RMS terrain roughness by finding maximum speed at which average absorbed power at the driver seat is lower than 6 W. Shock performance was evaluated by finding maximum speed for the driver not to exceed 2.5-G acceleration when riding over varying-size half-round obstacles. The forces on wheel axes and accelerations were measured for the vehicle dropped from the height of 6, 12, 18, and 24 in. Maximum longitudinal slope climbing capability was estimated on hard
Jelinek, BohumirSalmon, EthanMason, GeorgeGibson, MichaelHannis, TylerPachel, NathanJarrell, WalkerTowne, Brent
ABSTRACT High life cycle costs coupled with durability and environmental challenges of tracked vehicles in South West Asia (SWA) have focused R&D activities on understanding failure modes of track components as well as understanding the system impacts on track durability. The durability limiters for M1 Abrams (M1, M1A1, and M1A2) T-158LL track systems are the elastomeric components. The focus of this study is to review test methodology utilized to collect preliminary data on the loading distribution of a static vehicle. Proposed design changes and path forward for prediction of durability of elastomers at the systems level from component testing will be presented
Ostberg, DavidBradford, Bill
ABSTRACT This paper presents the comparative analysis of virtual and experimental proving ground for the performance capabilities of front suspensions in the Family of Medium Tactical Vehicles (FMTV) cargo truck. The front suspension of the current baseline FMTV is a solid axle with leaf springs and shock absorbers. Two other types of suspensions including passive and semi-active suspensions are evaluated in solid and fully independent axle configurations. Virtual proving ground for on- and off-road tests are simulated in the Trucksim environment to include constant radius circular steer, double lane change, sinusoidal steer, washboard road surfaces, and half-round curb strike. Physical proving ground tests are conducted to provide some experimental correlation and validation of the baseline vehicle simulation results. The comprehensive experiments also evaluate the capabilities of various suspensions which have been considered in future FMTV design for mobility performance improvement
Liao, Y. GeneCard, BrandonWasylyk, John
ABSTRACT This paper addresses some aspects of an on-going multiyear research project of GP Technologies for US Army TARDEC. The focus of the research project has been the enhancement of the overall vehicle reliability prediction process. This paper describes briefly few selected aspects of the new integrated reliability prediction approach. The integrated approach uses both computational mechanics predictions and experimental test databases for assessing vehicle system reliability. The integrated reliability prediction approach incorporates the following computational steps: i) simulation of stochastic operational environment, ii) vehicle multi-body dynamics analysis, iii) stress prediction in subsystems and components, iv) stochastic progressive damage analysis, and v) component life prediction, including the effects of maintenance and, finally, iv) reliability prediction at component and system level. To solve efficiently and accurately the challenges coming from large-size
Ghiocel, Dan M.Negrut, DanLamb, DavidGorsich, David
ABSTRACT The analysis and design of a novel active suspension system incorporating a negative stiffness spring are investigated in this paper. The suspension structure consists of the mechanism that employs a combination of ordinary and negative stiffness springs and damping element. The resulting system yields superior performance in terms of mobility, maneuverability, and stability, particularly in harsh terrains and/or off-road environment. However, its dynamics are highly nonlinear and cannot be handled directly by conventional design techniques and methodologies. In this paper, the formulation of the proposed active suspension system consists of two phases: analysis and synthesis. In the analysis phase, nonlinear controls based on the advanced feedback linearization methodologies of the differential geometric theory is considered. The approach renders the difficult task of developing nonlinear controls rather simple. In the synthesis phase, which is required for real-world
Loh, Robert N. K.Thanom, WittBrock, Derrick
Abstract Semi-active suspensions have drawn particular attention due to their superior performance over the other types of suspensions. One of their advantages is that their damping coefficient can be controlled without the need for any external source of power. In this study, three control approaches are implemented on a quarter-car model using MATLAB/Simulink. The investigated control methodologies are Acceleration Driven Damper, Power Driven Damper, and H∞ Robust Control. The three controllers are known as comfort-oriented approaches. H∞ Robust Control is an advanced method that guarantees transient performance and rejects external disturbances. It is shown that H∞ with the proposed modification, has the best performance although its relatively high cost of computation could be potentially considered as a drawback
Ghasemalizadeh, OmidTaheri, SaiedSingh, AmandeepGoryca, Jill
ABSTRACT Motion planning algorithms for vehicles in an offroad environment have to contend with the significant vertical motion induced by the uneven terrain. Besides the obvious problems related to driver comfort, for autonomous vehicles, such “bumpy” vertical motion can induce significant mechanical noise in the real time data acquired from onboard sensors such as cameras to the point that perception becomes especially challenging. This paper advances a framework to address the problem of vertical motion in offroad autonomous motion control for vehicular systems. This framework is first developed to demonstrate the stabilization of the sprung mass in a modified quarter-car tracking a desired velocity while traversing a terrain with changing height. Even for an idealized model such as the quarter-car the dynamics turn out to be nonlinear and a model-based controller is not obvious. We therefore formulate this control problem as a Markov decision process and solve it using deep
Salvi, AmeyaBuzhardt, JakeTallapragada, PhanindraKrovi, VenkatBrudnak, MarkSmereka, Jonathon M.
ABSTRACT Vehicle prognostics are used to estimate the remaining useful life of components or subsystems, based on a limited number of measured vehicle parameters. Ideally, sensors would be available for every component and failure mode of interest, such that accurate data could be measured and used in prognostic estimates. However, this is impractical in terms of the number of sensors required and the costs to install such a system and maintain its integrity. A better solution is to relate the loading on a specific component to more generic vehicle behavior. This paper reviews a methodology referred to as the “Durability Transfer Concept”, which suggests that damage, or severity of usage, at various points of interest on a vehicle can be predicted simply from measured accelerations at some nominal location – a wheel axle, for example. Measured accelerations are double integrated to get displacements. Those displacements are then filtered using the Rupp or Lalanne method. A transfer
Halfpenny, AndrewHussain, ShabbirMcDougall, ScottPompetzki, Mark
ABSTRACT A significant challenge for wheel- and propeller-driven amphibious vehicles during swimming operations involves the egress from bodies of water. The vehicle needs to be able to swim to the ramp of a vessel, and then propel itself up the ramp using water propellers and wheels simultaneously. To accurately predict the ability of the vehicle to climb the ramp, it is important to accurately model: (1) the interaction of the flow through the propellers, around the vehicle hull, and away from the ramp; (2) the wheel / ramp interaction; (3) the suspension system spring, damping, and motion-limiting forces, tire deformation and loading characteristics, and wheel and hull motions (both translation and rotation); and (4) the drivetrain power distribution to the wheels. Detailed modeling and simulation of these physics and processes -- such as the wheel, hull, and suspension system motions and force interactions, propeller rotation and resulting flow, etc. -- would be highly
Tison, Nathan
ABSTRACT At the request of the US Army’s Tank Automotive Command (TACOM) a device was built to measure the suspension parameters of any military wheeled vehicle. This is part of an ongoing effort to model and predict vehicle dynamic behavior. The new machine is called the Suspension Parameter Identification and Evaluation Rig (SPIdER) and has a capacity intended to cover all of the military’s wheeled vehicles. The machine operates by holding the vehicle body nominally fixed while hydraulic cylinders move an “axle frame” in bounce or roll under each axle being tested. Up to two axles may be tested at once. Forces at the tires and motions of the wheel centers in three dimensions and two angles are measured. Other motions of the suspension and the minimal motions of the vehicle body are measured. For steer axles the steering ratio, Ackerman steer characteristics, and kingpin orientation are measured
Andreatta, DaleHeydinger, GarySidhu, AnmolBixel, RonaldKurec, AleksanderSingh, AmandeepBaseski, IgorSkorupa, Thomas
ABSTRACT There have been several hundred rollovers in military vehicles in the last decade of deployment, of which approximately fifty percent are fall-based that occur during off-road operations. Off-road fall-based rollovers occur at lower speeds during road breakaway when the soft road gives way underneath the vehicle on one side as the soil is unable to support the vehicle load (Figure 1). A simulation-based study was conducted to explore potential off-road rollover mitigation benefits for the heavy vehicles with higher center of gravity such as MRAPs, MATV, and JLTV through the use of high performance active suspension systems. The study developed a system architecture based on the ElectroMechanical Suspension (EMS) technology and developed a medium fidelity MATLAB-Simulink-DADS model. Simulation results indicated substantial rollover mitigation benefits for MRAP/JLTV class vehicles, especially in road breakaway scenarios. Potential DoD beneficiaries include the Army and Marines
Beno, JosephBryant, AdamSingh, AmandeepKovnat, AlexanderHayes, RichardWeeks, Damon
ABSTRACT This research paper addresses the ground vehicle reliability prediction process based on a new integrated reliability prediction framework. The paper is an extension of the paper presented last year at the GVSETS symposium. The integrated stochastic framework combines the computational physics-based predictions with experimental testing information for assessing vehicle reliability. The integrated reliability prediction approach incorporates the following computational steps: i) simulation of stochastic operational environment, ii) vehicle multi-body dynamics analysis, iii) stress prediction in subsystems and components, iv) stochastic progressive damage analysis, and v) component life prediction, including the effects of maintenance and, finally, iv) reliability prediction at component and system level. To solve efficiently and accurately the challenges coming from large-size computational mechanics models and high-dimensional stochastic spaces, a HPC simulation-based
Ghiocel, Dan M.Negrut, DanLamb, DavidGorsich, David
ABSTRACT Model based design techniques are being used increasingly to predict vehicle performance before building prototype hardware. Tools like ADAMS and Simulink enable very detailed models of suspension components to be developed so vehicle performance can be accurately predicted. In creating models of vehicle systems, often there is a question about how much component detail or model fidelity is required to accurately model system performance. This paper addresses this question for modeling shock absorber performance by comparing a low fidelity and high fidelity shock absorber model. A high fidelity and low fidelity mathematical model of a shock absorber was developed. The low fidelity shock absorber model was parameterized according to real shock absorber hardware dimensions. Shock absorber force vs. velocity curves were calculated in Simulink. The results from the low fidelity and high fidelity model were compared to shock absorber force vs. velocity test results. New vehicle
Masini, ChrisYang, Xiaobo
ABSTRACT The need for up-armored vehicles has increased over the years. This has put a greater emphasis on suspensions that can provide improved ride and handling capabilities while facing the additional weight. One of the challenges with these vehicles traditionally has been increased likelihood of rollover. Increased rollover is due to high center of gravity, kinematics of the overloaded suspension, and the low damping that is needed to satisfy 6-Watt ride speed performance criteria. The Lord magneto-rheological (MR) suspension system addresses these issues by improving the ride quality and handling characteristics thereby increasing safety and mission effectiveness. During handling maneuvers, algorithms inside the controller unit apply corrective forces to minimize peak roll angle and peak roll rate. The benefit of this has been tested on a vehicle comparing the stock passive dampers to the MR dampers over NATO Lane change events. Furthermore, the controller has the capability to
Hildebrand, StephenMargolis, DonaldMathew, AbrahamMattson, Michael
ABSTRACT GenShock is an energy-harvesting, semi-active shock absorber. The device converts vertical travel of a vehicle suspension system to useful electricity. On defense platforms, this power ranges from a few hundred watts to several kilowatts. Conventional shock absorbers provide damping by dissipating suspension energy as heat, while GenShock provides damping by generating electricity. For an internal combustion engine (ICE) vehicle, the energy harvested by GenShock is used for reducing alternator load. The energy can also be conditioned for battery charging to address vehicle hotel loads. GenShock is also semi-active capable, in which each unit can stiffen or loosen in concert with the terrain, vehicle speed and load conditions for improved maneuverability. This paper presents a characterization of GenShock technology in its form and function of a direct replacement shock absorber that has regenerative and semi-active capabilities
Avadhany, Shakeel N.Anderson, Zack M.Diamond, DavidWendell, Ross
ABSTRACT With the particular passage capability, all-terrain vehicle (ATV) has been widely used for off-road scenarios. In this research, we conduct a lateral sway stability analysis for the suspension mechanism of a general vehicle and establish a mathematical model of static and dynamic stability based on the maximum lateral sway angle and lateral sway acceleration, by considering the combined angular stiffness of independent suspension, angular stiffness of the lateral stabilizer bar and vertical stiffness of tires. 3D point cloud data of a terrain environment is collected using an RGB-Depth camera, and a triangular topography map is constructed. The results in ADAMS show that the proposed stability model can accurately predict the critical tipping state of the vehicle, and the method deployed for real-world terrain modeling and simulation analysis is generalizable for the stability assessment of the interaction between ATV and real-world terrain. Citation: H. Luo, Z. Chen, A
Luo, HaitaoChen, ZhiminNaveen, AryanLi, Bing
ABSTRACT A time-accurate multibody dynamics model of the suspension system of a tracked vehicle is experimentally validated using a full-scale tracked-vehicle on an N-post motion simulator. The experiments consist of harmonic excitations at various amplitudes and frequencies and ramp excitations of the vehicle road-wheels (without the track), with each road wheel under one linear actuator of the N-post motion simulator. A high-fidelity multibody dynamics model of the vehicle along with the N-post motion simulator is constructed. The multibody dynamics model consists of rigid bodies, joints, rotational springs (that include non-linear rotational stiffness, damping and friction), actuators and contact surfaces. The rigid bodies rotational equations of motion are written in a body-fixed frame with the total rigid-body rotation matrix updated each time step using incremental rotations. Connection points on the rigid bodies are used to define joints between the bodies including revolute
Wasfy, Tamer M.O’Kins, JamesRyan, David
ABSTRACT Reconnaissance of distant targets with long reaching sensor technology demands a stable platform upon which to operate. Traditionally this requires vehicles deploying mast mounted sensors to remain stationary while collecting data. Pairing electronically controlled active Electromechanical Suspension System (EMS) technology developed by The University of Texas Center for Electromechanics (UT-CEM) with current reconnaissance vehicle platforms creates highly mobile intelligence gathering systems capable of operating on the move over rough and unimproved terrain. This report documents the establishment of criteria by which to judge sensor platform stabilizing performance of EMS and then uses these metrics to evaluate performance improvements over conventional passive vehicles. Based on this analysis it may be possible to operate effectively over cross-country terrains at speeds of 10 to 15 mph while collecting useful reconnaissance data
Beno, JosephBryant, AdamWeeks, Damon
ABSTRACT <underline>Problem outline</underline>: Adding armor to protect vehicle occupants leaves conventional suspensions incapable of delivering ride quality and handling needed for mission objectives. The current up-armored HMWWV has exceeded the design weight for the M1113 variant by a considerable amount. The rated GVW is 11,500 lb, yet the mission ready weight often reaches 14,500 lb. This results in greatly reduced reliability and frequent breakage of suspension components. When the suspension is overloaded, the ride height is reduced and the vehicle is no longer capable of safely traversing rough terrain. In addition, the lack of available compression travel results in severe bottoming that transmits extremely high shock loads into the suspension, chassis and ultimately the occupants. A semi-active suspension upgrade kit for the up-armored HMWWV was developed with the objective of achieving comparable performance for the weight range of 8300lbs curb weight to 14,500lbs combat
ABSTRACT Vehicle prognostics are used to estimate the remaining useful life of components or subsystems, based on measured vehicle parameters. This paper presents an overview of a vehicle prognostic system, including the critical tasks associated with configuring such a system. The end user of a vehicle prognostic system focuses on the reports generated by the system that provide indications of vehicle readiness, condition and remaining useful life. These reports are based on measurements recorded from sensors on the vehicle and analyzed either on the vehicle or remotely by a “back office” information management system; the latter also provides usage severity trends. To implement such a system, an engineer must first define the vehicle components of interest and determine “damage correlates”: the relationship between damage occurring on key component(s) and key vehicle parameters that can be obtained from vehicle “bus data”. These “damage correlates” and the associated analysis methods
Pompetzki, MarkDabell, BrianGothamy, JosephBechtel, James
Abstract Active and semi-active suspension systems are mechatronic systems that require a disciplined approach to synergistically combine the traditional engineering fields of mechanical, electronic, controls, power, systems, automotive, and suspension. Integrating suspension design is particularly challenging because it strongly interfaces with safety issues and driver perceptions, which are not easily optimized. Since 1993, the University of Texas Center for Electromechanics (UT-CEM) has successfully developed high performance active suspension technology and systems for a wide range of military vehicles, including small tactical trucks (e.g., HMMWV), medium tactical trucks (e.g., LMTV), and hybrid electric tanks (e.g., BAE’s Lancer prototype). In addition to developing active suspension technology, UT-CEM has developed, refined, and validated an integrated simulation based design approach for controlled suspension systems that is the topic of this paper
Beno, Joseph H.Weeks, Damon A.Mock, Jason R.
Abstract RedRAVEN is a pioneered autonomous robot utilizing the innovative Linked-Bogie dynamic frame, which minimizes platform tilt and movement, and improves traction while maintaining all the vehicle’s wheels in contact with uneven surfaces at all times. Its unique platform design makes the robot extremely maneuverable since it allows the vehicle’s horizontal center of gravity to line up with the center of its differential-drive axle. Where conventional differential-drive vehicles use one or more caster wheels either in front or in the rear of the driving axle to balance the vehicle’s platform, the Linked-Bogie design utilizes caster wheels both in the front and in the rear of the driving axle. Without using any springs or shock absorbers, the dynamic frame allows for compensation of uneven surfaces by allowing each wheel to move independently. The compact and lightweight ground vehicle also features a driving-wheel neutralizing mechanism, a rigid aluminum frame, and a translucent
Mekhtarian, AraHorvath, JosephLin, C.T.
ABSTRACT This paper discusses the semi-active suspension system developed by A.M. General to provide mobility and maneuverability for tactical, wheeled vehicles
Tackett, WendellLovell, JeffreyBrown, Chris
ABSTRACT This paper presents an experimental methodology for regeneration of course profiles, with tire acceleration and speed, suspension force and pitch data collected from an instrumented trailer wheel running over the course profile to be identified. The collected data is used to derive the course profile as a function of time, while the speed data is used to map the ground elevation data from a time domain into a spatial domain. To verify the course re-generating rationale, the required test data was simulated with the data extracted from a trailer model running over selected course profiles. The regenerated course profiles are then compared against those used as the inputs to the trailer model, demonstrating the feasibility of using the methodology to regenerate course profiles which statistically align with real-world course profiles. The methodology may be used to develop the inputs statistically equivalent to realistic course profiles as needed in dynamic simulation of terrain
Zhang, XiongKnezevic, ZeljkoEng, M.
This study proposes a multi-mode switching control strategy based on electromagnetic damper suspension (EMDS) to address the different performance requirements of suspension systems on variable road surfaces. The working modes of EMDS are divided into semi-active damping mode and energy harvest mode, and the proposed mode switching threshold is the weighted root mean square value of acceleration. For the semi-active damping mode, a controller based on LQR(Linear Quadratic Regulator) was designed, and a variable resistance circuit was also designed to meet the requirements of the semi-active mode, which optimized the damping effect relative to passive suspension. For the energy harvest mode, an energy harvest circuit was designed to recover vibration energy. In order to reduce the deterioration of suspension performance caused by frequent mode switching in the mode switching strategy, as frequent system switching can lead to system disorder, deterioration of damping effect, and
Zeng, ShengZhang, BangjiTan, BohuanQin, AnLai, JiewenWang, Shichen
Air suspension systems are increasingly in demand in high-end cars due to their ability to vary ride height based on vehicle loads, road conditions, and speeds. This trend has driven manufacturers to enhance the performance of these systems. Predicting and optimizing the performance of the air spring system for various vehicle loads and conditions has become essential. The performance of an air suspension system is typically measured by its ability to suspend the vehicle within a specified target time. Therefore, it is necessary to model the air spring system—including the air spring, compressor, pneumatic lines, and valves—and integrate it with the vehicle. This modeling helps in predicting performance and optimizing the system. Additionally, a validated system model enables other important calculations, such as sizing the valves, pneumatic hoses, and compressors. In this study, a complete air spring system model has been developed alongside a 15-degrees-of-freedom car chassis to
Ahmed, Saad AnwarHupfeld, JanRajput, Brijesh
In order to modify both stiffness and damping rates according to various road conditions, this research introduces a pneumatic spring in conjunction with a magnetorheological (MR) fluid damper as a single suspension unit for each wheel in the truck. Preventing weight transfer and improving riding comfort during braking, acceleration, and trajectory prediction are the main objectives. A two-axle truck has been used, consisting of three degrees of freedom for the sprung mass, including vertical, pitch, and roll motions, and four degrees of freedom for the unsprung masses, which have been redesigned according to the different types of springs and dampers. Pneumatic-controlled springs, often referred to as dynamic or classic models, replace laminated leaf springs commonly found in vehicles. Additionally, an MR damper replaces a hydraulic double-acting telescopic shock absorber. These models are studied to evaluate the effect of pneumatic spring parameters on truck dynamics. Pneumatic
Shehata Gad, AhmedEl-Zomor, Haytham M.
With the advent of electric and hybrid drivetrain in the commercial vehicle industry, electrically driven reciprocating compressors have gained widespread prominence. This compressor provides compressed air for key vehicle systems such as brakes, suspension systems and other auxiliary applications. To be a market leader, such an E-compressor needs to meet a myriad of design requirements. This includes meeting the performance by supplying air at required pressure and flow rate, durability requirements and having a compact design while maintaining cost competitiveness. The reed valve in such a compressor is a vital component, whose design is critical to meet the aforementioned requirements. The reed valves design has several key parameters such as the stiffness, natural frequency, equivalent mass, and lift distance which must be optimized. This reed valve also needs to open and close rapidly in response to the compressor operating speed. Since it is the order of milliseconds, the valve
J, BharadwajT, SukumarPendyala, Vamsi KrishnaPaul Pandian, Adheenthran
Elastomeric bushings are common components in vehicles, used to reduce noise, vibration, and harshness. Rubber bushings are employed in suspension components such as control arm bushings, subframe bushings, and motor mount bushings, each with varying static and dynamic stiffness requirements depending on vehicle weight and ride and handling performance. Traditional rubber bush simulations typically use simple material models like hyperelastic or viscoelastic models. However, recent advancements have introduced more sophisticated material models to capture the nonlinear and time-dependent behavior of rubber materials. These advanced models may incorporate nonlinear viscoelasticity, strain rate dependency, and damage mechanics. Rubber bushings experience multiple physical phenomena simultaneously, such as mechanical loading, thermal effects, and fluid-structure interaction. New simulation techniques enable the coupling of different physics domains, allowing for a comprehensive analysis
Hazra, SandipMore, VishwasTangadpalliwar, Sonali
Three dynamic models of a passenger car including the one-dimensional dynamic model, two-dimensional dynamic model, and three-dimensional dynamic model are built to evaluate the ride quality of the passenger car as well as the isolating performance of the SNS (structure of negative stiffness). The decrease of the root-mean-square (RMS) accelerations in the seat and car’s body shaking is the research goal. The investigation results indicate that under all working conditions including the various excitations of the road surface and various velocities of the passenger car, the seat’s acceleration with SNS is strongly ameliorated in comparison without SNS in all three models of the passenger car. Particularly, the RMS seat acceleration with SNS in one-, two-, and three-dimensional models is strongly reduced in comparison without SNS by 76.87%, 66.15%, and 70.59%, respectively. Thus, the seat’s SNS has a good effect in isolating the vertical vibration of the passenger car’s seat. However
Zhang, LeiLi, TaoYang, Guixing
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