Front Suspension Research Articles

Vehicle posture wheelbase preview control of in-wheel motors drive intelligent vehicle on potholed road

The in-wheel motors drive intelligent vehicle (IMDIV) has a strong ability of dynamic control, which makes it be a major development path of intelligent vehicles in the future. However, its stability is easily deteriorated by the impact of the road when driving on potholed road. To tackle this issue, a vehicle posture control method based on road feedback and elevation recognition is proposed. Firstly, an elevation recognition algorithm of adaptive Kalman filter (AKF) based on vehicle dynamic response is proposed after considering the flooded road and the system noise uncertainty. Secondly, a vehicle posture controller of fuzzy active disturbance rejection control (FADRC) is designed, with the function of dynamically adjusting the active disturbance rejection control (ADRC) parameters. It is designed to implement front suspension feedback control and rear suspension wheelbase preview control. At last, the road elevation recognition algorithm and vehicle posture control method are proved by Simulink simulation and off-line hardware in the loop test. The results revealed that the AKF can effectively recognize both white noise pavement and potholed road, and the recognition accuracy is greater than 90%. The FADRC controller realizes accurate front suspension feedback control and rear suspension wheelbase preview control by adjusting the real-time online parameters of ADRC. The proposed vehicle posture control method can effectively control the pitch and roll motion, which significantly improves the stability of IMDIV on potholed road. This study can serve as a reference for the posture stability control of IMDIV on potholed road.

Numerical Evaluation of the Effectiveness of the Use of Endplates in Front Wings in Formula One Cars under Multiple Track Operating Conditions

The last change in the technical regulations of Formula One that came into force in 2022 brought with it significant changes in the aerodynamics of the vehicle; among these, those made to the front wing stand out since the wing was changed to a more straightforward shape with fewer parts but with no less efficiency. The reduction in its components suggests that if one part were to suffer damage or break down, the efficiency of the entire front wing would be affected; however, from 2022 to date, there have been occasions in which the cars have continued running on the track despite losing some of the endplates. This research seeks to understand the endplates’ impact on the front wing through a series of CFD simulations using the k-ω SST turbulence model. To determine efficiency, the aerodynamic forces generated on the vehicle’s front wing, suspension, and front wheels were compared in two different operating situations using a model with the front wing in good condition and another in which the endplates were removed. The first case study simulated a straight line at a maximum speed where the Downforce is reduced by 2.716% while the Drag and Yaw increase by 7.092% and 96.332%, respectively, when the model does not have endplates. On the other hand, the second case study was the passage through a curve with a decrease of 17.707% in Downforce, 6.532% in Drag, and 22.200% in Yaw.

Research on Coordinated Control of Vehicle Inertial Suspension Using the Dynamic Surface Control Theory

In the process of driving, the steering, braking, and driving conditions and different road conditions affect the vibration characteristics of the vehicle in the vertical, roll, and pitch directions. These factors greatly impact the riding comfort of the vehicle. Among them, the uneven distribution of vertical load between the left and right or the front and rear suspension is one of the important factors affecting the performance indicators of the vehicle’s roll angle acceleration and pitch angle acceleration. In order to improve the ride comfort of the vehicle in vertical, roll, and pitch motion, the inerter is introduced in this paper to form a new type of suspension structure with the “spring-damping” base element, inertial suspension. It breaks away from the traditional “spring-damping” base element of the inherent suspension structure. In this paper, the mechatronic inerter is taken as the actual controlled object, and the inertial suspension structure is considered as the controlled model based on the dynamic surface control theory and the pseudo-inverse matrix principle. Thus, the coordinated control of the inertial suspension can be achieved. Under random road input, compared with passive suspension, the ride comfort performance indicators of the vehicle with inertial suspension based on dynamic surface control are significantly improved. Finally, a Hardware-in-the-Loop (HiL) test of the controller based on dynamic surface control is carried out to verify that the performance of the vehicle inertial suspension using the dynamic surface control algorithm had improved in terms of vehicle ride comfort. The error between the experimental results and the simulation results is about 8%, which verifies the real-time performance and effectiveness of the dynamic surface controller in the real controller.

Ride Test on Vehicles Travelling Over Speed Bumps: Simulation with CarSim Software

This study explores the effects of different speed bump geometries—flat-topped, sinusoidal, and parabolic—on vehicle dynamics and ride comfort using CarSim simulations. The analysis focuses on key parameters such as vertical forces on the suspension, vertical acceleration, and the wheel surface adhesion index. The results show that flat-topped bumps generate the highest vertical forces, reaching peaks of up to 6,000 N on the front suspension, leading to increased discomfort. Sinusoidal bumps, in contrast, generate smoother transitions, with vertical forces peaking at approximately 3,500 N, improving ride comfort. At vehicle speeds of 30 km/h, the vertical forces on the suspension increase significantly, with flat-topped bumps reducing the wheel surface adhesion index to as low as 0.6, indicating a higher risk of wheel slip and compromised vehicle stability. In contrast, sinusoidal bumps maintain a more favorable adhesion index of 0.85 at similar speeds. These reductions in adhesion elevate the risk of loss of control, especially at higher speeds. The findings suggest that adaptive suspension systems, capable of adjusting damping and stiffness based on the bump geometry and vehicle speed, would enhance ride quality and stability. Additionally, smoother bump designs, such as sinusoidal profiles, are recommended to reduce the impact on vehicle dynamics, particularly in urban environments. These insights contribute to improving both vehicle design and road safety, ensuring safer and more comfortable driving experiences.

Topology optimization with the redesigned suspension system of the internal combustion vehicle converted to an electrical vehicle

Abstract In this paper, the topology optimization of lower wishbone for a passenger car which is the converted of an internal combustion engine vehicle to an electrical vehicle was presented. On the other hand, the need to study on a suspension system arose for electrical car that was redesigned. In study, topology optimization of the structural design of the lower wishbone to be used in the front suspension was carried out by Finite Element Analysis (FEA) Method. For this purpose, firstly, the suspension spring curves and damper curves that will improve the handling, ride and comfort behaviour of the vehicle were determined, suspension system was modelled with the Multi Body Dynamics (MBD) approach. Hardpoints is necessary for vehicle dynamics and that is also an input for FEA were obtained from new suspension system via MBD analysis. In the second step, The preliminary design of the lower wishbone was created, taking into account together with the positions of the wheel drive shaft, suspension spring and brake system structural elements according to hardpoints. After designing the structure suitable for the joint types, initial design was studied on the remaining region that is for weight reduction region except the joint connection surfaces. Then, topology optimization was applied to the preliminary design for the selected load types that is come from MBD analysis. Thus, the excess volume on the preliminary design was determined for each load type. In the last stage, the results of topology optimization analysis were evaluated to reach out target weight and the producible design of the wishbone was made. Finally, Finite Element Analysis were applied to the final design for validation purposes within topology optimization work was done with the forces coming from Multi Body Dynamics. After statically solved Finite Element Analysis, a modal neutral file(.mnf) was created via FEA solver and was integrated to Adams Car as a flexbody. Flexbody was attahced to the other parts which are rigid bodies like nuckle according to Multi Body Dynamics approach. Dynamics durability cases was carried out via Adams Car. Stress results was compared to FEA results and evaluated depends on yield stress. Study results shows that the new design is lighter and competitive design and also safe in dynamics analysis for redesigned passenger car.

Effect of Suspension Preload on Fatigue Life of Two Wheeler Frame

A suspension unit is a significant component in a vehicle. It provides a smooth ride, improves traction, maintains ride geometry and facilitates better handling. A typical suspension setup in a two-wheeler consists of a front and rear suspension setup working independently to achieve the desired function. It connects the wheel to the chassis of the vehicle, transferring road load and hence affecting the durability of the structural members. This research work focuses on the durability aspect of the suspension unit with its preload as the control parameter. A rear suspension with seven preload settings was chosen for this study. The provision requirements of preload settings in suspension were experimentally analyzed using static measurements. The vehicle was instrumented with transducers (strain gauges, accelerometers, linear displacement sensors, and Global Positioning System (GPS) sensors), and dynamic road load data was acquired at different rear suspension preload settings by changing from the minimum, i.e., the 1st setting, to the maximum, i.e., the 7th setting, while keeping other parameters constant. Statistical analysis and fatigue analysis were utilized to study the dynamic effects. It was observed and quantified that increasing the preload for higher static load conditions or rough road conditions provides a smoother ride and improved life due to lower bump stopper engagement and full bump conditions owing to increased compression stroke availability. Keywords: Suspension, Fatigue Life, Stiffness, Riding, Strain Gauges

Modeling and Experimental Validation of an Off-Road Truck’s (4 × 4) Lateral Dynamics Using a Multi-Body Simulation

In the automotive sector, the use of multi-body software for modeling of existing vehicles has become essential due to its advantages in understanding vehicle dynamics in different situations and improving vehicle performances. This paper aims to model an off-road truck (4 × 4) by using ADAMS software 2020. Several steps must be achieved, including experimentally identifying some truck characteristics such as the mass, center of gravity coordinates, and tire vertical stiffness. The truck features leaf springs in both the front and rear suspensions, which must be validated before their integration into the full model due to their modeling complexity. This validation is performed by comparing the force–displacement characteristics obtained experimentally with simulation results from ADAMS, showing a good agreement. Then, the full truck is modeled in ADAMS software and validated through an experimental test using a repeated double-lane change scenario with two tests for the validation of the truck’s lateral dynamics. The comparison between the results shows a good correlation, validating the multi-body truck model.

Studying the influence of engine speed on the entire process of span-lowering of the heavy mechanized bridge

The paper presents a dynamic model of the TMM-3M heavy mechanized bridge during the span lowering stage. The model is constructed as a multi-body mechanical system, taking into account the elastic deformation of the cable, rear outriggers, front tires, and front suspension system. It is a mechanical model driven by a cable mechanism. Lagrangian equations of the second kind have been applied to establish a system of differential equations describing the oscillations of the mechanical system and serve as the basis for investigating the dynamics of the span-lowering process. The system of differential equations is solved using numerical methods based on MATLAB simulation software. The study has revealed laws of the displacement, velocity, and acceleration of components within the mechanical system, especially those related to the bridge span depending on the choice of the drive speed of the engine during lowering by operator. The research results show that the lowering time increases from 52 seconds to 104 seconds when the engine speed decreases from 1800 rpm to 900 rpm. The tension force on the cable is surveyed to confirm the safety conditions during the span-lowering process. The study also provides recommendations for selecting appropriate engine speeds to minimize span-lowering time while ensuring the safety conditions of the TMM-3M bridge during the span-lowering process. This research is an important part of a comprehensive study on the working process of the heavy mechanized bridge TMM-3M to make practical improvements, aiming to reduce deployment time, decrease the number of deployment crew members, and increase the automation capability of the equipment

Design and experiment of hydraulic stepless speed front suspension double disc mower

Design and experiment of hydraulic stepless speed front suspension double disc mower

Dynamics of Heavy Mechanized Bridge During Span-Lowering Process

Heavy mechanized bridge is utilized to be rapidly deployed as a temporary bridge to facilitate the movement of vehicles and personnel across obstacles. This paper presents a dynamic model of the TMM-3M heavy mechanized bridge during the span-lowering process, including considerations of cable deformation, rear outriggers, elasticity of tire, and front suspension system. Based on the dynamic model, the authors establish a system of differential equations describing the oscillation of the system using Lagrangian equations of the second kind. The article provides a fundamental basis for studying the entire process of deploying the TMM-3M bridge and aims to improve the rear outriggers and cable winding system to reduce bridge deployment time.

Calculation Model for Evaluating Suspensions during Maneuvers of a 4WD Vehicle with a 6x6 Wheels

The article describes the purpose, scope, main parameters of the flowchart of the procedure used to calculate control devices when comparing vehicle suspension structures with a 6x6 wheel arrangement. Methods for comparing suspensions during maneuvers are described. A description of the cab suspension system, a block diagram of the simulation program is presented. The visualization of the process of rebuilding the studied model of a 6*6 vehicle with two different types of front suspension is shown. An estimate of the load on the front and rear axles during the rebuilding for a period of time t = 5 s, their energy output and inertia is given. The distribution of the load along the axes of the investigated 6*6 vehicle model is presented when rebuilding with the front suspension of the first and second types. The coordinates of the base points of the front axle allow you to evaluate the numerical values for specific coordinates at a given point in time.

An electric kickscooter multibody model: equations of motion and linear stability analysis

AbstractIn this work, a detailed multibody model of an electric kickscooter is presented. The model includes toroidal wheels as well as rear and front suspensions. The equations of motion are derived and linearized along the steady forward motion of the vehicle. Using an efficient linearization approach, suitable for complex multibody systems with holonomic and nonholonomic constraints, allows for obtaining the reduced linearized equations of motion as a function of the geometric, dynamic, wheels’, and suspensions’ parameters. The proposed electric kickscooter multibody model is validated with the stability results of a previously presented electric kickscooter benchmark. Since the resulting eigenvalues are parameterized regarding the design parameters, a detailed linear stability analysis of the system is performed. In particular, the influence on the stability of the toroidal geometry of the wheels, the elliptic cross-section of the toroidal wheels, the rider model, the steering axis inclination angle, the inertia tensor of the front frame, and the rear and front suspensions is analyzed. The model presented, together with the linearized equations of motion obtained in this work, enables a systematic analysis of the stability of these vehicles, which helps design new electric kickscooters with improved vehicle safety conditions and oriented to a wider range of potential users.

Evaluation of reliability indicators of shock absorbers struts of M1 category cars in conditions of violation of established market relations between end users of spare parts and suppliers

Introduction. Over the past two years, there has been a violation of established market relations between end users of spare parts and suppliers. This led, on the one hand, to a significant increase in the cost of automotive components, and, on the other, to a reorientation of the market to new alternative manufacturers and suppliers. The main purpose of the work was a statistical assessment of the reliability indicators of the most expensive suspension element – the McPherson suspension strut, in the conditions of replacing the original struts with analogues available on the market.Methods. The study of the operational reliability of systems, components and assemblies of M1 cars was conducted in a dealership during 2022-2023. The study mainly involved cars with a sedan body and a McPherson front suspension. At the same time, the reason for contacting the service, the mileage of the car, as well as the types of work performed were recorded in each work order. The experimental data were processed using MSExcel and MatLab software from MathWorks.Resultsand conclusions. The conducted research allowed us to conclude that the appeals on the suspension of the car are almost twice as high as other appeals. The most expensive elements – the front shock struts, account for up to a third of all suspension failures. To assess the reliability indicators of alternative racks, the failure distribution law (normal), the probability of failure and uptime are determined, and the parameters of the distribution law are determined: mathematical expectation, standard deviation and coefficient of variation. It was found that the resource of the rear shock absorbers is at least 30% more, and there are significantly fewer calls at the service station. Thus, the operation of a car with racks from alternative manufacturers is quite reasonable, despite the fact that the resource of racks from alternative manufacturers is usually lower than that of the original brands.

Optimization Design of Double Wishbone Front Suspension Parameters for Large Mining Dump Truck and Analysis of Ride Comfort

With the advancement of technology, mining trucks are gradually becoming larger, imposing higher performance requirements on the front suspension. There is a need to transform the original integral non-independent front axle of mining dump trucks with a payload exceeding 300 tons into an independent front suspension with a double-wishbone suspension. The changing of the front suspension is bound to have an impact on the overall vehicle’s handling stability and ride comfort. Therefore, the following research is conducted to investigate and analyze these effects. Firstly, the paper proposes a method for optimizing the parameters of the double-wishbone front suspension. The double-wishbone front suspension is modeled, and a comparison with a kinematic model is conducted to validate the accuracy of the model. Secondly, unreasonable hardpoint parameters are optimized. Thirdly, a dynamic model of the entire vehicle is established based on the optimized parameters, and an analysis of handling stability and ride comfort for the entire vehicle is performed. Finally, simulation results are compared and analyzed against experimental data. The results indicate that the optimized positioning parameters not only effectively enhance the suspension performance of the mining dump truck but also meet the requirements for handling stability and smoothness. The overall smoothness of the vehicle is significantly improved after the modification. This study not only holds significant engineering value in reducing vibrations in dump trucks and enhancing driver comfort, but also provides theoretical support for subsequent research and development in the industry.

Research on the dynamics of a heavy mechanized bridge in the deployment phase of the lifting frame

This article presents a dynamic model of the TMM-3M heavy mechanized bridge during the frame lifting stage, which is driven by a hydraulic system, constituting the initial phase of the bridge erection process. The model is constructed as a multi-body dynamic system, taking into account the elastic deformation of the rear outriggers, front tires, and front suspension system. The research model integrates a mechanical system controlled by hydraulic cylinders, with pressure being considered as a variable reacting to external loads during the system's operation. Lagrangian equations of the second kind are utilized to establish a system of differential equations describing the oscillations of the system and form the basis for investigating the dynamics of the frame lifting process. The system of differential equations is solved numerically using MATLAB simulation software based on the Runge-Kutta algorithm. The study has revealed laws regarding the displacement and velocity of components within the system, evaluating the stability of the TMM-3M heavy mechanized bridge during operation. This research paves the way for a comprehensive understanding of the working process of the TMM-3M heavy mechanized bridge, aiming for practical improvements to minimize deployment or retrieval time, reduce the number of deployment team members, enhance the automation of the operation process to reduce the workload for operators

Modelling of SOLO’s Car Suspension System

The use of a virtual analysis approach to develop and modify vehicle sub-system is becoming popular nowadays as it is less time consuming, reduces the workmanship and overall testing cost compared to the experimental approach. In this paper, an actual virtual suspension system based on UiTM’s Perodua Eco Challenge (PEC) competition fullbody vehicle named SOLO was modelled using multi-body dynamic software, MSC/ADAMS Car. The virtual suspension system model was developed starting from identifying the components’ hard points, parameter setting, and joint type between the suspension components. The complete model was simulated using a static vertical parallel movement test with 30 mm as the selected bump travel movement. Following that, the values of kinematic and compliance of toe, camber and caster change were obtained. It was found that the front toe change was negative when subjected to wheel bound at 30mm (-0.3<sup>o</sup>), while the trend is opposite with the rear toe change (0.2<sup>o</sup>). Camber and caster change shows similar trends for both front and rear suspension system. Further analysis was then done to study the dynamic performance and suspension improvement after the virtual suspension system is verified.

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.

The dependent coordinates in the linearization of constrained multibody systems: Handling and elimination

In this paper, the handling of the dependent coordinates in the linearization of constrained multibody systems is clarified. To this end, a brief but comprehensive overview of linearization approaches used in the field of Multibody System Dynamics is presented. These procedures are illustrated by using a common notation and classified into four groups, depending on the initial form of the nonlinear equations of motion and the selection of the generalized coordinates (a redundant or a minimal set). The handling of the dependent coordinates in each of the procedures is discussed. The linearized equations of motion of constrained multibody systems are of great importance in several applications, such as linear stability and modal analyses, the design of linear state feedback controllers or the building of state and input estimators, like Kalman filters. When modeling a constrained multibody system, a number of coordinates greater than the number of degrees of freedom of the system is usually used. While some linearization approaches make use of the complete set of coordinates, several procedures are based on a coordinate partition in terms of independent and dependent coordinates to reduce the number of linearized equations of motion. In this latter scenario, the role of the dependent coordinates in the linearization is important and, in a general case, these dependent coordinates cannot be ignored to obtain the correct linearized equations of motion. This aspect, which may seem obvious, is not straightforward and is addressed in this work. The importance of considering the set of dependent coordinates in the linearization is demonstrated with a well-acknowledged bicycle benchmark multibody model and an electric kickscooter multibody model with rear and front suspensions. To this end, the Jacobian matrix and the linear stability results of these case studies are computed by considering different choices of independent and dependent coordinates.

Structural Analysis & Shape Optimization for a Control Arm of a Vehicle’s Suspension.

This paper's primary goal is to develop and conduct a structural analysis of a sheet metal control arm used in the front suspension system. The control arm permits the wheel to move up and down but prohibits it from moving forward or backward. Additionally, the part is exposed to intense loads while performing its duty because the wheelbase is attached to the chassis on one end. To create sustainable and competitive products, component material and design selection is a crucial topic in the industry. Shape optimization can be utilized as a design tool in the initial stages of the design process to fully satisfy the strength and endurance requirements on a component level. Here the focus is on a control arm where the structural requirements on it involve the part being exposed to stress-strain due to the applied forces which can be treated and reduced during the optimization process. This would enable engineers to design better products while reducing the cost of development significantly.

The Double Wishbone Suspension Design of The Gajah Oling Electric Vehicle

The ongoing development of electric vehicles is aimed at swapping conventional fossil fuel-powered automobiles, namely those reliant on petrol and diesel. In order to achieve optimal use in practical scenarios, electric vehicles must possess the capability to navigate diverse terrain elements. The utilization of suspension systems serves the objective of reducing the magnitude of the load exerted on the tires, hence facilitating enhanced driver control over the electric vehicle. The spring performance of the suspension system in an electric car design is evaluated for different weight configurations. Specifically, when the car weight 120.4 Kg, the suspension exhibits a spring constant of 59.0N/m. Similarly, when the weight is 115.4 Kg, the suspension system demonstrates a spring constant of 62.8N/m. Finally, in the front suspension configuration with a weight of 129.4 Kg, the spring constant is measured to be 57.7 N/m. The constant data have been aggregated to determine that the maximum load capacity of the suspension system under shock conditions is 365.8 kg. Based on the findings of the design results, it was seen that the highest damping constant was recorded in the case of a load weighing 120.4 Kg, specifically in the low mode with a value of 285.41 Ns/m, and in the mid mode with a value of 196.6 Ns/m.