Control of Active Suspension System by Using H8Theory

2009

There are many types of car suspensions control. H1 control of vehicle suspension is studied in the literature for a brave time ago. We can define active suspensions as control systems incorporating a parallel spring and an electronically controlled damper. The contribution of this paper relies on H1 control design to improve comfort and road holding of the car, and on control validation through simulation on an quarter Car and Half Car model with seat-passengers of the suspensions system. In this paper an H1 controller is designed for a actuated active suspension system of a quarter-modelled and half-modelled with seat-passengers vehicle in a cascade feedback structure. In this paper we will make a comparison between application of quarter car and half car model. In the framework of Linear Matrix Inequality (LMI) optimization, constrained H1 active suspensions are designed on half-car models.

Abstract Results confirmed in simulation and experiment that an improved control performance can be obtained when the optimal preview control method was applied to an active suspension system for a quarter car model. In order to investigate the effectiveness not only in riding comfort but also in mad handling, an half-car model with the hydro-pneumatic active suspension system is proposed in this study. Whole preview control method and partial preview control method, in which the road information detected by the front wheel is sent to the controller to decide the input to rear suspension, are taken into design of the active suspension control system. Results of numerical simulation show that satisfactory control efficiency could be achieved in both whole preview control and partial preview control. "Ilae comparison of results suggests that whole preview control method can provide better system performance, but the partial preview control method is superior due to its lower cost.

—There are many types of car suspensions control. H∞ control of vehicle suspension is studied in the literature for a brave time ago. We can define active suspensions as control systems incorporating a parallel spring and an electronically controlled damper. The contribution of this paper relies on H∞ control design to improve comfort and road holding of the car, and on control validation through simulation on an quarter Car and Half Car model with seat-passengers of the suspensions system. In this paper an H∞ controller is designed for a actuated active suspension system of a quarter-modelled and half-modelled with seat-passengers vehicle in a cascade feedback structure. In this paper we will make a comparison between application of quarter car and half car model. In the framework of Linear Matrix Inequality (LMI) optimization, constrained H∞ active suspensions are designed on half-car models.

International Journal of Vehicle Noise and Vibration, 2018

The nonlinear behaviour of suspension elements is substantial when the vehicles experience large road disturbances. These nonlinearities lead to performance deterioration of active suspension systems, which in turn degrades ride comfort, road holding and road handling. Standard control trends on the active suspension count on linear models to benefit from the well established linear control theory, while neglecting the nonlinear dynamics of the suspension systems. In this study, the quarter-car model has a nonlinear suspension spring with a hysteretic nature. The presented design is based on the combination of feedback linearisation (FBL) and H ∞ controller. This approach is selected to take in consideration the nonlinear behaviour of the suspension system, while maintaining the opportunity to conduct the linear control theory. The main objective is maximising the ride comfort while keeping the suspension stroke, tyre dynamic load, and actuator force bounded. To assess the efficiency of the proposed design, simulations are performed on two types of road disturbances. The time and frequency domain simulations show the superiority of the proposed feedback controller in providing ride comfort in comparison with the passive suspension system. Moreover, the proposed design guarantees an agreement between the ride comfort and the other design constraints.

… OF MATHEMATICAL MODELS AND METHODS IN …, 2009

There are many types of car suspensions control. H∞ control of vehicle suspension is studied in the literature for a brave time ago. We can define active suspensions as control systems incorporating a parallel spring and an electronically controlled damper. The contribution of this paper relies on H∞ control design to improve comfort and road holding of the car, and on control validation through simulation on an quarter Car and Half Car model with seat-passengers of the suspensions system. In this paper an H∞ controller is designed for a actuated active suspension system of a quarter-modelled and half-modelled with seat-passengers vehicle in a cascade feedback structure. In this paper we will make a comparison between application of quarter car and half car model. In the framework of Linear Matrix Inequality (LMI) optimization, constrained H∞ active suspensions are designed on half-car models.

International Journal of Control and Automation, 2016

In order to improve the road handling and passenger comfort of a vehicle, suspension is provided. An active suspension is considered to be better than a passive suspension. In this paper, 2 degree of freedom model of quarter car active suspension system is designed, which is subjected to road disturbance. Due to the fact that strong nonlinearity inherently exist in the spring ,damper and actuator components, therefore nonlinear effects must be taken into account in designing the controller for practical suspension systems. Since parametric uncertainty in the spring, damper and actuator has been considered, therefore robust control is used. H ∞ and µ-synthesis controllers are used to improve the ride comfort and road handling ability of the car as well as to check the robust performance of the system. The results shows that both controllers give good performance, but µ synthesis controller has superior robust performance as compared to H ∞ controller as well as settling time of body acceleration and suspension deflection is also minimum with µ synthesis controller.

irjmets, 2020

This paper affords the design and improvement of a semi-active suspension system for an automobile. The main idea is to increase the semi-active suspension system damping vibration of the automobile body even as crossing the bump and sine pavement on the road. This system is modelled for 1 / 4 car system after which the entire system has been simulated using Mat lab/Simulink. It is used to physically simulate the quarter vehicle system of the automobile and have a look at the time domain response to the road disturbances. H infinity controllers is used to govern the damping properties of the semi-active suspension system mechanically. The system is designed in contrast to the most of the available suspension systems using a third order hydraulic actuator. The proposed system is compared with H2 optimal controller to test the performance of the system for the control targets suspension deflection, body acceleration and body travel for the bump and sine road disturbances. The simulation result of this studies reveal the efficiency of the advanced H∞ controller for the quarter car semi-active suspension system.

2009

Control of vehicle suspension systems has been the focus of extensive work in the past two decades. Many control strategies have been developed to improve the overall vehicle performance, including both ride quality and stability conditions. However, the concerns regarding the wheel motions affecting significantly on the handling and steering are ignored by researchers in the control formulation. A H ∞ control methodology is employed to design an active suspension system so that ride quality and wheel motions are improved simultaneously. In addition, a three-dimensional kinematic model of a specific suspension system, namely Macpherson suspension, is developed to study the alteration of those of kinematic suspension parameters which represent the wheel motions. The results show that the proposed robust design provides superior kinematic and dynamic performances compared to those of the passive system. C C C C J J J J M M M M C C C C J J J J

International Journal of Vehicle Noise and Vibration, 2018

The nonlinear behaviour of suspension elements is substantial when the vehicles experience large road disturbances. These nonlinearities lead to performance deterioration of active suspension systems, which in turn degrades ride comfort, road holding and road handling. Standard control trends on the active suspension count on linear models to benefit from the well established linear control theory, while neglecting the nonlinear dynamics of the suspension systems. In this study, the quarter-car model has a nonlinear suspension spring with a hysteretic nature. The presented design is based on the combination of feedback linearisation (FBL) and H ∞ controller. This approach is selected to take in consideration the nonlinear behaviour of the suspension system, while maintaining the opportunity to conduct the linear control theory. The main objective is maximising the ride comfort while keeping the suspension stroke, tyre dynamic load, and actuator force bounded. To assess the efficiency of the proposed design, simulations are performed on two types of road disturbances. The time and frequency domain simulations show the superiority of the proposed feedback controller in providing ride comfort in comparison with the passive suspension system. Moreover, the proposed design guarantees an agreement between the ride comfort and the other design constraints.

In this paper the H ∞ control strategy is addressed. This control technique was tested in a system where saturation is present, the semi-active suspension problem and was evaluated using performance indexes regarding comfort and road handling, and solved by the use of some specific tools of the MATLAB software. The main goal is to obtain optimal performance, in order to minimize the sprung mass (chassis) acceleration and to ensure road-holding characteristics. A comparison is then made with a passive system, by means of numerical simulation, using a quarter-car model, real road profiles, by means of the performance indexes and frequency response comparisons. A single-sensor approach is also suggested, to reduce the number of sensors used per quarter-car model.