Zero-Energy Active Suspension System for Automobiles With Adaptive Sky-Hook Damping

2013 ◽  
Vol 135 (1) ◽  
Author(s):  
Kalpesh Singal ◽  
Rajesh Rajamani

Previous research has shown that a semiactive automotive suspension system can provide significant benefits compared to a passive suspension but cannot quite match the performance of a fully active system. The advantage of the semiactive system over an active system is that it consumes almost zero energy by utilizing a variable damper whose damping coefficient is changed in real time, while a fully active suspension consumes significant power for its operation. This paper explores a new zero-energy active suspension system that combines the advantages of semiactive and active suspensions by providing the performance of the active system at zero energy cost. Unlike a semiactive system in which the energy is always dissipated, the proposed system harvests and recycles energy to achieve active operation. An electrical motor-generator is used as the zero-energy actuator and a controller and energy management system are developed. An energy adaptive sky-hook gain is proposed to prevent the system from running out of energy, thereby eliminating the need to switch between passive and active systems. The results show that the system performs at least as well as a passive system for all frequencies, and is equivalent to an active system for a broad range of frequencies including both resonant frequencies.

Author(s):  
Sorin MARCU ◽  
◽  
Dinel POPA ◽  
Nicolae-Doru STANESCU ◽  
Nicolae PANDREA

The main purpose of the suspension is to minimize vertical acceleration. Through this paper we aim to analyze two PID and LQR control techniquesto reduce system vibrations. The active system will be compared to a passive system using two types of profile. Matlab / Simulink software is used to evaluate the performance of the two controllers using a system with two degrees of freedom. The analysis shows that we can control the suspension system using the two techniques to improve the comfort and safety of the vehicle.


Author(s):  
D. J. Purdy ◽  
D. N. Bulman

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.


2016 ◽  
Vol 24 (5) ◽  
pp. 956-974 ◽  
Author(s):  
Jonathan Rodriguez ◽  
Paul Cranga ◽  
Simon Chesne ◽  
Luc Gaudiller

This paper considers experiments on the control of a helicopter gearbox hybrid electromagnetic suspension. As the new generation of helicopters includes variable engine revolutions per minute (RPMs) during flight, it becomes relevant to add active control to their suspension systems. Most active system performance derives directly from the controller construction, its optimization to the system controlled, and the disturbances expected. An investigation on a feedback and feedforward filtered-x least mean square (FXLMS) control applied to an active DAVI suspension has been made to optimize it in terms of narrow-band disturbance rejection. In this paper, we demonstrate the efficiency of a new hybrid active suspension by combining the advantages of two different approaches in vibration control: resonant absorbers and active suspensions. Here, a hybrid active suspension based on the passive vibration filter called DAVI is developed. The objective of this paper is to prove the relevancy of coupling a resonant vibration absorber with a control actuator in order to create an active suspension with larger bandwidth efficiency and low energy consumption. The simulations and experimentation achieved during this suspension system development support this hypothesis and illustrate the efficiency and low energy cost of this smart combination.


2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Yan-yang Wang ◽  
Yi-nong Li ◽  
Wei Sun ◽  
Chao Yang ◽  
Guang-hui Xu

The vibration of SRM obtains less attention for in-wheel motor applications according to the present research works. In this paper, the vertical component of SRM unbalanced radial force, which is named as SRM vertical force, is taken into account in suspension performance for in-wheel motor driven electric vehicles (IWM-EV). The analysis results suggest that SRM vertical force has a great effect on suspension performance. The direct cause for this phenomenon is that SRM vertical force is directly exerted on the wheel, which will result in great variation in tyre dynamic load and the tyre will easily jump off the ground. Furthermore, the frequency of SRM vertical force is broad which covers the suspension resonance frequencies. So it is easy to arouse suspension resonance and greatly damage suspension performance. Aiming at the new problem, FxLMS (filtered-X least mean square) controller is proposed to improve suspension performance. The FxLMS controller is based on active suspension system which can generate the controllable force to suppress the vibration caused by SRM vertical force. The conclusion shows that it is effective to take advantage of active suspensions to reduce the effect of SRM vertical force on suspension performance.


Author(s):  
Yiming Zhang ◽  
Ye Lin

Abstract This paper investigates a reference control strategy for Vehicle semi-active suspension. The control is conducted by following the idea optimal active controller. The passive actuator is set to optimal whenever the active and passive actuators have the same signs; and set to zero output whenever the two signs are opposite. The simulation results of a 2DoF vehicle show that the semi -active suspension system can follow the ideal active system very well, both are superior to conventional passive systems. In this paper, a 2DoF vehicle model was also used to study a statistical optimal control strategy of the semi-active suspension system. The statistical optimal concept is the result of the combination of the nonlinear programming and controllable damper. A way of estimating statistical characteristics of road irregularities was also proposed. Vehicle active, suspension, due to its perfect v i bra t i on isolation performance, gets moreand more attention. Active suspension can be generally divided into two categories, totally active suspension system and semi-active suspension system. From the published results it is known that active suspension can surpass the performance limit of conventional passive suspension and greatly improve the vehicle riding comfort and steering ability. But active suspension has a critical disadvantage of less applicability, due to its high cost and low reliability. Also it consumes large amount of energy as it works. The idea of semi-active suspension was put forward to overcome the shortcoming of active suspension. It is a compromise between active suspension and passive suspension. Semi-active suspension has approximately the same behavior as active suspension, and almost consumes no energy as it works. So semi-active suspension possesses a great potential in application. At. present, in the field of suspension research over the world, a great deal of attention is paied to semi-active suspension. At present, for the cotrol of semi-active suspension the widely studied strategy is “on off” control [1] [2], which is first put forward by Karnopp. “On-off” control can eliminate the phenomenon of vibration amplification for passive suspension, thus it can improve the suspension performance to certain extent. At present, no substantive result has been obtained yet in the field of optimal control of semi-active suspension. This paper will investigate a reference control strategy on the basis of linear optimal control. The control is conducted by following the optimal ctive controller. The referrence control result is optimal when the outputs of the active and semi-active force generators have the same signs.


Author(s):  
N J Leighton ◽  
J Pullen

This paper describes a novel type of active suspension based on a buckling spring element installed in an actively controlled variable leverage system. The development of the suspension system through stages of computer simulation, implementation and test is outlined, together with the test results. The suspension system does not fall into any of the established categories of active system but may be seen as fitting into a recently identified category of variably leverage systems. The system is shown to be capable of controlling a vehicle body's motion while providing excellent road input isolation and requiring input power levels of below 150 watts per wheel.


Author(s):  
Amit Shukla ◽  
Jeong Hoi Koo

Nonlinear active suspension systems are very popular in the automotive applications. They include nonlinear stiffness and nonlinear damping elements. One of the types of damping element is a magneto-rheological fluid based damper which is receiving increased attention in the applications to the automotive suspension systems. Latest trends in suspension systems also include electronically controlled systems which provide advanced system performance and integration with various processes to improve vehicle ride comfort, handling and stability. A control bifurcation of a nonlinear system typically occurs when its linear approximation loses stabilizability. These control bifurcations are different from the classical bifurcation where qualitative stability of the equilibrium point changes. Any nonlinear control system can also exhibit control bifurcations. In this paper, control bifurcations of the nonlinear active suspension system, modeled as a two degree of freedom system, are analyzed. It is shown that the system looses stability via Hopf bifurcation. Parametric control bifurcation analysis is conducted and results presented to highlight the significance of the design of control system for nonlinear active suspension system. A framework for the design of feedback using the parametric analysis for the control bifurcations is proposed and illustrated for the nonlinear active suspension system.


2015 ◽  
Vol 759 ◽  
pp. 77-90 ◽  
Author(s):  
Tomasz Nabagło ◽  
Andrzej Jurkiewicz ◽  
Janusz Kowal

In the article, a new solution of a semi-active suspension system is presented. It is based on a sky-hook strategy model. This solution in 2S1 tracked platform is applied to improve body vehicle stability and driving comfort. The solution is applied in two versions of the 2S1 vehicle suspension model. First one is a basic model. This suspension is based on existing construction of the 2S1 platform suspension. It is based on torsion bars. Second one is a modified model, based on spiral torsion springs. In this model a new solution of idler mechanism is applied. It provides constant tension of the tracks. Semi-active suspensions simulations results are compared with results of models with passive versions of the suspension to highlight the improvement level. Simulations are conducted in the Yuma Proving Ground conditions. Results of all models simulations are compared and analyzed to improve stability and comfort level in conditions of the modern battlefield. Stability level is analyzed for weapon aiming tasks. Comfort level is analyzed for the vehicle crew efficiency.


Author(s):  
P.P.D. Rao ◽  
S. Palli ◽  
R.C. Sharma

Conventional vehicle suspension systems, which are passive in nature consists of springs with constant stiffness and dampers with constant damping coefficient. These suspension systems cannot meet the characteristics such as ride comfort, road handing and suspension deflection during abnormal road conditions simultaneously. Active and semi-active suspension systems are the solutions to achieve the desired suspension characteristics. Since, active system is bulky and requires high energy for working, a semi-active suspension system is considered in the present work to analyze vehicle traversing over various road profiles for ride comfort. Mathematical model of a 7 DoF passenger car is formulated using Newton’s method. A semi-active suspension system with skyhook linear control strategy avoids the road excitations at resonant frequencies by shifting the natural frequencies of the model by varying damping coefficients based on the vehicle response for different road conditions where the excitations could be harmonic, transient and random. Modal analysis is carried out to identify the un-damped natural frequencies and mode shapes for different values of damping. The above analyses are carried out through analytical and numerical methods using MATLAB and ANSYS software respectively and the results obtained from both are in good agreement.


Author(s):  
E.M Allam ◽  
M.A.A Emam ◽  
Eid.S Mohamed

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.


Sign in / Sign up

Export Citation Format

Share Document