Vehicle Suspension Performance Research Articles

Design optimization of variable inerter based on vehicle suspension performance criteria

Design optimization of variable inerter based on vehicle suspension performance criteria

Performance analysis of vehicle magnetorheological semi-active air suspension based on S-QFSMC control

The performance of the suspension is a crucial criterion for evaluating both vehicle handling and passenger comfort. To enhance suspension performance, this study proposes the design of a Quantum Genetic Fuzzy Sliding Mode Controller (S-QFSMC) based on the Smith predictor estimator, building upon the foundation of the vehicle magneto-rheological semi-active air suspension. According to the physical model of the vehicle suspension, a mechanical model of a quarter-vehicle magneto-rheological semi-active air suspension with time delay is established. On this basis, a conventional sliding mode controller is designed, and quantum genetic algorithm and fuzzy control principles are employed to optimize the chattering issue associated with sliding mode control. The Smith predictor estimator is utilized to effectively compensate for the time delay in the suspension system. Subsequently, a simulation analysis of the vehicle suspension performance is conducted. The results indicate that, compared to passive suspension control, both the QFSMC controller and the S-QFSMC controller improve the suspension performance, with the S-QFSMC controller exhibiting superior comprehensive improvement. This validates the effectiveness of the designed controllers.

Modeling and Experimental Validation of the Performance of Electromechanical Height Adjustment Vehicle Suspension with Eccentric Mounted Screw System

This paper describes the modeling and experimental validation of the performance of two height adjustment suspensions with concentrically and eccentrically mounted screws. In the former solution, an anti-rotation system is required for the generation of reaction torque on the power screw–nut mechanism. The anti-rotation represents the main drawback of such mechanisms. In contrast, the eccentric solution attempts to solve this problem by placing the screw–nut mechanism eccentrically with respect to the shock absorber tube axis. In this paper, the working principle of the eccentric solution is explained. Its performance is compared to the concentric counterpart through simulations and experiments. Although the efficiencies of eccentric and concentric systems are very similar at the power screw, overall efficiencies differ substantially. During lifting, average efficiencies are around 3.4% and 6.5% for concentric and eccentric systems, respectively. When lowering, these values are 6.2% and 26%. The higher overall efficiency of the eccentric screw system is attributed to the anti-rotation system and the balancing of the bending moment due to the offset application of the load. To yield a complete perspective on the eccentric mounted screw solution, four prototypes are installed and tested on a demo vehicle.

Bio-inspired structure reference model oriented robust full vehicle active suspension system control via constraint-following

It is hard to realize the bio-inspired structure (BIS) directly in the vehicle suspension due to space limitation, even though the beneficial nonlinearity of BIS for anti-vibration has been extensively proved. This paper adopts active suspension control to take the advantage of BIS on anti-vibration to improve vehicle comfort, i.e., formulating the ideal BIS dynamics model as nonholonomic servo constraints and then designing the control via constraint-following to drive the dynamics of full vehicle active suspension system (FVASS) to follow the servo constraints. It is of novelty for this study to introduce the constraint-following controls (CFC) into the linear FVASS to follow the servo constraints, considering possibly fast time-varying uncertainties including large mismatched portions. The CFC views the nonlinear control problem from a new perspective of servo constraint. This leads to a simple and natural control that is capable of ‘exactly’ following the servo constraints of nonlinear BIS in the second-order form without the requirement of linearization and/or nonlinear cancellation. Furthermore, a robust CFC is designed based on an uncertainty decomposition technique to consider possibly fast time-varying uncertainties including large mismatched portions, which are unavoidable in underactuated systems but are usually ignored or assumed very small in existing studies. The proposed robust CFC is proved to be able to fulfill the control task with controllable constraint-following error by the Lyapunov stability analysis, even in the presence of uncertainties. Experimental and simulation results reveal the validity of the proposed approach in improving vehicle suspension performance.

Effect of time-delay feedback control on vehicle seat vibration reduction and suspension performance

To reduce seat vibration caused by uneven road surfaces, the time-delay feedback control into the seat suspension system was introduced and an active seat suspension control method based on time-delay feedback was proposed in this paper. A three-degree-of-freedom (3-DOF) suspension model with time-delay feedback control was established. The time-delay independent stability region and critical stability curve of the system were derived using the method of characteristic root and stability switching. The effect of feedback control parameters on system vibration was investigated in the stability region. The seat acceleration (SA), body acceleration (BA), suspension dynamic deflection (SDD), and tire dynamic displacement (TDD) were used as multi-objective optimization functions and the optimal values of feedback control parameters were obtained based on the particle swarm algorithm (PSO) with above optimization functions. The numerical simulation was conducted to validate the proposed model. The simulated results show that the time-delay feedback control can significantly suppress the vibration response of the seat and effectively improve the suspension performance under different road excitation compared with the passive suspension. It can be seen that the active seat suspension with time-delay control significantly improve ride comfort and handling stability of the vehicle, which can be used as a reference for the active control technology of vehicle suspension.

Assessment of Risky Cornering on a Horizontal Road Curve by Improving Vehicle Suspension Performance

Vehicle stability during cornering on horizontal road curves is a risky stage of travel because of additional factors acting. The main stability factor is centrifugal force, which depends on road curve sharpness and is very sensitive to driving speed usually controlled by the driver. However, the counterforce is produced at tire-road interaction, where different pavement types and states cause a wide variation of tire contact forces and vehicle stability. In the paper, the part of vehicle suspension performance while moving on a sharp horizontal road curve with different levels of pavement roughness was simulated by 14 degrees of freedom vehicle model. The model was built in MATLAB/Simulink software with available pavement roughness selection according to ISO 8608. The influence of variable suspension damping available in modern vehicles on risky cornering is analysed when a vehicle reaches the edge of the pavement with its specific roughness. Critical parameters of vehicle stability depending on road curvature, pavement roughness and driving speed are selected to assess the solutions for safe cornering.

Optimized Fuzzy Skyhook Control for Semi-Active Vehicle Suspension with New Inverse Model of Magnetorheological Fluid Damper

To improve the performance of vehicle suspension, this paper proposes a semi-active vehicle suspension with a magnetorheological fluid (MRF) damper. We designed an optimized fuzzy skyhook controller with grey wolf optimizer (GWO) algorithm base on a new neuro-inverse model of the MRF damper. Because the inverse model of the MRF damper is difficult to establish directly, the Elman neural network was applied. The novelty of this study is the application of the new inverse model for semi-active vibration control and optimization of the semi-active suspension control method. The calculation results showed that the new inverse model can accurately calculate the required control current. The fuzzy skyhook control method optimized by the grey wolf optimizer (GWO) algorithm was established based on the inverse model to control the suspension vibration. The simulation results showed that the optimized fuzzy skyhook control method can simultaneously reduce the amplitude of vertical acceleration, suspension deflection, and tire dynamic load.

A Semi-active Vehicle Suspension Control Strategy Based on Negative Stiffness Characteristics

A suspension is an indispensable part of a vehicle. It is of great significance for passengers’ comfort and vehicle stability. This paper proposes a semi-active vehicle suspension model with negative stiffness, and analyzes the effect of negative stiffness characteristics upon vehicle response. When analyzing the performance of semi-active vehicle suspension, a quarter vehicle suspension model is established, and the space state model is built for numerical simulation. After contrasting and analyzing the response of semi-active passive suspension with negative stiffness and semi-active suspension controlled by Skyhook damping algorithm, we conclude that semi-active suspension with negative stiffness decreases the vibration speed of the vehicle body and the deflection of the tire in the low-frequency stage, and improves the smoothness and stability of the suspension. Hence, the negative stiffness characteristic is beneficial to improve the comfort and stability of the vehicle.

Novel Method of Forecasting Performance of Full Vehicle Suspension by Decoupling Analysis and Vibration Sensing Experiments

Novel Method of Forecasting Performance of Full Vehicle Suspension by Decoupling Analysis and Vibration Sensing Experiments

Vibration suppression of terrains irregularities using active aerodynamic surface for half-car model sport vehicles

Riding quality is considered a key element in automotive industry which imposes a challenge on car manufacturers to develop new alternative control strategies for the classical suspension system. To this extent, many efforts have been carried out on developing several active or semi-active suspension systems. In the past few years, the decreasing cost of electromechanical actuators has, however, opened new trends to face this challenge. Active aerodynamic surfaces (spoilers) represent an alternative and effective solution to the issue. Two contradicting criteria of good vehicle suspension performance are typically their ability to provide good road handling and increase passengers comfort. The main disturbance affecting these two criteria is terrain irregularities. Active suspension control systems reduce these undesirable effects by isolating car body motion from vibrations at the wheels. In this article, we are trying to investigate the use of active aerodynamic surfaces to enhance ride comfort in sport vehicles for half car model. The article describes also the model and controller used in the study and discusses the vehicle response results obtained from a typical road sinusoidal signal input. The effect of active aerodynamic surfaces could enhance the ride comfort by (15%) without affecting road holding.

Implementation of an Electromagnetic Regenerative Tuned Mass Damper in a Vehicle Suspension System

High cost and significant power absorption do not allow exploiting modern active control strategies for improving vehicle suspension performance. Meanwhile, the semi-active control policies are not able to overcome a weighted unsprung adverse effect, which represents a cornerstone of the implementation in-wheel motors for a new type of electric vehicle. This paper discusses and analyses the implementation of a proposed energy-harvesting based tuned mass damper (TMD) to be implemented in electric vehicles. In this manner, a full vehicle suspension model embedded with four TMDs was created to simultaneously enhance the car comfort and road-holding responses with a corresponding large-scale energy harvesting. In the proposed 11-DOFs (degrees-of-freedom) vehicle model, the full-vehicle body was suspended using suspension systems, including the compacted back-iron based design of an electromagnetic TMD. The performed simulations indicated the considerable advantage and potentialities of using the TMDs based suspension. In terms of the RMS (root-mean-square), the car body acceleration was reduced by 21.7%, while the road-holding was enhanced by 5.7%. Moreover, the proposed regenerative electromagnetic tuned mass damper (ETMD) allows for harvesting vibration energy up to 58 W for a vehicle driven on a road class D and a speed of 30 m/s.

Vibration Performance of Two-Stage Vehicle Suspension with Inerters

Vibration Performance of Two-Stage Vehicle Suspension with Inerters

Simulation and Analysis of Two-Mass Suspension Modification Using MATLAB Programming

The designs of automotive suspension system are aiming to avoid vibration generated by road condition interference to the driver. This final project is about a quarter car modeling with simulation modeling and analysis of Two-Mass modeling. Both existing and new modeling are being compared with additional spring in the sprung mass system. MATLAB program is developed to analyze using a state space model. The program developed here can be used for analyzing models of cars and vehicles with 2DOF. The quarter car modelling is basically a mass spring damping system with the car serving as the mass, the suspension coil as the spring, and the shock absorber as the damper. The existing modeling is well-known model for simulating vehicle suspension performance. The spring performs the role of supporting the static weight of the vehicle while the damper helps in dissipating the vibrational energy and limiting the input from the road that is transmitted to the vehicle. The performance of modified modelling by adding extra spring in the sprung mass system provides more comfort to the driver. Later on this project there will be comparison graphic which the output is resulting on the higher level of damping system efficiency that leads to the riding quality.

Applicability of A Rotary Eddy Current Damper in Passenger Vehicle Suspension with Parallel Inerter

Numerous studies have proven that the performance of vehicle suspension can be benefited by an inerter in parallel to conventional spring-damper setup, yet its usability in passenger vehicle suspension is still limited by practical consideration in physical implementation. One way of achieving better physical implementation of the parallel inerter suspension layout is to exploit the inerter’s flywheel as a metallic conductor to integrate passive damping in the form of a rotary eddy current damper. However, the feasibility of eddy current damping in this specific application remains unknown. This study investigates the applicability of eddy current damping incorporated in an inerter in terms of the achievable damping rates as required in typical passenger vehicle suspensions. In the study, passive eddy current damping due to constant magnetic field around the flywheel of a mathematically designed inerter was computed through simulation, and the range of achievable damping rates due to parametric variations, for instance air gap and magnetic coverage, was evaluated. Results of the parametric analysis showed that the induced eddy current damping from a rack-and-pinion inerter’s flywheel, considering the designed inertance as prerequisite, was at least capable of achieving 1500 Nsm-1. As the achievable damping was within the range of suitable damping rates for typical passenger vehicles, rotary eddy current damper was deemed applicable in passenger vehicle suspension employing parallel inerter.

Improvement of the lateral stability of vehicle suspension incorporating inerter

As a newly proposed two terminals mechanical element, inerter has been successfully applied in vehicle suspension system to improve its vertical vibration isolation performance. The novelty of this paper is to explore the advantages of lateral stability of vehicle suspension by the use of inerter element. A full car model considering the steering condition is built, and the standard fishhook steering input is chosen to test the lateral stability of the suspension system. By considering the ride comfort performance and the rollover resistance performance, three basic suspension layouts incorporating inerter element are optimized by means of genetic algorithm. Constraints of the suspension working space and road holding ability are also taken into account during the optimization. Two steering input condition, namely the sine-steer input and the fishhook steer input are performed to evaluate the vehicle suspension performance. Results show that, the ride comfort and the lateral stability of the vehicle suspension system can be synchronously improved by including the inerter element.

Performance improvement of passive suspension of vehicles using position dependent damping

This paper presents the analysis of position dependent damping (PDD) and a methodology for estimation of its parameters for passive suspension of vehicles. The time domain simulation of a quarter-car model with non-linear PDD is performed over the generated random road profile for different forward speeds of vehicle. The time domain response is transformed to frequency domain power spectral density (PSD) and root mean square (RMS) response is determined. Also, the time domain simulation with half sine bump is performed to obtain the bump response spectrum to evaluate the performance of vehicle suspension to transient road excitation. The performance of passive suspension with PDD is compared with that of linear damping in terms of ride comfort, suspension travel and road holding ability. It is shown that the concept of PDD has potential to improve the performance of vehicle suspension by minimising the well-known ride-handling conflict associated with passive suspensions.

Performance improvement of passive suspension of vehicles using position dependent damping

This paper presents the analysis of position dependent damping (PDD) and a methodology for estimation of its parameters for passive suspension of vehicles. The time domain simulation of a quarter-car model with non-linear PDD is performed over the generated random road profile for different forward speeds of vehicle. The time domain response is transformed to frequency domain power spectral density (PSD) and root mean square (RMS) response is determined. Also, the time domain simulation with half sine bump is performed to obtain the bump response spectrum to evaluate the performance of vehicle suspension to transient road excitation. The performance of passive suspension with PDD is compared with that of linear damping in terms of ride comfort, suspension travel and road holding ability. It is shown that the concept of PDD has potential to improve the performance of vehicle suspension by minimising the well-known ride-handling conflict associated with passive suspensions.

Fluid flow modeling of a four-stage damping adjustable shock absorber and its experimental research

PurposeIn order to improve the ride comfort of vehicle suspension, this paper first proposed a shock absorber with four-stage adjustable damping forces. The purpose of this paper is to validate its modeling and characteristics, indicator diagrams and velocity diagrams, which are the main research points.Design/methodology/approachIn order to validate the fluid flow modeling, a series of mathematical modeling is established and solved by using Matlab/Simulink. An experiment rig based on electro-hydraulic loading servo system is designed to test the prototype. Finally, indicator diagram and velocity diagram are obtained and compared both in simulation and experiments.FindingsResults indicate that at the same damping position, damping force will increase with the rise of rod’s velocity: if the rod’s velocity is fixed, the damping force changes apparently by altering the damping position. The shock absorber is softest at damping position 1, and it is hardest at damping position 4; although there is no any badly empty stroke and skewness in indicator diagram by simulation, a temporary empty stroke happens at maximum displacement of piston rob, both in rebound and compression strokes.Research limitations/implicationsCompared with results of the simulation and experiments, the design of a four-stage damping adjustable shock absorber (FDASA) is validated correctly in application, and may improve the overall dynamic performance of vehicle.Originality/valueThis paper is mainly focused on the design and testing of an FDASA, which may obtain four-stages damping characteristics, that totally has a vital importance to improve the performance of vehicle suspension.

Influence of fluid inerter nonlinearities on vehicle suspension performance

An ideal inerter has been widely used in various vibration isolation fields. Due to its mechanical construction, some nonlinear properties of the inerter need to be taken into consideration. This a...

L2 gain state derivative feedback control of uncertain vehicle suspension systems

This paper is concerned with the design of a robust L2 gain state derivative feedback controller for an active suspension system. An uncertain quarter vehicle model is used to analyze vehicle suspension performance. Parametric uncertainty is assumed to exist in sprung mass, tire stiffness and suspension damping coefficients. Polytopic type state space representation is used to enable robust controller design via a linear matrix inequalities (LMIs) framework. Then nominal and robust L2 gain state derivative feedback controllers having bounded controller gains and robust L2 gain state feedback controllers are tested against ISO2631 random road disturbances with different road grades and vehicle horizontal velocities. Simulation results show that the proposed robust L2 gain state derivative feedback controller is very effective in improving ride comfort without deterioration on road holding ability.