Mixed H2/H∞ with Pole-Placement Control Design Outline for Active Suspension Systems

2014 ◽  
Vol 663 ◽  
pp. 152-157
Author(s):  
Aghil Shavalipour ◽  
Sallehuddin Mohamed Haris
Keyword(s):  
State Space ◽  
Ride Comfort ◽  
Control Method ◽  
Space Vehicle ◽  
Active Suspension ◽  
Optimization Techniques ◽  
Pole Placement ◽  
Vehicle Body ◽  
Linear Matrix ◽  
Road Disturbance

This paper consider the control of active automotive suspensions applying Mixed (H2/H∞) state-space optimization techniques. It is well known that the ride comfort is improved by reducing vehicle body acceleration generated by road disturbance. In order to study this phenomenon, Two Degrees of Freedom (DOF) in state space vehicle model was built in. However, the H∞ control method attenuates the agitation effect on the output while H2 is employed to improve the input of the controller. Linear Matrix Inequality (LMI) technique is employed to calculate the dynamic controller parameters. The outcome of the simulation revealed that ride comfort for the vehicle upgraded adequately by applying mixed H2/H∞ Control method for active suspension system, and also the mixed H2/H∞ Control method was more effective than the H∞ Control method.

scholarly journals Symmetry Control of Comfortable Vehicle Suspension Based on H∞

Symmetry ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 171
Author(s):  
Jiguang Hou ◽  
Xianteng Cao ◽  
Changshu Zhan
Keyword(s):  
Ride Comfort ◽  
Control Method ◽  
Output Feedback Control ◽  
Lyapunov Stability Theory ◽  
Active Suspension ◽  
Vehicle Body ◽  
Vertical Acceleration ◽  
Control Force ◽  
Traffic Conditions ◽  
Suspension Model

Suspension is an important part of intelligent and safe transportation; it is the balance point between the comfort and handling stability of a vehicle under intelligent traffic conditions. In this study, a control method of left-right symmetry of air suspension based on H∞ theory was proposed, which was verified under intelligent traffic conditions. First, the control stability caused by the active suspension control system running on uneven roads needs to be ensured. To address this issue, a 1/4 vehicle active suspension model was established, and the vertical acceleration of the vehicle body was applied as the main index of ride comfort. H∞ performance constraint output indicators of the controller contained the tire dynamic load, suspension dynamic stroke, and actuator control force limit. Based on the Lyapunov stability theory, an output feedback control law with H∞-guaranteed performance was proposed to constrain multiple targets. This way, the control problem was transformed into a solution to the Riccati equation. The simulation results showed that when dealing with general road disturbances, the proposed control strategy can reduce the vehicle body acceleration by about 20% and meet the requirements of an ultimate suspension dynamic deflection of 0.08 m and a dynamic tire load of 1500 N. Using this symmetrical control method can significantly improve the ride comfort and driving stability of a vehicle under intelligent traffic conditions.

Wheelbase preview control of an active suspension with a disturbance-decoupled observer to improve vehicle ride comfort

2019 ◽  
Vol 234 (6) ◽  
pp. 1725-1745
Author(s):  
Baek-soon Kwon ◽  
Daejun Kang ◽  
Kyongsu Yi
Keyword(s):  
Simulation Study ◽  
Control Algorithm ◽  
Ride Comfort ◽  
Active Suspension ◽  
The Body ◽  
Vehicle Body ◽  
Preview Control ◽  
The Road ◽  
Road Disturbance ◽  
Suspension Control

This article deals with the design of a partial preview active suspension control algorithm for the improvement of vehicle ride comfort. Generally, while preview-controlled active suspension systems have even greater potential than feedback-controlled systems, their main challenge is obtaining preview information of the road profile ahead. A critical drawback of the “look-ahead” sensors is an increased risk of incorrect detection influenced by water, snow, and other soft obstacles on the road. In this work, a feasible wheelbase preview suspension control algorithm without information about the road elevation has been developed based on a novel 3-degree-of-freedom full-car dynamic model which incorporates only the vehicle body dynamics. The main advantage of the employed vehicle model is that the system disturbance input vector consists of vertical wheel accelerations that can be measured easily. The measured acceleration information of the front wheels is used for predictive control of the rear suspension to stabilize the body motion. The suspension state estimator has also been designed to completely remove the effect of unknown road disturbance on the state estimation error. The estimation performance of an observer is verified via a simulation study and field tests. The performance of the proposed suspension controller is evaluated on a frequency domain and time domain via a simulation study. It is shown that the vehicle ride comfort can be improved more by the proposed wheelbase preview control approach than by the feedback approach.

Analytical and Experimental Evaluation of Various Active Suspension Alternatives for Superior Ride Comfort and Utilization of Autonomous Vehicles

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Ivan Cvok ◽  
Mario Hrgetić ◽  
Matija Hoić ◽  
Joško Deur ◽  
Davor Hrovat ◽  
...  
Keyword(s):  
Autonomous Vehicles ◽  
High Performance ◽  
Ride Comfort ◽  
Simulation Analysis ◽  
Linear Quadratic Regulator ◽  
Active Suspension ◽  
Vertical Acceleration ◽  
Linear Quadratic ◽  
Seat Suspension ◽  
Road Disturbance

Abstract Autonomous vehicles (AVs) give the driver opportunity to engage in productive or pleasure-related activities, which will increase AV’s utility and value. It is anticipated that many AVs will be equipped with active suspension extended with road disturbance preview capability to provide the necessary superior ride comfort resulting in almost steady work or play platform. This article deals with assessing the benefits of introducing various active suspensions and related linear quadratic regulator (LQR) controls in terms of improving the work/leisure ability. The study relies on high-performance shaker rig-based tests of a group of 44 drivers involved in reading/writing, drawing, and subjective ride comfort rating tasks. The test results indicate that there is a threshold of root-mean-square vertical acceleration, below which the task execution performance is similar to that corresponding to standstill conditions. For the given, relatively harsh road disturbance profile, only the fully active suspension with road preview control can suppress the vertical acceleration below the above critical superior comfort threshold. However, when adding an active seat suspension, the range of chassis suspension types for superior ride comfort is substantially extended and can include semi-active suspension and even passive suspension in some extreme cases that can, however, lead to excessive relative motion between the seat and the vehicle floor. The design requirements gained through simulation analysis, and extended with cost and packaging requirements related to passenger car applications, have guided design of two active seat suspension concepts applicable to the shaker rig and production vehicles.

Active Suspension of Output Feedback Robust Control Based on LMI Approach

Volume 1 ◽  
2004 ◽  
Author(s):  
Zhiqiang Gu ◽  
S. Olutunde Oyadiji
Keyword(s):  
Robust Control ◽  
Ride Comfort ◽  
Control Method ◽  
Active Suspension ◽  
Ride Quality ◽  
Control Methods ◽  
The Past ◽  
Suspension Control ◽  
Load Carrying ◽  
Automotive Suspension

Traditionally automotive suspension designs have been a compromise between the three conflicting criteria of road holding, load-carrying and passenger comfort. Active and semiactive suspension control methods have been considered as ways of increasing the freedom one has to specify independently the characteristics of load carrying, handling and ride quality. Consequently, these control methods have been enthusiastically investigated in the past decades. In this paper, active suspension control based on LMIs, including H∞ control and mixed H2/H∞ synthesis has been developed in this paper. The simulation results demonstrate that robust control method can suppress disturbance from road inputs, thus improving the ride comfort and maintaining the good road handling. The mixed H2/H∞ synthesis can provide both the robustness of H∞ control and the better performance of H2 (LQR) method.

An adaptive control approach for semi-active suspension systems under unknown road disturbance input using hardware-in-the-loop simulation

2020 ◽  
pp. 014233121989593 ◽  
Author(s):  
Gokhan Kararsiz ◽  
Mahmut Paksoy ◽  
Muzaffer Metin ◽  
Halil Ibrahim Basturk
Keyword(s):  
Adaptive Control ◽  
Control Method ◽  
Active Suspension ◽  
Magnetorheological Damper ◽  
Hardware In The Loop ◽  
Control Approach ◽  
The Road ◽  
Suspension Systems ◽  
Active Suspension Systems ◽  
Road Disturbance

This article presents an application of the adaptive control method to semi-active suspension systems in the presence of unknown disturbance and parametric uncertainty. Due to the technical difficulties such as time delay and sensor noise, the road disturbance is assumed to be unmeasured. To overcome this problem, an observer is designed to estimate the disturbance. It is considered that the road profile consists of a finite number of the sum of sinusoidal signals with unknown amplitudes, phases and frequencies. After the parametrization of the observer, the adaptive control approach is employed to attenuate the effect of the road-induced vibrations using a magnetorheological damper. It is proved that the closed-loop system is stable, despite the adverse road conditions. Finally, the performance of the controller is illustrated with a hardware-in-the-loop simulation in which the system is subjected to sinusoidal and random profile road excitations. To demonstrate the benefits of the adaptive controller, the results are presented in comparison with a conventional proportional integral derivative (PID) controller.

Vehicle Active Suspension with Four-Degrees of Freedom of Optimizing the Value of K Based on Genetic Algorithm

2011 ◽  
Vol 308-310 ◽  
pp. 1673-1678
Author(s):  
Yan Yan Zuo ◽  
Cai Bao Yan ◽  
Nan Yang
Keyword(s):  
Genetic Algorithm ◽  
Optimal Control ◽  
Optimal Control Theory ◽  
Degrees Of Freedom ◽  
Ride Comfort ◽  
Control Method ◽  
Active Suspension ◽  
Obvious Effect ◽  
Comprehensive Performance ◽  
Suspension Model

A vehicle active suspension model with 1 / 2 ，four-degrees of freedom is established and by combining genetic algorithm with optimal control theory，the author presents a new control method of active suspension that is to optimize the value of K controlled by LQG in default of road input based on genetic algorithm and makes a simulation in the environment of Matlab / Simulink. By simulation and analysis，the result indicates that，this method has an obvious effect on improving comprehensive performance of vehicles，such as ride comfort and operate stability and so on.

scholarly journals Automobile active tilt control based on active suspension

2018 ◽  
Vol 10 (10) ◽  
pp. 168781401880145 ◽  
Author(s):  
Jialing Yao ◽  
Zhihong Li ◽  
Meng Wang ◽  
Feifan Yao ◽  
Zheng Tang
Keyword(s):  
Tilt Angle ◽  
Load Transfer ◽  
Ride Comfort ◽  
Control Method ◽  
Sliding Mode ◽  
Active Suspension ◽  
Degree Of Freedom ◽  
Lateral Acceleration ◽  
Vehicle Speed ◽  
Rollover Prevention

The rolling control of a car that focuses on reducing the roll angle passively has limited performance of increasing handling stability, passing speed, ride comfort, and rollover prevention while turning. This project presents a method for controlling an automobile to tilt toward the turning direction using active suspension. A 6-degree-of-freedom vehicle model with a 2-degree-of-freedom steering model and a 4-degree-of-freedom tilting model is established. The active tilt sliding mode controller, which causes zero steady-state tilt angle error, is established after the desired tilt angle is determined by dynamic analysis. Simulation results confirm the effectiveness of the control method. The proposed controller reduces the perceived lateral acceleration and the lateral load transfer rate, thereby effectively improving handling stability, ride comfort, and vehicle speed, meanwhile decreasing the possibility of rollover while turning.

Development of Active Suspension System for a Pot Hole Using PID Controller

2011 ◽  
Vol 308-310 ◽  
pp. 2266-2270
Author(s):  
Mouleeswaran Senthilkumar
Keyword(s):  
Pid Controller ◽  
Ride Comfort ◽  
Control Method ◽  
Controller Design ◽  
Active Suspension ◽  
Suspension System ◽  
Operating Conditions ◽  
Hydraulic Actuator ◽  
Time Domains ◽  
Spool Valve

This paper describes the development of a controller design for the active control of suspension system, which improves the inherent tradeoff among ride comfort, suspension travel and road-holding ability. The developed design allows the suspension system to behave differently in different operating conditions, without compromising on road-holding ability. The effectiveness of this control method has been explained by data from time domains. Proportional-Integral-Derivative (PID) controller including hydraulic dynamics has been developed. The displacement of hydraulic actuator and spool valve is also considered. The Ziegler – Nichols tuning rules are used to determine proportional gain, reset rate and derivative time of PID controller. Simulink diagram of active suspension system is developed and analysed using MATLAB software. The investigations on the performance of the developed active suspension system are demonstrated through comparative simulations in this paper.

Modelling and Comparison of Semi-Active Control Logics for Suspension System of 8x8 Armoured Multi-Role Military Vehicle

2014 ◽  
Vol 592-594 ◽  
pp. 2165-2178 ◽  
Author(s):  
M.W. Trikande ◽  
Vinit V. Jagirdar ◽  
Muraleedharan Sujithkumar
Keyword(s):  
Active Control ◽  
Time Domain ◽  
Ride Comfort ◽  
Vertical Direction ◽  
Active Suspension ◽  
Suspension System ◽  
Road Surface ◽  
Vehicle Speed ◽  
The Road ◽  
Road Disturbance

Comparative performance of vehicle suspension system using passive, and semi-active control (on-off and continuous) has been carried out for a multi-axle vehicle under the source of road disturbance. Modelling and prediction for stochastic inputs from random road surface profiles has been carried out. The road surface is considered as a stationary stochastic process in time domain assuming constant vehicle speed. The road surface elevations as a function of time have been generated using IFFT. Semi active suspension gives better ride comfort with consumption of fraction of power required for active suspension. A mathematical model has been developed and control algorithm has been verified with the purpose/objective of reducing the unwanted sprung mass motions such as heave, pitch and roll. However, the cost and complexity of the system increases with implementation of semi-active control, especially in military domain. In addition to fully passive and fully semi-active a comparison has been made with partial semi-active control for a multi-axle vehicle to obviate the constraints. The time domain response of the suspension system using various control logics are obtained and compared. Simulations for different class of roads as defined in ISO: 8608 have been run and the ride comfort is evaluated and compared in terms of rms acceleration at CG in vertical direction (Z), which is the major contributor for ORV (Overall Ride Value) Measurement.

Robust Sliding Mode Control of a Full Vehicle Without Suspension Gap Loss

2005 ◽  
Vol 11 (11) ◽  
pp. 1357-1374 ◽  
Author(s):  
N. Yagiz ◽  
L. E. Sakman
Keyword(s):  
Sliding Mode Control ◽  
Degrees Of Freedom ◽  
Ride Comfort ◽  
Control Method ◽  
Sliding Mode ◽  
The Body ◽  
Vehicle Body ◽  
New Approach ◽  
Full Vehicle ◽  
Mode Control

A seven-degrees-of-freedom full vehicle model is used to design a robust controller and to investigate the performance of active suspensions without losing the suspension working space. Zero reference for vehicle body displacement finishes suspension working distance. Thus, a new approach is suggested in this paper. Force actuators are placed parallel to the suspensions and non-chattering sliding mode control is applied. Since any change in vehicle parameters because of different load or road conditions adversely affects the performance of the ordinary control methods, a robust control method is preferred. To obtain the desired improvement in ride comfort, we aim to decrease the magnitudes of the body vibrations and their accelerations. We present body bounce, pitch and roll motions of the vehicle with the conventional approach and the proposed approach without suspension gap loss, both in the time domain in the case of traveling over a step road profile and in the frequency domain. The results of both approaches are compared. The solution to the suspension gap loss problem has also been presented on periodic road surfaces. At the end of the paper, we discuss the improvement in the performance of the new controller with its robust behavior and the advantage of the new approach.

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