Road Vehicle Suspension System Research Articles

Multi-fidelity surrogate-based optimal design of road vehicle suspension systems

Ride comfort is a relevant performance for road vehicles. The suspension system can filter vibration caused by the uneven road to improve ride comfort. Optimization of the road vehicle suspension system has been extensively studied. As detailed models require significant computational effort, it becomes increasingly important to develop an efficient optimization framework. In this work, a multi-fidelity surrogate-based optimization framework based on the Approximate Normal Constraint method and Extended Kernel Regression surrogate modeling method is proposed and applied. An analytical model and a multi-body model of the suspension system are used as the low-fidelity and high-fidelity models, respectively. Compared with other well-known methods, the proposed method can provide good accuracy and high efficiency. In addition, the proposed method is applied to different types of vehicle suspension optimization problems and shows good robustness and efficiency.

Emerging approaches for nonlinear parameter varying systems

Emerging approaches for nonlinear parameter varying systems

A nonlinear parameter varying observer for real‐time damper force estimation of an automotive electro‐rheological suspension system

AbstractThis paper proposes a nonlinear parameter varying (NLPV) observer to estimate, in real‐time, the damper force of an electrorheological (ER) damper in a road vehicle suspension system. The objectives are to minimize the effects of bounded unknown road profile disturbances and measurement noises on the estimation errors in the framework. Furthermore, the nonlinearity coming from the damper model (and considered in the observer formulation) is handled through a Lipschitz condition. The observer inputs are data given by two low‐cost sensors (two accelerometers data from the sprung mass and the unsprung mass). For performance assessment, the observer is implemented on a 1/5‐scaled real vehicle testbench of GIPSA‐lab, namely INOVE (see www.gipsa‐lab.fr/projet/inove). Both simulation and experimental results demonstrate the effectiveness of the proposed observer in terms of the ability to estimate the damper force in real‐time and to minimize the effects of measurement noises and road disturbances.

Real-time Damper Force Estimation of Vehicle Electrorheological Suspension: A NonLinear Parameter Varying Approach

This paper proposes a nonlinear parameter varying (NLPV) observer to estimate in real-time the damper force of an electrorheological (ER) damper in road vehicle suspension system. First, a nonlinear quarter-car model equipped with the dynamic nonlinear model of ER damper is presented, which captures the main behavior of the suspension system. The estimation method of the damper force is developed using a NLPV observer whose objectives are to minimize the effects of bounded unknown road profile disturbances and measurement noises on the estimation errors in the H∞ framework. Furthermore, the nonlinearity coming from damper model (and considered in the observer formulation) is handled through a Lipschitz condition. The observer inputs are given by two low-cost sensors data (two accelerometers data from the sprung mass and the unsprung mass). For performance assessment, the observer is implemented on the INOVE testbench of GIPSA-lab (1/5-scaled real vehicle). Both simulation and experimental results demonstrate the effectiveness of the proposed observer in terms of the ability of estimating the damper force in real-time and of minimizing the effects of measurement noises and road disturbances.

Golden Section Search Based Optimization of Road Vehicle Suspension System

Suspension system is an important part of a vehicle which connects the road wheels and vehicle body. The major function of suspension is to isolate vehicle body from road disturbances. The design of suspension system is generally a compromise between many design requirements that aim to provide a comfortable ride and good vehicle handling. An optimization technique is used to choose the suspension parameters that meet these design requirements. In this present work a two degree of freedom quarter car vehicle vibration model is considered for optimization. Sprung mass acceleration and relative displacement of quarter car are considered as the measure of ride comfort and vehicle handling respectively. Golden section search optimization technique is used for single objective optimization of quarter car considering sprung mass acceleration as objective function and relative displacement as constraint. It is noticed that the accuracy level in getting the optimized value using this approach is comparatively high and reliable..

Indoor testing of road vehicle suspensions

The paper presents a method for the indoor testing of road vehicle suspension systems. A car suspension is positioned on a rotating drum located in the Laboratory for the Safety of Transport at the Politecnico di Milano and it is excited as the wheel passes over a cleat fixed on the drum. The wheel accelerations, displacements and the forces/moments acting at the suspension-chassis joints are measured in the frequency range 0–120 Hz. Five special six-axis load cells have been designed and used. Transient wheel motions have been recorded. The influence of the running conditions on the relevant performance indexes related to the vibration behavior of the tire/suspension system has been assessed.

On the Testing of Vibration Performances of Road Vehicle Suspensions

Both a test rig and a method are presented for the indoor testing of vibration performances of road vehicle suspension systems. A suspension (corner) has been positioned on a rotating drum (2.6 m diameter) placed in the Laboratory for the Safety of Transport of the Politecnico di Milano. The suspension system is excited by means of cleats fixed to the working surface of the rotating drum. The forces and the moments acting at the suspension-chassis joints are measured in the frequency range 0–120 Hz. Five special six-axis load cells have been conceived, manufactured, calibrated and employed. Transient wheel motions have been recorded. The influence of the vehicle speed on the relevant vibration performance indexes has been assessed. An approach for the identification of the suspension damping characteristics is introduced. A full and accurate characterization of a vehicle suspension system has been performed.

Road Vehicle Suspension System Design - a review

SUMMARY Based mainly on English language literature, information relating to the design of automobile suspension systems for ride comfort and control of wheel load variations for frequencies below body structure resonances is reviewed. The information is interpreted in the context of vehicles which travel through a wide speed range on roads of markedly differing quality, which do so carrying different loads and which are required to possess good handling qualities. Sections are devoted to describing road surfaces, modelling vehicles and setting up performance criteria, and to passive, active, semi-active and slow-active system types. Methods for deriving active system control laws are outlined. Strengths and weaknesses of the various systems are identified and their relative performance capabilities and equipment requirements are discussed. Attention is given to adaptation of the suspension or control system parameters to changing conditions. Remaining research needs are considered.

DISCUSSION NOTE on Karnopp's article “Active Damping in Road Vehicle Suspension Systems”

(1983). DISCUSSION NOTE on Karnopp's article “Active Damping in Road Vehicle Suspension Systems”. Vehicle System Dynamics: Vol. 12, No. 6, pp. 313-315.

Active Damping in Road Vehicle Suspension Systems

ABSTRACT Low order, linearized dynamic models of road vehicle suspension systems are analyzed to provide insight into the benefits of suspensions incorporating generalized velocity feedback compared with conventional passive suspensions. Damping forces from passive dampers are supplemented by forces generated by an active element requiring a power supply. A simple criterion is developed which indicates whether or not the introduction of activedamping forces will result in significant benefit for pneumatic tired vehicles. An extended active suspension concept involving a high-gain load leveler as well as active damping is analyzed. The realization of active or semi-active damping forces through electrical or hydraulic means is briefly discussed.

An optimized speed-controlled suspension of a 2-DOF vehicle travelling on a randomly profiled road

The spring and damper stiffnesses of a road vehicle suspension system are optimized with respect to both ride comfort and road holding. As the input from the road profile varies with the vehicle speed, optimized suspension parameters are dependent on this speed. The optimized active suspension system obtained is compared with a corresponding passive system where the constant suspension parameters coincide with those of the active system at a selected fixed speed (20 m/s).