• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.178.4-178
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• 2001

In this paper a self-tuning gain-scheduled skyhook control for semi-active suspension systems is investigated. The dynamic characteristics of a continuously variable damper including electro-hydraulic pressure control valves is analyzed. A 2-d.o.f. time-varying quarter-car model that permits variations in sprung mass and suspension spring coefficient is considered. The self-tuning skyhook control algorithm proposed in this paper requires only the measurement of body acceleration. The absolute velocity of the sprung mass and the relative velocity of the suspension deflection are estimated by using integral filters. The skyhook gains are gain-scheduled in such a way that the body acceleration and the dynamic tire force are optimized. An ECU prototype ...

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.3
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• pp.177-185
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• 2016

This paper presents a method to design a controller for active suspension with 1-DOF decoupled models. Three 1-DOF decoupled models describing vertical, roll and pitch motions are used to design a controller in order to generate a vertical force, roll and pitch moments, respectively. These control inputs are converted into active suspension forces with geometric relationship. To design a controller, a sliding mode control is adopted. Frequency domain analysis and simulation on vehicle simulation software, CarSim$^{(R)}$, show that the proposed method is effective for ride comfort.

• Journal of Mechanical Science and Technology
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• v.17 no.9
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• pp.1287-1296
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• 2003

In this paper the dynamic analysis of the Macpherson strut motor-vehicle suspension system is presented. The equations of motion are formulated using a two-step transformation. Initially, the equations of motion are derived for a dynamically equivalent constrained system of particles that replaces the rigid bodies by applying Newton's second law The equations of motion are then transformed to a reduced set in terms of the relative joint variables. Use of both Cartesian and joint variables produces an efficient set of equations without loss of generality For open chains, this process automatically eliminates all of the non-working constraint forces and leads to an efficient solution and integration of the equations of motion. For closed loops, suitable joints should be cut and few cut-joints constraint equations should be included for each closed chain. The chosen suspension includes open and closed loops with quarter-car model. The results of the simulation indicate the simplicity and generality of the dynamic formulation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.847-851
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• 1996

In this study, in order to adapt various types of suspensions that is not possible for a passenger car, and to validate the effect of the design change of a suspension upon ride and handling characteristics of vehicle, the modular experimental vehicle, which makes possible to exchange suspension systems, has been designed and developed. In order to enable the assemblage between the modules, the experimental vehicle design is based on a space frame construction through finite element analysis. Moreover, the module frames and the brackets are designed are designed using three- dimensionalsolid modeler to check the interference between each part of a vehicle. The results of simulation and experiment are compared.

• Journal of Power System Engineering
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• v.13 no.1
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• pp.26-32
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• 2009

This study is about roll characteristics evaluation to show the advantage of using MR(magneto-rheological) dampers for steering of a SUV(sports utility vehicle). Roll characteristics is very important to observe the roll-propensity of the SUV. ADAMS/Car program was used to simulate the basic steering motion, using 63 D.O.F. vehicle model. Sky-Hook and Ground-Hook control algorithms were used as a semi-active suspension system controller. The roll characteristics from the steering motion were compared between the simulation results from the semi-active suspension system and the passive suspension system.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.2
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• pp.67-73
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• 2010

In this study, a camber angle generating mechanism for rear suspension is suggested. An experimental device is implemented and tested. A full vehicle model with camber angle generating device by using ADAMS/Car is modeled. Rear left wheel and rear right wheel have 5 different camber angles in the simulations, respectively. Step steer and pulse steer simulations are carried out for investigating the effects of vehicle handling performance due to camber angle control of rear suspension. According to the results, the camber angle of rear suspension affects the vehicle handling performance during both simulations. Therefore, when the vehicle makes the right turn or left turn, left and right wheel should have the proper orientation for improving the handling performance, respectively.

• Journal of KSNVE
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• v.7 no.2
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• pp.239-246
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• 1997

This paper presents an active suspension control algorithm to improve the suspension performance trade-offs between riding comfort and handling stability. In this paper, a hybrid control scheme is proposed, the idea of which is that sliding mode control is used for nonlinear hydraulic system and the skyhook control is applied to control the vehicle behavior. The parameter variations in hydraulic system are considered for the robust controller design. The performance of the proposed control method is evaluated by simulation and experiments based on a half car roll model which can reveal both heave and roll behavior.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.2
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• pp.150-158
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• 2002

Through experimental works, the damping force vibration problem was investigated, which results from valve and surge pressure in the oil return line of the hydraulic circuit of an active suspension system in a passenger cu. Experiments were carried out under passive system, where an orifice valve was closed and non-active system, where an orifice valve was opened, using a pressure control valve controlled by solenoid. The effects of parameters of the valve overlap and accumulator on smoothing surge pressure was elucidated. It was proved that the apparent variation of damping force due to the overlap amount of pressure control valve is the most important factor to control the damping force variation. The procedure of the experimental works shows the development process of a proportional pressure control valve in the hydraulics system of an active suspension system of passenger car.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.6
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• pp.23-29
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• 2011

In this study, a camber angle generating mechanism for front and rear suspension is suggested. An experimental device is implemented and tested. A full vehicle model with camber angle generating device by using ADAMS/Car is modeled. Step steer simulations are carried out for investigating the effects of vehicle handling performance due to camber angle change of front and rear wheel. According to results, the camber angle of rear suspension affects the vehicle handling performance during both simulations. Therefore, when the vehicle makes the right turn or left turn, left and right wheel of front and rear suspension should have the proper orientation for improving the handling performance, respectively.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.50 no.3
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• pp.120-129
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• 2001

A two-degree-of-freedom quarter-car model is used as the basis for LQ and the proposed controller design for a semi-active suspension. The LQ controller results in the best rms performance trade-offs(as defined by performance index) between ride, handling and packaging requirements. In LQ controller, however, the conflict between road holding and ride comfort remains. The adaptive semi-active suspension control based on the road frequency are introduced in this paper. With this method, the trade-off between road holding and ride comfort can be relaxed. The road frequency is estimated by wavelet transform if rattle space signal. The simulation results show that the proposed controller is superior to the conventional LQ controller.