The Influence of Tire Damping in Quarter Car Active Suspension Models

1991 ◽  
Vol 113 (1) ◽  
pp. 134-137 ◽  
Author(s):  
J. A. Levitt ◽  
N. G. Zorka
Keyword(s):  
Damping Ratio ◽  
Active Suspension ◽  
Vertical Acceleration ◽  
Body Acceleration ◽  
Suspension Systems ◽  
Active Suspension Systems ◽  
Quarter Car ◽  
Control Forces ◽  
And Control ◽  
Suspension Models

Setting tire damping to zero when modeling automotive active suspension systems compels the misleading conclusions that, at the wheelhop frequency, no matter what forces are exerted between sprung and unsprung masses, their motion are uncoupled, and the vertical acceleration of the sprung mass will be unaffected. Alternatively, taking tire damping to be small but nonzero, the motions of the sprung and unsprung masses are coupled at all frequencies, and control forces can be used to reduce the sprung mass vertical acceleration at the wheelhop frequency. The effect of introducing tire damping can be quite large. In the case of a force law chosen to enhance ride along a straight smooth road, where road holding is not a major concern, setting the tire damping ratio to 0.02 reduces rms body acceleration by 30 percent.

Multi-Object Control of Active Suspension Subject to Parameter Uncertainties under Non-Stationary Running

2012 ◽  
Vol 224 ◽  
pp. 440-443
Author(s):  
Li Ping Zhang ◽  
Li Xin Guo
Keyword(s):  
Ride Comfort ◽  
Active Suspension ◽  
State Feedback Control ◽  
Parameter Uncertainties ◽  
Suspension Systems ◽  
Active Suspension Systems ◽  
Hard Constraints ◽  
Feedback Control Strategy ◽  
Control Forces ◽  
And Control

Based on the building of non-stationary road surface excitation mode, a study on the active suspension control under non-stationary running condition was conducted using control, state feedback control strategy for linear systems with time-domain hard constraints was propose. The proposed approach was applied to design active suspension systems on the basis of a two-degree-of-freedom quarter car mode, Simulation results show that the proposed constrained controller can achieve a promising improvement on ride comfort, while keeping dynamic suspension deflections, dynamic tire loads and control forces within given bounds, even non-stationary running.

Two-Dimensional Dynamics of Tracked Ram Air Cushion Vehicles With Fixed and Variable Winglets

1979 ◽  
Vol 101 (4) ◽  
pp. 321-331
Author(s):  
L. M. Sweet ◽  
H. C. Curtiss ◽  
R. A. Luhrs
Keyword(s):  
Active Suspension ◽  
Suspension System ◽  
Ride Quality ◽  
Vertical Acceleration ◽  
Suspension Systems ◽  
Active Suspension Systems ◽  
Air Cushion ◽  
Linearized Model ◽  
The One ◽  
Air Cushion Vehicles

A linearized model of the pitch-heave dynamics of a Tracked Ram Air Cushion Vehicle is presented. This model is based on aerodynamic theory which has been verified by wind tunnel and towed model experiments. The vehicle is assumed to be equipped with two controls which can be configured to provide various suspension system characteristics. The ride quality and dynamic motions of the fixed winglet vehicle moving at 330 km/hr over a guideway described by roughness characteristics typical of highways is examined in terms of the rms values of the vertical acceleration in the foremost and rearmost seats in the passenger cabin and the gap variations at the leading and trailing edges of the vehicle. The improvement in ride quality and dynamic behavior which can be obtained by passive and active suspension systems is examined and discussed. Optimal regulator theory is employed to design the active suspension system. The predicted rms values of the vertical acceleration in the one-third octave frequency bands are compared with the vertical ISO Specifications. It is shown that marked improvements in the ride quality can be obtained with either the passive or active suspension systems.

scholarly journals On the Benefits of Semi-Active Suspensions with Inerters

2012 ◽  
Vol 19 (3) ◽  
pp. 257-272 ◽  
Author(s):  
Xin-Jie Zhang ◽  
Mehdi Ahmadian ◽  
Kong-Hui Guo
Keyword(s):  
High Performance ◽  
Control Method ◽  
Hybrid Control ◽  
Active Suspension ◽  
Vertical Acceleration ◽  
Active Suspensions ◽  
Quarter Car Model ◽  
Suspension Systems ◽  
Car Model ◽  
Quarter Car

Inerters have become a hot topic in recent years especially in vehicle, train, building suspension systems, etc. Eight different layouts of suspensions were analyzed with a quarter-car model in this paper. Dimensionless root mean square (RMS) responses of the sprung mass vertical acceleration, the suspension travel, and the tire deflection are derived which were used to evaluate the performance of the quarter-car model. The behaviour of semi-active suspensions with inerters using Groundhook, Skyhook, and Hybrid control has been evaluated and compared to the performance of passive suspensions with inerters. Sensitivity analysis was applied to the development of a high performance semi-active suspension with an inerter. Numerical simulations indicate that a semi-active suspension with an inerter has much better performance than the passive suspension with an inerter, especially with the Hybrid control method, which has the best compromise between comfort and road holding quality.

Parametric Study on Proportional Integral Derivative Controlled Semi-Active Suspension System

2016 ◽  
Vol 8 (1) ◽  
Author(s):  
E.M Allam ◽  
M.A.A Emam ◽  
Eid.S Mohamed
Keyword(s):  
Active Suspension ◽  
Suspension System ◽  
Proportional Integral Derivative ◽  
Active System ◽  
Proportional Integral ◽  
Quarter Car Model ◽  
Suspension Systems ◽  
Working Space ◽  
Active Suspension Systems ◽  
Quarter Car

This paper presents the effect of the suspension working space, body displacement, body acceleration and wheel displacement for the non-controlled suspension system (passive system) and the controlled suspension system of a quarter car model (semi-active system), and comparison between them. The quarter car passive and semi-active suspension systems are modelled using Simulink. Proportional Integral Derivative controllers are incorporated in the design scheme of semi-active models. In the experimental work, the influence of switchable damper in a suspension system is compared with the passive and semi-active suspension systems.

Modelling and Control of an Electro-Hydraulic Active Suspension System

2013 ◽  
Vol 60 (1) ◽  
pp. 37-54 ◽  
Author(s):  
Oussama Ajala ◽  
Dieter Bestle ◽  
Jochen Rauh
Keyword(s):  
Active Suspension ◽  
Degree Of Freedom ◽  
Nonlinear Controller ◽  
Control Approach ◽  
Suspension Systems ◽  
Model Free ◽  
Active Suspension Systems ◽  
Linear Framework ◽  
And Control ◽  
Two Degree Of Freedom

Active suspension systems ease the conflict between comfort and handling. This requires the use of suitable actuators that in turn need to be efficiently controlled. This paper proposes a model-based control approach for a nonlinear suspension actuator. Firstly the concept is derived in the linear framework in order to simplify the synthesis and analysis phase. There a linear model of the actuator is proposed and discussed. Further, this design phase includes a comparison between model-free PID controllers and a newly proposed two-degree-of-freedom controller which allows one to shape reference and disturbance responses separately. Subsequently, the two-degree-of-freedom controller, which proves to be superior, is adapted to the nonlinear framework by considering a linear parameter varying representation of the nonlinear plant. Finally, the nonlinear controller is implemented in a test car confirming the concept applicability to real hardware.

H∞ Control of Active Suspension System for a Quarter Car Model

2016 ◽  
Vol 8 (1) ◽  
Author(s):  
N.M. Ghazaly ◽  
A.S Ahmed ◽  
A.S Ali ◽  
G.T Abd El- Jaber
Keyword(s):  
Ride Comfort ◽  
Active Suspension ◽  
Suspension System ◽  
Passive Suspension ◽  
Quarter Car Model ◽  
Suspension Systems ◽  
Car Model ◽  
Active Suspension Systems ◽  
Passive Suspension System ◽  
Quarter Car

In recent years, the use of active control mechanisms in active suspension systems has attracted considerable attention. The main objective of this research is to develop a mathematical model of an active suspension system that is subjected to excitation from different road profiles and control it using H∞ technique for a quarter car model to improve the ride comfort and road handling. Comparison between passive and active suspension systems is performed using step, sinusoidal and random road profiles. The performance of the H∞ controller is compared with the passive suspension system. It is found that the car body acceleration, suspension deflection and tyre deflection using active suspension system with H∞ technique is better than the passive suspension system.

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