Suspension Design Research Articles

Analysis of an all-terrain tracked robot with innovative suspension system

Tracked robots are gaining interest in the current context of off-road mobile robotics, especially in soft-terrain applications, because they offer a large contact area with the ground, which provides better traction than wheels or legs. In this paper, a novel passively articulated tracked robot is introduced. On each side, Polibot features a rubber track wrapped around four independently suspended road wheels, an idler wheel, and the sprocket, and it can adapt to many kinds of terrain. An inverse kinematic model for the proposed architecture is also developed to predict the system configuration given the terrain topography. The analytical model is based on constraint equations and a quasi-static force analysis, and it is validated against results obtained from the real prototype, showing good agreement. It can also be used to evaluate the influence of the many suspension design parameters and operating conditions, proving that it can be a useful tool for the proper setup of the robot.

Optimal Design of Agricultural Mobile Robot Suspension System Based on NSGA-III and TOPSIS

The stability of vehicles is influenced by the suspension system. At present, there are many studies on the suspension of traditional passenger vehicles, but few are related to agricultural mobile robots. There are structural differences between the suspension system of agricultural mobile robots and passenger vehicles, which requires structural simplification and modelling concerning suspension of agricultural mobile robots. This study investigates the optimal design for an agricultural mobile robot’s suspension system designed based on a double wishbone suspension structure. The dynamics of the quarter suspension system were modelled based on Lagrange’s equation. In our work, the non-dominated sorting genetic algorithm III (NSGA-III) was selected for conducting multi-objective optimization of the suspension design, combined with the Technique for Order Preference by Similarity to the Ideal Solution (TOPSIS) to choose the optimal combination of parameters in the non-dominated solution set obtained by NSGA-III. We compared the performance of NSGA-III with that of other multi-objective evolutionary algorithms (MOEAs). Compared with the second-scoring solution, the score of the optimal solution obtained by NSGA-III increased by 4.92%, indicating that NSGA-III has a significant advantage in terms of the solution quality and robustness for the optimal design of the suspension system. This was verified by simulation in Adams that our method, which utilizes multibody dynamics, NSGA-III and TOPSIS, is feasible to determine the optimal design of a suspension system for an agricultural mobile robot.

One necessary condition for passive all-wheel attachment of a wheeled planetary rover

A planetary rover is designed to traverse rough, unpaved terrain. The all-wheel-attachment property, i.e., that each rover wheel maintains firm contact with the terrain, is considered crucial in modern rover suspension design. This paper proposes one necessary condition associating the DOF of the suspension with the number of wheels for the all-wheel-attachment property. The paper first describes an equivalent single wheel–ground contact model and then the whole rover model, through which the mobility value of 3 was calculated for the all-wheel-attachment condition. The necessary condition is finally acquired through the fact that in the all-wheel-attachment condition, mobility should equal the difference of DOF of the whole rover and constraints. Furthermore, a type synthesis is proposed for the rovers with passive all-wheel-attachment property using the necessary condition. The necessary condition was further verified and interpreted by case studies of various excellent rovers by different institutes and the simulation of newly proposed rovers.

Design and Fabrication of Electro-Mechanical Active Suspension System Test Rig

This abstract discusses the design and fabrication of an active suspension system. The goal is to enhance ride comfort, stability, and vehicle dynamics. The research focuses on analyzing the quarter car model dynamics and employing advanced control algorithms and actuators for adaptive suspension adjustment. Integration of sensors, control units, and actuators is crucial for real-time monitoring and control of the suspension. With the help of this rig, we are analyzing the linear acceleration in passivesuspension and active suspension. By doing so we can determine the load acting on the chassis.The active suspension system test rig is a valuable tool for automotive engineers and designers. It allows them to evaluate the performance of different suspension systems in a controlled environment, under various operating conditions

Design and Fabrication of Electro-Mechanical Active Suspension System Test Rig

This abstract discusses the design and fabrication of an active suspension system. The goal is to enhance ride comfort, stability, and vehicle dynamics. The research focuses on analyzing the quarter car model dynamics and employing advanced control algorithms and actuators for adaptive suspension adjustment. Integration of sensors, control units, and actuators is crucial for real-time monitoring and control of the suspension. With the help of this rig, we are analyzing the linear acceleration in passivesuspension and active suspension. By doing so we can determine the load acting on the chassis.The active suspension system test rig is a valuable tool for automotive engineers and designers. It allows them to evaluate the performance of different suspension systems in a controlled environment, under various operating conditions.

Application of simulation methods on vibration analysis of a bus driver seat using the quarter car 3DOF model subjected under harmonic excitation

Vibration of bus driver's seat subjected under harmonic excitation, 3DOF (3 degrees of freedom) dynamic model is employed to carry out the calculation by 3 simulation methods. Mathematical model - numerical using Matlab programming language (Numerical model), Multi Body Dynamics (MBD) using Matlab Simmechanics tool (MBD model) and finite element model using Ansys APDL (FEM model) are employed. The strengths and limitations of each method are analyzed through the process of building models and retrieving the resulting data. The evaluation indexes include the response of driver's seat acceleration, response of the seat suspension's relative displacement and the seat suspension's vibration isolation ability according to two investigated cases of natural frequency and damping ratio. The obtained results from all 3 methods have no difference and the evaluation indexes are suitable according to the studies on vehicle vibration response. The Numerical model method requires the user to perform complex mathematical modeling. The MBD model method using Matlab Simmechanics is simpler, using built-in function blocks, requiring declarations to establish the exact initial equilibrium position of the mass elements. The FEM model method using Ansys APDL with keypoints and lines describing the model elements requires precise setting of the displacement of each keypoint. However, both the MBD and FEM model methods are only effective when investigating the response in the time domain for a particular instance of the excitation frequency. When analyzing the response in the frequency domain, which requires accessing and synthesizing data of many cases in the investigated frequency range, these two methods have many limitations in the calculation process, specifically, in performing complex computations with many loops and variables. Solving problems also takes longer than numerical method using mathematical model. The obtained results are analyzed in the time domain, frequency domain, and the value domain of the driver's seat suspension parameters. This result serves as a basis for developing the design of the driver's seat suspension system with nonlinear spring and shock absorber, and the selection of a calculation method suitable for each problem in the field of vehicle vibration.

Optimization Design of Suspension and Steering System for FSAE Racing Car

The China Formula Student Car Competition has been growing in recent years. In order to improve the steering lightness and body stability of FSAE cars when driving under high-speed and multi-curve conditions. This paper constructs a three-dimensional model of suspension and steering system through CATIA according to the requirements of race rules, applies ADAMS/Car module to simulate the suspension system with two-wheel isotropic excitation, obtains the change curve of suspension performance parameters, and uses ADAMS/Insight module to optimize the unreasonable parameters through the analysis results. Based on the preliminary optimized suspension system, MATLAB is used to optimize the steering trapezoidal mechanism to make the wheel steering on both sides of the race car more closely match the ideal Ackerman geometry relationship. Finally, ANSYS is applied to finite element analysis of the important parts of the suspension and steering system to ensure that their structure and materials can meet the requirements of the whole car design.

Design and optimisation of double wishbone suspension for high performance vehicles

Design and optimisation of double wishbone suspension for high performance vehicles

Research on compliance steers of strut type front suspension subject to lateral force and self-aligning torque during cornering

In this paper, mechanism of compliance steers for lateral force and self-aligning torque is studied for strut type front suspension, which is commonly used in front wheel drive vehicle with transverse engine. First, through qualitative consideration, it is clarified that both of the compliance steers for lateral force and self-aligning torque consist of changes in toe-angle of three modes. Mode I is the change in toe-angle due to difference of displacements of the points on steering knuckle. Mode II is the change in toe-angle due to rotation of the lower arm. Mode III is the change in toe-angle due to displacement of the upper support of the suspension. In addition, it is shown that effects of design specifications of the suspension on the modes of compliance steer for lateral force and those for self-aligning torque are different. Based on this consideration, guidelines for design of strut type front suspension in terms of compliance steers for lateral force and self-aligning torque are presented. Then, CAE analysis for a suspension model based on a commercial vehicle is performed to confirm validity of the qualitative consideration as well as to show that compliance steer for self-aligning torque can have significance greater than that for lateral force.

QbD-based optimization of guar gum suspension medium for optimum pourability and sedimentation volume

A stable, adequately pourable guar-gum suspension medium has been developed by using the QbD approach. For this, the QTPP is defined followed by its subset CMA (guar gum and sucrose concentration). The CQA are viscosity and sedimentation volume. The target range for viscosity is 99 - 101.3 cps and sedimentation volume 0.98-1 for preparing the optimized suspension. To achieve this optimization, the central composite design has been opted which would fit well to the quadratic model. The quadratic equations and the ANOVA results are validated. The analysis phase of graphical and numerical optimization suggested that 0.1g of guar-gum and 20g of sucrose can achieve an optimized viscosity and sedimentation volume suspension. This contour plots and surface plots are utilized to check the combined interaction of the variables. The checkpoint analysis reveal appropriate percentage variance, which signify the predictive ability of the developed model and validated the design for an optimum suspension. Further, scale-up and stability studies will verify the projected promising results which may be scaled up for its applications in pharmaceutical, food and chemical industries.

Design and optimisation of double wishbone suspension for high performance vehicles

Design and optimisation of double wishbone suspension for high performance vehicles

Modelling and simulation of the energy regenerative system for active horizontal seat suspension driven by an induction motor

The paper investigates the design and performance of an active horizontal seat suspension driven by an induction motor, with the aim of reducing harmful vibrations and enhancing energy efficiency. The physical model employs a permanent magnet synchronous motor (PMSM) as a modern actuator to generate the active force. Both passive and active seat suspensions are examined, revealing that the active system significantly reduces resonant vibration by applying electromagnetic torque from an induction motor. The motoring/braking principle is explored, where braking an induction motor returns electric energy to the servo drive system, and regenerative braking is utilized to charge batteries. However, the current regenerative braking system recovers only 3% of power. A novel control design methodology is proposed for the subsequent project to enhance suspension dynamics, attenuate vibrations transmitted to the human body, and minimize energy consumption during operation. The proposed energy-regenerative electromagnetic actuator model, in conjunction with advanced programmable micro-controller algorithms and inverter switching schemes, aims to optimize energy recuperation and vibration energy harvesting in the vibration reduction system.

Adaptive Fuzzy Output Feedback Control Design for Pneumatic Active Suspension With Unknown Dead Zone

Adaptive Fuzzy Output Feedback Control Design for Pneumatic Active Suspension With Unknown Dead Zone

Modern trends in the design of leaf spring suspensions of trucks

The article provides an analysis of the improvement of methods for calculating of leaf spring suspensions in retrospect; features of modern calculation methods and own experience in developing of a spring suspension design for a medium-tonnage truck with a gross weight of 6 tons.

Specifical features of designing of magneticaly levitated transport systems using permanent magnets

The purpose of the present research is to find approaches for the implementation of constructive solutions that allow for stable suspension and transverse stabilization of magnetolevitation transport systems based on permanent magnets. In order to achieve this goal, the methods of physical modeling were used. Measurements of the magnitude of magnetic induction were carried out using a certified magnetometer Aktakom ATE-8702. While conducting experiments and creating physical models, NdFeB permanent magnets with dimensions of 21x21x21 mm were used. As a result, the suspension and transverse stabilization design based on permanent magnets has been developed and patented. Within the framework of the research, a mock-up of a suspension device for a magnetolevitation transport system was developed and manufactured. The outcomes obtained can be used in the development of technical units with reduced energy consumption, with a minimum coefficient of friction in the guides (escalators, travelators, elevators, etc.), with reduced vibration (magnetic supports) and with minimal consumption of lubricants.

МОДЕЛЬ ДВОМАСОВОЇ КОЛИВНОЇ СИСТЕМИ З ПАРАЛЕЛЬНИМИ ПРУЖНИМ І ДЕМПФУЮЧИМ ЕЛЕМЕНТАМИ

Aim. Development of a method of analytical research of a two-mass oscillating system with parallel elastic and damping elements, which makes it possible to expand the design of such systems in various tasks of the functioning of machines and equipment. Method. We will conduct a parametric study of the dynamic oscillation system to assess the effect of the elasticity coefficient and damping on the change in the natural frequency, using the Laplace transform method. A mathematical model of the system with two masses connected by elastic and damping elements placed in parallel is presented. Disturbances are transmitted to the masses through an elastic-damping system. Results. The solution of the system of differential equations through the Laplace transform for two variants of the characteristic equation is given. The biquadratic characteristic equation is solved by the Ferrari method. Both for the roots with complex numbers and for the roots with real numbers, the values of the roots λ1 ... λi are obtained. The value of the roots of the biquadratic equation for the general solution of a homogeneous system of differential equations enables stability for the values of the six roots of the characteristic equation. Unlike previous studies, where applied disturbances were described in the form of harmonic oscillations, we proposed a solution for disturbances in the form of discrete single pulses of different durations and different tracking frequencies, from one pulse to n pulses. Scientific novelty. The analytical solution of the system of differential equations that describe the mutual oscillation of masses connected in parallel by elastic and viscous elements refers to a subspecies of the classical Kelvin-Voigt body. In comparison with other mathematical models, the analytical solution of the system of differential equations describing the movement of the masses of the system will allow to study the system with structural parameters in a wide numerical range of their numerical values. Practical value. The analytical model allows modeling technical systems that work according to this principle. For example, suspensions of cars and other vehicles for various purposes. The mathematical model is analytically solved and allows to optimize suspension designs

ОЦІНЮВАННЯ ВПЛИВУ «КОНСТРУКЦІЙНОГО» ТЕРТЯ В ПІДВІСЦІ НА ПРОСТОРОВІ КОЛИВАННЯ ТРАНСПОРТНОГО ЗАСОБУ

In the process of creating and modernizing ground vehicles for various purposes, in particular armored vehicles, there is a problem of assessing the influence of design features on working processes in operating conditions. These features include the presence of "structural" friction, in its manifestations and the effect similar to "dry" friction. In some cases, this leads to the appearance of self-oscillations, which is undesirable. Therefore, the development of the theory and practice of numerical assessment of vehicle performance with the possibility of manifestation of self-oscillating properties is an urgent task. Obviously, in the framework of the methodology of applied optimal design of complex technical systems, it is necessary to have an adequate mathematical model of the object of study. An original mathematical model of free spatial vibrations of the sprung part of the transport machine (body) is proposed, which allows one to evaluate the influence of the features of the new vehicle suspension design. The new suspension is hydropneumatic, with a helical gear, with the presence of "structural" friction. Calculations carried out numerically using the original program confirmed the correspondence of the mathematical model to modern ideas about the theory and practice of work processes with free vibrations of complex technical systems. The motion parameters during the manifestation of self-oscillating properties and parametric vibrations of an object close in weight and size to the BTR70 and BTR80 are numerically estimated.

Simulative study on integrated optical multimode waveguides with guided beams based on the system standardization of elements

Abstract This study has outlined simulative study on integrated optical multimode waveguides with guided beams based on the system standardization of elements. Deflection of a cantilever are clarified with a point force at the free end, due to the distributed weight at the beam, with a mass at the free end, and at the free end under acceleration. The bending of a double clamped beam under its distributed weight, deflection with the central mass double clamped beam under its weight, the buckling of a double clamped beam due to a compressive stress, out of plane deflection (OPD) of a bent beam suspension, OPD of a folded beam suspension, and OPD of a serpentine beam suspension are also clarified and reviewed. Dependence of cross section of beam on torsion constant is outlined. The stiffness ratio of lateral to vertical motion of hammock suspension is also clarified. The design of a crab-leg suspension and the dependence of the stiffness on thigh section of the crab leg flexure and the design of a folded flexure suspension and the dependence of stiffness on ratio of column beam lengths are also reported.

Preparation and Performance Evaluation of a Variable Viscosity Friction Reducer Suspension with High Salt Tolerance and Low Damage

In view of challenges such as the long dissolution time of powder friction reducers in high-salinity water, poor environmental friendliness of water-in-oil (W/O) emulsion friction reducers, and the poor proppant-carrying capacity of conventional slickwater, a novel variable viscosity friction reducer suspension (EACM) with high salt tolerance, low damage, and strong proppant-carrying capacity was prepared by dispersing salt-tolerant polymer powder in alcohol solvents. The solubility, drag reduction ability, viscoelasticity, proppant-carrying capacity, temperature and shear resistance, and gel breaking ability of EACM were investigated. The results showed that the best solvent for the friction reducer suspension was polyethylene glycol 400, in which EACM exhibited a rapid dissolution rate with a thickening rate of 89.5% within 2 min. Due to the synergic effect between fumed silica and polyamide wax as antisedimentation agents, both at a concentration of 2.0 wt %, the EACM could remain stable for 60 days. EACM showed an excellent drag reduction performance at both low and high viscosities in 100 000 mg/L salt brine. Specifically, a drag reduction of up to 72.4% was obtained using 0.21 wt % EACM (4.65 mPa s), and a 60.8% drag reduction was achieved using 1.0 wt % EACM (35.5 mPa s). When the concentration increased from 0.13 to 1.0 wt %, the EACM solution changed from viscous to elastic; the spatial network structure of the solution became more compact, and the proppant-carrying capacity was enhanced. The viscosity of 1.6 wt % EACM solution could be maintained at 55.9 mPa s after shearing at 90 °C for 120 min at a shear rate of 100 s–1. EACM solution also exhibited the advantages of easy breaking and low residue. This paper provides guidance for the design and selection of a novel friction reducer suspension in the oil and gas industry.

ОЦЕНКА ЭФФЕКТИВНОСТИ ИСПОЛЬЗОВАНИЯ ТРАДИЦИОННЫХ КОНСТРУКЦИЙ ПОДВЕСОК В СПЕЦИАЛИЗИРОВАННОМ АВТОМОБИЛЬНОМ ТРАНСПОРТЕ

In order to identify the reasons for the decrease in the efficiency of vehicles equipped with traditional suspension designs and to identify promis-ing areas for improving their efficiency, an analysis was made of the results of a review of studies obtained in the scientific field under consideration by foreign and Russian scientists. The article substantiates the relevance of increasing the efficiency of suspensions of specialized trucks and road trains operated in difficult changing climatic and road conditions. The main disadvantages that appear during the operation of vehicles equipped with traditional suspension designs are given. The consequences of the operation of such vehicles equipped with traditional suspension designs in conditions of a low level of road infrastructure are listed. The advantages of hydropneumatic suspensions, leaf springs made of composite materials in comparison with steel springs, independent suspension structures over dependent ones, semiactive air suspensions over passive and active ones, as well as regenerative suspensions are considered. The dependences of the change in the time between failures of the elements of the spring suspension, the estimated durability of the spring on the speed of movement, the acceleration of the sprung mass of the trailer of a road train when driving over bumps, the resistance forces of the hydraulic shock absorber on the ambient tem-perature are presented. The dependences of the change in natural frequencies and the damping coefficients of oscillations of the sprung and un-sprung masses of the car with an increase in the mass of its sprung part are given. The perspective directions for increasing the efficiency of suspensions of timber trucks and road trains identified as a result of the analysis are given.