Much research has gone into developing advanced control algorithms for semi-active suspension. Experimental validation of these control algorithms is critical for their practical applications. This paper investigates a state-observer-based Takagi–Sugeno fuzzy controller (SOTSFC) design for a semi-active quarter-car suspension installed with a magnetorheological (MR) damper and provides proof of the effectiveness of the proposed controller. To conduct the test, a quarter-car test rig and control system hardware were used. Then, a new MR damper was designed and built to fit with the test rig. After that, the SOTSFC for the quarter-car test rig was developed. Finally, several tests were conducted on the quarter-car suspension in order to investigate the real effect of the SOTSFC. It was then compared with the use of a skyhook controller to demonstrate its benefits.

Takagi–Sugeno Fuzzy Control for Semi-Active Vehicle Suspension With a Magnetorheological Damper and Experimental Validation

The paper presents a study on the direct voltage control of a magnetorheological (MR) damper for application in vehicle suspensions. As MR damper dynamics is highly nonlinear, the direct control system design for an MR damper is difficult. Representing an MR damper by a Takagi?Sugeno (TS) fuzzy model enables the linear control theory to be directly applied to design the MR damper controller. In this paper, first the MR damper dynamics is represented by a TS fuzzy model, and then an H? controller that considers the suspension performance requirements and the constraint on the input voltage for the MR damper is designed. Furthermore, considering the case that not all the state variables are measurable in practice, the design of an H? observer with immeasurable premise variables and the design of a robust controller are proposed, respectively. Numerical simulations are used to validate the effectiveness of the proposed approaches.

https://iopscience.iop.org/article/10.1088/0964-1726/22/10/105016/pdf

Direct voltage control of magnetorheological damper for vehicle suspensions

The capability of a variable stiffness and damping (VSVD) suspension system via a magnetorheological (MR) damper on improving vehicle lateral stability is investigated in this paper. First, a type of the VSVD suspension system is briefly introduced with the application of variable damping to realize the capability of VSVD. Then, variable damping via the MR damper is extended, and the characteristics of damping force are presented with the Bouc-Wen model. Then, the proposed VSVD system is inserted into a full vehicle model as a front suspension system to control tire normal forces. A control strategy composed of a fuzzy controller that the output is wheel slip ratio and a simple on/off controller to model the application of VSVD is developed to illustrate its ability in improving vehicle stability. It is shown from simulation that VSVD can increase tire normal forces and make vehicles present better performance on lateral stability.

Improving Vehicle Lateral Stability Based on Variable Stiffness and Damping Suspension System via MR Damper

The main function of a vehicle suspension system is to isolate the vehicle body from external excitation in order to improve passenger comfort and road holding and to stabilise its movement. This p...

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An Adaptive Neuro Fuzzy Hybrid Control Strategy for a Semiactive Suspension with Magneto Rheological Damper

This research work presents an H ∞ controller based on a Takagi–Sugeno (T–S) fuzzy model for a two-degrees-of-freedom (2-DOF) one-quarter-vehicle semi-active suspension with a magnetorheological damper where the actuator dynamics are included in the control synthesis. These dynamics enclose nonlinear damper phenomena, avoided in many other studies, and that can improve the suspension system by means of a more accurate model. The objective is to obtain a semi-active suspension that considerably improves the passive suspension efficiency based on some frequency domain performance criteria. The advantage of having the T–S system as a reference is that each piecewise linear system can be exposed to the well-known control theory. Besides, the proposed solution is compared with the recent reported work to highlight its advantages. A case of study is included and simulation work supports the results. The methodology applied herein can be extended to a half-vehicle model, and to the four wheels to have a global c...

H ∞ control of a suspension with a magnetorheological damper

Magnetorheological (MR) dampers have proved to be an attractive solution in improving vehicle stability and passenger comfort. However, handling with these dampers, which contain highly nonlinear phenomena, implies a strong effort in modeling and control. This research presents a Takagi-Sugeno (T-S) fuzzy model, not reported before, for a two-degrees-of-freedom (2-DOF) one-quarter-vehicle semiactive suspension with an MR damper. The objective is to prove that an MR damper, represented by the Bouc-Wen approach, is suitable for control purposes. Moreover, the model developed in [14], was reformulated into a more compact control-oriented model. The stability condition is given in terms of Lyapunov stability theory, and carried out by means of Linear Matrix Inequalities (LMI). Due to system's fuzzy nature, the controller gain is applied via Parallel Distributed Compensation (PDC) through a static state feedback controller for each linear subsystem. The advantage of having the T-S system as a reference is that each piecewise linear system can be exposed to the well-known control theory regarding: stability, robustness, and performance. Besides, the novel model encloses the nonlinear damper phenomena, avoided in another reported work, i.e. [9], and [11], which can improve the suspension study by means of a more accurate model. A numerical case and simulation work support the results. This research introduces a more accurate control oriented model that can be applied in the suspensions performance domain towards comfort and stability improvement.

Control of a semi-active suspension with a magnetorheological damper modeled via Takagi-Sugeno

Automotive suspensions are important systems in improving passenger comfort and vehicle stability. Magnetorheological dampers are actually being used intensively in vehicle suspensions, improving stability and comfort by changing the damping factor in milliseconds. The difficulty about MR dampers are the highly nonlinear characteristics and inherent hysteresis that turn the damper's modeling in a complicated task. This research proposes a solution to the problem of semi-active vehicle suspension modeling through a type of Takagi-Sugeno (T-S) fuzzy model, not reported before, for a one-quarter-vehicle semi-active suspension with a Magnetorheological (MR) damper. The model has the advantage of being composed of linear subsystems, where all the linear control theory can be applied, thus further control work can be more accessible than the one applied directly to the nonlinear equations. Moreover, the new model contains all the nonlinear damper's characteristics arduous to model and avoided in other reported work. The T-S approach breaks- down the nonlinear system into linear subsystems connected by fuzzy membership functions. Simulation work included herein, provides evidence of similarity among the differential equation model and the T-S model. The present research is an introduction to important opportunity areas in suspensions performance and other vehicle dynamics, considering that T-S approach can be extended to other subsystems of the vehicle.

Takagi-Sugeno fuzzy model of a semi-active suspension with a magnetorheological damper

In order to enhance ride comfort and vehicle stability, numerous control approaches have been applied in vehicle suspension research. One of these control approaches is the family of fuzzy controllers. The literature is rich in research about fuzzy techniques focused on vehicle suspension performance but exists a lack of work on semi-active suspensions models that includes accurate actuator dynamics as in the present investigation. In addition, the reported fuzzy controllers work with too many rules in their decision engine, increasing the computational time to generate a control signal, and making real-time control a difficult task. This paper work presents a trial and error tuned fuzzy controller addressed for a new two-degrees-of-freedom one-quarter-vehicle semi-active suspension model with a magnetorheological (MR) damper. Moreover, the use of singleton-like output fuzzy as in this research reduces the computational time to generate the control signal. Simulation work in MATLAB, compare comfort and stability, in frequency and time domains, of an average city car for: a passive suspension, an H ∞ tuned suspension, and the proposed fuzzy controller developed herein. For the simulation tests presented in this paper, the semi-active suspension with fuzzy control improves the H ∞ approach. Even though the fuzzy controller tuning, and membership functions are based on the trial and error method, the obtained results are excellent. The proposed approach is effective and simple.

L. C. Felix-Herran

Papers

Control of a semi-active suspension with a magnetorheological damper modeled via Takagi-Sugeno

Takagi-Sugeno fuzzy model of a semi-active suspension with a magnetorheological damper

Fuzzy control for a semi-active vehicle suspension with a magnetorheological damper