Browse Topic: Suspension systems

Items (3,590)
This article presents a novel mechanical model for simulating the behavior of pavement deflection measuring systems (PDMS). The accuracy of the model was validated by comparing the acceleration of the new model with the data achieved through experimental tests fusing a deflection measurement system mounted on a Ford F-150 truck. The experimental test for the PDMS is carried out on a random road profile, generated by an inertial profiler, over a 7.4-mile (12 km) loop around a lake near Austin, Texas. Integrating a reliability-based optimization (RBO) algorithm in a PDMS aims to optimize system parameters and reduce vibrations effectively. The PDMS noises and uncertainties make it crucial to use a robust system to ensure the stability of the system. This article presents a robust algorithm for considering the uncertainties of PDMS parameters, including the damping coefficients and spring stiffness of the supporting brackets. Moreover, it considers the variation of system parameters, such
Yarmohammadisatri, SadeghSandu, CorinaClaudel, Christian
This paper aims to explore the application of machine learning techniques to the analysis of road suspension systems, with particular emphasis on mechanical leaf spring suspensions. These systems are essential for vehicle performance, as they guarantee comfort and stability while driving, and they have an intrinsically complex and non-linear dynamic behavior. Because of this complexity, traditional approaches often prove costly and insufficient to represent operating conditions. In this context, machine learning techniques stand out for their ability to learn patterns from experimental data, allowing the modelling of non-linear phenomena that characterize road implement suspensions. One of the main contributions of this study is the demonstration that machine learning algorithms are capable of identifying complex patterns to represent the behavior of the system, as well as facilitating the detection of anomalies and potential faults in the suspension system, contributing to predictive
Colpo, Leonardo RosoMolon, MaiconGomes, Herbert Martins
It is widely common for commercial vehicles to use Hotchkiss suspension with leaf springs attached to the solid axles. This configuration is cost effective and robust enough for the required application. The leaf springs evolved in the past decades in terms of new materials and construction, and the validation methods also changes. Since the application can be aggressive in some markets, physical tests are done to validate their durability and performance. Looking for a way to reduce development time and costs, high confidence level virtual validations are targeted by the whole industry. Using FEA fed by road load data as inputs for the loads applied to the leaf springs is an evolving methodology that can be considered as a high confidence level validation method, achieving very representative results, allowing engineering team to dismiss physical tests and release the item for production. The stages of spring development will be described in this paper, focusing on the virtual
Belli, Milton Monteverdeda Costa, Mateus Cesário
Advanced motion control technologies are essential to modern aerospace design, supporting a wide range of safety-critical and comfort-driven applications. In aerospace, motion control components such as gas springs, actuators, and dampers are integral to nearly every commercial aircraft, rocket, satellite, and space vehicle. These critical elements support flight safety and transport functions, from the dependable deployment of landing gear and cargo doors to the smooth, ergonomic operation of seating for pilots and passengers.
The continuous improvement of validation methodologies for mobility industry components is essential to ensure vehicle quality, safety, and performance. In the context of mechanical suspensions, leaf springs play a crucial role in vehicle dynamics, comfort, and durability. Material validation is based on steel production data, complemented by laboratory analyses such as tensile testing, hardness measurements, metallography, and residual stress analysis, ensuring that mechanical properties meet fatigue resistance requirements and expected durability. For performance evaluation, fatigue tests are conducted under vertical loads, with the possibility of including "windup" simulations when necessary. To enhance correlation accuracy, original suspension components are used during testing, allowing for a more precise validation of the entire system. Additionally, dynamic stiffness measurements provide valuable input for vehicle dynamics and suspension geometry analysis software, aiding in
Zahn, André N.Graebin, MatheusMalacarne, RodrigoToniolo, Juliano C.
A DRL (deep reinforcement learning) algorithm, DDPG (deep deterministic policy gradient), is proposed to address the problems of slow response speed and nonlinear feature of electro-hydrostatic actuator (EHA), a new type of actuation method for active suspension. The model-free RL (reinforcement learning) and the flexibility of optimizing general reward functions are combined with the ability of neural networks to deal with complex temporal problems through the introduction of a new framework called “actor-critic”. A EHA active suspension model is developed and incorporated into a 7-degrees-of-freedom dynamics model of the vehicle, with a reward function consisting of the vehicle dynamics parameters and the EHA pump–valve control signals. The simulation results show that the strategy proposed in this article can be highly adapted to the nonlinear hydraulic system. Compared with iLQR (iterative linear quadratic regulator), DDPG controller exhibits better control performance, achieves
Wang, JiaweiGuo, HuiruDeng, Xiaohe
The design, development, and optimization of modern suspension systems is a complex process that encompasses several different engineering domains and disciplines such as vehicle dynamics simulation, tire data analysis, 1D lap-time simulation, 3D CAD design and structural analysis including full 3D collision detection. Typically, overall vehicle design and suspension development are carried out in multiple iterative design loops by several human specialists from diverse engineering departments. Fully automating this iterative design process can minimize manual effort, eliminate routine tasks and human errors, and significantly reduce design time. This desired level of automation can be achieved through digital modeling, automated model generation, and simulation using graph-based design languages and an associated language compiler for translation and execution. Graph-based design languages ensure the digital consistency of data, the digital continuity of processes, and the digital
Borowski, JulianRudolph, Stephan
Vibration control is most important in automotive applications, and generally, rubbers are used to dampen these vibrations due to their inherent nature and low-cost manufacturing methods. Now, to select a rubber material, Shore hardness is considered in engineering applications, but to additionally control the behaviour, we need to understand its static and dynamic stiffness. These values help to determine the vibration isolation obtained by these rubbers. In this paper, we will discuss methods to calculate the static and dynamic stiffness of rubber grommets using experimental methods and FEA modelling. As elastomers have non-linear material properties, various material modelling techniques in FEA are used to capture multiple phenomena like creep, fatigue, and dynamic conditions. Rubber compounding is used in order to improve the physical and chemical properties, which in turn would give desirable linear characteristics. Certain guidelines and thumb rules are used in the rubber
Khamkar, Prasad SubhashGaikwad, Vikrant Chandrakant
The chassis bushing is one of the key components affecting the vibration isolation efficiency of a vehicle, and a comprehensive optimization method combining the experimental process and transmission path analysis (TPA) is proposed to reduce the low- and medium-frequency road noise response in the passenger compartment of a battery electric vehicle (BEV). First, the noise signals were obtained in the vehicle road noise test under two working conditions of 40 and 60 km/h at uniform speeds on rough road surfaces. Then, the excitation transmission path was analyzed based on the structural noise transmission model, and the chassis bushing parts with more considerable vibration isolation contribution were screened out. By matching the stiffness values of the chassis bushings in the optimization problem through experimental methods, the optimization scheme reduces the stiffness of the front swing arm bushing and the rear longitudinal arm bushing by 30%. Additionally, a flexible connection is
Liu, KeLiao, YinghuaWang, HongruiZhou, Junchao
This article is mainly to present a deep learning–based framework for predicting the dynamic performance of suspension systems for multi-axle vehicles, which emphasizes the integration of machine learning with traditional vehicle dynamics modeling. A multitask deep belief network deep neural network (MTL-DBN-DNN) was developed to capture the relationships between key vehicle parameters and suspension performance. Numerical simulation–generated data were utilized to train the model. This model also showed better prediction accuracy and computational speed compared to traditional deep neural network (DNN) models. Full sensitivity analysis has been performed in order to understand how different vehicle and suspension parameters may affect suspension dynamic performance. Furthermore, we introduce the suspension dynamic performance index (SDPI) in order to measure and quantify overall suspension performance and the effectiveness of multiple parameters. The findings highlight the
Lin, Bo-YiLin, Kai-Chun
This research presents a semi-active suspension system that combines an air spring and a magneto-rheological (MR) fluid damper to produce both active force and variable damping rates based on the road conditions. The suspension system used for the military light utility vehicle (MLUV) has seven degrees of freedom. A nonlinear model predictive control system generates the desired active force for the air spring control signal, while the linear quadratic regulator (LQR) estimates the target tracking of the intended damping force. The recurrent neural network is designed to develop a controller for an identification system. To achieve the optimal voltage for the MR damper without log time, it is used to simultaneously determine the active control force of the air spring by modifying the necessary damping force tracking. The MLUV suspension system is integrated with the traction control system to improve overall vehicle stability. A fuzzy traction controller adjusts the throttle angle
Shehata Gad, Ahmed
The article introduces the air springs, CDC, rear-wheel steering system, braking system, front-wheel steering system, and electric drive system in the vehicle’s central coordinated motion control system. It explores achieving more comfortable shock absorption by adjusting the CDC (Continuously Variable Damping system) damping and other means. By combining open-loop and closed-loop rear-wheel steering control, the turning radius in small-radius steering mode is reduced by up to 10%, enabling crab-walking, optimizing the moose test entering speed up to 90.9 kph, and improving vehicle behavior on split-friction surfaces. Through the cooperation of IBS (Intelligent Brake System) and VMC, an extremely comfortable braking process is achieved.
Zhou, YuxingLi, Wen
This paper presents an analytical approach for identifying suspension kingpin alignment parameters based on screw axis theorem and differential calculation model. The suspension kingpin caster and inclination alignment parameters can produce additional tire force, which affects vehicle handling dynamics. In wheel steering process, the multi-link suspension control arms lead to movement of the imaginary kingpin, which can cause change in suspension kingpin alignment parameters. According to the structure mechanism of commercial vehicle multi-link independent suspension, the kinematics characteristics of imaginary kingpin were analyzed based on the screw axis theorem. The angular velocity and translation velocity vectors were calculated. In order to avoid the influence of bushing deformation, the unique differential identification model was established to evaluate the suspension kingpin alignment parameters, and the identification results were compared with the ADAMS/Car data. The
Ding, JinquanHou, JunjianZhao, DengfengGuo, Yaohua
Basic structures of vehicle frames、aircraft fuselages and ship hulls are made of beams、columns and trusses. If Acoustic Black Holes(ABH) are carefully arranged alongside with the wave propagation paths in those structures, the wave propagation paths could be changed at NVH engineers’ will and the structure vibrations can be reduced. Two kinds of ABHs are used in this paper: one is ABH made of Polyurethane(PU), other one is ABH composed of several steel plate 1D ABH stacked up in parallel. Three structures are used to test the effectiveness of ABHs for vibration reductions: a squared hollow sectional steel commonly used in motorcoach/bus chassis and frame structures, a simple frame for motorcoach airbag suspension and a 12m chassis structure. The attached ABHs show a great vibration attenuation in terms of transfer functions on the basic structure element for a motorcoach. The lateral, vertical and longitudinal transfer functions for steel ABHs were greatly reduced from 13.2~14.7 dB
Xu, ChuanyanWang, JianjunXing, QisenChen, HengbinHuang, Xianli
Road noise caused by road excitation is a critical factor for vehicle NVH (Noise, Vibration, and Harshness) performance. However, assessing the individual contribution of components, particularly bushings, to NVH performance is generally challenging, as automobiles are composed of numerous interconnected parts. This study describes the application of Component Transfer Path Analysis (CTPA) on a full vehicle to provide insights into improving NVH performance. With the aid of Virtual Point Transformation (VPT), blocked forces are determined at the wheel hubs; afterward, a TPA is carried out. As blocked forces at the wheel hub are independent of the vehicle dynamics, these forces can be used in simulations of modified vehicle components. These results allow for the estimation of vehicle road noise. To simulate changes in vehicle components, including wheel/tire and rubber bushings, Frequency-Based Substructuring (FBS) is used to modify the vehicle setup in a simulation model. In this
Kim, JunguReichart, Ronde Klerk, DennisSchütler, WillemMalic, MarioKim, HyeongjunKim, Uije
Wheel Force Transducers (WFT) are precise and accurate measurement devices that seamlessly integrate into any vehicle. They can be applied in numerous vehicle applications for both on-road and in laboratory settings. The instrumentation requires replacing an original equipment manufacturer (OEM) wheel with a custom WFT system which is specific to the wheel hub design. An ideal design will minimally impact a vehicle's dynamics, but the vehicle system is inherently modified from the mass of the measurement device. Research and technical documentation have been published which provide conclusions explaining reduction in the unsprung mass reduces dynamic wheel load. However, there doesn’t appear to be clear compensation techniques for how a modified unsprung mass can be related to the original system, thus allowing the WFT signals to be more accurate to the OEM wheel forces. An experimental study was performed on a prototype motorcycle to better understand these differences. An
Frisco, JacobLarsen, WilliamRhudy, ScottOosting, NicholasLaurent, Matthew
More and more captain-seat-like, luxury individual seats have been appeared inside MPV vehicles in order to meet various customer needs and improve market competitiveness. In the same time, customer complaints about seat vibration also increase significantly. Thus, luxury captain seat vibration is becoming MPV issues facing the vehicle development engineers. Typically, luxury captain seats are much heavier due to the added mechanisms to provide functions like massage or temperature controls, etc., and it is not feasible to structurally improve the seat modal frequencies to meet the need for NVH issue resolution. This paper presents a systematical study on the second-row luxury captain seat vibration issue between 10-25Hz with MPV vehicles. An axle contribution is analyzed with a 4-poster shaker test, and the test data show that the seat vibration is more sensitive to rear axle excitation than that of front axle, and to the out-of-phase excitation than the in-phase one. The similar
Zhou, ChangshuiYu Sr, JingGu, PerryZhang, FanBu, KunquanLiu, Xinhua
Cairo’s soundscape has witnessed changes due to the ongoing urban structure developments that accommodate the number of vehicles passing through the city. The soundscape produced by this growing automobility is affected not only by vehicles but also by their owners' behavior. Cairenes use their cars as a communication tool and an extension of private space. By viewing the vehicle as a component of the soundscape as well as a space that filters it, this study examines the synergy between social behavior, automobility, urban structure, and their interdependent relationship on the soundscape of Cairo. The study responds to literature elaborating on acoustic ecology, car culture, urban structure, and social behavior. The methodology applied in this study follows practice-based phenomenological research while documenting and reflecting on car cultural practices in Cairo from an aural perspective. Grounded theory contextualizes the analysis of archived audio and video material, semi
Abd El Naby, Abla Mohamed
In this work, Genetic Algorithm (GA) optimized Proportional Integral Derivative (PID) controller is employed in the active suspension. The PID gain values are optimally tuned based on the objective function by the Integral Time Absolute Error (ITAE) criteria of various suspension measures like vehicle body displacement, suspension and tire deflections. The proposed GAPID controller is experimentally validated through the 3-DOF quarter-car (QC) test rig model. The fabricated model with passive suspension system (PASS) and active suspension system (ACSS) with an electrical actuator is presented. The schematic representation of the fabricated test set-up with and without ACSS is also illustrated. Further, simulation and experimental response of the fabricated model with and without ACSS are compared. It is identified that the proposed GAPID controller attenuates the sprung mass acceleration by about 41.64 % and 29.13 % compared with PASS for the theoretical as well as experimental cases
A, ArivazhaganKandavel, Arunachalam
In the highly competitive automotive industry, optimizing vehicle components for superior performance and customer satisfaction is paramount. Hydrobushes play an integral role within vehicle suspension systems by absorbing vibrations and improving ride comfort. However, the traditional methods for tuning these components are time-consuming and heavily reliant on extensive empirical testing. This paper explores the advancing field of artificial intelligence (AI) and machine learning (ML) in the hydrobush tuning process, utilizing algorithms such as random forest, artificial neural networks, and logistic regression to efficiently analyze large datasets, uncover patterns, and predict optimal configurations. The study focuses on comparing these three AI/ML-based approaches to assess their effectiveness in improving the tuning process. A case study is presented, evaluating their performance and validating the most effective method through physical application, highlighting the potential
Hazra, SandipKhan, Arkadip Amitava
The application of virtual point transformation for determining the transfer dynamic stiffness of a helical coil spring is demonstrated in this experimental study. Rigid fixtures are attached to both ends of the spring, and frequency response functions are measured using impact hammer excitations. These frequency response functions are transformed into virtual points, analogous to a node in finite element analysis, with six degrees of freedom. The six degrees of freedom transfer dynamic stiffness is then extracted using the inverse substructuring method, which eliminates the need to account for fixture dynamics. The results are validated by a direct measurement approach. Additionally, the study investigates the effect of liquid applied sprayed damping coatings on the spring's transfer dynamic stiffness, revealing that the coating significantly reduces vibration amplitudes at the surge frequencies. This suggest that the springs effective damping properties are enhanced.
Neihguk, DavidHerrin, D. W.de Klerk, Dennis
The recent addition of fully electric powertrains to propulsion system options has increased the relevance of sound and vibration from electric motors and gearboxes. Electrified beam axles require different metrics from conventional beam axles for noise and vibration because they have multiple sources of vibration energy, including an electric motor and a reduction gearbox. Improved metrics are also driven by the stiff suspension connections and lack of significant isolation compared to electric drive units. Blocked force is a good candidate because it can completely characterize the vibration energy transmitted into a receiver and is especially useful because it is theoretically independent of the vehicle-side structure. While the blocked force methodology is not new, its application to beam axles is relatively unexplored in the literature. This paper demonstrates a case study of blocked force measurement of an electrified beam axle with a leaf spring suspension. The axle was tested
Shaw, Matthew DGrimmer, Michael J
To optimize the noise that heard like ‘kalakala’ produced by the plug hybrid electric vehicle when accelerating with a small accelerated pedal opening while in the charging state of series modal. The LMS test device was used to acquire the noise of the driver's outer ear. Through filtering and playback analysis, it was confirmed that the noise is mainly contains the frequency bands of 250-400Hz and450-700Hz. The frequency bands of the noise were used as carriers for Hilbert transform, and their envelopes were obtained for Fourier transform analysis. It was found that the modulation order of the noise is 0.5 times of the engine ignition order, and the modulation frequency is 20-30Hz, which let the customer hears like roughness. Regarding the spectral characteristics of this noise, firstly, at the excitation source, selected a reasonable moment of inertia and frequency of the Crank torsional damper, to decrease the torsional excitation of the engine. Secondly, investigated the structural
Shouhui, HuangZhongxun, HuZhao, YunShanyin, RenRuifeng, DongTeng, CharlieChangshui, ZhouXu, Ling
A vehicle powertrain system with a two-stage spring isolator separating a combustion engine from a transmission can exhibit significant nonlinear dynamics if the input torques cause the spring to continuously alternate between its first-stage and second-stage stiffnesses. In particular, this nonlinearity can result in subharmonic resonance of the system’s natural frequencies at half the frequency of the engine’s primary excitation order. A 1D torsional vibration model was prepared using Siemens’s Simcenter Amesim software to study these nonlinear vibrations. First, a correlated vehicle-level model was developed to replicate a half-order torsional resonance that was measured in a test of a research vehicle. Then, simplified theoretical models were used to study and demonstrate the sensitivity of this kind of subharmonic resonant response to changes in mean input torque level, amplitude of input torque oscillation, first-stage capacity of the spring isolator, and other factors.
Villiger, Jacob
This article conducts a thorough review of contemporary air suspension systems on the market for passenger cars. The evolution of suspension structures and control methodologies are briefly discussed. The layout of air suspension systems is introduced in detail, with each component receiving a comprehensive description and analysis. The open-loop and closed-loop arrangements are explained. Various types of air springs are discussed and compared. The sensory system, special working conditions, and failure analysis are also elaborated. In the case studies, some example models are listed to show a complete guide of how air suspension is implemented on passenger cars, which includes functionalities, air spring configurations, control methods, signal flow, service modes, and diagnostic messages. The major sources are OEMs’ official websites and previously released documents, such as user manuals and maintenance manuals, which are valid up to April 2023. Finally, the article concludes with a
Ma, ChangyeLu, YukunZhen, RanLiu, YegangPan, BingweiKhajepour, Amir
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, TetsunoriKaneko, Tetsuya
The rear swing arm, a crucial motorcycle component, connects the frame and wheel, absorbing the vehicle’s load and various road impacts. Over time, these forces can damage the swing arm, highlighting the need for robust design to ensure safety. Identifying potential vulnerabilities through simulation reduces the risk of failure during the design phase. This study performs a detailed fatigue analysis of the swing arm across different road conditions. Data for this research were collected from real-vehicle experiments and simulation analyses, ensuring accuracy by comparing against actual performance. Following CNS 15819-5 standards, road surfaces such as poorly maintained, bumpy, and uneven roads were tested. Using Motion View, a comprehensive multi-body dynamic model was created for thorough fatigue analysis. The results identified the most stress-prone areas on the swing arm, with maximum stress recorded at 109.6N on poorly maintained roads, 218.3N on bumpy surfaces, and 104.8N on
Chiou, Yi-HauHwang, Hsiu-YingHuang, Liang-Yu
Automotive signal processing is dealt with in several contributions that propose various techniques to make the most out of the available data, typically for enhancing safety, comfort, or performance. Specifically, the accurate estimation of tire–road interaction forces is of high interest in the automotive world. A few years ago the T.R.I.C.K. tool was developed, featuring a vehicle model processing experimental data, collected through various vehicle sensors, to compute several relevant virtual telemetry channels, including interaction forces and slip indices. Following years of further development in collaboration with motorsport companies, this article presents T.R.I.C.K. 2.0, a thoroughly renewed version of the tool. Besides a number of important improvements of the original tool, including, e.g., the effect of the limited slip differential, T.R.I.C.K. 2.0 features the ability to exploit advanced sensors typically used in motorsport, including laser sensors, potentiometers, and
Napolitano Dell’Annunziata, GuidoFarroni, FlavioTimpone, FrancescoLenzo, Basilio
Distributed electric vehicles, equipped with independent motors at each wheel, offer significant advantages in flexibility, torque distribution, and precise dynamic control. These features contribute to notable improvements in vehicle maneuverability and stability. To further elevate the overall performance of vehicles, particularly in terms of handling, stability, and comfort, this paper introduces an coordinated control strategies for longitudinal, lateral, and vertical motion of distributed electric vehicles. Firstly, a full-vehicle dynamics model is developed, encompassing interactions between longitudinal, lateral, and vertical forces, providing a robust framework for analyzing and understanding the intricate dynamic behaviors of the vehicle under various operating conditions. Secondly, a vehicle motion controller based on Model Predictive Control is designed. This controller employs a sophisticated multi-objective optimization algorithm to manage and coordinate several critical
Jia, JinchaoYue, YangSun, AoboLiu, Xiao-ang
Adverse weather conditions such as rain and snow, as well as heavy load transportation, can cause varying degrees of damage to road surfaces, and untimely road maintenance often results in potholes. Perception sensors equipped on intelligent vehicles can identify road surface conditions in advance, allowing each wheel’s suspension to actively adjust based on the road information. This paper presents an active suspension control strategy based on road preview information, utilizing a newly designed dual-chamber active air suspension system. It addresses the issue of point cloud stratification caused by vehicle body vibrations in onboard LiDAR data. The point cloud is processed through segmentation, filtering, and registration to extract real-time road roughness information, which serves as preview information for the suspension control system. The MPC algorithm is applied to actively adjust the nonlinear stiffness and damping of the suspension’s dual-chamber air springs, enhancing
Dong, FuxinShen, YanhuaWang, KaidiLiu, ZuyangQian, Shuo
This study focuses on the dynamic behavior and ride quality of three different modes of oil-gas interconnected suspension systems: fully interconnected mode, left-right interconnected mode, and independent mode. A multi-body dynamics model and a hydraulic model of the oil-gas suspension were established to evaluate the system's performance under various operating conditions. The research includes simulations of pitch and roll excitations, as well as ride comfort tests on different road surfaces, such as Class B roads and gravel roads. The analysis compares the effectiveness of the modes in suppressing pitch and roll movements and their impact on overall ride comfort. Results show that the independent mode outperforms the other two in minimizing roll, while the fully interconnected mode offers better pitch control but at the cost of reduced comfort. These findings provide valuable insights for the future design and optimization of oil-gas interconnected suspension systems, especially in
Xinrui, WangChen, ZixuanZhang, YunqingWu, Jinglai
Electric vehicles (EVs) are particularly susceptible to high-frequency noise, with rubber eigenmodes significantly influencing these noise characteristics. Unlike internal combustion engine (ICE) vehicles, EVs experience pronounced variations in dynamic preload during torque rise, which are substantially higher. This dynamic preload variation can markedly impact the high-frequency behaviour of preloaded rubber bushings in their installed state. This study investigates the effects of preload and amplitude on the high-frequency dynamic performance of rubber bushings specifically designed for EV applications. These bushings are crucial for vibration isolation and noise reduction, with their role in noise, vibration, and harshness (NVH) management being more critical in EVs due to the absence of traditional engine noise. The experimental investigation examines how preload and excitation amplitude variations influence the dynamic stiffness, damping properties, and overall performance of
Hazra, SandipKhan, Arkadip Amitava
In this paper, an incremental coordinated control method through anti-squat/lift/dive suspension is proposed based on and suited to a distributed drive electric vehicle with front and rear dual motors. The precise relationship between the suspension reaction force and the driving force of the wheel is derived as the control model through an in-depth analysis of the wheel motion and force. Through imposing the first-order dynamics, the proposed method not only provides the longitudinal speed control of the vehicle but also suppresses the longitudinal, vertical and pitch vibration of the vehicle. Simulation results show that the suspension reaction force formula derived in this paper is more suitable for dynamic conditions, and compared with the control method based on the simplified suspension anti-squat/lift/dive control model, the proposed method using the accurate control model has superior comprehensive control performance.
Feng, CongWu, GuangqiangYang, Yuchen
Online road profiling capability is required for automotive active suspension systems to be realized in a consumer and commercial landscape. One challenge that impedes the realization of these systems is the need for the online road profiler to maintain an optimal spatial resolution of the oncoming road profile. Shifting of the road profiling sensor measurement frame of reference due to body motion experienced by the vehicle can negatively impact profiling accuracy. Prior work proposed a corrective look-ahead road profiling system (CLARPS) and demonstrated the CLARPS architecture and initial MATLAB/Simulink simulation environment. First, this work further develops the robust simulation environment. The simulation allows the look-ahead viewing angles to be optimized for the best road profile spatial resolution and facilitates a study on the impact of road profiler sensor location on the accuracy of the generated road profile. Second, this work introduces a lab-scale physical CLARPS
Morison, DaneMynderse, James
This study investigates the influence of magnetorheological (MR) dampers in semi-active suspension systems (SASSs) on ride comfort, vehicle stability, and overall performance. Semi-active suspension systems achieve greater flexibility and efficacy by combining MR dampers with the advantages of active and passive suspension systems. The study aims to measure the benefits of MR dampers in improving ride comfort, vehicle stability, and overall system performance. The dynamic system model meets all required performance criteria. This study demonstrates that the proposed artificial intelligence approach, including a fuzzy neural networks proportional-integral-derivative (FNN-PID) controller, significantly enhances key performance criteria when tested under various road profiles. The control performance requirements in engineering systems are evaluated in the frequency and time domains. A quarter-car model with two degrees of freedom (2 DOF) was simulated using MATLAB/Simulink to assess the
M.Faragallah, MohamedMetered, HassanAbdelghany, M.A.Essam, Mahmoud A.
To investigate the static and dynamic mechanical properties of air springs and their influencing factors, two models were established in this paper to calculate the static and dynamic mechanical properties of air springs, including a simulation model based on the finite element method and a mathematical calculation model based on thermodynamic theory. First, a performance calculation model for rolling lobe air springs with aluminum tubes was established, which considered the thickness of the bellow and the impact of the inflation and assembly process on the state of the bellow. The static and dynamic mechanical properties of air springs were calculated using this model, including static load-bearing capacity and static/dynamic stiffness. The calculation results showed that both the static characteristics of the air spring under isothermal conditions and the dynamic characteristics under adiabatic conditions were able to be calculated accurately. However, the changes in dynamic
Wang, SiruiKang, YingziXia, ZhaoYu, ChaoLi, JianxiangShangguan, Wen-Bin
Hydro-pneumatic suspension is widely used due to its favorable nonlinear stiffness and damping characteristics. However, with the presence of parameter uncertainties and high nonlinearities in the hydro-pneumatic suspension system, the effectiveness of the controller is often suboptimal in practical applications. To mitigate the influence of these issues on the control performance, an adaptive sliding mode control method with an expanded state observer (ESO) is proposed. Firstly, a nonlinear mathematical model of hydro-pneumatic suspension, considering seal friction, is established based on the hydraulic principle and the knowledge of fluid mechanics. Secondly, the ESO is designed to estimate the total disturbance caused by the nonlinearities and uncertainties, and it is incorporated into the sliding mode control law, allowing the control law to adapt to the operating state of the suspension system in real time, which solves the effect of uncertainties and nonlinearities on the system
Niu, ChangshengLiu, XiaoangJia, XingGong, BoXu, Bo
In this paper, the equivalent elliptic gauge pendulum model of liquid sloshing in tank is established, the pendulum dynamic equation of tank in non-inertial frame of reference is derived, and the dynamics model of tank transporter is constructed by force analysis of the whole vehicle. A liquid tank car model was built in TruckSim to study its dynamic response characteristics. Aiming at the problem that the coupling effect between liquid sloshiness in tank and tank car can easily affect the rolling stability of vehicle, the roll dynamics model of tank heavy vehicle is established based on the parameterized equivalent elliptic gauge single pendulum model, and the influence of different lateral acceleration and suspension system on the roll stability is studied. The results show that the coupling effect between the motion state of the tank car and the liquid slosh lengthens the oscillation period of the liquid slosh in the tank, and the amplitude of the load transfer rate of the tank car
Yukang, Guo
This study examines a closed air spring suspension system. To address issues such as over-inflation, over-deflation, and excessive overshoot during vehicle height adjustment, a threshold control method is implemented. This method controls the triggering conditions for height adjustment and effectively reduces overshoot while enhancing precision. Experimental results indicate that this control strategy decreases overshoot and improves accuracy. However, risks are associated with varying threshold settings across different control modules, which can lead to over-control. A fuzzy PID controller is developed to resolve this issue. This controller adjusts PID parameters in real time based on fuzzy rules, thereby refining height adjustments. During testing, it was found that the degree of electromagnetic valve opening could not be controlled by the fuzzy PID controller. Therefore, a control strategy to adjust the compressor speed is designed. Experiments show that the fuzzy PID controller
Zheng, GuoqingYin, ZhihongChen, ShiwenShangguan, Wen-Bin
Many methods have been proposed to accurately compute a vehicle’s dynamic response in real-time. The semi-recursive method, which models using relative coordinates rather than dependent coordinates, has been proven to be real-time capable and sufficiently accurate for kinematics. However, not only kinematics but also the compliance characteristics of the suspension significantly impact a vehicle’s dynamic response. These compliance characteristics are mainly caused by bushings, which are installed at joints to reduce vibration and wear. As a result, using relative or joint coordinates fails to account for the effects of bushings, leading to a lack of compliance characteristics in suspension and vehicle models developed with the semi-recursive method. In this research, we propose a data-driven approach to model the compliance characteristics of a double wishbone suspension using the semi-recursive method. First, we create a kinematic double wishbone suspension model using both the semi
Zhang, HanwenDuan, YupengZhang, YunqingWu, Jinglai
The suspension Kinematics & compliance (K&C) characteristic test bench can simulate the excitation of the road to the wheels under various typical working conditions in a quasi-static manner on the bench, enabling the measurement of the K&C characteristics of the suspension system without knowing the specific suspension structure form, parameters, etc., assisting in the entire design process of the vehicle. In this paper, aiming at various geometric source errors existing in the processing and assembly process of the K&C characteristic test bench, an evaluation method based on the homogeneous transformation matrix is proposed to establish the position error of the center of the end loading disk in the series motion chain. Firstly, the mapping relationship between the position error of the end loading disk in the series mechanism kinematic chain and the assembly error is established by using the homogeneous transformation matrix. Then, the change matrix of the coordinate system from the
Sun, HaihuaDuan, YupengWu, JinglaiZhang, Yunqing
Magnetorheological (MR) dampers, known for their remarkable dependability and cost-effectiveness, have established themselves as prime semi-active vibration control devices in engineering systems. MR dampers are categorized as adaptive devices because their features may be readily adjusted by applying a regulated voltage signal. Their ability to offer superior performance while mitigating the drawbacks of fully active actuators underscores their practical significance. This research is to investigate some system hybrid controllers using a combination state derivative feedback and a linear-quadratic regulator for use in conjunction with the damper controller of a semi-active suspension of a Quarter vehicle model to improve ride comfort and vehicle stability. The mathematical model of 3 degrees of freedom for semi-active suspension using MR dampers will be derived and simulated using MATLAB and SIMULINK software. In order to quantify the effectiveness of the suggested control strategies
M.Faragallah, MohamedMetered, HassanEssam, Mahmoud A.
The suspension system could transmit and filter the forces between the body and road surface, which affects vehicle ride comfort and road maintenance capability. Compared to traditional passive and semi-active suspension, Active Suspension Systems (ASS) could automatically adjust the suspension stiffness, damping force, and body height according to changes in the vehicle's load distribution, travelling speed, and braking action through the addition of a power source such as a linear motor. Although the existing advanced control methods could help to effectively improve the driving quality of vehicles equipped with ASS, the conflict between ride comfort and road maintenance capacity is still a difficult problem to be solved. Therefore, an Active Suspension System optimal control strategy considering vehicle ride comfort and road maintenance capability is proposed in this paper. Firstly, a quarter ASS model and a road model are respectively developed based on the system dynamics
Zhu, BingZhang, ChaohuiSun, JihangWang, ShiweiDing, ShuweiLi, LunChen, Zhicheng
Taking a commercial vehicle cab suspension system as the research focus, a rigid-flexible coupled dynamics model was established based on the nonlinear characteristics of the integrated damper air spring and bushings. Time-domain vibration acceleration signals were acquired at the connection points between the frame, cab, and suspension. The vibration signals at the frame and suspension connection points were input into the simulation model, where the vibration responses at the cab and suspension connection points were calculated and analyzed using the established cab suspension system model. The accuracy of the model was verified by comparing the simulation results with experimental data. The established cab suspension system model was further used to evaluate human vibration comfort within the cab, following national standards for subjective human perception. A piecewise polynomial function was employed to fit the stiffness-damping characteristics of the integrated damper air spring
Hao, QiZhu, YuntaoSun, WenSun, KaiSun, ZhiyongHuang, YuZhen, RanShangguan, Wen-Bin
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