Active Anti-roll Bar System Research Articles

Effect of Suspension Roll Angle Sensors on the Performance of H∞ Active Antiroll Bar Control System of Trucks

The rollover phenomenon is quite familiar with trucks and often has severe consequences worldwide. This article focuses on developing a new control structure for the active antiroll bar system using the robust control method. The main objective is to improve the vehicle’s roll stability by using additional suspension roll angle sensors. First, a truck model equipped with an active antiroll bar system is introduced. Then, the basic robust controller structure diagram is described in detail. Based on this basic robust controller, the authors develop a new robust controller considering the suspension roll angle sensors. Finally, the response of a truck using an active antiroll bar system with two robust (H∞) controllers and a passive antiroll bar system is compared and evaluated in the time domain and in the frequency domain. The results showed that the use of two sensors of the suspension roll angle sensors increased the efficiency by about 20% compared to the basic robust controller. This has proven the effectiveness of a new approach in improving the roll stability of trucks.

A lateral trajectory tracking control method for intelligent commercial vehicles considering active anti‐roll decision based on Stackelberg equilibrium

Existing research on path following strategies generally does not consider the interference effect of active anti-roll (AAR) action. This seriously affects the driving safety under extreme obstacle avoidance and other conditions. Therefore, based on the non-cooperative Stackelberg equilibrium theory, this research proposes a lateral trajectory tracking strategy that considers AAR decision. First, a yaw-roll coupled dynamic model of commercial vehicle with front wheel angle and AAR moment as input is established to describe the coupling effect of vehicle lateral and roll motions. Then, based on the Stackelberg equilibrium theory, active front steering (AFS) system and AAR bar system are modelled as the leader and follower in the leader–follower collaborative control strategy, respectively. Finally, simulation and experiments show that the leader–follower collaborative control strategy can effectively improve the control conflict between the two systems and improve the anti-roll performance during trajectory tracking.

Designing LQR Controllers for an Active Anti-roll Bar System with a Flexible Frame Model of a Single Unit Heavy Vehicle

Rollover accidents of heavy vehicles often cause serious consequences both in terms of vehicle and environmental damage as well the loss or injury of drivers, passengers and ordinary civilians. Currently, the active anti-roll bar system is considered as the most effective solution in enhancing vehicle roll stability. In this paper, we firstly investigated the role of a flexible frame of a single unit heavy vehicle in the rollover process. This approach is an important step forward in the research of the active anti-roll bar system. Then, the LQR control method is applied in designing controllers for the active anti-roll bar control system with this frame model. The active torque of the anti-roll bar system is considered as the control signal. The simulation results in the frequency and time domains with a double lane change maneuver show that the vehicle’s roll stability is improved by over 30 % compared to a vehicle using a passive anti-roll bar system.

Improving roll stability of tractor semi-trailer vehicles by using H∞ active anti-roll bar control system

Tractor semi-trailers are increasingly playing an important role in freight transportation worldwide. Although most tractor semi-trailers are equipped with a passive anti-roll bar system, however accidents involving this type of vehicle are still frequent and have serious consequences. This paper presents an H∞ controller design for an active anti-roll bar system in order to enhance the roll stability of a tractor semi-trailer with the torque control generated at all axles. The considered performance outputs include the lateral acceleration, the normalised load transfer for both tractor and semi-trailer, as well as the magnitude of the torque control to avoid the actuator’s saturation. The effectiveness of the proposed method is evaluated in the frequency domain via the transfer function magnitude from the steering angle to the survey signals, and in the time domain through the nonlinear vehicle model of TruckSim® software. The evaluation results show that the roll stability of the tractor semi-trailer using the H∞ active anti-roll bar system has improved by more than 20% compared to a passive vehicle.

Preventing rollover phenomenon with an active anti-roll bar system using electro-hydraulic actuators: A full car model

This paper discusses the role of the active anti-roll bar system in order to enhance the roll stability of cars, thereby preventing rollover phenomenon in high speed emergency situations. First, an integrated full car model is proposed including the longitudinal, lateral, vertical motions and an electro-hydraulic actuator model. In this full car model, the control signal being the input current which is supplied to the actuators to create the active torques to improve the car's stability. This is the most general model in theory to study this active roll control system and is a big step forward compared to previous related studies. The optimal LQR control method has then been used to synthesize the controller based on the integrated model with 26 degrees of freedom. The criteria used to assess the vehicle roll stability are the sprung mass roll angle and the interactive force between the wheels and the road surface. The simulation results in the frequency domain and the validation in the time domain through the CarSim software's nonlinear car model clearly show the advantages of this active system with an optimal LQR controller in preventing vehicle rollover.

Using an LQR active anti-roll bar system to improve road safety of tractor semi-trailers

Introduction: Tractor semi-trailer vehicles are playing an increasingly important role in the global freight chain. However, due to the heavy total load and height of the center of gravity, this type of vehicle is often at a higher risk of instability than other vehicles. This paper focuses on improving the vehicle roll stability by using an active anti-roll bar system.
 Methods: The Linear Quadratic Regulator (LQR) approach is used for this purpose with the control signal being the torque generated by the active anti-roll bar system. In order to synthesize the controller, the roll angle of the vehicle body and the normalized load transfer at all axles of the tractor semi-trailer vehicle are considered as the optimal goals.
 Results: The simulation results in time and frequency domains clearly show the effectiveness of the proposed method for the active anti-roll bar system, because the reduction of the desired criterias is about 40% less when compared to a vehicle using the passive anti-roll bar system.
 Conclusions: The effectiveness of the active anti-roll bar system on improving the vehicle roll stability, has been verified in this theoretical study with the LQR optimal controller. This is an important basis for conducting more in-depth studies and future experiments.

An Investigation into the Oil Leakage Effect Inside the Electronic Servo-valve for an $$\mathcal{H}_\infty$$/LPV Active Anti-roll Bar System

The Electronic Servo-Valve Hydraulic (ESVH) actuator is commonly used in the industrial sector and engineering practice. This paper investigates the robustness of the $$\mathcal{H}_\infty$$ /LPV active anti-roll bar system when the presence of an oil leakage inside the electronic servo-valve is taken into account. We propose a fully integrated model, including four ESVH actuators in a single unit heavy vehicle. Then, an $$\mathcal{H}_\infty$$ /LPV controller is synthesized in order to satisfy simultaneously the two main objectives of enhancing roll stability and the saturation of the actuators. Survey results indicate that the oil leakage has a positive effect in protecting the active anti-roll bar system if the controller stops working and it is indispensable for this type system. At each design point of the LPV system, the μ-tool method is used to test the robustness analysis in the frequency domain. It is shown that the active anti-roll bar system is always robust with the maximum uncertain level of the total flow pressure coefficient of 41%, when the forward velocity is considered to be over 130 km/h.

H∞/LPV controller design for an active anti-roll bar system of heavy vehicles using parameter dependent weighting functions

Vehicle rollover is a very serious problem when considering the safety of heavy vehicles, which can result in large financial and environmental consequences. This paper investigates the interest of a Linear Parameter Varying (LPV) controller for an active anti-roll bar system of single unit heavy vehicles, in order to enhance roll stability. We propose a parameter dependent H∞/LPV controller with weighting functions, scheduled by the forward velocity (the varying parameter of the vehicle LPV model) and by the normalized load transfers at the two axles (part of the parameter dependent weighting functions) providing an on-line performance adaptation to the vehicle rollover risk. The effectiveness of the proposed controller is validated by using the TruckSim® simulation software with two different types of heavy vehicle: a fully loaded bus and a truck. The simulation results, in the frequency and time domains, show that the proposed strategy drastically improves the vehicle roll stability when compared with a H∞/LTI controller, a fixed weighting functions H∞/LPV controller and a passive anti-roll bar system.

Performance and robustness assessment of H∞ active anti-roll bar control system by using a software environment

Abstract The active anti-roll bar system has been proven to be one of the most effective solutions to improve roll stability of heavy vehicles. In a previous work, the authors proposed an H∞ controller for this system. The Genetic Algorithms method was used to handle the vehicle roll stability and the energy consumption of the actuators via the Pareto optimality. This paper aims to assess the overall effectiveness of the proposed controller with nonlinear heavy vehicle models, which are already set up in the TruckSim® software. The controller is then evaluated in hard conditions to show the high performance and robust with the nonlinearity effects, such as the load distribution between the two axles, the side wind gusts and the abrupt steering. To conduct testing of the H∞ active anti-roll bar control system, we propose a co-simulation structure between TruckSim® and Simulink®: the nonlinear vehicle model is determined from TruckSim®, based on using the block S-function of Simulink. Meanwhile, the controller and the actuators are built directly in the Matlab/Simulink ® environment. The validation results are made through two different types of heavy vehicles: a tour bus and a truck, using a selection of different velocities and scenarios. The results show that by using the H∞ active anti-roll bar control system, in comparison to the passive anti roll bar system, roll stability is improved to minimise the risk of vehicle rollover.

Improving Vehicle Rollover Resistance Using Fuzzy PID Controller of Active Anti-Roll Bar System

Improving Vehicle Rollover Resistance Using Fuzzy PID Controller of Active Anti-Roll Bar System

Newly Developed Nonlinear Vehicle Model for an Active Anti-roll Bar System

This paper presents the development of a newly developed nonlinear vehicle model is used in the validation process of the vehicle model. The parameters chosen in a newly developed vehicle model is developed based on CARSIM vehicle model by using non-dominated sorting genetic algorithm version II (NSGA-II) optimization method. The ride comfort and handling performances have been one of the main objective to fulfil the expectation of customers in the vehicle development. Full nonlinear vehicle model which consists of ride, handling and Magic tyre subsystems has been derived and developed in MATLAB/Simulink. Then, optimum values of the full nonlinear vehicle parameters are investigated by using NSGA-II. The two objective functions are established based on RMS error between simulation and benchmark system. A stiffer suspension provides good stability and handling during manoeuvres while softer suspension gives better ride quality. The final results indicated that the newly developed nonlinear vehicle model is behaving accurately with input ride and manoeuvre. The outputs trend are successfully replicated.

Optimised Combinatorial Control Strategy for Active Anti-Roll Bar System for Ground Vehicle

The objective of this paper is to optimise the proposed control strategy for an active anti-roll bar system using non-dominated sorting genetic algorithm (NSGA-II) tuning method. By using an active anti-roll control strategy, the controller can adapt to current road conditions and manoeuvres unlike a passive anti-roll bar. The optimisation solution offers a rather noticeable improvement results compared to the manually-tuned method. From the application point of view, both tuning process can be used. However, using optimisation method gives a multiple choice of solutions and provides the optimal parameters compared to manual tuning method.

Double anti-roll bar hardware-in-loop experiment for active anti-roll control system

Active anti-roll bar (AARB) is a cheaper alternative for a fully active suspension system, which can be adapted into passenger cars, made possible by today’s technology. AARB minimizes body roll and improve ride comfort. In this paper, the design of a Hardware-in-loop (HIL) test bench is presented. The HIL test bench is able to test dual AARB system, each for front and rear of a car respectively. HIL testing will allow designer to analyze and validate the performance of the proposed AARB system before it could be implemented in a real car. This paper focuses on the practicality and adaptability of implementing Fuzzy based PID controllers into the AARB system. HIL experiment compares the performance of proposed Self-Tuning Fuzzy PI-PD (STF PI-PD) controller against the PI-PD Type Fuzzy Logic Controller (PI-PD Type FLC) and Self-Tuning Fuzzy PID (STF PID) controllers. STF PID controller was proposed by previous researchers for an AARB system. Experimental results suggest that the proposed AARB system, which incorporates STF PI-PD controller is able to reduce 87.68 % of roll angle and 50.04 % in roll rate in average, thus improving the vehicle dynamics. STF PI-PD controller significantly outperforms both STF PID and PI-PD Type FLC controllers in various handling tests.

Application of a self-tuning fuzzy PI–PD controller in an active anti-roll bar system for a passenger car

A fuzzy proportional-integral-derivative (PID) controller has not been widely investigated for active anti-roll bar (AARB) application due to its unspecific mathematical analysis and the derivative kick problem. This paper briefly explains how the derivative kick problem arises due to the nature of the PID controller as well as the conventional fuzzy PID controller in association with an AARB. There are two types of controllers proposed in this paper: self-tuning fuzzy proportional-integral–proportional-derivative (STF PI–PD) and PI–PD-type fuzzy controller. Literature reveals that the PI–PD configuration can avoid the derivative kick, unlike the standard PID configuration used in fuzzy PID controllers. STF PI–PD is a new controller proposed and presented in this paper, while the PI–PD-type fuzzy controller was developed by other researchers for robotics and automation applications. Some modifications were made on these controllers in order to make them work with an AARB system. The performances of these controllers were evaluated through a series of handling tests using a full car model simulated in MATLAB Simulink. The simulation results were compared with the performance of a passive anti-roll bar and the conventional fuzzy PID controller in order to show improvements and practicality of the proposed controllers. Roll angle signal was used as input for all the controllers. It is found that the STF PI–PD controller is able to suppress the derivative kick problem but could not reduce the roll motion as much as the conventional fuzzy PID would. However, the PI–PD-type fuzzy controller outperforms the rest by improving ride and handling of a simulated passenger car significantly.

RIDE AND HANDLING ANALYSIS FOR AN ACTIVE ANTI-ROLL BAR: CASE STUDY ON COMPOSITE NONLINEAR CONTROL STRATEGY

This paper presents a comparison of ride and handling analysis for an active anti-roll bar system using various types of controller. Work using conventional and modern control approaches has been investigated by previous researches. This study further extends this work by investigating a particular modern control technique using a linear quadratic regulator, linear quadratic Gaussian and composite nonlinear feedback controller in designing the closed loop feedback for an anti-roll bar system control scheme. A simple linear quadratic regulator and a linear quadratic Gaussian are first investigated. An active anti-roll bar system has to balance the trade-off between ride comfort and handling performance. The new linear quadratic Gaussian composite nonlinear feedback (LQG-CNF) fusion control strategy is developed to improve the performances on vehicle ride comfort and handling for an active anti-roll bar system. The linear half car model is combined with a single track model with roll dynamics. The performance of the controllers is compared and the simulation results show that the proposed control strategy gives better performance in terms of vehicle ride comfort and handling.

LQG Control Design for Vehicle Active Anti-Roll Bar System

The objective of this paper is to design a linear quadratic regulator (LQR) and linear quadratic Gaussian (LQG) controllers for an active anti-roll bar system. The use of an active anti-roll bar will be analysed from two different perspectives in vehicle ride comfort and handling performances. This paper proposed the basic vehicle dynamic modelling with four degree of freedom (DOF) on half car model and are described that show, why and how it is possible to control the handling and ride comfort of the car, with the external forces also control strategies on the front anti-roll bar. By simulation analysis, the design model is validity and the performance under control of linear quadratic regulator (LQR) and linear quadratic Gaussian (LQG) controller are achieved. Both two controllers are modeled in MATLAB/SIMULINK environment. It has to be determined which control strategy delivers better performance with respect to roll angle and the roll rate of half vehicle body. The result shows, however, that LQG produced better response compared to a LQR strategy.

Combined CNF with LQR in Improving Ride and Handling for Ground Vehicle

This paper presents and analyses a performance comparison between a Linear Quadratic Regulator (LQR) and Composite Nonlinear Feedback (CNF) controllers for an active anti-roll bar (ARB) system. The anti-roll bar system has to balance the trade-off involving ride comfort and handling performance. The basic vehicle dynamic modelling with four degree of freedom (DOF) on half car model is proposed. The design model is validity and the performances of roll angle and roll rate under control of LQR and CNF controller are achieved by using simulation analysis. Both two controllers are modeled in MATLAB/SIMULINK environment. It has to be determined which control strategy delivers better performance with respect to roll angle and the roll rate of half vehicle body to achieve this goal. The result shows, the CNF LQR fusion control strategy improve the performance compared to LQR and CNF control strategy.

Improving Vehicle Ride and Handling Using LQG CNF Fusion Control Strategy for an Active Antiroll Bar System

This paper analyses a comparison of performance for an active antiroll bar (ARB) system using two types of control strategy. First of all, the LQG control strategy is investigated and then a novel LQG CNF fusion control method is developed to improve the performances on vehicle ride and handling for an active antiroll bar system. However, the ARB system has to balance the trade-off between ride and handling performance, where the CNF consists of a linear feedback law and a nonlinear feedback law. Typically, the linear feedback is designed to yield a quick response at the initial stage, while the nonlinear feedback law is used to smooth out overshoots in the system output when it approaches the target reference. The half car model is combined with a linear single track model with roll dynamics which are used for the analysis and simulation of ride and handling. The performances of the control strategies are compared and the simulation results show the LQG CNF fusion improves the performances in vehicle ride and handling.