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.

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.

Active Suspension Systems With Optimal Jerk Control

2006 ◽  
Author(s):  
M. Taghipour ◽  
D. Shahriari ◽  
A. Shahsavari
Keyword(s):  
Performance Index ◽  
Active Suspension ◽  
Suspension System ◽  
The Body ◽  
Ride Quality ◽  
Suspension Systems ◽  
Car Model ◽  
Active Suspension Systems ◽  
Ricatti Equation ◽  
The Cost

An active suspension system should be designed/optimized in conjunction with the tradeoff between ride and handling. In recent years, jerk as a measure of ride quality is considered in performance index. In this paper, effects of jerk in active suspension system for a 1/4 car model is investigated. In contrast to the previous papers, the body acceleration and jerk are derived directly from the system Hamiltonian instead of solving Ricatti Equation. The result shows that a reduction of jerk and acceleration is obtained against a higher rattle space and tire deflection. The compromise/tradeoff can be managed by setting appropriate weights in the cost function.

A Fuzzy Logic Controller for Vehicle-Active Suspension Systems

2013 ◽  
Vol 805-806 ◽  
pp. 1645-1649 ◽  
Author(s):  
Yun Quan Sun ◽  
Li Feng Zhao ◽  
Wei Xiang
Keyword(s):  
Fuzzy Logic ◽  
Fuzzy Logic Controller ◽  
Ride Comfort ◽  
Active Suspension ◽  
Suspension System ◽  
Vertical Acceleration ◽  
Suspension Systems ◽  
System A ◽  
Active Suspension Systems ◽  
The Stability

This paper propose the study of automobile active suspension system for the purpose of improving ride comfort to passengers and simultaneously improving the stability of vehicle by reducing vibration effects on suspension system. A fuzzy-logic-based control for vehicle-active suspension is suggested. The vehicle vibration and disturbance are reduced considerably with a fuzzy logic controller, to enhance comfort in riding faced with uncertain road terrains. A quarter-car active suspension system is controlled to reduce the vertical acceleration, suspension stroke and tire deflection. Simulation studies clearly demonstrate the effectiveness of the fuzzy logic controller for active suspension systems. The performance of the fuzzy logic controller under variations in the suspension component characteristics are also studied and are found to give reasonably good responses.

A research of sliding mode control method with disturbance observer combining skyhook model for active suspension systems

2019 ◽  
Vol 26 (11-12) ◽  
pp. 952-964 ◽  
Author(s):  
Wu Qin ◽  
Wen-Bin Shangguan ◽  
Kegang Zhao
Keyword(s):  
Sliding Mode Control ◽  
Disturbance Observer ◽  
Sliding Mode ◽  
Active Suspension ◽  
Suspension System ◽  
Suspension Systems ◽  
Mode Control ◽  
Active Suspension Systems ◽  
Mass Displacement ◽  
The Impact

Based on a nonlinear two-degree-of-freedom model of active suspension systems, an approach of the sliding mode control with disturbance observer combining skyhook model sliding mode control with disturbance observer combining is proposed for improving the performance of active suspension systems, and the effectiveness of the proposed approach is validated by the active suspension system plant. Two problems of active suspension systems are solved by using the proposed approach when the tire is excited by the step displacement. One problem is that the suspension deflection of active suspension systems, i.e. the difference between the sprung mass displacement and the unsprung mass displacement, using conventional sliding mode control with disturbance observer not converges to zero in finite time, and the phenomenon of the impact of suspension against the limit block is produced. This problem is solved by providing a reference value of the sprung mass displacement in an active suspension system, which is obtained from the skyhook model. The other problem is that disturbances exist in active suspension systems, which are caused by the inaccurate parameters of stiffness and damping. This problem is solved by designing a disturbance observer to estimate the summation of the disturbances. Finally, the performance indexes of the active suspension system with the sliding mode control with disturbance observer combining skyhook model are calculated and compared with those of using the conventional sliding mode control with disturbance observer and the linear quadratic regulator approach.

Guideway Camber and Three-Stage Passive Suspension for Improved Tracked Air Cushion Vehicle Ride Quality: Part II of a Parametric Study

1973 ◽  
Vol 95 (1) ◽  
pp. 86-91
Author(s):  
S. B. Biggers
Keyword(s):  
High Speed ◽  
Ride Quality ◽  
Attractive Alternative ◽  
High Quality ◽  
Passive Suspension ◽  
Suspension Systems ◽  
Active Suspension Systems ◽  
Air Cushion ◽  
Passive Suspension System

Two means of providing a high quality air cushion ride at high speed using simple passive suspension systems are investigated. The inclusion of the proper amount of camber in guideway beams is shown to greatly reduce both low and high speed heave accelerations. A three-stage passively suspended vehicle including two degrees of pitching motion is shown to eliminate the high speed peak in accelerations present with two-stage vehicles. The effects of secondary and tertiary damping, of the vehicle to span length ratio, and of guideway camber on the ride quality of this vehicle are investigated. Coupled with cambered guideway beams, the three-stage passive suspension system appears to be an attractive alternative to active suspension systems.

Control Bifurcations of a Magneto-Rheological Fluid Based Active Suspension System

2005 ◽  
Author(s):  
Amit Shukla
Keyword(s):  
Differential Equation ◽  
Nonlinear System ◽  
Center Manifold ◽  
Multiple Equilibria ◽  
Qualitative Change ◽  
Active Suspension ◽  
Suspension System ◽  
Suspension Systems ◽  
Active Suspension Systems ◽  
Magneto Rheological

Design of active suspension systems is well known, however the notion of control bifurcations for the design of such systems has been introduced recently. A nonlinear active suspension system consisting of a magneto-rheological damper is analyzed in this work. It is well known that a parameterized nonlinear differential equation can have multiple equilibria as the parameter is varied. A local bifurcation of a parameterized nonlinear system typically happens because some eigenvalues of the parameterized linear approximating differential equation cross the imaginary axis and there is a change in stability of the equilibrium. The qualitative change in the equilibrium point can be characterized by investigating the projection of the flow on the center manifold. A control bifurcation of a nonlinear system typically occurs when its linear approximation loses stabilizability. In this work the control bifurcations of a magneto-rheological fluid based active suspension system is analyzed. Some parametric results are presented with suggestions on how to design nonlinear control based on the parametric control bifurcation analysis as applied to the design of an active suspension system.

Controller Design and Road-Friendly Suspension Optimization: Half Vehicle Model

2020 ◽  
Author(s):  
Vikas Prasad ◽  
P. Seshu ◽  
Dnyanesh N. Pawaskar
Keyword(s):  
Controller Design ◽  
Active Suspension ◽  
Suspension System ◽  
Performance Criteria ◽  
Control Law ◽  
Vehicle Model ◽  
Nsga Ii ◽  
Suspension Systems ◽  
Active Suspension Systems ◽  
Active Damper

Abstract In this paper, the design of the suspension system for Heavy Goods Vehicles (HGV) is proposed, which deals with two performance criteria simultaneously. A semi-tractor trailer is used in present work and modeled with half vehicle model. Four types of linear, as well as non-linear, passive and semi-active suspension systems, are presented in this work. The control law is proposed for the semi-active suspension system using a PID controller to remove the need for passive damper along with active damper. Two objective optimization is performed using the Non-dominated Sorting Genetic Algorithm II (NSGA-II). Road Damage (RD) is taken as the first objective along with Goods Damage (GD) as the second objective. All problems are minimization problems. It is concluded based on Pareto front comparison of different suspension systems that the semi-active suspension system with the proposed control law performs well for HGV.

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.

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.

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