Vehicle Suspension Research Articles

Optimizing Hydro-Pneumatic Inerter Suspension for Improved Ride Comfort and Handling Stability in Engineering Vehicles Using Simulated Annealing Algorithm

This study introduces a novel hydro-pneumatic inerter suspension (HPIS) system for engineering vehicles, aiming at enhancing ride comfort and handling stability. The research focuses on addressing the limitations of conventional suspension systems by incorporating an inerter element into the vehicle suspension. The unique aspects of HPIS, such as nonlinear stiffness and nonlinear damping characteristics of the hydro-pneumatic spring, are explored. Firstly, a half-car dynamic model of the HPIS suspension is established, and an improved simulated annealing algorithm is applied to optimize the suspension parameters. Then, we compare the dynamic performance of different HPIS structures, specifically parallel and series layouts. For practical analysis, a simplified three-element HPIS suspension model is used, and the suspension parameters are optimized by a simulated annealing algorithm at speeds of 10 m/s, 15 m/s, and 20 m/s. Key findings reveal that compared to the traditional suspension system of S0, the front and rear suspension working space of S1 decreased by 40%, 40.1%, 40.2% and 30.7%, 30.8%, 30.9%, while with the body acceleration and pitch acceleration deteriorated by 3.1%, 3.2%, 3.3% and 63.4%, 63.8%, 64.0%. However, the S2 can improve all the dynamic performance and offer better ride comfort and handling stability.

Nonstationary time-frequency characteristics of vehicle suspension systems based on evolutionary power spectral density

Improving the ride comfort for vehicles that travel at varying speeds is a nonstationary problem and has been an increasingly important topic for suspension system research. Accurate identification of frequencies associated with the resonant responses is needed for effective design of active suspension control strategies. However, traditional time-frequency (TF) methods have resolution limitations in either the time domain or the frequency domain. This paper proposes a new methodology to employ the evolutionary power spectral density (EPSD) to describe the responses of vehicles in the time-frequency domain. The key to calculate the responses in nonstationary cases is to derive the nonuniform modulation function which is obtained by the pseudo excitation method. To illustrate the applicability of the proposed method, an example of a seven-degree-of-freedom vehicle model is investigated in which the nonstationary excitations acting on the wheels are computed by the nonuniform modulation function and a precise integration method. Results show that resolutions obtained by the EPSD are more precise than the traditional TF methods with less than 0.2 Hz of bandwidth in both the lower frequency range at the first natural frequency of 1 Hz and in the higher frequency around 10 Hz. Moreover, the changing of the resonant frequency with varying speeds provides the insights, from the perspective of human body’s sensitivity to frequencies of vibration, to improve the ride comfort for vehicles under nonstationary driving conditions.

Disturbance observer-based sliding mode control of active vertical suspension for high-speed rail vehicles

Disturbance observer-based sliding mode control (SMC) on the active vertical suspension (AVS) is developed to suppress the car body’s rigid and flexible vibration to improve ride comfort for a high-speed rail vehicle. A vertical-dynamics-intended vehicle model is foremost built with the bounce, pitch, and bending mode of the car body involved. Two sliding surfaces and disturbance observers are then designed for SMC, which only require the car body states, obviating the bogies’ states. The observer is successful in estimating the effect of unknown track irregularities perturbation as well as externally straightforwardly excitations on the car body with good accuracy. Control efficacy is verified through comparison with passive cases and sky-hook controls. With modal damping below 2% in passive cases, the mode shape function, especially with large displacement at the suspension support, would enlarge the car body acceleration. Moreover, the longitudinal traction rod can significantly multiply the flexible vibration at certain speeds. Comparative studies indicate that SMC provides satisfactory outcomes in the rigid and bending vibration suppression when all the car body’s three modes are considered in the sliding surface. However, it requires a high-frequency response actuator and allows a tighter tolerance of the control time delay than the sky-hook control.

A nonlinear model predictive control for air suspension in hub motor electric vehicle

The hub-motor electric vehicle (HM-EV) is considered as an ideal configuration for electric vehicles (EVs). However, the electromechanical coupling effect deteriorates HM-EV ride comfort, which limits its widespread application in EVs. In this study, the HM-EV dynamic system with air springs is proposed to intervene in vehicle attitude and ride comfort. The HM-EV dynamic model with air spring, considering the electromechanical coupling effect, is established and the test validation is investigated. Then quasi-infinite horizon nonlinear model predictive control (QIH NMPC) is designed to improve the longitudinal and vertical dynamic performance. The dynamic performance of passive suspension, air suspension based on QIH NMPC, air suspension based on MPC, and PID control receptively, are compared under several random road scenarios. Finally, the results indicated that the proposed control algorithm can improve ride comfort, reduce motor vibration, and improve longitudinal and vertical dynamic performance.

Design Analysis and Optimization of Coil Spring for Three-Wheeler Vehicles Using Composite Materials

The quest for lightweight, efficient, and corrosion-resistant coil springs for vehicle suspension systems has led to the exploration of alternative materials beyond traditional steel. This study delves into the potential of composite materials, particularly carbon/epoxy and carbon/carbon nanotube/epoxy, as replacements for conventional steel coil springs in light vehicles. Through a comprehensive analysis of mechanical properties under static and dynamic loading conditions, the study demonstrates the superior performance of composite springs compared to their steel counterparts. After optimization, the deflection of the carbon/carbon nanotube/epoxy and carbon/epoxy springs decreased to 15.003 mm and 18.703 mm, respectively, and the maximum shear stress decreased by 64.63% and 62.2%, respectively. Likewise, strain energies increased to 2.3644 and 3.5616, respectively. The springs were also studied under dynamic conditions, and the result showed these springs have the ability to perform in dynamic conditions. The carbon/carbon nanotube/epoxy composite emerged as the frontrunner, exhibiting remarkable improvements in shear stress, fatigue life, strain energy, and deformation properties. The study highlights the ability of carbon/carbon nanotube/epoxy composite springs to significantly reduce weight, enhance efficiency, and extend fatigue life, making them a promising alternative for next-generation vehicle suspension systems.

Feasibility of Modernizing the Acceptable International Roughness Index Value

The U.S. National Highway System has set a standard for acceptable pavement roughness, measured by the international roughness index (IRI) at less than 2.68 m/km (170 in./mi). This value corresponds to a present serviceability rating (PSR) of 2.5, where half of the highway drivers perceive the pavement ride quality as unacceptable with a repair need. For over 3 decades, public transportation agencies in the U.S. have used this IRI value to determine when pavement surface rehabilitation is needed. However, with advancements in vehicle suspension systems improving ride quality, the current acceptable IRI value corresponding to 2.5 PSR has been questioned. To our knowledge, studies in the literature have yet to explore this issue. This study aims to evaluate the feasibility of modernizing the acceptable IRI value through nationwide, large-scale field testing, which is typically expensive and time-consuming. The IRI-present serviceability index (PSI) equation that is capable of converting the acceptable IRI value into the estimated 2.5 PSR (i.e., the PSI) was selected and calibrated by applying test quarter-car parameters synthesized through a literature review. Then, the calibrated IRI-PSI equation was used to find a new acceptable IRI value that was evaluated for the statistical significance and the financial benefits of the new value. The evaluation results suggest a need for a nationwide field test to modernize the current acceptable IRI value. Public transportation agencies can easily adapt the technical approach we used to calibrate the IRI-PSI equation without altering their current IRI measurement systems.

A novel semi-active control of an integrated chassis and seat quasi-zero stiffness suspension system for off-road vehicles

This article introduces an innovative semi-active suspension system for off-road vehicles, incorporating a quasi-zero stiffness suspension to enhance driver comfort. The system includes a central pneumatic spring, double-acting pneumatic linear actuators for adjustable stiffness, and magnetorheological dampers for controlled damping. Using Lyapunov stability theory, a static output feedback control law is designed to address uncertainties in road profiles, driver body parameters, and actuator saturation, relying on measured variables as feedback. Performance constraints focus on driver head acceleration, suspension displacement, and dynamic tire load. The control law problem is converted into a convex optimization problem with linear matrix inequalities. The new semi-active QZSS system is theoretically tested via Matlab simulations and validated through hardware-in-the-loop testing. Comparative analysis between passive QZSS and the new semi-active QZSS on different roads, and vehicle speeds closely aligns with simulation results, with minor disparities attributable to network discrepancies and signal interruptions. Impressively, the semi-active QZSS system reduces driver head vertical acceleration between 26.53 and 35.0% compared to passive air QZSS, showing potential for significantly improving ride comfort, reducing vibration transfer, and enhancing driver wellbeing with minimal energy requirement.

A contrastive characterization of pure Mg and AZ91D alloy based on the testing of mechanical, corrosion, wear, and erosion properties

Abstract Magnesium alloy of grade AZ91D is utilized for a variety of applications in aircraft design and frames, as well as vehicle engine radiators, bumpers, and suspension components to reduce the weight of automobiles. This research compared the mechanical, corrosion, wear, and erosion resistance of pure Mg to that of AZ91 alloy. The corrosion media was NaCl, NaOH, and MgSO4, and the weight loss method was utilised to evaluate corrosion. The pin-on-disc configuration was utilized to assess the dry sliding wear mechanism of the Pure Mg and AZ91D alloy. Pure monolithic Mg and AZ91D magnesium alloy have a low resistance to wear as a result of an increase in contact temperature brought about by a shift of operational conditions. Erosive wear is caused when solid particles in a liquid or air jet strike a surface. Significantly influencing the erosive wear are particle velocity, impact angle, and erodent particle size. In this work, the erosive wear of AZ91D was studied using an Air jet erosion tester. SiO2 was used as the eroding material, and the flow rate of the eroding material and air was 5 gm min−1. The erosive factor experiments are designed using Taguchi orthogonal array (L16). The erosive factor response is erosion rate and primarily regulated by three factors as angle (30°, 45°, 60°, and 90°), time (5 and 10 min) and, contact pressure (1 and 2 bar). The results of the experiments showed that the rate of wear increased with increasing pressure, and that the angle of impact of the jet at 60° caused the most wear of any of the tested angles. Analysis of variance (ANOVA) shows that time is the most important factor in determining erosive rate for AZ91D. SEM is used to investigate the structure and morphology of worn-out materials, and its findings are then confirmed.

Development of a Novel Suspension System for Electric Vehicles Based on Mechanical Principles

Abstract The electric vehicle industry has witnessed significant growth in recent years, prompting heightened research interest in its various components. The suspension system, serving as a critical power-transmitting device between the frame and the axle, has garnered particular focus. This system is pivotal in meeting the dual performance objectives of ensuring driving smoothness and enhancing maneuvering stability. Accordingly, this study investigates the structural types of suspension systems and advances the design of a suspension guiding mechanism specifically tailored for electric vehicles. At the same time, the dynamic model of active suspension is constructed, and the algorithm for optimizing and establishing the active suspension system for electric vehicles is used. The simulation experiments on the suspension system, the control optimization method of the system in this paper’s car body spring loaded mass acceleration response, dynamic deflection ring, and the control input are stable between -0.4~0.5m/s², -0.005~0.01m and the suspension system’s between -0.7~0.6N, respectively. Moreover, the car body displacement and speed are gradually stabilized at about ±0 compared to the motion speed. In this paper, the suspension system can effectively solve the problem of automobile damping control and reduce the impact suffered by the body so as to improve the smoothness of the body in the process of driving and the operation of the stability of the new for the development and improvement of the suspension system in the electric vehicle industry to provide a reliable method.

Performance analysis of fuzzy-LQR and fuzzy-LQG controllers for active vehicle suspension systems

Suspension systems in vehicles are crucial to both ride quality and driving security. The challenge of creating an effective control mechanism for automotive active suspension systems is addressed in this work. In the event of unforeseen road disturbances, the active suspension systems are intended to deliver a more pleasant ride and good handling. Fuzzy-Linear Quadratic Gaussian (FLQG) and Fuzzy-Linear Quadratic Regulator (FLQR) controllers adapting to road disturbances are proposed to enhance vehicle comfort through the reduction of the driver's overall body acceleration. The simulation findings demonstrate that the FLQR and FLQG controllers are efficient in adjusting the automotive suspension configuration under varying road profiles compared to those of the conventional LQR and LQG controllers.

Development and Evaluation of Artificial Neural Networks for Real-World Data-Driven Virtual Sensors in Vehicle Suspension

Development and Evaluation of Artificial Neural Networks for Real-World Data-Driven Virtual Sensors in Vehicle Suspension

Modeling and Simulation of Semiactive and Active Suspension System using Quarter Car Model

A passive suspension system is used by the automotive industry to control the motion of the vehicle. Nowadays, semiactive and active suspension systems are a requirement of commercial vehicles to improve performance characteristics and road comfort. The objective of the paper is to present a comprehensive analysis of passive, semiactive, and active suspension systems. The fuzzy logic controller is used to present the active suspension system. The characteristic of the shock absorber (damper) is non-linear and hysteresis in nature. Hence, a Magneto-rheological (MR) damper-based Bouc-Wen model is utilized to present the semiactive suspension. The comparative analysis of vehicle suspension characteristics has been carried out by using a bump road profile. The modeling of the Bouc-Wen model and quarter car system is carried out in the Simulink environment. The simulated results show that the semiactive and active suspension systems can be a better option for vehicle suspension systems to provide passengers with road comfort.

Study of the operation of active suspension with magnetic fluid-less shock absorbers

The article presents the structure of an active suspension system for a commercial vehicle aimed at enhancing system performance. Solutions for integrating electromagnetic dampers into an intelligent active suspension system are identified. The behavior of the suspension system under challenging road conditions is examined. A block diagram of the active suspension system with a controller is provided. The article is published based on the findings of a research project conducted as part of a grant competition for scientific research projects by the teaching staff of Saint Petersburg State University of Architecture and Civil Engineering (SPbGASU) in 2024. Keywords magnetic shock absorbers, electromagnetic shock absorbers, suspension, damping, modeling

A Novel HPPD-type Fuzzy Switching Control Scheme of Active Vehicle Suspension Systems

A Novel HPPD-type Fuzzy Switching Control Scheme of Active Vehicle Suspension Systems

Enhanced Fuzzy Control of Active Vehicle Suspension Systems Based on a Novel HPPD-Type Non-PDC Control Scheme

Enhanced Fuzzy Control of Active Vehicle Suspension Systems Based on a Novel HPPD-Type Non-PDC Control Scheme

Vibration Analysis of Suspension System for 3DOF Quarter Car Model with Tire Damping

Quarter car model is the simplest way for the analysis of vehicle suspension system. The objective of this study is to propose the natural frequency and to identify the displacement analysis of 3 Degree of Freedom (3DOF) suspension system using Matlab software. Research methodology are state space modelling method and logarithmic decrement method. From the state space modelling, seat mass, sprung mass and unsprung mass displacement have been calculated. Logarithmic decrement method is a time domain technique to obtain experimental damping ratio. The novelty of this research has demonstrated the experimental approach by using Quantum X (catman AP v5 software). Natural frequency and acceleration results are obtained from the time domain response of experimental data. The value of sprung mass natural frequency for theoretical (1.23 Hz) and experimental (1.134 Hz) result are within 1Hz to 2Hz. The maximum displacement transmissibility values for theoretical (2.7) and experimental (2.54) approach are less than the reference value (3.5) at the resonance point. The findings demonstrated that the results of natural frequency and damping ratio are within the acceptable limit. So, the obtained results are validated the suspension system of Nissan Sunny model for vehicle safety and passenger comfort.

Dijagnostika kvarova zasnovana na bestežinskoj neuronskoj mreži u sistemu vešanja

Vehicle suspension systems play a critical role in ensuring passenger comfort and safety. Detecting faults in these systems is vital for maintaining safety, performance, and cost-effectiveness. Traditional inspection methods have limitations, such as visual checks, bounce tests, and alignment assessments. This study explores Wilkie, Stonham, and Aleksander Recognition Device (WiSARD), a weightless neural network (WNN), for suspension fault diagnosis. A WNN model is employed to classify suspension system faults using sensor data. The dataset includes both normal and faulty conditions to train the model. The study assesses WiSARD under various fault conditions, including strut damage, mount failure, worn-out components, and low wheel pressure. Comparative evaluations demonstrate that the approach outperforms other classification techniques, achieving an impressive 95.63% accuracy with a rapid 0.05-second computation time for test data. This WNN-based method proves superior in detecting suspension faults and holds potential as a candidate for real-time vehicle fault diagnosis systems.

Theoretical investigation of the rail vehicle suspension system using different optimised controllers by harmony search algorithm incorporating magnetorheological dampers

Theoretical investigation of the rail vehicle suspension system using different optimised controllers by harmony search algorithm incorporating magnetorheological dampers

Predefined-Time Fault-Tolerant Control for Active Vehicle Suspension Systems With Reference X-Dynamics and Conditional Disturbance Cancellation

Predefined-Time Fault-Tolerant Control for Active Vehicle Suspension Systems With Reference X-Dynamics and Conditional Disturbance Cancellation

Data-Driven ToMFIR-Based Incipient Fault Detection and Estimation for High-Speed Rail Vehicle Suspension Systems

Data-Driven ToMFIR-Based Incipient Fault Detection and Estimation for High-Speed Rail Vehicle Suspension Systems