Road-Holding-Oriented Control and Analysis of Semi-Active Suspension Systems

Author(s):  
Zhengkai Li ◽  
Weichao Sun ◽  
Huijun Gao

The most important function of a vehicle suspension system is keeping the tires on the road surface, imposing requirements on the road-holding performance. As is well known, a semi-active suspension can improve road-holding performance, but little effort has been made to build road-holding-oriented semi-active suspension controllers (RHSAC). This study improved four model reference controllers (MRCs) as RHSAC, including the road-Hook (RH), inverse ground-Hook (IGH), sky-Hook (SH), and ground-Hook (GH). These MRCs have optimal performances in different frequency ranges, and their working principle is analyzed from an energy perspective. To combine the advantages of different MRCs, a mixed control strategy is proposed to enhance the road-holding performance of the MRCs. By mixing SH and RH, the mixed SH–RH performs almost as well as a finely tuned model predictive controller, which outperforms any single MRCs. Based on CarSim-matlab cosimulations, the effectiveness of the mixed RHSAC controller is verified by various real road tests.

2020 ◽  
Vol 4 (2) ◽  
pp. 109-114
Author(s):  
Iyasu T. Jiregna ◽  
Goftila Sirata

The driving comfort of the vehicle is primarily determined by the design of the suspension system, which transmits the force between the vehicle and the ground. There are different types of vehicle suspension systems, including active suspension systems that provide significant benefits for ride comfort while driving. However, the existing active suspension systems have limited functions such as power, and also complex structure. To overcome the problem, the proper design of the active suspension system by considering its present limitations is essential. A well-designed active suspension system controls the load on the wheels under the resonance of the body structure and ensures driving comfort. It reduces the vibrational energy of the vehicle body caused by the excitation of the road while keeping the stability of the vehicle within an acceptable limit. For a proper design of the active suspension system, the road surface, the seat suspension, and the wheel load are the most important elements to consider. In this study, different types of vehicle suspension systems with their limitations have been thoroughly investigated. Many aspects of control and some of the essential practical considerations are also explored.


2021 ◽  
Vol 11 (19) ◽  
pp. 8912
Author(s):  
Seunghoon Woo ◽  
Donghoon Shin

This paper presents a double sky-hook algorithm for controlling semi-active suspension systems in order to improve road-holding property for application in an in-wheel motor. The main disadvantage of the in-wheel motor is the increase in unsprung masses, which increases after shaking of the wheel, so it has poor road-holding that the conventional theoretical sky-hook algorithm cannot achieve. The double sky-hook algorithm uses a combination of damper coefficients, one from the chassis motion and the other from the wheel motion. Computer simulations using a quarter and full car dynamic models with the road conditions specified by ISO2631 showed the effectiveness of the algorithm. It was observed that the algorithm was the most effective in the vicinity of the wheel hop frequency. This paper also proposed the parameter set of the double sky-hook algorithm to differentiate the driving mode of vehicles under advanced development.


2021 ◽  
Vol 69 (6) ◽  
pp. 485-498
Author(s):  
Felix Anhalt ◽  
Boris Lohmann

Abstract By applying disturbance feedforward control in active suspension systems, knowledge of the road profile can be used to increase ride comfort and safety. As the assumed road profile will never match the real one perfectly, we examine the performance of different disturbance compensators under various deteriorations of the assumed road profile using both synthetic and measured profiles and two quarter vehicle models of different complexity. While a generally valid statement on the maximum tolerable deterioration cannot be made, we identify particularly critical factors and derive recommendations for practical use.


2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Hui Pang ◽  
Ying Chen ◽  
JiaNan Chen ◽  
Xue Liu

As the road conditions are completely unknown in the design of a suspension controller, an improved linear quadratic and Gaussian distributed (LQG) controller is proposed for active suspension system without considering road input signals. The main purpose is to optimize the vehicle body acceleration, pitching angular acceleration, displacement of suspension system, and tire dynamic deflection comprehensively. Meanwhile, it will extend the applicability of the LQG controller. Firstly, the half-vehicle and road input mathematical models of an active suspension system are established, with the weight coefficients of each evaluating indicator optimized by using genetic algorithm (GA). Then, a simulation model is built in Matlab/Simulink environment. Finally, a comparison of simulation is conducted to illustrate that the proposed LQG controller can obtain the better comprehensive performance of vehicle suspension system and improve riding comfort and handling safety compared to the conventional one.


Author(s):  
Prajwal V R ◽  
Chandrashekar Murthy B N ◽  
Yashwanth S D

Active suspension is a type of suspension systems which can vary its damping value in order to adjust the spring firmness in accordance with the road conditions. Real Active Suspension incorporates an external actuator which helps in raising or lowering of vehicle chassis independently at each wheel. Generally, the actuators that are used for active suspension are Hydropneumatic, Electro-hydraulic or Electromagnetic actuators. A new concept of two-way electromagnetic actuation with the help of magnetic damping is proposed in this paper, which can extend its arm on both sides to facilitate active suspension mechanism in both humps and potholes. This increases the ride quality while maneuvering not only in humps, but also in dumps. It also describes about the comparison of spring materials, sophisticated design, construction and working principle of newly proposed actuator. Catia V5 software has been used to design and simulate the actuator model, different spring materials are analyzed and their shear stress and deflections are compared.


2021 ◽  
Vol 40 ◽  
pp. 01001
Author(s):  
Sarvesh Walavalkar ◽  
Viraj Tandel ◽  
Rahul Sunil Thakur ◽  
V.V Pramod Kumar ◽  
Supriya Bhuran

The value of a self-tuning adaptive semi-active control scheme for automotive suspension systems is discussed in this paper. The current vehicle suspension system uses fixed-coeffcient springs and dampers. The ability of vehicle suspension systems to provide good road handling and improve passenger comfort is usually valued. Passive suspension allows you to choose between these two options. Semi-Active suspension(SAS), on the other hand, can provide both road handling and comfort by manipulating the suspension force actuators directly. The semi-active suspension system for a quarter car model is compared to passive and various controllers such as Proportional-Integral, Proportional-Integral-Derivative, Internal model control (IMC)-PID, IMC-PID with filter, FUZZY, and Adaptive-network-based fuzzy inference system(ANFIS) in this analysis. This research could be relevant in the future for designing better car suspension adjustments to eliminate vertical jerks and rolling motion experienced by the vehicle body on bumps and humps.


Author(s):  
Gokhan Kararsiz ◽  
Mahmut Paksoy ◽  
Muzaffer Metin ◽  
Halil Ibrahim Basturk

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.


Symmetry ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1286
Author(s):  
Ayman Aljarbouh ◽  
Muhammad Fayaz

Rigorous model-based design and control for intelligent vehicle suspension systems play an important role in providing better driving characteristics such as passenger comfort and road-holding capability. This paper investigates a new technique for modelling, simulation and control of semi-active suspension systems supporting both ride comfort and road-holding driving characteristics and implements the technique in accordance with the functional mock-up interface standard FMI 2.0. Firstly, we provide a control-oriented hybrid model of a quarter car semi-active suspension system. The resulting quarter car hybrid model is used to develop a sliding mode controller that supports both ride comfort and road-holding capability. Both the hybrid model and controller are then implemented conforming to the functional mock-up interface standard FMI 2.0. The aim of the FMI-based implementation is to serve as a portable test bench for control applications of vehicle suspension systems. It fully supports the exchange of the suspension system components as functional mock-up units (FMUs) among different modelling and simulation platforms, which allows re-usability and facilitates the interoperation and integration of the suspension system components with embedded software components. The concepts are validated with simulation results throughout the paper.


2013 ◽  
Vol 340 ◽  
pp. 631-635
Author(s):  
Yong Fa Qin ◽  
Jie Hua ◽  
Long Wei Geng

Vehicles with active suspension systems become more ride comfort and maneuverable stability, many types of active suspensions have been applied to passenger vehicles, but one of the shortcomings of an active susupension system is that the additional control power consumption is needed. The core issues of designing an active suspension system are to minimiaze vibration magnitute and control energy comsuption of the active suspension system. A new mathematic model for an active suspension system is established based on vehicle dynamics and modern control theory. An optimal control law is constructed through solving the Riccati equation, and then the transfer function is deduced to describe the relationship between the vetical velosity of the road roughness and the output of suspension system. Three typical parameters of vehicle ride comfort are researched, such as vertical acceleration of vehicle body, dynamic deflection of suspension system and dynamic deformation of tires. A case of a quarter vehicle model is studied by simulation to show that the proposed method of modeling and designing optimal controller are suitable to develop active suspension systems.


2020 ◽  
Vol 142 (12) ◽  
Author(s):  
Siyang Song ◽  
Junmin Wang

Abstract In preview-based vehicle suspension applications, the preview of the road profile is highly dependent on the preview sensors. In some scenarios such as heavy traffic situations, the preview of road profile can only be estimated by other vehicles because the view of the preview sensors may be blocked by other vehicles. The estimated preview road information can contain errors, which thus requires the controller to have a good robust performance. In this paper, an incremental model predictive control (MPC) strategy for active suspension systems along with a road profile estimator using preview information from a lead vehicle is proposed. The efficacy of the proposed strategy is experimentally validated on two scaled-down active suspension stations with comparison to two conventional active suspension control approaches.


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