Validation of Simulation of Nonlinear Passive Vehicle Suspension System (original) (raw)
Related papers
2012
The objectives of this study are to obtain a mathematical model for the passive and active suspensions systems for quarter car model. Current automobile suspension systems using passive components only by utilizing spring and damping coefficient with fixed rates. Vehicle suspensions systems typically rated by its ability to provide good road handling and improve passenger comfort. Passive suspensions only offer compromise between these two conflicting criteria. Active suspension poses the ability to reduce the traditional design as a compromise between handling and comfort by directly controlling the suspensions force actuators. In this study, the Linear Quadratic Control (LQR) technique implemented to the active suspensions system for a quarter car model. Comparison between passive and active suspensions system are performed by using different types of road profiles. The performance of the controller is compared with the LQR controller and the passive suspension system.
International Journal of Advanced Technology and Engineering Exploration
The purpose of the car suspension was to enhance the safety and comfortability to the driver when driving car in the road or highway. Car suspension was a system of spring or shock absorbers connecting between the wheels and axles to the chassis of a car. In this study, the comparison between mathematical modelling and experimental work for the ride performance of a passive quarter car model suspension system was showed and discussed. The mathematical modelling of double passive quarter car model suspension system was formulated and solved numerically using the second-order linear differential equation. The outputs from the Mathematical Modelling were plotted using MATLAB software. The vertical displacement was produced from the mathematical modelling was at 0.015 m identified as a maximum point while the minimum point was at-0.015 m. The vertical displacements from the experimental work were at 0.02 m and-0.03 m at the minimum point. The comparison showed the oscillation of vertical displacement for the mathematical modelling and the experimental work were identical. All displacements were produced by the mathematical modelling tend to close to its mean which was 0.000176 m (almost zero). When the zero displacement achieved, less-vibration was occurred. Due to the finding, the mathematical modelling has showed some potentials to be further explored especially for predicting the suspension system model.
The three main objectives that a suspension system of an automobile must satisfy are ride comfort, vehicle handling and suspension working space. Ride comfort is directly related to the vehicle acceleration experienced by the driver and the passengers. Lesser vertical acceleration, higher is the level of comfort. The aim of the Project was to design and analyze the semi active suspension system models using skyhook, ground hook and hybrid control for quarter car. The project work includes modeling of semi-active suspension system in MATLAB simulink, using 2 degree of freedom quarter car model. The skyhook on-off, ground hook and hybrid control strategies were designed using control laws stated in literatures. Simulated results have been compared with passive system for time response analysis of body vertical displacement and vertical displacement of quarter car. Simulation was carried out for various road conditions such as random road excitation, road bump excitation, step input etc. The simulated results for quarter car model are shows similar trends and within range when compared with reference research paper.
Modelling and simulation of motor vehicle suspension system
IOP Conference Series: Materials Science and Engineering, 2021
In this work, using a quarter-car model was adopted, the equations of motion were derived for a passive and then the sky-hook semi-active suspension systems. The derived differential equations, solved using the Dormand-Prince pair numerical formula, was then used to simulate values of displacements as affected by damping coefficients and the sky-hook constant. The simulated results showed that the maximum amplitude of the sprung mass, which is linked to ride discomfort, increases while those of unsprung masses, which affects the road holding ability, decreases with increasing depth of pothole. Furthermore, displacements for both sprung and unsprung masses varied directly with damping coefficient. Finally, as the sky-hook constant of the semi active system model increases, values of amplitudes of unsprung masses decreases while those of sprung masses increases. It was, thus, shown that the vertical displacements of vehicle bodies and wheels are dependent on the depth of potholes, dam...
International Journal of Modelling, Identification and Control, 2009
Several control policies of semi-active system, namely skyhook, groundhook and hybrid controls are presented using a half-car model, as a continuation of the previous work on quarter-car model. Their ride comfort, suspension displacement and road-holding performances are analysed and compared with passive system. The analysis covers both transient and steady state responses in time domain and transfer function in frequency domain. The results show that the hybrid control policy yields better comfort than a passive suspension, without reducing the road-holding quality or increasing the suspension displacement for typical passenger cars. The hybrid control policy is also shown to be a better compromise between comfort, road-holding and suspension displacement than the skyhook and groundhook control policies.
The suspension system plays a major role in any automobile as far as the vehicle stability and ride comfort of the passengers are considered. In conventional or passive suspension systems performance parameters like ride comfort, road holding and suspension travel, are mutually contradicting while active suspension system has the potential to improve these factors. The present work aims to study a full vehicle model having passive and active suspension system subjected to random road profile as per ISO standards. The linear quadratic controller (LQR) is used for active suspension system. Using optimization procedure the actuator force, which minimizes the performance index is determined. Passenger ride comfort is directly related to the passenger seat acceleration and road holding relates to wheel displacement and suspension travel. The active suspension system performance is compared with passive suspension system subjected to random road profile. Results show passenger bounce and acceleration are reduced drastically in active suspension system indicating improvement in both road holding and comfort.
suspensıons, 2018
Quarter-car model is in use for years to study the car dynamics. The objection of this paper is to examine the dynamics of a car passing a circular hump for sake maintaining ride comfort for the passengers. Passive suspension elements are considered with suspension damping coefficient in the range 1 to 15 kNs/m. Car speed in the range 5 to 25 km/h is considered when passing the hump. Important phenomenon evolved from the analysis of the car dynamics which is performed using MATLAB. The mathematical model of the quarter-car model is derived in the state form and the dynamics are evaluated in terms of the sprung mass displacement and acceleration. The effect of suspension damping and car speed on the sprung-mass displacement and acceleration is examined. The study shows that for ride comfort the car speed has not to exceed 6.75 km/h when passing a circular hump depending on the suspension damping. .
Performance Evaluation of Active Suspension for Passenger Cars Using MATLAB
The aim of this study are to obtain a mathematical model for the passive and active suspension systems for quarter car model and construct an active suspension control for a quarter car model subject to excitation from a road profile using PID controller. Current automobile suspension systems using passive components only by utilizing spring and damping coefficient with fixed rates. The purpose of the suspension system is to improve passenger comfort while providing good road handling characteristics subject to different road profile. Passive suspensions only offer compromise between these two conflicting criteria. Active suspensions possess the ability to reduce the traditional design as a compromise between handling and comfort by directly controlling the suspensions force actuators. In this study, the active suspension system is proposed based on the Proportional Integral Derivative (PID) control technique for a quarter car model for the enhancement of its road handling and comfort. Comparison between passive and active suspensions system are performed by using road profile as an input. The performance of the active suspension system is evaluated by comparing it with passive suspension system. The performance of these will be determined by performing computer simulations using the MATLAB and SIMULINK toolbox. The simulation is enhanced with 3-D animation of car going on bump created in VRML.
Simulation of Active Suspension System for Half Vehicle Model under Different Road Profile
University of Thi-Qar Journal for Engineering Sciences
The main function of the vehicle suspension system is to provide comfort for passengers, road handling and vehicle stability. This paper proposes the application of PID controller (proportional, integral and derivative controller) for active suspension system of a half automobile model using MATLAB / SIMULINK. Time domain simulations are carried out to test the performance of the suspension system under different types of road profiles which are the primary inputs of the system. In this paper, three types of road profile inputs (bump, sine wave, random wave) are introduced to excite the suspension system. According to these road profile inputs, the performance response of passive and active suspension systems is simulated. Simulation results show that there is a significant improvement in the performance of the active system over the passive one.
Design and Development of a Suspension System for Vehicles
This paper aims to design a controller for a vehicle active suspension system of an automobile. The vehicle cab motion is limited to heave in the y-direction and a small amount of pitch u of the vehicle’s longitudinal axis. The tires are assumed to remain in contact with the road surface at all times. Vehicle is subjected to random excitation due to road unevenness and variable velocity and sometimes due to speed bumps. The system has three translational degree of freedom. Based on the degree of freedom, from a rider’s comfort point of view the damping parameters and spring stiffness are adjusted to fit the criteria of a less bumpy ride. For controlling the vehicles degree of movement, the controller is designed based on Proportional controller, PID Controller, and pole placement. For the purpose of analysis, this paper only deals with the linear part of the system and excludes non-linear portion from the equation. The result shows that the response of the controlled suspension system can trace the input signal that is the PID controller is successfully able to control the variable shock absorber in order to eliminate the road surface disturbances effect to the car body.