A new insight into modelling passive suspension real test rig system with consideration of nonlinear friction forces

Abstract

The vital purpose of a vehicle suspension system is to isolate the car body and hence passengers, from roadway unevenness disturbances. Implementation of passive suspension systems has continuously improved disconnection from disturbances through available deflection constraints to provide maximum isolation. In the majority of relevant reported research studies, a quarter car is modelled as moving vertically straight for both a viscous damper and a stiffness spring. The motivation for this study, reported here, is to extend the modelling to take account of the actual configuration of a test rig system. Accordingly, a new passive suspension system model is presented, which includes nonlinear lubricant friction forces that affect the linear support body bearings. The friction model established relies on dynamic system analysis and the fact of slipping body on lubricant bearings; this model captures most of the friction behaviours that have been observed experimentally. The suspension model is composed of a car body and wheel unit, and only vertical motion (bounce mode) is addressed. In addition, an active actuator is used to generate the system inputs as a road simulator. Therefore, a nonlinear hydraulic actuator, including the dynamic of servovalve and proportional–integral controller model, is established. This study is validated by experimental work, with simulations achieving C++compiler. As a result, a good agreement is obtained between the experimental and simulation results, that is, the passive suspension system with considered nonlinear friction and the nonlinear hydraulic actuator with servovalve equation models are entirely accurate and useful. The suggested proportional–integral controller successfully derives the hydraulic actuator to validate the control scheme. The ride comfort and handling response are close to that expected for the passive suspension system with road disturbances.

Design and investigation of pole assignment controller for driving nonlinear electro hydraulic actuator with new active suspension system model

“…This model has been able to give a more satisfactory explanation for the observation of removing the body dynamics fluctuation as was investigated by Alzughaibi et al 1 In addition, the model simulates the symmetric hysteresis loops observed at the body bearings undergoing forcing inputs. In general, this friction model considers the static, stiction region and dynamic friction, which consists of Stribeck effect, Coulomb friction and viscous friction.…”

“…The dynamic equation of motion for the mass body test rig with the consideration of the friction forces for PS system, as previously researched by Alzughaibi et al, 1 is…”

“…Because the friction has occurred at linear supported body bearings, it will, therefore, be supposed that the friction had the same behaviours as mentioned for PS. 1 However, the friction presents some differences depending on the types of input force and the quantity of vertical force according to replacement of the active hydraulic actuator instead of the spring and viscous damper (PS units). The mathematical expression for the general friction model consists of three different sectors depending on the acceleration or deceleration and direction of the body velocity, as follows…”

Influence of the Size and Distribution of Load on the Damping Coefficient of Shock Absorbers in Passenger Vehicles

“…If excessively large vibrations are transferred to the passenger space, they may cause discomfort and may be harmful to the health of drivers and passengers [12,14]. For many years, there have been attempts to provide for the best isolation of drivers and passengers from road conditions, by developing high damping coefficient shock absorbers [3,11,14]. In addition, through the construction and characteristics of shock absorbers and springs in suspensions, the goal is to decrease the frequency and amplitude of vibrations [4,7,11].…”

Assessment of adjustable damping in the ride comfort of a baja SAE vehicle

“…However, such systems have disadvantages compared to passive systems, since they present issues on cost, complexity and reliability [14][15][16][17], what still secures a wide use of passive systems for cheaper cost and reliable performance [18]. In order to make passive systems achieve a comparable level of comfort, many recent studies focus on damping properties [6,17,[19][20][21][22][23] or modified constructions [1,14,15,24], where all studies achieve a better suspension ride. More expressive results achieved a 31% reduction in sprung mass acceleration by using asymmetrical dampers [19]and obtained 20% of sprung mass acceleration reduction by the change in the bleed orifice area of the inside piston [1].…”