Independent Front Suspension Research Articles

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.

Experimental Investigation on Improving the Comfort of the Vehicle Based on Damping Characteristics of Passive Suspension System using Quarter Car Model

This paper presents detailed experimental research performed on a coil spring that uses the passive mode suspension operation with different road profiles. A quarter car model comprised of two degrees of freedom was developed for ride comfort assessment. The quarter car test rig model for a single independent front suspension that embodies sprung mass, unsprung mass, suspension system and the tire was used. The damping factor is calculated at different road profiles and operating frequencies. An excitation of sinusoidal road profiles with constant amplitude is enforced via an electric motor representing the road profiles. The experimental results of the sprung mass and unsprung mass displacements due to road excitation are measured, recorded and processed. In this study, the sprung mass responses were received for the generated road profiles in contracted and stretched modes of the static compression coil enabling the researchers to select a suitable controller design and innovative materials for the passive, active vehicle suspension systems based on the feedback of the displacement sensors in future developments.

Development of an Independent Front Suspension for Truck Tractors

Design and experimental validation stages of an independent front suspension (IFS) that is designed for truck tractors of articulated commercial vehicles are summarised. Firstly, the suspension geometry, which satisfies the required conditions of minimum deviation of camber angle and track width during wheel travel, is obtained within the given design volume by using Multibody Systems (MBS) and Design of Experiments (DOE) approaches. Subsequently, the kinetic analysis is carried out for the suspension system and the critical design loads that may act on the structural elements are determined. Taking these loads into account, the mechanical design of the suspension system elements is performed. The Finite Element Analysis (FEA) is applied to the complete suspension system for the chosen critical load conditions. Stress concentrated regions on the crucial system elements are determined and improvements are indicated, which result in the reduction of stress concentrations. In the last part of the study, prototyping and fatigue tests are carried out. Throughout bench tests, in which real service conditions are simulated, no failure of any sort is encountered. The final suspension system (pair) is 31% lighter than an equivalent rigid front axle in terms of load capacity.

Design and comparisons of adaptive harmonic control for a quarter-car active suspension

Car suspensions have the job to keep the tires in contact with the road surface as much as possible, to deliver steering stability with good handling and to guarantee passenger comfort. Most modern vehicles have independent front suspension and many vehicles also have independent rear suspension. Independent suspensions are preferred instead of dependent suspensions for their better ride handling, stability, steering and comfort but they provide less overall strength and a complex design which increases the cost and maintenance expenses for such a suspension. For this reason, automotive engineers struggle to discover new suspension components or advanced control solutions. Taking a step forward in this direction, the paper presents in the beginning one of the well-known mathematical models of a quarter-car active suspension. The obtained model is then implemented in a MATLAB/Simulink simulation which compares multiple control solutions. The only feedback considered for each control algorithm is the measurement of the body acceleration. Among these investigated control algorithms is the adaptive harmonic control solution proposed by this paper. The controller generates a harmonic control signal with variable amplitude and frequency based on the body acceleration feedback. The comparison analysis shows that the proposed control solution demonstrates quite good potential, generating in some cases better results than the other control algorithms.

Axle Efficiency Comparison Method and Spin Loss Benefit of Front Axle Disconnect Systems

<div class="section abstract"><div class="htmlview paragraph">There are a variety of test protocols associated with vehicle fuel economy and emissions testing. As a result, a number of test protocols currently exist to measure axle efficiency and spin loss. The intent of this technical paper is to describe a methodology that uses a singular axle efficiency and spin loss procedure. The data can then be used to predict the effects on vehicle FE and GHG for a specific class of vehicles via simulation. An accelerated break-in method using a comparable energy approach has been developed, and can be used to meet the break-in requirements of different vehicle emission test protocols. A “float to equilibrium” sump temperature approach has been used to produce instantaneous efficiency data, which can be used to more accurately predict vehicle FE and GHG, inclusive of Cold CO<i><sub>2</sub></i>. The “Float to Equilibrium” approach and “Fixed Sump Temperature” approach has been compared and discussed. Independent Front Suspension (IFS) axles were used for this project as an enabler to determine the spin loss benefits of Front Axle Disconnect (FAD) systems. The test protocol has been validated with axles of different sizes and designs.</div></div>

Research on the influence of electric vehicle driven system on vehicle shimmy based on numerical calculation

A 6 degrees of freedom shimmy model for four in-wheel motors independent drive electric vehicle with independent front suspension is established, and numerical analysis and simulation are used to study the dynamic response of vehicle shimmy. The influence of electric vehicle driving system on shimmy is studied by comparing with fuelengined vehicle, and the influence of vehicle structural parameters such as the caster angle, the inclination angle of front suspensions and the centre of gravity of vehicle on shimmy are studied too. It shows that as the in-wheel motor in drive system increases the weight of wheel, the amplitude of each degree of freedom in electric vehicle are larger than in fuel-engined vehicle when vehicle shimmies. The influence of the caster angle and the centre of gravity of vehicle on vehicle shimmy is obvious, but the inclination angle of front suspension have little influence.

Optimization and Analysis of Double Wishbone Independent Front Suspension Based on Virtual Prototype

The simulation model of the double wishbone independent front suspension with a single degree of freedom is built based on the dynamics simulation software ADAMS/VIEW in this paper. Through the optimization and analysis of the upper cross arm (UCA) and the low cross arm (LCA), we can achieve the goal of decreasing the sideways displacement and the tire wear.

Simulation and Optimization of FSAE Racing Suspension

In this paper, kinematics analysis software ADAMS/Car was used to establish the FSAE car racing double wishbone independent front suspension simulation model, kinematics simulation analysis has been used to get the wheel beats of each parameters variation. For the simulation results, part of the suspension of the hard points position have been optimized by ADAMS/Insight module, to improve the characteristics of the suspension movement.

Ride Comfort Analysis Using Quarter Car Model

This paper presents a detailed theoretical and experimental investigation for ride comfort evaluation at different vehicle speeds. For the purpose of ride comfort evaluation, a quarter car model with two degrees of freedom has been developed. For realistic investigation, the equivalent characteristics of suspension stiffness and the shock absorber characteristics are calculated and incorporated to simulation. Using available quarter car test rig for single independent front suspension, that embodies sprung mass, unsprung mass, suspension system and tire. An excitation of sinusoidal road profiles with constant amplitude is imposed via eccentric wheel that represents the road profiles. The experimental results of sprung mass and unsprung mass accelerations due to road excitation are measured, recorded and processed. A validation of the theoretical results with experimental results has been carried out at different speeds. Good agreement has been obtained when using the equivalent suspension stiffness and damping coefficient as input parameters to quarter car modelrepresenting the independent front suspension.

Kinematic Performance Analysis of the Double Wishbone Independent Front Suspension

The vector method is applied to study the kinematic performance of the double wishbone independent front suspension.The model of the right front suspension is established in this paper, on this basis, the local motion reference frames of the upper and lower arms are established by using the coordinate transformation method. Therefore, the space relations between of the arms can be transformed into the plane motion of their respectively local reference frame by this method. Furthermore, the variable law of the wheel alignment parameters with the swing angle φ of the lower arm, is obtained through establishing the constrain equations of the key points.

Design and Research on Micro Pure Electric Garbage Transfer Vehicle

Based on the analysis of characteristics and Application requirements, one type of micro pure electric garbage transfer vehicle was designed. The power layout program, chassis layout and hydraulic lifting mechanism were researched to meet the driving safety need and automobile ride. The McPherson independent front suspension and the coil spring integral rear suspension were selected as the suspension program. The type of motor front and front drive was the arrangement of power system. The ladder frame chassis was selected for its high strength and low cost and the finite element analysis of frame was executed to verify the strength. The lifting mechanism was the key of the vehicle, one integrated hydraulic lifting mechanism was selected and the lifting time and angle and cylinder diameter were calculated. The tests confirm the sample vehicle being of reliable design and good performance.

Innovative concept design of an independent front suspension and steering system

This paper investigates the innovative design of an independent suspension that has invariable orientation parameters when the wheel is jumping up and down and a steering system that satisfies the Ackermann law in turning. With group theory, it first discusses the synthesis of kinematic chains of a rigid body guidance mechanism which can realize straight-line translation. Then, it synthesizes a symmetrical redundant suspension mechanism with constant orientation parameters. This kind of independent suspension should not only eliminate the shambling shocks induced by the jumping of wheels but also decrease the wear of tyres. A new steering mechanism that satisfies the Ackermann law during turning is also proposed to satisfy the straight-line motion of the suspension. Therefore, these kinds of independent suspension can be used as both front and rear suspensions. The steering system accompanying the rectilinear moving suspensions should greatly improve the ride and handling properties of advanced automobiles.

Predication of Steering Geometry of Front Suspension using Experimental Data Based Model

Automobile Industry is one of the key industries in the business sector. Automobile industry has the largest growth because of changes in consumer preferences, business policies and changing economic conditions. Almost all modern cars have independent front suspension, which means that each front wheel of your auto is linked separately to the automobile frame. The front wheels must steer as well as respond to the road surfaces because of bounces up and down when either wheel hits a bump or pothole. Automobile should drive down on the road in comfort and safety. The performance of front suspension of automobile is based on the steering geometry of the suspension. The steering geometry parameters are kingpin angle, camber angle, caster angle, scrub radius, toe in and toe out. In this paper model equations are formulated based on which steering geometry can be predicated and vehicle performance can be determined.

Condition-Triggered Maintenance for Mine Haul Roads with Reconstructed-Vehicle Response to Haul Road Defects

The management of unpaved mine road networks—characterized by high axle loadings, low traffic volumes, variable materials and construction quality, and rapid rates of deterioration—is often inadequate. This situation results in either overmaintenance of the road or failure to recognize significant deterioration, which both lead to the application of suboptimal road maintenance strategies with the attendant increase in total road-user costs. A real-time condition-triggered maintenance management system was identified as a solution, in which onboard monitoring of vehicle dynamic response to road condition forms the basis of road defect recognition and maintenance response. A practical approach to road defect reconstruction using measured truck response is presented. Initially, the application context is introduced, then the field testing program is described, in which data sets were generated that served as the basis for mathematical modeling of the truck response. A modeling approach utilizing the concept of independent front suspension dynamic equilibrium is described as the basis for road defect recognition. On the basis of measured suspension forces and the acceleration of the unsprung mass, the approach to tire force and road defect reconstruction is presented. It is concluded that the methodology developed enables reconstruction of road defect geometries with an accuracy sufficient to allow specific types and dimensions of defects to be recognized for the purpose of road maintenance. By extending the methodology to public unpaved roads, maintenance could be applied as and where needed with a resultant reduction in authority cost and improvement in service provided for the road user.

Steering Mechanisms

It is considered that this survey will be most useful if it is concerned with the principles employed and some typical methods of applying them rather than attempting to provide a comprehensive catalogue of all the component parts of steering mechanisms, especially as at least some history may be interesting. For instance, rocker shaft type boxes, which were originally practically universal, so long as they were concerned with front axles had to play their part in absorbing road shocks due to gyroscopic action of the wheels, and with high pressure tyres did not need to be very efficient. Now that Independent Front Suspension (I.F.S.) has generally reduced gyroscopic and other action and low pressure tyres have put up steering torques, efficiency has become much more important and has affected the construction used.