Suspension Parameters Research Articles

Harmonic analysis of a marine shaft-bearing suspension system and its semi-active control with PID strategy

A stable operating state of the marine shaft-bearing system is essential to minimize the vibration level and improve the transmission efficiency of the ship power system. A semi-active control with PID strategy is proposed through an adjustable damping magnetorheological shock absorber and the combination of the electromagnetic actuator based on the existing suspension system. The harmonic response of the system is calculated through transfer function with various suspension stiffness and damping. The controlled behaviors include suspension travel, soleplate deflection, sprung shaft and unsprung bearing, are obtained through Matlab/Simulink. The proposed controller is demonstrated to be applicable through robustness analysis by comparing with passive and LQR control based on the disturbance of pulse width modulation. The controlled behaviors with minor stiffness and significant damping are noticed to be more satisfied through the influence comparison of suspension parameters. The controlled performance includes reduction rate, overshoot rate and setting time with various values of control factors are discussed to prove the suitability. The semi-active control for the transverse vibration of the marine shaft-bearing system is thus realized based on the adjustment of control parameters.

Research on optimal matching of vehicle suspension parameters for improving vehicle ride comfort on bump road

A rigid-flexible dynamics model is built. In view of established 7-DOF vibration model, the expressions of the output indexes are derived and the influence mechanism of suspension parameters on ride comfort is revealed. The effects of different vehicle speeds on ride comfort on bump road are studied in the frequency and time domains by analyzing the suspension dynamic disturbance by taking the vertical acceleration of the foot floor and seat rail, the wheel dynamic loads, and the suspension dynamic deflections of the suspension as the objects of analysis. The effects of dynamic changes in the suspension spring and damper parameters on the time and frequency domain response indices are analyzed. Two window functions are used on the bump road to process and analyze the time domain charts of the front and rear of foot floors and seat rails in the vertical direction, and the [Formula: see text] values of the global and local vibrations of the foot floor and seat rail obtained are used as one of the evaluation indicators of ride comfort. The evaluation index of the total vehicle considering local and global vibration is determined, and the suspension parameters are collaboratively optimized by genetic algorithm to improve vehicle ride comfort.

Hydropneumatic suspension testing of a wheeled armoured personnel carrier

The purpose of this study was to determine the effect of gas pressure and temperature on the spring characteristic of a HP strut used in a wheeled armoured personnel carrier. The research was performed based on a simulation model. Data to validate the model were obtained during experimental tests. The results indicate, among other things, that the friction generated in the seals is an important source of resistance force. Comparison of the simulation results with the measured characteristics indicates a proper modelling of the strut operation. Simulation studies have indicated that it is easy to modify the required suspension parameters by adjusting the initial gas pressure. A linear effect of pressure on static deflection can be assumed. Temperature has a strong influence on the spring characteristic. When it changes, significant changes in vehicle height are observed due to the lack of a compensation system. The temperature changes are not only due to changes in ambient temperature, but also by intense heating of the HP struts caused by the vehicle moving over rough terrain.

Intracellular microcystins degradation and acute toxicity decrease towards Daphnia similis by low electron-beam irradiation doses

Ionizing radiation has attracted attention due to its ability to inhibit pathogens and microorganisms, with low doses reported as being able to degrade cyanotoxins and inhibit toxic cyanobacteria growth. In this context, the aim of the present study was to investigate how electron beam irradiation (EBI) applied at doses between 1 and 10 kGy affect intracellular and extracellular microcystin variants. Effects on M. aeruginosa culture recovery, as well as changes in physico-chemical cyanobacterial suspension parameters and water quality alterations were assessed through ecotoxicity assays. The findings indicate that doses over 2 kGy may are lethal to M. aeruginosa even at 48 h post-irradiation. Concerning physico-chemical parameters, exposure to 2–5 kGy doses decrease pH values and later stabilizing. At least 50 % of intracellular MC led to significant degradation of all variants at 3 kGy. No acute toxicity effects were observed in Daphnia similis exposed to sample supernatants. Statistically significant differences were observed when cladocerans were exposed to M. aeruginosa cells treated with EBI doses ranging from 3 to 10 kGy compared to non-treated cyanobacterial suspensions. These findings suggest that low EBI radiation doses are suitable for the control of toxic cyanobacteria in water treatment processes, providing a less toxic environment compared to non-treated solutions.

Динаміка підресореної частини КТЗ і стійкість руху

The article investigates the influence of longitudinal-angular vibrations of the sprung mass of wheeled vehicles (WV) with nonlinear characteristics of the suspension system and kinematic parameters of move-ment along the curved sections of the road on the stability of WV. The main results of the work were obtained using the equations of kinetic statics, a mathematical model of relative nonlinear longitudinal-angular oscillations of the sprung mass (SM), based on the analysis of the quantitative and qualitative influence of the main force parameters of the suspension system (SS) and the determining parameters of longitudinal-angular oscillations of the SM on the level of interaction of the tires with the road coating. The critical speed of steady movement of the vehicle is determined as a function of the geometric and power parameters of the SS, the characteristics of the road surface, and the amplitude of longitudinal and angular oscillations. The numerical analysis of obtained ratios has shown that the critical values of steady motion speed for the skidding of the WV along the curved sections of the road are different: a) a larger value of the amplitude of SM oscillations corresponds to a smaller value of the critical speed of steady motion; b) it is significantly overestimated if the longitudinal and angular fluctuations of the sprung mass are not taken into account; c) the value is bigger for WV with the progressive force characteristic of the shock absorbers at small amplitudes of oscillations compared to the linear force characteristic (under the condition of equality of static deformation), and vice versa for the “large” ones; d) the value for the regressive force characteristic of elastic shock absorbers at small amplitudes of oscillations is smaller than for the linear characteristic of the shock absorbers, and the opposite for the “large” ones; e) the critical value of the speed of steady motion is bigger for the progressive characteristic of elastic shock absorbers at larger values of the static deformation of the SS and, on the contrary, it is smaller for the regressive one. The obtained results can be used for the designing or modernization of suspensions and well as a basis for development of a new software product for the controlled suspension systems. They coincide in the limiting case with those known in the scientific literature, which confirms their credibility. Keywords: Oscillations of sprung mass, amplitude, frequency, critical speed of steady motion.

Simulation analysis on vertical vehicle dynamics of three in-wheel motor drive configurations

The hub-driven technology provides several remarkable benefits to overcome some of today’s challenges in electrification of the transport sector. Although there are advantages by using in-wheel motors, their application results in increased unsprung masses, which have a negative impact on ride comfort and road holding of the vehicle. A novel but unexplored concept to inhibit the negative effects of the wheel hub motor is the two-stage-suspension structure. To investigate this in-wheel motor design and to compare it with established concepts for reducing the negative effects of the unsprung masses, three full-vehicle models were established. The vehicle models are based on a two-stage-suspension structure, a design where the motor functions as a tuned mass damper and a conventional in-wheel motor design. The suspension parameters of the three in-wheel motor configurations were further optimized using a genetic algorithm with respect to several vertical vehicle performance parameters. Subsequently, the full-vehicle models of the in-wheel motor configurations were compared by simulation in numerous different driving situations regarding their vertical vehicle dynamics. The results demonstrate that the two-stage-suspension causes an increase of the pitching and vertical vehicle body acceleration in several driving conditions, while the acceleration of the motor in general and the roll acceleration of the vehicle body especially during cornering maneuvers can be reduced significantly.

Nano-copper suspension filling based fabrication and application of FBG temperature sensor with fast response function

The fast response is a significant index for measuring the performance of temperature sensors. In this paper, a copper capillary temperature sensor is developed utilizing fiber Bragg grating (FBG) as the sensing element and nano-copper suspension as the filler. Nano-copper suspension with high thermal conductivity is meaningful to improve the response speed of this sensor. The relationship between the preparation parameters of nano-copper suspension and the thermal conductivity is accurately established to obtain the optimum response time of the temperature sensor. The suspension with small particle size and high concentration significantly improves the sensor's response speed, which is close to the bare FBG. In addition, the temperature sensor encapsulated with a copper capillary tube has high sensitivity, which is three times that of the bare FBG. This temperature sensor and bare FBG are simultaneously applied to the motor with a winding inter-turn short circuit as the initial fault. Both this sensor and the bare FBG capture the coincident temperature field, which implies that the sensor has no apparent response lag compared with the bare FBG in practical applications. Results demonstrated here may afford some valuable references for obtaining temperature filed in small electromechanical components.

Effect of primary suspension and friction wedge maintenance parameters on safety and wear of heavy-haul rail vehicles

Wheel wear is of major interest in railways due to the high cost of wheel reshaping, rail wear, and safety issues in operation. Recent researches employ onboard sensors to evaluate the dynamic behavior of the wagon and determine railway running conditions. However, sensors and computing units are expensive and some maintenance scenarios are impossible to be deliberately generated. In this work, several maintenance parameters for primary suspension, friction wedge, and flange backspacing are evaluated within operational ranges in a Box-Behnken design of experiment (DoE), set in a quadratic surface model. Such a modeling approach uses few experimental points and a significantly small computational cost when compared to a full factorial method, which uses multibody dynamic models on a simulating platform, like Simpack, to determine which parameters are more influential in safety against derailment (Y/Q) and wheel and flange wear (Tγ). The present work evaluates such parameters for heavy-haul gondola rail cars, with meter and broad gauge, running on tangent track and curves, with and without FRA irregularities. The analysis makes it possible to identify non-uniformities in wheel wear and to set different inputs for condition-based maintenance for freight rail wagons. Results show that the primary suspension longitudinal clearance and stiffness affect Y/Q and wear by over 100%, increasing the operational risk and maintenance cost because of wheel wear.

Research of the influence of car suspension characteristics on the dynamics of its sprung part

A method of determining the parameters of the car suspension has been developed, which allows taking into account the influence of the main characteristics of the suspension. In particular, the influence of static deformation, nonlinearity parameter, and such external factors as the movement of a car over rough terrain, stability of movement are taken into account. Mathematical models of vertical oscillations - dynamics of the sprung part of the vehicle with non-linear force characteristics - have been improved for the specified method. With this aim, a mathematical apparatus was developed for the analytical research of the influence of vertical oscillations on traction-speed characteristics, performance, smoothness, and stability of movement.

The Influence of the Relative Motion Dynamics of the Wheeled Vehicle Sprung and Unsprung Part on the Motion Stability along Curved Road Sections

The research method of the influence of the main suspension parameters on the motion stability of a wheeled vehicle was developed on the basis of a flat model of the dynamics of its relative motion. The mathematical model is a system of two nonlinear differential equations of the second order. The basic parameters of transverse angular oscillations of the sprung and unsprung part, which determine the dynamics of relative motion, are described using the basic principles of the perturbation method in combination with Ateb-functions. Kinetostatic equations and conditions of motion stability in the aggregate made it possible to determine the critical value of the steady motion speed as a function of the main parameters that characterize the suspension and the oscillations amplitudes of the sprung and unsprung part.It was established that an increase in the oscillations amplitude of the unsprung part from 0.01 rad to 0.015 rad causes a decrease in the critical speed of steady motion by up to 35%.The main results can serve as a basis for the suspension modernization of wheeled vehicle, and their reliability is confirmed by obtaining, in the extreme case, known results concerning suspensions with linear characteristics of elastic elements and damping devices

Machine learning approaches to estimate suspension parameters for performance degradation assessment using accurate dynamic simulations

The suspension is one of the most vital systems in a vehicle. Its performance degrades over time due to road conditions. The suspension parameters of a moving vehicle are difficult or sometimes impossible to measure within the desired level of accuracy due to high costs and other associated impracticalities. In this work, we comprehensively investigate various machine learning (ML) methods to estimate the suspension parameters for assessing performance degradation. These methods include particle swarm optimization backward propagation, radial basis function neural network, generalized regression neural network, deep belief network, wavelet neural network, Elman neural network, extreme learning machine, and fuzzy neural network. During the training process, the vehicle states, calculated using a semi-recursive multibody model, are used as the inputs to predict the stiffness and damping coefficients of the suspensions. The semi-recursive multibody model considers the dynamic properties of all the components, which enables accurate vehicle states and characteristics. In addition, we compare the performance of the ML methods by using the reference data (multibody model data). The results show that the ML approaches can estimate accurate stiffness and damping coefficients in real-time. • An accurate multibody model is used for simulations to acquire vehicle states in real-time. • ML methods are created to assess the suspension performance degradation using vehicle states. • The capabilities of ML methods are explored for performance degradation assessment.

Analysis of ride comfort and road friendliness of heavy vehicle inertial suspension based on the ground-hook control strategy

In order to comprehensively improve the ride comfort performance and the road friendliness performance of the heavy vehicles, an inertial suspension using ground-hook (GH) control is proposed in this paper, and the suspension performances are compared at different loading rates and driving speeds. Firstly, a half vehicle model of the inertial suspension of the heavy vehicle based on the GH control is established. Then, the key parameters of the GH inertial suspension are optimized by the genetic algorithm and the system simulations are carried out. By comparing to the conventional passive suspension, the root-mean-square (RMS) of the vertical acceleration of the body centroid is reduced by 4.87%, and the RMS of the dynamic tire loads of the front and the rear wheels are reduced by 16.19% and 10.02%, respectively. Results show that the GH inertial suspension can effectively coordinate and improve the ride comfort and road friendliness of heavy vehicles simultaneously.

On calculational analysis of suspensions with hydraulic springs

BACKGROUND: The information about application of hydraulic springs in suspension systems of tanks and self-propelled artillery weapons may be found in domestic scientific and nonfiction literature. In addition, machines, which prototypes were equipped with this type of suspension, are known. For instance, possibility of hydraulic suspension implementation was proven on the T-34 tank prorotype, whereas application of this type of suspension with heavy tanks gave the most prospectivity. Complication of sealing build-up with sufficient life span, development of technologies of metal springs strengthening and shutdown of heavy tanks development did not allowed hydraulic suspensions to become widespread. At present, they are not used at all, whereas methods of analytical calculation are not in public access, despite of the interest of a group of scientists. AIMS: Development of the method of determination of main parameters of suspensions with hydraulic springs and analysis of properties of the T-34-76 Soviet middle tank prototype hydraulic suspension from the point of modern theory of nonlinear suspension systems. METHODS: Justification and confidence of given dependencies for properties calculation, conclusions and recommendations are confirmed with application of strict mathematical apparatus of mechanics, hydraulics and thermodynamics as well as scientifically justified theoretical backgrounds. RESULTS: Historic data on liquids compressibility researches, method of analytical determination of main properties of hydraulic springs with various design schemes, allowing restoring of properties of suspensions of existing tracked vehicles, synthesizing properties of other suspensions and, moreover, estimating reasonability of properties of suspension with hydraulic springs, are presented in the article. According to the method, proposed in the article, properties of the hydraulic spring from the T-34-76 Soviet middle tank prototype, equipped with hydraulic suspension, were restored and analyzed. In addition, suspension properties for the same vehicle were synthesized and used for a comparative analysis. CONCLUSIONS: The information, presented in the article, is helpful for research engineers, interested in study of elastic behavior of liquids in case of their application in suspension systems, whereas the proposed method, allowing synthesis of reasonable properties of hydraulic springs, gives an opportunity to study the ride comfort of tank propotypes, equipped with hydraulic suspension, with a good quality and, moreover, to synthesize hydraulic springs properties according to the demands, given to a design engineer.

Linear Quadratic Optimal Control with the Finite State for Suspension System

The control algorithm could greatly help the suspension system improve the comprehensive performance of the vehicle. Existing control methods need to obtain the intermediate states, which are difficult to obtain directly or accurately when estimated by filters or observers. Thus, this paper proposed a new practical finite state LQR control method to deal with this problem. By combining with the output state of the finite sensor of the vehicle suspension system and weakening the unknown state as the goal, an optimization model is established with the design variables as the LQR weight coefficients. Then, the direct relationship between the current control input and the finite sensor output is obtained, and the finite state LQR control is realized. Taking the quarter-car suspension model as an example, the corresponding noise is added considering sensor accuracy, and the control performance of the four control methods is studied considering the uncertainties of suspension system parameters. In addition, the acceleration of sprung mass and the dynamic travel coefficient of suspension have been separately calculated by methods of finite state LQR control, LQR control, and PID control. The results show that there is not much difference between them under shock excitation or random excitation. However, the finite state LQR control method has the best comprehensive control performance in that its dynamic tire load coefficient is better than other methods; it could take into account the suspension work stroke coefficient, dynamic tire load coefficient, and sprung mass’ acceleration of the vehicle suspension system at the same time. In order to realize the optimal control effect with limited sensor arrangement, the finite state LQR control method only needs to obtain the current sensor output and the current control input, without estimating the unknown intermediate state. By this means, the proposed control method greatly simplifies the design of the control system and has great advantages on practical value.

The effect of suspension parameters on the properties of the coating obtained by the slip method

The development of modern gas turbine engineering imposes increasingly high requirements for the properties of the alloys used, associated with an increase in gas temperature before the turbine. However, the applicable nickel alloys have low heat resistance at high temperatures. The solution to this problem is achieved through the joint use of a heat-resistant alloy that takes loads at high temperatures, and the application of protective coatings to ensure heat resistance. The coating and the heat-resistant alloy form a complex system. Each component of the system performs the primary and secondary functions in the operation, and the system must meet operational requirements. The choice of the applied coating and its application technology are quite complicated, since its structure and thickness depend on many factors, in particular, on the composition of the original components, temperature, and time parameters of its application, etc. This affects the performance of the formed coating under operating conditions. In recent years, slip coating methods specifically formed from aqueous suspensions have been successfully developed abroad and in our country. This method is technically simple and economical. The quality of the coating formed from the aqueous suspension is determined by the percentage of the suspension composition, its rheological and physical properties, compliance with the technology of its application and processing of parts. In order to understand the mechanism of coating formation from the aqueous suspension, it is necessary to imagine the effect of the suspension parameters on the coating properties. The article presents the results of the study carried out by the computational method of the influence of the aqueous suspension parameters on the quality of the coating obtained. The dependence of the coating thickness on the particle sizes of the powders introduced into the suspension is shown. Calculations of the density and thickness of the obtainable coating from the ratio of the solid and liquid phases of the aqueous suspension are presented. It is indicated that in a real suspension, the influence of the aqueous suspension parameters on the coating parameters being formed is more complex than when performing calculations. This is primarily associated with the fact that in a real suspension there are powder particles of various diameters, in particular aluminum. In addition, the interaction of orthophosphoric acid with the introduced oxides of aluminum, silicon, etc., having molecular dispersion, their chemical interaction complicates considering all these factors in calculations. However, the obtained results of the study allow us to assess the influence of the aqueous suspension composition parameters on the technological and service properties of the obtainable coating obtained by the slip method from this suspension.

Analysis and optimization of mass percentage of zycoprint polymer and abrasives in achieving stability of suspension mixture in abrasive water jet machining

The suspension parameters are vital in the suspension-type abrasive water jet (AWJ) machining of several engineering materials, more so in difficult-to-cut materials, because it significantly influences the suspension stability and sedimentation behaviour of the suspension mixture and abrasive particle acceleration into the AWJs. The suspension stability and abrasive particle acceleration of the suspension-type AWJs are improved by using polymer additives. Hence, it is necessary to study the effect of suspension parameters (abrasive and polymer concentrations) on suspension stability. In this direction, the novel work reported in the paper analyses the stability of suspension by varying the mass percentage of abrasives (garnet and aluminum oxide (Al 2 O 3 )) ( ω a ) and mass percentage of the zycoprint polymer ( ω p ) in water by considering the Taguchi L 9 Orthogonal array (OA). The linear regression (LR) models for the percentage of suspension volume with garnet ( V s G ) and the percentage of suspension volume with Al 2 O 3 ( V s A ), are developed. The JAYA algorithm is used to find the optimal combination of the suspension parameters, and its results are in close agreement with the findings from the LR results. The optimum setting of the suspension parameters for both, V s G and V s A , is 3% of ω a and 0.80% of ω p .

Development of an algorithm for refineding parameters vehicle suspensions

The research results of the oscillations for sprung and unsprung masses in the frequency range are presented. The amplitude-phase frequency characteristics of individual masses during vibrations with follow-up presentation of transient processes, and the main results on the refinement of vehicle suspension parameters are determined. The function of the damping time of vehicle oscillations is considered. The time function a program algorithm that can be used when designing a vehicle to find the minimum value is developed. The purpose of the work is to rice the comfort of the vehicle by minimizing the damping time of the sprung mass oscillations. Keywords oscillation frequency, suspension system, static and dynamic suspension deflection, oscillation damping time, suspension parameters refinement algorithm

Determination of the pressure flow parameters of a structured suspension

The subject of the research is the methods of calculating the parameters and flow regimes of structured suspensions, which have significant potential for substantial reduction in energy consumption and specific water consumption of all hydromechanization technologies used in mining enterprises. The main topic of the research is the stability of the suspension structure and uniform distribution of particles of its solid phase throughout the volume during pressure flow through the pipeline. The aim of the work is to establish dependencies on the relative radius that defines the flow area where the suspension structure is not destroyed, not only on the rheological characteristics of the suspension and hydraulic flow parameters but also on the gravitational and repulsive forces between the particles of the solid phase of the suspension, which have an ion-electrostatic and Van der Waals nature. It is established that forces having ion-electrostatic and Van der Waals nature lead to a decrease in the maximum value of the relative radius, at which the suspension structure is still preserved during its flow in the pipeline, since the addition that takes into account their influence is always positive and subtracted from the addition that takes into account the relationship between the initial tangential stress and the hydraulic frictional stress on the inner surface of the pipe. The range of existence of the addition that takes into account the influence of forces having ion-electrostatic and Van der Waals nature and the range of variation of its values аt different values of the parameter of the energy interaction of particles of the solid phase of the structured suspension are investigated. It is established that the dependence of this addition on the distance between particles of the solid phase of the suspension is maximum. The magnitude and coordinates of the maximum depend on the parameter of the energy interaction of the solid phase particles. It is established that with an increase in the value of the parameter of the energy particles interaction of the suspension solid phase, the maximum value of the addition decreases, and the coordinate of this maximum increases. Keywords: structured suspension, radius of undeformed flow core, ion-electrostatic forces, pressure flow, pipeline.

Approximate Bayesian Estimation of Suspension Parameters of In-service High-speed Trains Based on Kriging Surrogate Model

Approximate Bayesian Estimation of Suspension Parameters of In-service High-speed Trains Based on Kriging Surrogate Model

Active Suspension Parameters Identification: An Algebraic Approach and its Application to Suspension Travel Control

The parameters of an active suspension need to be identified online, such that the suspension control system can be adapted to mechanical wear and load change. Recursive least squares and observer-based methods are frequently utilized to fulfill this purpose. However, they can yield slow parameter identification due to their asymptotic nature. We propose an algebraic identifier to estimate the parameters of an active suspension online, which does not maintain an asymptotic convergence phase. Simulation results demonstrate the effectiveness of the proposed algebraic approach.