Control of Suspensions for Vehicles With Flexible Bodies—Part II: Semi-Active Suspensions

1996 ◽  
Vol 118 (3) ◽  
pp. 518-525 ◽  
Author(s):  
Aleksander Hac´ ◽  
Iljoong Youn ◽  
Hsien H. Chen
Keyword(s):  
Time Delays ◽  
Control Strategies ◽  
Structural Response ◽  
Vehicle Body ◽  
Structural Vibrations ◽  
Active Suspensions ◽  
Suspension Systems ◽  
Active Suspension Systems ◽  
Sufficient Distance ◽  
Control Forces

Two methods of control of semi-active suspensions that specifically address the problem of structural vibrations of the vehicle body are considered. These control strategies are based on those developed for active suspension systems in Part I of this study and rely on either modifications of suspension control forces that account for body compliance or on the addition of a proof-mass actuator to reduce structural vibrations. A half-car model that includes body compliance is used to evaluate the effects of these control strategies on the performance of the suspensions with two-state and continuously modulated dampers. The performances of the systems are evaluated in both the time and frequency domains. The effect of time delays in the process of actuating the adjustable dampers is investigated. Significant reductions of structural vibrations are observed when the nodes of body beaming modes are a sufficient distance away from the suspension mounting points, and the time delays in the control system are negligible. The results deteriorate markedly when two-state dampers are used instead of continuously variable dampers or when a time delay in excess of 5 ms is present in the control loop. When the preference in suspension design shifts toward road holding it becomes increasingly difficult to improve the vehicle structural response without sacrificing other aspects of performance.

scholarly journals Control of Automotive Semi-Active MR Suspensions for In-Wheel Electric Vehicles

2020 ◽  
Vol 10 (13) ◽  
pp. 4522 ◽  
Author(s):  
Mauricio Anaya-Martinez ◽  
Jorge-de-J. Lozoya-Santos ◽  
L.C. Félix-Herrán ◽  
Juan-C. Tudon-Martinez ◽  
Ricardo-A. Ramirez-Mendoza ◽  
...  
Keyword(s):  
Internal Combustion Engine ◽  
Electric Vehicles ◽  
Combustion Engine ◽  
Control Strategies ◽  
Vertical Control ◽  
Suspension Systems ◽  
Full Vehicle ◽  
Active Suspension Systems ◽  
Resonance Frequencies ◽  
Suspension Performances

In this work, four different semi-active controllers for a quarter of vehicle and full vehicles are evaluated and compared when used in internal combustion engine (ICE) vehicles vs electric vehicles (EVs) with in-wheel motor configuration as a way to explore the use of semi-active suspension systems in this kind of EVs. First, the quarter of vehicle vertical dynamics is analyzed and then a full vehicle approach explores the effectiveness of the control strategies and the effects of the traction in the vertical Control performances. Aspects like the relation between traction and suspension performances, and the resonance frequencies are also discussed.

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.

Fault-tolerant control with state and disturbance observers for vehicle active suspension systems

2020 ◽  
Vol 234 (7) ◽  
pp. 1912-1929
Author(s):  
Baek-soon Kwon ◽  
Daejun Kang ◽  
Kyongsu Yi
Keyword(s):  
Ride Comfort ◽  
Fault Tolerant ◽  
Fault Tolerant Control ◽  
Active Suspension ◽  
Vehicle Body ◽  
Control Input ◽  
Suspension Systems ◽  
Active Suspension Systems ◽  
Fault Compensation ◽  
Fault Mode

This paper deals with the design of a fault-tolerant control scheme of active suspension systems for vehicle ride comfort. Unknown actuator failures from a variety of reasons cause performance deterioration of the active suspension controller. The proposed fault-tolerant control algorithm consists of two parts: a compensation for actuator failure and a fault mode selector. The main function of the fault compensation strategy is to estimate and compensate for the loss of effectiveness of the actuators. A suspension state observer and a disturbance observer operate simultaneously to determine the feedback control input. The controller and observer have been developed based on a reduced full-car dynamic model that contains only the vehicle body dynamics. The main advantage of the proposed observer is that an easily accessible and inexpensive measurement is only required and the effect of unknown road disturbance on the estimation error is completely removed. To cope with complete failure cases, the fault mode selector is also designed to redistribute the control input to the remaining healthy actuators. Tracking of the loss of effectiveness of the actuators is used for the fault model identification. The performance of the proposed approach has been evaluated via simulation studies. It is shown that the vehicle ride comfort in the presence of actuator faults can be improved by the proposed combined strategy of the fault compensation method and the fault mode selector.

Potentialities of Active Suspensions for the Improvement of Handling Performances

2010 ◽  
Author(s):  
Francesco Braghin ◽  
Alessandro Prada ◽  
Edoardo Sabbioni
Keyword(s):  
Load Transfer ◽  
Ride Comfort ◽  
Control Strategies ◽  
Active Suspension ◽  
Suspension Spring ◽  
Suspension Systems ◽  
Active Suspension Systems ◽  
In Series ◽  
High Bandwidth ◽  
Damper Control

Active and semi-active suspension systems are widely diffused into the automotive industry and several control strategies have been proposed in the literature both concerning ride comfort and handling. The capability of several suspension active control systems in enhancing the vehicle handling performances are compared in this paper. In particular, a low-bandwidth active suspension (actuator in series with the suspension spring), an active antiroll bar, an active camber suspension and a semi-active high-bandwidth suspension (closed loop damper control) are considered. The benchmark is represented by an ideal vehicle which does not present any load transfer and has no yaw moment of inertia. The possibility of combining more than one active/semi-active suspension system is also discussed.

An experimental and theoretical investigation into the design of an active suspension system for a racing car

1997 ◽  
Vol 211 (3) ◽  
pp. 161-173 ◽  
Author(s):  
D. J. Purdy ◽  
D. N. Bulman
Keyword(s):  
Active Suspension ◽  
Open Loop ◽  
Suspension System ◽  
Active System ◽  
Ride Height ◽  
Active Suspensions ◽  
Suspension Systems ◽  
System A ◽  
Active Suspension Systems ◽  
The Difference

The well-established quarter car representation is used to investigate the design of an active suspension system for a racing car. The work presented is from both a practical and theoretical study. The experimental open-loop and passive responses of the suspension system are used to validate the model and estimate the level of damping within the system. A cascade control structure is used, consisting of an inner body acceleration loop and an outer ride height loop. Comparisons are made between the experimental results and those predicted by the theory. During the 1980s and early 1990s a number of Formula 1 teams developed active suspension systems to improve the performance of cars. Little detail was published about these systems because of the highly competitive nature of the application. Some of these systems were very sophisticated and successful. Because of this, speed increased considerably and because of the costs involved, the difference in performance between the lower and higher funded teams became unacceptable. For this reason, the governing body of motor sport decided to ban active suspensions from the end of the 1993 racing season. Both authors of this paper were involved with different racing teams at that time, and this paper is an introduction to the very basic philosophy behind a typical active system that was employed on a Formula 1 car.

Fixed-Order Controller Design for a High Speed Railway Vehicle

2017 ◽  
Author(s):  
Semiha Türkay ◽  
Aslı S. Leblebici ◽  
Hüseyin Akçay
Keyword(s):  
High Speed ◽  
Degrees Of Freedom ◽  
Transfer Functions ◽  
Controller Design ◽  
Railway Vehicle ◽  
Active Suspensions ◽  
Suspension Systems ◽  
Active Suspension Systems ◽  
Smooth Optimization ◽  
Order Restricted

Advanced active suspension systems has attracted considerable attention in modern railway vehicle designs in recent years. The purpose of the suspension is to attenuate the vehicle vibrations due to various rail excitations. With active suspensions it is aimed to improve the performance in some cases, while not making it worse in others. The performance-related objectives can be approximately translated in different norm bounds on certain transfer functions or impulse responses. In this paper, a multi-objective problem is formulated as a non-convex and non-smooth optimization problem for a full-car railway vehicle modelled with seventeen-degrees-of-freedom (17 DOF) and excited by random rail inputs. The controller order restricted to be less than or equal to the passive system model order. For a range of orders, controllers are synthesized by using the HIFOO toolbox.

Performance Evaluation of Motor Vehicle Active Suspension Systems

1987 ◽  
Vol 201 (2) ◽  
pp. 135-148 ◽  
Author(s):  
B B Hall ◽  
K F Gill
Keyword(s):  
Performance Evaluation ◽  
System Performance ◽  
Closed Loop ◽  
Motor Vehicle ◽  
Passive Systems ◽  
Active Suspensions ◽  
Suspension Systems ◽  
Active Suspension Systems ◽  
Performance Results ◽  
Pole Location

The essential features and potential of active suspensions are presented and selected systems are examined to relate the effects of closed-loop pole location to system performance. Results are compared with those for well-designed passive systems.

Research on Optimal Control and Simulation for Active Suspension Systems

2013 ◽  
Vol 340 ◽  
pp. 631-635
Author(s):  
Yong Fa Qin ◽  
Jie Hua ◽  
Long Wei Geng
Keyword(s):  
Optimal Control ◽  
Ride Comfort ◽  
Mathematic Model ◽  
Active Suspension ◽  
Suspension System ◽  
Vehicle Body ◽  
Vertical Acceleration ◽  
The Road ◽  
Suspension Systems ◽  
Active Suspension Systems

Vehicles with active suspension systems become more ride comfort and maneuverable stability, many types of active suspensions have been applied to passenger vehicles, but one of the shortcomings of an active susupension system is that the additional control power consumption is needed. The core issues of designing an active suspension system are to minimiaze vibration magnitute and control energy comsuption of the active suspension system. A new mathematic model for an active suspension system is established based on vehicle dynamics and modern control theory. An optimal control law is constructed through solving the Riccati equation, and then the transfer function is deduced to describe the relationship between the vetical velosity of the road roughness and the output of suspension system. Three typical parameters of vehicle ride comfort are researched, such as vertical acceleration of vehicle body, dynamic deflection of suspension system and dynamic deformation of tires. A case of a quarter vehicle model is studied by simulation to show that the proposed method of modeling and designing optimal controller are suitable to develop active suspension systems.

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.

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