Browse Topic: Anti-roll

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Parameter Optimization of Anti-Roll Bar Based on Stiffness2020-01-09214/14/2020
The anti-roll bar is an important structural component of the automobile, which can effectively prevent the automobile from rolling and improve the safety of the automobile during steering. In the design of the current anti-roll bar, the stiffness is determined by empirical or oversimplified mathematical models, often not reaching the optimal value. In this paper, eight parameters are used to determine the structure of the anti-roll bar. Combining the Deformation Energy theorem and Castigliano’s theorem, a mathematical model of the stiffness is established. The optimal solution and corresponding parameter values of the mathematical model are obtained by nonlinear programming and genetic algorithm. The influence of structural parameters on the anti-roll bar stiffness is analyzed, and the regular pattern of design is obtained. In addition, the finite element method is used to verify the stiffness solution model. In the experiment, the anti-roll bar designed by the regular pattern is attached to the Baja Racing, and the stiffness of the bar is changed by adjusting the length of the arm of the bar, then the correctness of the design regular pattern is verified by testing the roll response. The improved anti-roll bar can effectively improve the anti-roll stiffness and has a better effect on the cornering stability of the automobile.
Wang, Zhenyu, Guo, Donghua, Wang, Haoyu, Tan, Gangfeng, Jiang, Yifeng, Li, Ming, Hou, Xiaoge
Model Reference Control for Active Suspension System2019-01-01654/2/2019
The objective of this study is to develop a Model Reference Control (MRC) strategy for active suspension System. The MRC strategy employs both the suspension look-ahead preview and wheelbase preview concepts, and the methodology of the MRC based on the ideal hybrid skyhook-groundhook concept. The study performed using a 13 degree-of-freedom (DoF) vehicle vertical dynamics model including the active suspension actuators masses. The engine mass, driver seat and anti-roll bar are considered in the model. The MRC strategy uses eight Proportional-Integral-Derivative (PID) controllers for both body and wheel control. A gradient-based optimization algorithm is applied to obtain the controller parameters using a cost function including both ride comfort and road holding performance. Comparison between the active suspension system provided with proposed MRC strategy, the ideal hybrid skyhook-groundhook suspension system, and the passive suspension system in terms of ride comfort and road holding is performed. The obtained results showed that, the proposed MRC strategy with the PID controllers are able to track the performance of the ideal hybrid skyhook-groundhook system, and provided significant improvements in both ride comfort and road holding.
Kaldas, Mina M.S., Soliman, Aref M.A., Abdallah, Sayed A., Amien, Fomel F.
2019 Chevrolet Blazer just right for the voracious SUV market19AUTP03_183/1/2019
Leaving its dirt roots in the past, the all-new 2019 Chevrolet Blazer is a stylish, on-road-focused 2-row SUV that slots between Chevy's Equinox and Traverse, deftly closing a gap in its SUV lineup. Based on the GM global-C1 architecture underpinning the Cadillac XT5, the new Chevy Blazer is quite conventional but contains a host of keen features including a versatile AWD setup. The all-new 5-door, 5-passenger FWD/AWD Blazer will compete with other 2-row SUVs-including the Ford Edge and Nissan Murano-in a segment which relies heavily on styling for purchase consideration. “The first time we saw the concept sketches we were excited about it,” said Jeff Boike, the Chevrolet Blazer program engineering manager. “I think the big challenge for engineering is to deliver. A lot of times you'll see a theme, and by the time you incorporate all the engineering criteria, you kind of lose the very thing you were after.”
Seredynski, Paul
WHAT WE'RE DRIVING19AUTP02_092/1/2019
As this month's cover story makes clear, the 2019 Audi e-tron is not an electric screamer. It doesn't redefine ludicrous 0-60-mph acceleration times every time you step on the accelerator. In fact, if you're used to a high-performance Tesla Model X, the e-tron feels decidedly neutered. The overall e-tron package combines Audi's elegant and attractive exterior (that intentionally fits the brand's current design language), slightly tweaked for the electric powertrain, with an incredibly quiet cabin, even while cruising at 75 mph.
Development of Block Cycle Test Load for Structural Durability Validation of MacPherson Strut2019-26-03151/9/2019
The MacPherson strut is a simple and common across all automotive’s front suspension of passenger cars. It is an independent suspension type, including a single suspension arm (spring and damper), an anti-roll bar and a lower arm. The MacPherson strut must have sufficient stiffness to support cornering force and fore/aft loads. Fatigue test of MacPherson strut suspension can be done in multiple ways. Most common method is laboratory testing/rig test. The objective of laboratory testing is to validate the MacPherson strut physically for all possible real-time events. Replicating all real-time events in lab environment is a challenging task. For many years this limitation was addressed through experience, however it has often led to either over or inferior design. The expected life span of automotive components like MacPherson strut varies considerably but it can be measurable in years/miles. It becomes virtually challenging to prove the product under service conditions over its whole design life. Hence, it becomes necessary to depend on accelerated testing methods to predict long-term performance and brings out feebleness in the structure in a very minimal time, compared to the time required for proving ground tests or physical component testing in the laboratory with real time load.
Murthy, Nuli Veda, Gopal, Sritharan, T, Siddeshwaran, Kilburn, Kevin
Composite Material for Development of Stabilizer Bar for Light Weight Vehicle2019-26-01671/9/2019
The selection of material in automotive design is one of the most important factors. There are variety of materials that can be used in automotive Body and Chassis system design. However challenge is to select a right kind of material to meet functional requirement of a component or system. Some of the criterions that a material should meet are lightweight, economic effectiveness, safety, recyclability and life cycle requirements. Some of these criterions are result of regulatory, vehicle performance or customer needs. However, some of these requirements would be conflicting to each other, therefore optimization is need of the hour. In today’s scenario automotive engineers are being challenged to use lightweight materials considering all design and commercial conditions. As industry is moving towards electrification of vehicles, we need to have light weight vehicles in order to meet range requirement. In this paper I would be presenting my research on stabilizer bar development using various composite materials in place of steel considering all design, manufacturing and economic analysis.
Sharma, Praveen
Simulation Research of a Hydraulic Interconnected Suspension Based on a Hydraulic Energy Regenerative Shock Absorber2018-01-05824/3/2018
The current paper proposes a hydraulic interconnected suspension system (HIS) based on a hydraulic energy-regenerative shock absorber (HESA) comparatively with the passive suspensions. The structure and working principles of the HIS system are introduced in order to investigate the damping performance and energy regeneration characteristics of the proposed system. Then, the dynamic characteristics of the HIS-HESA system have been investigated based on a 4-DOF longitudinal half vehicle model. In the simulation, two different road inputs were used in the dynamic characterization of the HIS-HESA; the warp sinusoidal excitation, and the random road signal. In addition, a comparative analysis was provided for the dynamic responses of the half vehicle model for both the HIS-HESA and the conventional suspension. Furthermore, a parametric analysis of the HIS-HESA has been carried out highlining the key parameters that have a remarkable effect on the HIS-HESA performance. The dynamic performance evaluation includes both of the body acceleration and the pitch angle as the main analysis criteria of the vehicle dynamic performance. The results showed that the vehicle with the HIS-HESA system has good anti-pitch performance and excellent ride performance against the traditional suspensions. Moreover, the HIS-HESA suspension system can regenerate some of the dissipated power due to the damping process.
Zou, Junyi, Guo, Xuexun, Xu, Lin, Abdelkareem, Mohamed A. A., Gong, Bian, Zhang, Jie, Tan, Gangfeng
Honda infuses Civic Type R with racing pedigree17AUTP11_1211/1/2017
The development bogey for the new Honda Civic Type R was clear and simple in its scope if not its execution-beat the Nürburgring lap time of its predecessor. Mission accomplished. The vehicle shaved 7 sec off that time, dropping it to 7 min. 43.8 sec and setting a new track record for a front-wheel-drive production car in the process.
Gehm, Ryan
Development of Full Air Pneumatic Suspension Type for Commercial Vehicles2017-01-14903/28/2017
The air suspension development and its applications have becoming increasingly relevant for commercial vehicles to provide dynamic ride comfort to driver and reduce the load impact onto driver and or cargo. This paper shows the analysis and application of an air suspension system for commercial tractor vehicles and its dynamic influence. A special focus was given to pneumatic actuation system, responsible for leveling and control of suspension´s stiffness under different conditions of usage, laden and unladed. The project was conducted starting with the vehicle dynamic performance analysis, evaluating the pneumatic suspension circuit modifications in order to obtain vehicle dynamic behavior improvement, ensuring directional stability under different maneuvering conditions. During the development quality tools were used, considering the possible failure modes and effects to guide the design changes in order to achieve the desired behavior, as well as virtual simulation tools (Adams) and rig test validations. Using data acquisition and vehicle test analysis, the improved dynamic results proposed were validated and considered as the final design solution.
Iombriller, Silvia Faria
Methodology to Study the Effect of Variation of Suspension Characteristics on Body Durability2017-01-03483/28/2017
In an automobile, road loads due to tire-road interaction are transferred to vehicle body through suspension. This makes suspension a critical component from the body durability perspective. During vehicle design and development, optimization of suspension parameters to suit ride and handling performance is a continuous and iterative process. These changes on suspension can affect vehicle body durability performance. This paper tries to establish a process to evaluate the effect of changes in suspension parameters on body durability, thus helping in understanding the impact of these changes. The process starts with virtual model building in Multi Body Dynamics software. The base line model is correlated with testing using fatigue at some critical locations on Body in White (BIW). Once correlated, Design of Experiments (DOE) approach is used on suspension parameters like spring properties, damper properties etcetera to identify critical parameters that will affect the magnitude of loads on the body-suspension attachment points. These loads are further used to evaluate effect on durability of the body using Finite Element Method (FEM) approach.
Shankar, Mani, Sri Harsha, I V N, Sunil, K V, Ramachandran, Ramsai
Sensitivity study of front suspension parameters in elastokinematics and handling behavior of a vehicle2016-36-018210/25/2016
There are many variables involved in the design of a front suspension, such as hardpoints' coordinates, steering geometry or even an anti-roll bar, which could make design difficult and time consuming. The MacPherson strut, due to the simplicity of its construction, less occupied space and low manufacturing cost, is widely used in vehicles in contrast to double wishbone and multi-link suspensions. Although its tuning process still demands time, it can be done with the aid of multibody dynamics simulations, by testing several configurations in a virtual way. In this work, a front suspension model with MacPherson strut is studied, so that the influence of variation of its parameters is analyzed in its elastokinematics behavior and in handling performance of a vehicle.
Morales, Eduardo Domingo
Force Measurement Applied in Rod Ball End the Suspension of an Automotive Prototype2016-36-044410/25/2016
This study aims to determine the force acting on the rod ball end of an automotive suspension prototype from competition, participant in the Brazilian Tourism Championship 2016, used in training and to determine the fast lap time. The rod ball end is manufactured in SAE 4140 steel with heat treatment (body and ball) and the bush of polyacetal. To determine the force on the rod ball end the lower balance arm was converted into two load cells, through the setting of strain gage in each of the arms that compose it. It was recorded runway images with a camera in the cockpit and another camera placed inside the vehicle with the rear wheel housing, making possible to observe the suspension movement. When the prototype makes a chicane, the centripetal force is higher because the radius curve is small, when is accelerated it generates a force in line with the wheel, the front bar is compressed even more, and the rear is tensioned, that generates a load near to zero in this bar. The greatest force applied to the rod ball end was 9600 N. The largest loads in the rod ball end were generated during curves outputs, because in this condition the centripetal forces and the forces aligned with the wheels generated by the transmission system are high. In curve inputs the loads are relatively smaller, since the braking forces are smaller than the acceleration forces. In the straight line the resultant force is low due to high speed.
Gertz, L.C., Rodrigues, A.F.A., Cervieri, A., Salis, J.I., Theis, J.S., Rolim, G.S., Oliveira, A.B.
Tenneco's predictive active ride control may doom the anti-roll bar by 202116AUTP09_069/1/2016
Are the anti-roll bar's days numbered? The answer is probably “yes” - at least for premium-model cars and light trucks, as advanced active ride control systems that use the vehicle's sensor array become more widely adopted. Tenneco, through its Monroe subsidiary, is currently developing a fully active suspension system with significant advances over incumbent semi-active systems. Current production suspension systems typically rely on electronic actuation of the damper valves to improve damping response. In the case of the Monroe CVSA2 system, the dampers are equipped with two electronically activated valves to control both the rebound and compression strokes of the dampers. The aim is to improve ride and handling particularly for luxury models, SUVs and sports cars.
Kendall, John
Development of Pneumatic Suspension Type Full Air for Commercial Vehicles2016-36-00695/11/2016
The air suspension development and application has becoming increasingly applied also in commercial vehicles, offering to the driver more dynamic comfort as well as contributing to the reduction of impact loads on highways. Through this project pursuit show the analysis and application of an air suspension system for commercial tractor vehicles application. A special focus was given to pneumatic actuation system, responsible for leveling and control of suspension′s stiffness under different conditions of usage, laden and unladen. The project was conducted starting with the vehicle dynamic performance analysis, evaluating the pneumatic suspension circuit modifications in order to obtain the vehicle dynamic behavior improvement, ensuring directional stability under different maneuvering conditions. For entire development were also used quality tools, considering the possible failure modes and effects as well as virtual simulation tools (Adams) and bench validations. Through data acquisition and vehicular analysis, the better dynamic results proposed was validated and considered the final design solution.
Silva, Misael Neris da, Belli, Milton Monteverde, Iombriller, Silvia Faria, Knoll, Paulo Henrique, Conde, Ramon, Netto, Robson, Carraro, Eduardo
Dynamic Modeling and Simulation Analysis of Interconnected Air Suspension System2016-01-04424/5/2016
Interconnected air suspension system can change a vehicle’s operation characteristics by exchanging gas between air springs. In this paper, we analyze the structure and working principle of interconnected air suspension based on thermodynamics and vehicle dynamics. Then air suspension’s mathematical model including interconnected characteristics is established to study gas exchange principle of air suspension system. Interconnected pipeline parameters and excitation phase differences’ influence on characteristics of air suspension system in whole vehicle are calculated and analyzed. Simulation results show that the stiffness of air suspension is reduced when air springs of the suspension system are interconnected, as well as it decreases gradually with the increase of interconnected pipeline diameter; the stiffness of air springs is minimum if the excitation phase difference between both sides of air springs is 180 degrees. In the condition of twist pavement (tires at diagonal positions are excited simultaneously), the interconnected air suspension can reduce dynamic load difference between left tire and right tire markedly, which can increase adhesive force between tire and road effectively. On the other hand, with the condition of double lane-change testing, the bigger the interconnected pipeline diameter is, the larger the roll angle of car body is. Meanwhile, the increasing pipeline diameter has no obvious influence on roll angle when it is over 10 mm.
Xu, Xing, Nannan, Zou
Enhanced Vehicle Handling and Ride through Anti-Pitch Anti-Roll Hydraulically Interconnected Suspension2016-01-15614/5/2016
Development of a passive anti-pitch anti-roll hydraulically interconnected suspension (AAHIS) with the advantage of improving vehicle directional stability and handling quality is presented. A 7 degrees-of-freedom full car model and a 20 degrees-of-freedom anti-pitch anti-roll hydraulically interconnected suspension model dynamically coupled together through boundary conditions are developed and used to evaluate vehicle handing dynamic responses under steering/braking maneuvers. The modeling of mechanical subsystem is established based on the Newton’s second law and the fluid subsystem is modelled using a nonlinear finite-element approach. A motion-mode energy method (MEM) based on the calculation of the motion-mode energy is employed to investigate the effects of an anti-pitch anti-roll hydraulically interconnected suspension (AAHIS) system on vehicle body-wheel motion-mode energy distribution. The performance of AAHIS system and its contribution to the vehicle body-wheel motion-mode energy distribution are demonstrated under combined steering and braking maneuvers. The dynamic response of AAHIS system shows enhanced handling and ride performance as well as improved vehicle anti-roll and anti-pitch properties.
Shao, Xinxin, Du, Haiping, Naghdy, Fazel
Optimization of Suspension System of Self-Dumping Truck Using TOPSIS-based Taguchi Method Coupled with Entropy Measurement2016-01-13854/5/2016
This study presents a hybrid optimization approach of TOPSIS-based Taguchi method and entropy measurement for the determination of the optimal suspension parameters to achieve an enhanced compromise among ride comfort, road friendliness which means the extent of damage exerted on the road by the vehicles, and handling stabilities of a self-dumping truck. Firstly, the full multi-body dynamic vehicle model is developed using software ADAMS/Car and the vehicle model is then validated through ride comfort road tests. The performance criterion for ride comfort evaluation is identified as root mean square (RMS) value of frequency weighted acceleration of cab floor, while the road damage coefficient is used for the evaluation of the road-friendliness of a whole vehicle. The lateral acceleration and roll angle of cab were defined as evaluation indices for handling stability performance. The spring stiffness and shock absorber damping of the front suspension, spring stiffness of the rear suspension, torsional stiffness of the front and rear anti-roll bar are taken as the design variables, which are considered at three levels. A L18 orthogonal array is applied to implement the simulations, and the TOPSIS is thus used to integrate all determined performance criteria of ride comfort, road friendliness and handling stability into a single performance index. Meanwhile, the weights of the quality characteristics are determined by employing the entropy measurement method. Furthermore, the best factor levels are identified according to the Taguchi method principles for single response optimization. Finally, the optimal combination of suspension parameters is confirmed to illustrate the effectiveness of the proposed hybrid optimization method.
Jiang, Rongchao, Wang, Dengfeng
Mathematical Model for Kinematic Analysis of McPherson Strut Suspension2016-28-01842/1/2016
Kinematic inputs such as camber, caster variation are very important for design of any suspension setup. Usual procedure is to get these inputs from kinematic software. But every designer cannot have this software & one has to learn them too. We have developed a method for kinematic analysis of McPherson strut type suspension which can be implemented on easily available and familiar software like MS Excel. Results obtained are in correlation with results from commercially available mechanism tools such as Pro mechanism. All links in suspension layout are considered as rigid. Vector calculus and other mathematical methods have been used to come up with final solution. Inputs required for mathematical program are suspension hardpoints, Lower arm angle from design orientation as wheel travel input and Rack stroke as steering input. Suspension characteristics which can be derived by using proposed mathematic model are curves for camber, caster, toe change &curves for bump and rebound steer. Also we can get changed position of hardpoints for any given wheel and rack travel. Designer can play with hardpoints using this tool to get desired wheel motion & to tweak camber, caster and bump steer curves as per vehicle level targets.
Patil, Aditya Anant
Lighter, more powerful 2016 Honda Pilot15AUTP10_0210/1/2015
The third-generation SUV gets a sleek new look and plenty of slick technology for enhanced performance and safety. Programs for new re-engineered vehicles pose a great challenge for the engineers and other professionals assigned to them: load the vehicle with more advanced technology, consumer-friendly amenities, and safety features required to meet stringent requirements, all while trimming weight from any area necessary to maintain-or ideally decrease-overall weight compared to the previous generation. The 2016 Honda Pilot development team, faced with said challenge, succeeded brilliantly. The new three-row SUV is 289 lb (131 kg) lighter-the previous Pilot Touring weighed 4632 lb (2101 kg) vs. the new Pilot Elite, which includes more features but weighs 4343 lb (1970 kg)-while recently earning a 2015 Top Safety Pick+ rating from the Insurance Institute for Highway Safety (IIHS).
Gehm, Ryan
Experimental Investigation of Interconnected Hydraulic Suspensions with Different Configurations to Soften Warp Mode for Improving Off-Road Vehicle Trafficability2015-01-06584/14/2015
Hydraulic suspension systems with different interconnected configurations can decouple suspension mode and improve performance of a particular mode. In this paper, two types of interconnected suspensions are compared for off-road vehicle trafficability. Traditionally, anti-roll bar, a mechanically interconnected suspension system, connecting left and right suspension, decouples roll mode from the bounce mode and results in a stiff roll mode and a soft bounce mode, which is desired. However, anti-roll bars fail to connect the front wheel motions with the rear wheels', thus the wheels' motions in the warp mode are affected by anti-roll bars and it results an undesired stiffened warp mode. A stiffened warp mode limits the wheel-ground contact and may cause one wheel lift up especially during off-road drive. In contrast with anti-roll bars, two types of hydraulic suspensions which interconnect four wheels (for two-axis vehicles) can further decouple articulation mode from other modes. Based on previous researches, the mass-spring-damper method is used in modeling a sport utility vehicle, the full-car transient modeling approach is utilized for modeling two hydraulic suspensions. An experimental vehicle fitted with these systems has been tested on different type of terrains under the same condition, and the comparison of the experimental results is presented.
Zhou, Min, Wang, Lifu, Zhang, Jie, Zhang, Nong
Modeling and Feasibility Study of Nonlinear Suspension Components in Multibody Systems using Absolute Nodal Coordinate Formulation Based Beam Elements -Application to Stabilizer Bar2015-01-06424/14/2015
This study concerns the modeling of the stabilizer bar in a car suspension. This is a crucial and difficult task if its non-linear behavior should be captured correctly. In this study, the modeling of a stabilizer bar is done using beam finite elements based on the absolute nodal coordinate formulation (ANCF). An ANCF beam element is reviewed and its implementation in a multibody dynamics framework is explained. The specific element is chosen since it is assumed to be appropriate for modeling stabilizer bars. To test the feasibility of using the chosen ANCF beam element for modeling stabilizer bars, several numerical studies have been performed. These include eigenfrequency and static analyzes where results obtained using ANCF beam elements are compared with results obtained using other methods. Furthermore, the ANCF beam element has been implemented in a multibody dynamics model together with rigid bodies, springs and dampers to generate a representative model of a vehicle front suspension. This model is then subjected to a transient analysis to assess the influence of including a stabilizer bar in a front suspension.
Hyldahl, Per, Andersen, Sebastian, Mikkelsen, Sebastian, Balling, Ole
Triple-Control-Mode for Semi-Active Suspension System2015-01-06214/14/2015
There is an increasing customer demand for adjustable chassis control features which enable adaption of the vehicle comfort and driving characteristics to the customer requirements. One of the most promising vehicle control systems which can be used to change the vehicle characteristics during the drive is the semi-active suspension system. This paper presents a Rule-Optimized Fuzzy Logic controller for semi-active suspension systems which can continuously adjust itself not only according to the road conditions but also to the driver requirements. The proposed controller offers three different control modes (Comfort, Normal and Sport) which can be switched by the driver during driving. The Comfort Mode minimizes the accelerations imposed on the driver and passengers by using a softer damping. On the other hand, the increased damping in Sport Mode provides better road holding capability, which is critical for sporty handling. The Normal Mode is adjusted to provide an overall balance between the vehicle ride comfort and road holding. The controller synthesis is performed by using an eleven degree of freedom full vehicle ride dynamics simulation model which is validated through laboratory tests performed on a hydraulic four-poster shaker. A unique optimization process is employed for obtaining the optimum Fuzzy Logic membership functions and the optimum rule-base of the proposed semi-active suspension controller. Discrete optimization is performed with Genetic Algorithm (GA) to find the global optima of the cost function which considers the ride comfort and road holding performance of the full vehicle. A comparison between the three control modes in terms of ride comfort and road holding is performed. The results show that, the proposed control modes provide three different vehicle characteristics to the driver. In addition to this, all three control modes are superior to the optimal passive suspension in terms of both ride comfort and road holding.
Kaldas, Mina M.S., Çalışkan, Kemal, Henze, Roman, Küçükay, Ferit
Improving Light Bus Handling and Stability by Anti-roll Bar and Bushing Adjustment2015-01-00263/10/2015
In order to improve the handling and stability of a light bus at high speed, a virtual model was established in Adams-Car and its anti-roll bar and bushing parameters were virtually optimized. The tyre mechanical characteristics were firstly tested by using a plate-type tyre tester and the Magic Formula parameters of the tyre were obtained. Then the virtual bus model's handling performance were studied by the simulation of central steering test and steady static circular test. An optimal matching method was put forward. By using genetic algorithm to conduct optimization, the optimised parameters were obtained. After that the anti-roll bar and bushing samples were respectively manufactured. At last, the comparative trials were performed in an automotive proving ground, and the subjective evaluation of the light bus's handling and stability was taken by three specialized assessors. The evaluation result showed that the score of subjective evaluation was 8.6, which was 31% higher than the original bus's. Therefore the handling and stability was improved by the adjustment of front and rear anti-roll bars and bushings and achieved the expected purpose.
Shi, Wenku, Wang, Changxin, Li , Zan
Fatigue Based Optimization of Cast Iron Bracket Depending On Proving Ground Data2014-01-23099/30/2014
Nowadays, a lightweight component design plays a significant role in both cost of a vehicle and fuel economy in competitive heavy duty truck industry. This paper describes the optimization study of an Anti-Roll Bar (ARB) bracket used in a heavy duty truck. ARB system is used to avoid rolling of a vehicle. In order to measure real forces acting on ARB links, calibration study is performed in laboratory conditions. According to this study, measured strains are correlated with theoretical strain-force curve. After the correlation study, fatigue based topology optimization is made on ARB cast iron bracket according to correlated Road Load Data (RLD) which is performed at Proving Ground. Most of the optimization studies in the literature depend on maximum static loading condition. However, many components or structures in the industry subjected to fluctuating loads when they are in service condition. Small loads in a fluctuating load domain may cause potential danger in the design because there will be damage accumulation on the part when those loads are repeated. The failure of components under cyclic load is called fatigue which plays important role in the design. In this study packaging volume, different road profiles, fatigue cycle limits, material of bracket and manufacturing constraints are taken into consideration. Compared with initial design, the weight of ARB bracket is reduced by 25% while keeping the fatigue life in an acceptable level.
Kosar, Fatih, Yegin, Mehmet Burak, Dogru, Okan, Akarsu, Cüneyt
Development of Tubular Stabilizer for Commercial Vehicle Using Advanced High Strength Steel Material2014-28-00064/28/2014
Tubular stabilizer bar for commercial vehicle is developed using advanced high strength steel material. Tubular section is proposed to replace the existing solid section. The tubular design is validated by component simulation using ANSYS Software. The tubes are then manufactured of the required size. The bend tool is designed to suit the size of the profile stabilizer bar and the prototypes are made using the tube bending machine. The strength of the tubular stabilizer is increased by using robotic induction hardening system. The tubular stabilizer bar is tested for fatigue load using Instron actuators. Higher weight reduction is achieved by replacing the existing solid stabilizer bar with the tubular stabilizer bar.
Ravi, Rohitt, Simhachalam, Bade, Balakrishnan, Dhanooj, Srinivas, Krishna
Application of Structure Optimization Method to Dynamic Tuning2014-01-04114/1/2014
The understeer of vehicle is desired for the vehicle's handling performance, and the roll rate of rear suspension is one of the key characteristics to achieve the understeer performance. A proper roll rate of the rear suspension is required to assure a certain level of understeer. Generally, in the vehicle dynamic tuning process, several methods are available for improving understeer performance, e.g., changing the hard-points of suspensions, adjusting stiffness of bushings, etc. On the other hand, structure optimization of components can be used in some case to improve the performance. In this paper, the optimization method is applied to the twist beam of rear suspension. The change in local geometry by optimized design leads to appropriate adjustment of the roll rate. Finally the vehicle understeer performance reaches design target.
Qu, Yuan, Hongbin, Wang, Zhang, Dechao, Zhang, Linbo, Wu, Shen
Preview Enhanced Rule-Optimized Fuzzy Logic Damper Controller2014-01-08684/1/2014
New developments in road profile measurement systems and in semi-active damper technology promote the application of preview control strategies to vehicle suspension systems. This paper details a new semi-active suspension control approach in which a rule-optimized Fuzzy Logic controller is enhanced through preview capability. The proposed approach utilizes an optimization process for obtaining the optimum membership functions and the optimum rule-base of the preview enhanced Fuzzy Logic controller. The preview enhanced Fuzzy Logic controller uses the feedforward road input information and the feedback vehicle state information as the controller inputs. An eleven degree of freedom full vehicle model, which is validated through laboratory tests performed on a hydraulic four-poster shaker, is used for the controller synthesis. The cost function including both ride comfort and road holding performance of the full vehicle is minimized through a discrete optimization process utilizing Genetic Algorithm (GA). The preview distance is also considered as a design parameter during the optimization process. The performance of the preview enhanced rule-optimized Fuzzy Logic controller is evaluated by using a measured stochastic road profile as vehicle model input. The results demonstrate the potential of the preview enhanced controller in improving all aspects of system performance compared to the rule-optimized Fuzzy Logic controller without preview.
Kaldas, Mina, Caliskan, Kemal, Henze, Roman, Küçükay, Ferit
Modeling and Model Analysis of a Full-Car Fitted with an Anti-Pitch Anti-Roll Hydraulically Interconnected Suspension2014-01-08494/1/2014
In this paper, a passive anti-pitch anti-roll hydraulically interconnected suspension is proposed for compromising the control between the pitch and roll mode of the sprung mass. It has the advantage in improving the directional stability and handling quality of vehicles during steering and braking manoeuvres. Frequency domain analysis of a 7-DOF full-car model with the proposed system is presented. The modeling of mechanical subsystem is established based on the Newton's second law. Then the mechanical-hydraulic system boundary conditions are developed by incorporating the hydraulic strut forces into the mechanical subsystem as externally applied forces. The hydraulic subsystem is modelled by using the impedance method, and each circuit are determined by the transfer matrix method. And then the modal analysis method is employed to perform the vibration analysis between the vehicle with the conventional suspension and the proposed HIS. Comparison analysis focuses on natural frequencies and modal shapes with identified eigenvalues and eigenvectors. Experiment setup has been introduced in this paper, The present result offer confirmation that the effectiveness of the anti-pitch anti-roll HIS system in increasing the pitch stiffness and roll stiffness and simultaneously maintaining the bounce stiffness.
Shao, Xinxin
Application of Finite Element Method in the Study of Variables that Influence the Stiffness of the Anti-Roll Bar and the Body Roll2013-36-064310/7/2013
The objective of this work is to analyze the main geometric variables that alter the stiffness of the anti-roll bar, which consequently influence the charge transfer between the wheels of the axle, while in a curve, and the body roll. The study was based on the application of this component in a vehicle of simplified construction, but the methodology can also be applied to commercial vehicles. To calculate the stiffness a software, based on the Finite Element Method, was used. In the numerical model was applied a unit force at the ends of the anti-roll bar and was observed the response of the system in terms of deformation. It was verified the change in stiffness caused by varying the position of the bushings that are used to hold the bar, profile cross-section and the change of the opening angle of the arms. Equations from the literature were used to determine the action of centrifugal force on the roll angle of the body, however they do not take into account all the characteristics of the suspension. It was considered the equilibrium condition between the moments of the force acting on the suspension and non-suspended masses and moments of reaction of the springs and anti-roll bar used in suspensions. The ratio between stiffness and weight served as a comparison for the bars, and revealed for what configuration studied was achieved the best effect in reducing rollover and with minor addition of weight to the vehicle. It was possible to obtain a considerable gain in reducing rolling when using the anti-roll bar.
Ribeiro, Sérgio Yuri, Silveira, Márcio Eduardo
Rule Optimized Fuzzy Logic Controller for Full Vehicle Semi-Active Suspension2013-01-09914/8/2013
This paper presents a new and effective control concept for semi-active suspension systems. The proposed controller uses a Fuzzy Logic scheme which offers new opportunities in the improvement of vehicle ride performance. The Fuzzy Logic scheme tunes the controller to treat the conflict requirements of ride comfort and road holding parameters within a specified range of the suspension deflection. An eleven degree of freedom full vehicle ride dynamics model is constructed and validated through laboratory tests performed on a hydraulic four-poster shaker. A new optimization process for obtaining the optimum Fuzzy Logic membership functions and the optimum rule-base of the proposed semi-active suspension controller is proposed. Discrete optimization has been performed with a Genetic Algorithm (GA) to find the global optima of the cost function which considers the ride comfort and road holding performance of the full vehicle. The proposed Fuzzy Logic semi-active controller is compared to the optimum Linear Quadratic Regulator (LQR) semi-active controller and the optimum passive suspension system in terms of ride comfort and road holding. The results showed that the proposed semi-active suspension system controller provides significant improvements in both ride comfort and road holding performance of the vehicle.
Kaldas, Mina M.S., Çalışkan, Kemal, Henze, Roman, Küçükay, Ferit
Experimental Comparison of Anti-Roll Bar with Hydraulically Interconnected Suspension in Articulation Mode2013-01-07104/8/2013
A detailed experimental study to quantitatively compare a roll-plane hydraulically interconnected suspension with anti-roll bar in articulation (warp) mode is presented in this paper. Anti-roll bar as part of conventional vehicle suspension system is a standard configuration widely used in road vehicles to provide the essential roll-stiffness to enhance vehicle handling and safety during fast cornering. However the drawback of anti-roll bar is apparent that they limit the wheels' travel on uneven road surface and weaken the wheel/ground holding ability, particularly in articulation mode. Roll-plane Hydraulically Interconnected Suspension (HIS) system, as a potential replacement of anti-roll bar, could effectively increase vehicle roll-stiffness and provide the tunable damping effect, without compromising vehicle's flexibility in articulation mode. This paper presents the finding of an experimental analysis of roll-plane HIS system in comparison with anti-roll bar on a sport utility vehicle in articulation mode. The test vehicle has three different configurations for comparison: 1) conventional suspension without anti-roll bar, 2) with anti-roll bar, and 3) with roll-plane HIS. The test results demonstrate that in articulation mode, anti-roll bar limit wheel's travel, while HIS system has a negligible effect on wheel's travel. A detailed analysis and discussion of test results are provided to conclude the paper.
Wang, Lifu, Xu, Guangzhong, Zhang, Nong, Roser, Holger
Functional Vehicle Dynamics Simulation2012-36-019410/2/2012
Functional vehicle dynamics simulation differs from the regular multi-body simulation especially by means of modeling parameters. The models are usually parametric, involving suspension properties that are commonly used by OEM's. Input data for a multi-body simulation (MBS) is, normally, raw information about suspension hard points coordinates, flexible elements stiffness (such as bushing and springs), etc. As for a functional simulation, the input data can be one outcome of a multi-body one, such as K&C data or even measured data of a bench test. However, the results of both ways of simulation must be the similar. Functional simulation software does not solve the multi-body equations for each integration step as any regular MBS software and, as such, can run the model in a faster way. In this way, software-in-the-loop and hardware-in-the-loop starts to become a clear advantage of these art of simulation. However, even at early stages of a project, functional simulation plays also an important role in the sense of building up models in a fast way, not requiring much engineering time to get results from CAE models. Using functional simulation approach, a mathematical vehicle model was developed based mainly on the kinematic and compliance data of the both front and rear suspensions. Different maneuvers were validated against measured data in order to certify the modeling for different conditions. Using this model, a sensitivity analysis was done identifying the main steering parameters (scrub radius, caster trail, lateral and longitudinal offset) that influence the most a few dynamic characteristics such as steering returnability, dynamic torque and on center feeling of the vehicle. Using a functional simulation, the sensitivity analysis can reveal information not possible for a multi-body analysis, since such steering parameters cannot be change individually, without changing K&C properties. This information represents strategical advantage on pre-project stages, since it will lead the suspension conception choice for a given set of attributes demand for vehicle dynamics.
Fernandes, Claudio, Noguchi, Eric, Castro, Romulo, Almeida, Uilian, Peixoto, Vinicius, Silva, Eder
Evaluation of the Torsion Beam of a Twist-Beam Suspension by Numerical Simulation2012-36-048310/2/2012
Considering the competitiveness of the automotive market current, the search for low cost solutions that meet all quality demands, it has become essential in the process of product development. The principles of large-scale production have become a limiter component complexity, mainly due to difficulties in the manufacturing process. Twist-beam suspensions are an example of this competitive environment. This solution presents a very satisfactory performance when applied to light vehicles and has an excellent relationship between cost / benefit for the Brazilian market. It is estimated that more than 95% of light vehicles manufactured in Brazil using this type of suspension at the rear. Despite the large use in the Brazilian automotive market, there are few studies related to the twist-beam suspension. There is little literature available on the design and research in suspensions of this type, perhaps because of its simplicity and low cost design and ease of manufacturing. The main objective of this work was to evaluate through numerical simulation based on finite element method, the influence of the torsion beam on the kinematic behavior of a twist-beam suspension. It were evaluated the influence of factors such as moment of inertia and polar moment of inertia of the torsion beam on the toe-in and camber of the suspension.
Vasconcelos, Luize S., Silveira, Marcio E., Christoforo, Andre L.
Steering System Optimization of a Ford Heavy-Commercial Vehicle Using Kinematic & Compliance Analysis2012-01-19379/24/2012
The basic scope of heavy-commercial vehicle (HCV) development which was just concentrated on fuel-economy, durability and performance feel is not capable of fulfilling the increasing customer expectations anymore. HCV developers concentrate on additional vehicle attributes such as steering, ride comfort, NVH, braking, ergonomics and exterior-interior design in order to provide the passenger-car like perception to HCV drivers during long distance drives. The objective of this paper is to present the model validation methodology and the optimization study on suspension & steering hard points of a HCV. The results of the optimization study on suspension kinematics and steering performance of the vehicle is verified using both full vehicle simulations and vehicle testing. A full vehicle ADAMS/Car model is used for the validation and optimization study which has beam-element leaf springs on solid axle and air springs on drive axle for front and rear, respectively. The steering system of the mentioned HCV consists of a steering wheel, steering column subsystem, a variable-ratio steering gear with recirculating ball mechanism, a pitman arm, a drag link, an upper steering arm, two lower steering arms and a tie-rod. All steering linkages are modeled as rigid bodies in ADAMS/Car model during the optimization study. The optimization factors are selected as pitman arm-to-drag link hard point, drag link-to-upper steering arm hard point, and lower steering arm-to-tie rod hard point. The aim of this optimization study is to improve and find an optimum point for the kinematic properties such as bump steer, roll steer, percent Ackermann, maximum wheel angle and their symmetry. The improvements on kinematic properties are verified with vehicle testing on different maneuvers with the prototype vehicles.
Oz, Yahya, Ozan, Berzah, Uyanik, Eren
Vehicle Dynamics Simulation at Commercial Vehicle Development2012-36-00185/16/2012
This paper discusses the benefits of truck simulation for ride and handling tuning at product development. Virtual simulation can guide the conception of new vehicles to a better "first guess" of dynamics characteristics, providing calibrated options to define parameters for springs, dampers and anti-roll bars, closer to the desired condition. TruckSim™, from Mechanical Simulation, was the chosen software due to its user-friendly interface, fast modeling and post-processing that matches with challenging product time-to-market. The scope of analysis is to evaluate/compare virtual results against subjective/objective tests on real prototypes, in order to proof software correlativity. The first step was to develop the vehicle model, using 3D CAD models information, data acquired from real prototypes and product specifications. The chosen vehicle was a 9-ton 4X2 rigid truck. The next step was to model the procedures: constant speed at 60 km/h, pass through a smooth bump at 15 km/h, double lane change at 60 km/h (ISO 3888) and step steer at 45 km/h (ISO 7401). These procedures were simulated with different sets of dampers and anti-roll bars. Comparative tests were performed in order to evaluate simulation results with empirical procedures, both for comfort level and cornering. The outputs chosen to validate the simulation were: acceleration, displacements of the CG and tires reaction forces at the contact path. The analysis indicated that it is possible to reduce loops of suspension tuning therefore reducing time of tuning, saving prototype/test cost and development time. So far, simulated procedures are recommended even in conceptual phase to shift vehicle dynamic parameters into confident initial approaches.
Alvarez, Andre Carneiro Couto, Corte, Everton, Garbin, Leandro, de Almeida Lima, Vinicius
Experimental Investigation of a Hydraulically Interconnected Suspension in Vehicle Dynamics and Stability Control2012-01-02404/16/2012
Mainly motivated by developing cost-effective vehicle anti-roll systems, hydraulically interconnected suspension has been studied in the past decade to replace anti-roll bars. It has been proved theoretically and practically that hydraulic suspensions have superior anti-roll ability over anti-roll bars, and therefore they have achieved commercial success in racing cars and luxury sports utility vehicles (SUVs). However, since vehicle is a highly coupled complex system, it is necessary to investigate/evaluate the hydraulic-suspension-fitted-vehicle's dynamic performance in other aspects, apart from anti-roll ability, such as ride comfort, lateral stability, etc. This paper presents an experimental investigation of a SUV fitted with a hydraulically interconnected suspension under a severe steady steering maneuver; the result is compared with a same type vehicle fitted with anti-roll bars. Furthermore, an insight of how the hydraulic suspension response to extreme maneuvers has been presented, which is of great interest to the optimization of the hydraulic suspension design. Real time simulations are used to assist the experiment to provide a complete picture of the hydraulic system response. The findings are discussed.
Wang, Lifu, Zhang, Nong, Du, Haiping
Effect of Added Mass of Spindle Wheel Force Transducer on Vehicle Dynamic Response2012-01-02104/16/2012
Wheel force and moment transducers (WFT) are widely used in vehicle testing and analysis [1], [2], [3]. There are many benefits of using these sensors. To install the transducer, vehicle wheel has to be modified. Transducer mounting adaptors are required to interface the sensor with the modified wheel rim. To study the effect of added mass with wheel force transducers, three vehicles, two types of passenger cars, and one SUV, were instrumented with an MTS spindle wheel force transducer (SWIFT 30A) as well as with regular wheels. The instrumented vehicles were driven on multiple proving ground surfaces with three passes for each vehicle. This experimental data was analyzed using RPC Pro software to assess both per pass variation and data trends from 3 passes without WFT (baseline) and 3 passes with WFT added mass. A validated ADAMS model of a production passenger vehicle, with and without added weight of the wheel force transducers, was also used to assess the added weight effect. The ADAMS vehicle model with Ftire tire model was simulated on 3-bumps and Belgian Blocks events.
You, Shawn S.
Front Suspension Modeling Using an Integrated FEM - Multi Body Approach2011-28-007810/6/2011
Today's competitive environment in automotive industries worldwide demands high standard of Ride and Handling for customer satisfaction. As Maruti Suzuki is pioneer in manufacturing passenger car in India, and we are consistently designing and developing the vehicles to meet the customer requirements of good ride and handling parameters, thus creating Customer Delight. The vehicle structure is designed to meet requirements in terms of Ride, Handling, Safety and Durability. Integrity and functionality of the vehicle components are very important so that vehicle can sustain full service life. When the vehicle passes through bump or pothole, very high intensity forces are experienced on the body and various suspension parts. This may result in Body Cracks. CAE is extensively used to predict these body and suspension cracks in design stage. Ground tests and multi body dynamics (ADAMS) were used to collect road load profile and Forces, which served as boundary conditions for CAE analysis. Using an integrated multi body - FEM approach a new methodology has been developed wherein the effect of changes in suspension forces on the BIW Strength was studied.
Gupta, Sanjay Kumar, Bardhan, Amritashu, Khanger, Rakesh, Matharu, Ranjit Singh
Balance of Static and Dynamic Rollover Thresholds for a Three-Axle Vehicle2011-01-21529/13/2011
In this study, a three-axle vehicle model established with ADAMS/Car is first correlated with field test data from quasi-static tilt table and highly dynamic NATO double lane change maneuver tests, respectively. It is then applied to predict the vehicle static rollover threshold (SRT) and dynamic rollover threshold (DRT). With the optimization approach proposed in this study it is possible to efficiently tune the anti-roll bar stiffness at each axle, to either maximize SRT or DRT, or balance both. The sensitivity results derived from the optimization iteration process can be applied to effectively size the three anti-roll bars that balance the static and dynamic roll stability performances. The proposed method can be potentially applied to include other parameters to address the roll stability issues and beyond.
Yang, Xiaobo
GM Approach to Chassis Based Load Management2011-01-00244/12/2011
Global programs are placing demands on vehicle platforms to achieve structural durability robustness across a broader spectrum of vehicle configurations and use conditions. This robustness is optimally achieved by (a) localizing energy absorption to lower cost components, and (b) narrowing the spread in loads generated during durability events, which in turn minimizes the cost and mass impact to the vehicle platform. A generalized philosophy for conducting load optimization and for improving energy management for various types of events is presented here. Various techniques that have been employed at GM are explained by way of illustration.
Schudt, Joseph A., Geisler, Robert L.
Process Automation Wizard for Vehicle Dynamics Applications2011-01-07404/12/2011
The imperative to get to the market faster with new and better products, has determined all automotive OEM to rethink their product development cycle, and, as a result, many hardware based processes were replaced and/or augmented with virtual, software based ones. However, the virtualization itself does not guaranties better and faster products. In the area of vehicle dynamics, we concentrate on improving the multi-body model development process, facilitating comprehensive virtual testing, and verifying the robustness of the design. The authors present a highly flexible and efficient environment that encourages, enforces, and facilitates model sharing, reusing of components, and parallelization of vehicle dynamics simulations, developed on top of an existing commercial off-the-shelf engineering software application.
Buzdugan, Laurentiu, Liang, Cwo Gee
Anti-Roll Bar Link Toggling: Investigation and Optimization of a Robustness Problem2011-01-00634/12/2011
Because of package constraints the anti-roll bar link (ARB-link) of a rear axle stabilizer had to be designed with a very short length. When the rear suspension is in extreme opposite wheel travel conditions - as it happens when driving on parking garage ramps - this design results in a toggling effect of the ARB-link. The toggling starting point depends strongly on the location of the upper and lower attachment point of the ARB-link. Therefore, a nominal optimization based on MB S simulations of the critical ramp driving load case is applied to find within the given package space an optimized position of the attachment points, where no toggling occurs. Indeed, such attachment points can be found, but a robustness analysis reveals that the nominal optimum is located at a bifurcation edge and that - consequently - the result is not robust. To solve the robustness problem, two methods are applied and compared: Firstly a Kriging based approach and secondly a simple “pushing-away” strategy. The results of both methods are compared and discussed. In particular, an explanation is given why the standard Kriging approach can be applied to a bifurcation problem. Additionally, the most important variables are indentified based on a linear regression model as well as on a functional ANOVA. Here again, both approaches and their results are discussed and compared.
Harzheim, Lothar, Warnecke, Ulrike
Active Suspension Handling Simulation using Cosimulation2010-01-158212/1/2010
In this study the capabilities of a semi-active suspension and an active roll suspension are evaluated for comparison with a passive suspension. The vehicle used is a utility truck modeled as a multi-body system in ADAMS/Car while the ECU (electronic control unit) is built in Matlab/Simulink. Cosimulation is used in linking the vehicle model with the controller by exchanging the input and output values of each sub-system with one another. For the simulation models considered, results indicate that for a fish-hook cornering maneuver the semi-active suspension is limited in increasing vehicle performance while the active roll suspension significantly improves it. Further analysis is needed to confirm these findings.
Maiorana, Joseph, Minaker, Bruce P.
Kinematics and Compliance (K & C) Simulation Using a Nonlinear Finite Element Model2010-01-09514/12/2010
Kinematics and Compliance (K&C) testing is used to evaluate the ride and handling performance of an automobile. During a typical K&C test, the vehicle body is fixed while controlled forces or displacements are applied to the wheels. The results of the test include vehicle suspension parameters, such as toe, camber, etc. Numerical simulations of this test are usually performed using multibody dynamics software that introduces simplifying rigid body assumptions. However, the need for component flexibility in K&C simulation is increasing along with demand for more precise suspension system designs. In this paper, a new methodology for K&C simulation is proposed using Abaqus. First, rigid body suspension mechanism analyses are performed using Abaqus and Adams, and the results are compared. Then a nonlinear Abaqus finite element model, with flexible suspension components and vehicle body, is analyzed and the results are compared with the rigid body suspension analyses. Significant differences are observed between the results of these two models, which imply that flexibility plays an important role in K&C testing.
Hahn, Youngwon
Twist Beam Suspension Design and Analysis for Vehicle Handling and Rollover Behavior2010-01-00854/12/2010
The concept vehicle under study was equipped with a rear twist beam suspension. Apart from designing and analyzing the twist beam for structural integrity, the effects of its directional stiffness values on vehicle dynamic behavior had to be taken into account. The twist beam suspension was initially modeled using beam elements to offer more parametric freedom, followed by DOE and optimization for the target suspension kinematic and compliance (K & C) performances within MBD environment. The data obtained from DOE within the MBD environment, such as the mounting locations, geometrical requirements, etc. were the critical inputs to structural definitions used for constructing the FE model. The resulting FE suspension subsystem was then evaluated for full vehicle performances using typical cornering maneuvers within MBD.
Sistla, Pranava K., Kang, Hong Tae
Design and Simulation of the Suspension System of Chassis Platform Based on Handling Stability2010-01-07234/12/2010
Chassis platform is usually supplied for several types of cars which have their individual requirement for handling stability and ride comfort. Therefore the stiffness, damping and the dimension of the guide mechanism of the suspension have to be adjusted to meet the different performance requirements of different styles of cars. In this paper a module exclusively used for handling stability analysis of chassis platform is developed based on ADAMS/Car. With this module chassis engineers can easily adjust the parameters of suspension such as stiffness, damping and locations of hard points to match the front and rear suspension suitably and then predict and optimize the performance of the suspension system. Therefore different types of cars that using chassis platform can fulfill their own handling stability and ride comfort requirements. By using the module, parameterized models of the front, rear suspension and the chassis platform were built in this paper, and the kinematic simulation of the suspensions were carried out to analyze their kinematic performance. Then two cars of different type which use the chassis platform were taken as an example to do the cornering simulation and evaluation according to the Chinese National Standard to verify the good applicability of the module for the analysis of suspension kinematic performance and chassis platform handling stability.
Ning, Xiaobin, Meng, Bin, Shen, Jisheng, Dong, Xizhuang, Zi, Xiaolin, Zhang, Jie
Investigation of Vehicle Handling and Ride Comfort Oriented Cooperative Optimization2010-01-07224/12/2010
The characteristics of suspension elastic elements (i.e., spring, damper and anti-roll bar) are directly related to the handling and ride comfort performances, how to tune the characteristics of suspensions' elastic elements is always a big issue in developing the chassis of a vehicle. In this paper, a multi-body dynamics model of a passenger car within MSC.ADAMS® is integrated with iSight FD®, an optimization tool, to carry out a multi-objective optimization for improving the behavior of vehicle handling and ride comfort. The characteristics of suspension elastic elements (i.e., spring, damper and anti-roll bar) are considered as design variables. For handling, the objectives are defined by the measurements from multi-body dynamics simulation of typical double lane change according to ISO3888 standard. For ride comfort, the frequency-weighted RMS (Root Mean Square) value of vertical acceleration of the front seat rail according to ISO2631 standard is set as the objective. The optimization methods which is suitable to the multi-objective trade-offs in vehicle development are discussed, and some simulation results about the cooperative optimization between handling & ride comfort are presented in this paper.
Rongshan, Yang, Huang, Xiangdong, Kegang, Zhao
Performance of Active Suspension with Fuzzy Control2009-01-16145/13/2009
Vehicle suspension along with tires and steering linkages is designed for safe vehicle control and to be free of irritating vibrations. Therefore the suspension system designs are a compromise between ride softness and handing ability. However, this work is concerned with a theoretical investigation into the ride behavior of actively suspended vehicles. It is based on using fuzzy logic control (FLC) to implement a new sort of active suspension system. Comparisons between the behavior of active suspension system with FLC with those obtained from active systems with linear control theory (LQR), ideal skyhook system and the conventional passive suspension systems. Results are introduced in such a way to predict the benefits that could be achieved from fuzzy logic system over other competing systems. Furthermore, a controller is designed and made by using results of FLC system, theoretical inputs are used to examine the validity of this controller. Moreover, comparison between actual outputs from this controller with those obtained theoretical is made to judge the validity of the controller. The results indicate that the controller has a good capability in simulation of the theoretical model. NOMENCLATURE A Road input amplitude, m 0.05 BA Body acceleration, m/s2 - C Coefficient of power spectral density 5 C2 Suspension damping coefficient, Ns/m 1300 C3 Skyhook damping coefficient, Ns/m 20000 DTD Dynamic tire deflection, m - K1 Tire stiffness, N/m 192000 K2 Suspension stiffness, N/m 20000 M1 Unsprung mass, kg 45 M2 Sprung mass, kg 310 Rc Road roughness coefficient 4 × 10−4 SWS Suspension work space, m - ts Sampling time, s 0.01 V Vehicle velocity, m/s - y1 Body acceleration as an output, m/s2 - y2 Suspension working space as an output, m - y3 Dynamic tire loading as an output, m - λ Road wave length, m 10.46 ωc Sprung mass natural frequency, rad/s 7
Elbab, Hesham Fath, Allam, Essam, Hady, Magdy Abdel, Abouel-Seoud, Shawki
Endurance Testing and FE Analysis of Four Wheeler Automobile Stabilizer Bar2009-26-00661/21/2009
Durability of automobile stabiliser bar is assessed in the present study. Finite element analysis of the stabiliser bar is performed based on the experimental observations. Fatigue analysis is performed under cyclic loading. Fatigue analysis is performed for maximum cyclic loading conditions. Improvement is the fatigue life of stabilizer bar is analysed by shot peening. Special purpose machine is used to simulate the fatigue life of stabilizer bar. Commercial software ABAQUS is used for numerical simulation. Computational fatigue simulation software, fe-safe is used for the fatigue analysis to predict the fatigue life (number of cycles for crack initiation) and crack site location. Predicted results were compared with that of the physical test results for validation.
P., Senapathi, S., Shamasundar, G, Venugopala Rao, B.M., Sachin, Srinivas, Krishna, N., Dasari, Shripadraj, Ponkshe, Raju, Basava
Simulation with a Vertical Oscillating Race Car Model2008-01-296312/2/2008
The subject of this paper is the creation of a vertical oscillation model of a race car in MATLAB and applying it to transient real-time simulations. The race car model is based upon a multi-body simulation model. That means the entire race car is divided into six discrete and rigid masses connected together with springs and dampers. To calibrate the model and to compute the surface of the real track the following data acquisition signals are required: four pushrod loads of each wheel, the speed, and the longitudinal and lateral acceleration. Based on this model the user can adjust the vehicle suspension setup and simulate the new movements and velocities of the masses as well as the forces acting on them. One result of this simulation can be the relative performance (according to the contact patch loads) in every point of the circuit during one lap as compared to the basis setup.
Graf, Michael, Kosuch, Steffen
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