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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. [ABSTRACT FROM AUTHOR]

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Copyright of Automotive Engineer (1674-6546) is the property of Auto Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction. In accordance with one of the ways of solving the problem of increasing the smoothness of the vehicles, a controlled suspension is proposed, which is created on the basis of the use of «smart» materials – magnetorheological elastomers, the mechanical properties of which, in particular, damping, can be changed with the help of a controlling magnetic field. This is implemented with the help of the magnetorheological actuator of the suspension control system, which has the form of an elastic bushing of the suspension arm, consisting of several electrically connected in series toroid-like coils (with a core of magnetorheological elastomer). The device is powered by current, the value of which is controlled by the operator, or automatically, depending on the road profile and driving mode. Magnetorheological actuators (elastic bushings) are placed in the holes of the suspension levers instead of standard rubber ones and combined with a controlled current source. Thus, the suspension becomes controllable, which makes it possible to set the necessary vibration damping of the vehicle body to increase its smoothness. Problem. The disadvantage of the previous designs of the magnetorheological actuator is the insufficient amount of the magnetic flux density and the unevenness of its distribution within the elastic bushings. As a result, the damping properties of such controlled suspensions become insufficiently effective, which reduces the possibility of increasing the smoothness of the vehicles. The purpose of the work is to increase the damping properties of the magnetorheological actuator of the vehicle suspension control system, which will increase the control efficiency. The task is to improve the design of the performing magnetorheological device, to carry out calculations and develop a calculation scheme of the study, to determine the average magnetic flux density value and its distribution across the crosssection of the device, to calculate the dependence of the device damping indicator on the magnetic flux density, to compare the damping indicators of the improved device with previously known ones. Methodology. Research tasks were solved on the basis of magnetic field analysis using methods of magnetic field theory and SOLIDWORKS® and FEMM software packages, as well as analysis of the dependence of the damping properties of bushings from magnetorheological elastomers on magnetic flux density. A description of the design and principle of operation of the magnetorheological actuator of the vehicle suspension characteristics control system is given, based on which the calculation scheme was developed. Results. The results of research calculations showed that the average value of magnetic flux density in the proposed design of the device reached 0.85 T, its distribution became fairly uniform, and there were no zones where it was abnormally small. For the first time, the dependence of the damping index on the magnetic flux density of the controlling magnetic field has signs of scientific novelty. It was found that this indicator for the proposed design of the device increased by 22 % compared to previous other designs, which will increase the efficiency of the control system and the smoothness of the vehicle. A positive result was achieved due to the following features of the proposed design of the suspension actuator: the elastic sleeve consists of several coaxially located actuators made of anisotropic magnetorheological elastomer, in which the conglomerates of the ferromagnetic filler during the manufacturing process are located collinear to the direction of the angular deformations of the sleeve and the control magnetic field flux density vector, and the devices have control coils located on their surfaces, which are made of conductive elastic elastomer and electrically connected in a series circuit. Originality. The control method, previous designs and construction of this controlled suspension are protected by patents of Ukraine. Practical value. The direction of further research is to optimize the parameters of the control coils in order to reduce the energy consumption for them and to protect them from overheating. References 20, figures 10. [ABSTRACT FROM AUTHOR]

Introduction. In accordance with one of the ways of solving the problem of increasing the smoothness of the vehicles, a controlled suspension is proposed, which is created on the basis of the use of «smart» materials – magnetorheological elastomers, the mechanical properties of which, in particular, damping, can be changed with the help of a controlling magnetic field. This is implemented with the help of the magnetorheological actuator of the suspension control system, which has the form of an elastic bushing of the suspension arm, consisting of several electrically connected in series toroid-like coils (with a core of magnetorheological elastomer). The device is powered by current, the value of which is controlled by the operator, or automatically, depending on the road profile and driving mode. Magnetorheological actuators (elastic bushings) are placed in the holes of the suspension levers instead of standard rubber ones and combined with a controlled current source. Thus, the suspension becomes controllable, which makes it possible to set the necessary vibration damping of the vehicle body to increase its smoothness. Problem. The disadvantage of the previous designs of the magnetorheological actuator is the insufficient amount of the magnetic flux density and the unevenness of its distribution within the elastic bushings. As a result, the damping properties of such controlled suspensions become insufficiently effective, which reduces the possibility of increasing the smoothness of the vehicles. The purpose of the work is to increase the damping properties of the magnetorheological actuator of the vehicle suspension control system, which will increase the control efficiency. The task is to improve the design of the performing magnetorheological device, to carry out calculations and develop a calculation scheme of the study, to determine the average magnetic flux density value and its distribution across the cross-section of the device, to calculate the dependence of the device damping indicator on the magnetic flux density, to compare the damping indicators of the improved device with previously known ones. Methodology. Research tasks were solved on the basis of magnetic field analysis using methods of magnetic field theory and SOLIDWORKS® and FEMM software packages, as well as analysis of the dependence of the damping properties of bushings from magnetorheological elastomers on magnetic flux density. A description of the design and principle of operation of the magnetorheological actuator of the vehicle suspension characteristics control system is given, based on which the calculation scheme was developed. Results. The results of research calculations showed that the average value of magnetic flux density in the proposed design of the device reached 0.85 T, its distribution became fairly uniform, and there were no zones where it was abnormally small. For the first time, the dependence of the damping index on the magnetic flux density of the controlling magnetic field has signs of scientific novelty. It was found that this indicator for the proposed design of the device increased by 22 % compared to previous other designs, which will increase the efficiency of the control system and the smoothness of the vehicle. A positive result was achieved due to the following features of the proposed design of the suspension actuator: the elastic sleeve consists of several coaxially located actuators made of anisotropic magnetorheological elastomer, in which the conglomerates of the ferromagnetic filler during the manufacturing process are located collinear to the direction of the angular deformations of the sleeve and the control magnetic field flux density vector, and the devices have control coils located on their surfaces, which are made of conductive elastic elastomer and electrically connected in a series circuit. Originality. The control method, previous designs and construction of this controlled suspension are protected by patents of Ukraine. Practical value. The direction of further research is to optimize the parameters of the control coils in order to reduce the energy consumption for them and to protect them from overheating. References 20, figures 10.

The development of energy recovery systems in vehicles is a form of synergy between energy efficiency and renewable energy to overcome the energy crisis and global warming problems. This paper addresses such challenges by introducing a novel design of a piezoelectric energy harvester (PEH) for a vehicle suspension system. The PEH is designed to capture the linear vibration of the suspension system subjected to road surface roughness and move on uniform bridges. The vibration is amplified by a pressurized liquid cylinder-piston mechanism which deforms the piezoelectric bar to produce electric power. An additional novel mechanism in the form of a piezoelectric protector is also proposed to avoid physical damage due to excessive unidirectional compressive force as a result of an unpredictable uneven road. Given the key design parameters, the electric power can be harvested up to 67.5 W for a PEH with a span of 150 m of the bridge, a velocity of 40 m/s, and a vehicle mass of 2,691.6 kg.

The development of energy recovery systems in vehicles is a form of synergy between energy efficiency and renewable energy to overcome the energy crisis and global warming problems. This paper addresses such challenges by introducing a novel design of a piezoelectric energy harvester (PEH) for a vehicle suspension system. The PEH is designed to capture the linear vibration of the suspension system subjected to road surface roughness and move on uniform bridges. The vibration is amplified by a pressurized liquid cylinder-piston mechanism which deforms the piezoelectric bar to produce electric power. An additional novel mechanism in the form of a piezoelectric protector is also proposed to avoid physical damage due to excessive unidirectional compressive force as a result of an unpredictable uneven road. Given the key design parameters, the electric power can be harvested up to 67.5 W for a PEH with a span of 150 m of the bridge, a velocity of 40 m/s, and a vehicle mass of 2,691.6 kg. [ABSTRACT FROM AUTHOR]

The advancement of transportation machinery has played a crucial role in driving global economic and societal growth. However, this progress has also given rise to challenges, such as the depletion of chemical resources and the escalating impact of climate change. As a result, automobile companies are now prioritizing energy efficiency and transitioning towards eco-friendly vehicles. In response to this demand, various efforts have been made to harvest energy and improve the efficiency of eco-friendly vehicles, with energy-harvesting dampers emerging as a promising solution. This study focuses on the optimization of the shape and design of a rotary power generation system integrated within an energy harvesting system. The primary objective of the rotary power generation system is to convert mechanical motion into electrical energy, thereby enhancing the overall efficiency and sustainability of eco-friendly vehicles. By considering the specific characteristics of SAE 30 W working oil within the damper, the optimal blade shape and generator can be determined to maximize the power generation capabilities of the system. [ABSTRACT FROM AUTHOR]

As a newly conceived vibration isolation element, an inerter can be implemented in different forms, and it is easily introduced in different vibration isolation scenarios. This paper focuses on a novel inerter device called an electromagnetic inerter (EMI), which combines a linear generator with a fluid inerter. Firstly, the structure and the working principle of the EMI is stated. Then, the parameter sensitivity of the fluid inerter is analyzed, and two parameters that have great influence on the inertance coefficient are obtained. Subsequently, the influence of the change of the external circuit on the output characteristics of the device is also discussed. This proves that the introduction of external circuits can simplify complex mechanical topologies. Finally, the topological structures of vehicle suspension are changed in the form of an EMI (including external circuit), and the dynamic performance of these structures in the typical vibration isolation system of a vehicle's suspension is obtained. It is found that an L4 layout should be considered as the best suspension structure. Compared with traditional passive suspension, it not only ensures that its handling stability is not weakened, but also reduces the root mean square value of body acceleration and the peak of suspension work space by 4.56% and 11.62%, respectively. [ABSTRACT FROM AUTHOR]

Vehicle comfort, handling, and stability can be improved by a semi-active suspension with advanced control algorithms using the vertical velocities of the sprung mass (SM) and the unsprung masses (UMs) as inputs. Displacement and acceleration sensors are often used to estimate vertical velocities of UMs. However, these sensors are expensive and are susceptible to degradation. Virtual sensors (VS) have been proposed as a solution, and previous research using simulation data has shown that artificial neural networks (ANNs) can provide usable UM vertical velocity estimates. This study aims at finding ANNs structure and input sample window size to achieve best performance on real-world data. Novel dataset was created and used to test VSs based on eight structures of ANNs combining multilayer perceptron, convolutional neural network, long-term short-term memory (LSTM), and bidirectional LSTM layers. This article presents the results of 104 combinations of ANN structure and sample window size, which required 6240 training sessions. A Bayesian search was used to tune the hyperparameters of ANNs’ layers minimizing the root-mean-square error (RMSE) of estimations on the validation data, while a grid search was used to select the sample window size that minimizes RMSE of estimation on test data, ensuring that selected combinations are well generalized. The VS based on ANN with convolutional layers, achieved the lowest RMSE of 0.0210 m/s, and processing time of 0.421 ms for a window size of 23 samples while estimating vertical velocities of vehicle UMs from real-world data.

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.

Active suspension technique normally provides the best vibration mitigation performance at the cost of high-energy consumption. In contrast, the energy consumption of a semi-active suspension is normally much smaller than that of an active suspension, whereas the control performance is compromised as well. Observing the core issue that caused such a phenomenon is that the existing semi-active control force, unlike the active control force, shall always oppose to the relative motion of the actuator (i.e. clipping phenomenon). This paper subsequently proposes a novel semi-active vehicle suspension system that incorporates a passive negative stiffness (NS) spring and a semi-active damper (SD) to realize uncompromised active control force while consuming energy of a typical semi-active suspension system. In specific, the proposed system allows for decomposition of the target active control force and tracked via the collaboration of the NS and SD components. Herein, the NS element is capable of releasing the store potential energy that subsequently eases the aforementioned clipping phenomenon of a traditional semi-active suspension. In this paper, besides the relevant clarifications on the system topology and working mechanism, its feasibility and performance enhancement are also validated via systematic numerical simulations of a vehicle suspension; and the results indicate, for the first time, that the proposed semi-active suspension can fully track the active control force and subsequently achieve unprecedented control performance comparable to an active controller. [ABSTRACT FROM AUTHOR]

This article proposes a hybrid system for increasing the electric vehicles' (EVs) driving range considering regenerative shock absorbers. The proposed hybrid approach is a combination of atomic orbital search (AOS) and wild horse optimizer (WHO); later, it was called AOSWHO method. The major objectives of the proposed work are to extend vehicle range, reduce the charging time of the vehicle, reduce the battery size, and increase the efficiency of vehicle. In this proposed work, linear Permanent magnet (PM) generators are used as the sole instrument and on-board source is utilized to absorb vibration energy of the moving vehicle. Here, the proposed method has four key modules: (a) suspension vibration input, (b) transmission mechanism, (c) generator module, and (d) power storage. A suspension vibration is mostly pretentious by road roughness and speed vibration, which is optimally handled by the proposed hybrid technique. The conversion of the alternating linear vibration into unidirectional rotation of generator shaft is processed by proposed hybrid technique. Based on the volume and efficiency of the dampers, a small volume, brushless DC motor with low rotor inertia is selected to produce electricity. By then, the proposed AOSWHO run on MATLAB site and its performance is related to several existing systems. From the simulation result, it is concluded that proposed system delivers an State of Charge (SOC) of 40.33, which is high compared to existing approaches. [ABSTRACT FROM AUTHOR]

As a newly conceived vibration isolation element, an inerter can be implemented in different forms, and it is easily introduced in different vibration isolation scenarios. This paper focuses on a novel inerter device called an electromagnetic inerter (EMI), which combines a linear generator with a fluid inerter. Firstly, the structure and the working principle of the EMI is stated. Then, the parameter sensitivity of the fluid inerter is analyzed, and two parameters that have great influence on the inertance coefficient are obtained. Subsequently, the influence of the change of the external circuit on the output characteristics of the device is also discussed. This proves that the introduction of external circuits can simplify complex mechanical topologies. Finally, the topological structures of vehicle suspension are changed in the form of an EMI (including external circuit), and the dynamic performance of these structures in the typical vibration isolation system of a vehicle’s suspension is obtained. It is found that an L4 layout should be considered as the best suspension structure. Compared with traditional passive suspension, it not only ensures that its handling stability is not weakened, but also reduces the root mean square value of body acceleration and the peak of suspension work space by 4.56% and 11.62%, respectively.

The advantages of the proposed novel magnetic energy-harvesting suspension (MEHS) are high safety, compact structure and convenient maintenance, compared with the previous studies. However, the force generated by the energy harvester with harvesting energy can affect the motion of the mechanical system. Therefore, this paper aims to analyze the ride comfort and road handling of the MEHS, and investigates the dynamic performance of the MEHS. Firstly, the structure and the working principle of the MEHS are illustrated and introduced, and the dynamic mechanism of the quarter-vehicle with the MEHS is revealed and investigated. Secondly, the effects of the electromechanical coupling coefficient and external load resistance on the dynamic performance are investigated by numerical calculation. An experimental setup is established to verify the dynamic performance of the proposed MEHS. According to the experimental results, the dynamic performance of the suspension is contradictory with the increase of the external load resistance at the periodic frequency 7 Hz. And compared with the passive suspension, the dynamic performance of the MEHS is changed at various excitations, in which the sprung displacement and relative dynamic load of the tire of MEHS at the periodic frequency 3.3 Hz are reduced by 39.45% and 41.18%, respectively. Overall, the external load resistance of the proposed MEHS can be utilized to realize the variable damping of the suspension system and reduce the effect of vibration on the suspension system at the resonance frequency. And the dynamic performance has been verified in the laboratory, which lays the foundation for the dynamic analysis in a real vehicle. [ABSTRACT FROM AUTHOR]

The vehicle suspension system is not only used to consume the vibration energy transmitted from the ground to the vehicle body but also provides good handling stability for the vehicle. This can be a challenging tradeoff, especially for vehicles with a high center of gravity and heavy loads, such as trucks and SUVs. These vehicles are prone to large load deviations during emergency steering, causing the vehicle to roll over. The emergence of a hydraulically-interconnected suspension (HIS) could effectively maintain the vehicle body’s stability. As a unique hydropneumatic suspension, the HIS system has prominent nonlinear damping characteristics and can decouple the bounce motion and roll motion of the vehicle. This increases the vehicle’s roll stiffness without affecting the vertical rigidity of the vehicle, thereby substantially reducing the possibility of rollover accidents. This paper introduces a novel energy-harvesting hydraulically-interconnected suspension (EH-HIS), which has the dynamic characteristics of the HIS and can even harvest the vibration energy that is traditionally dissipated into heat using the oil shock absorbers. Working principles of bounce motion, roll motion, and pitch motion of the EH-HIS system have been analyzed. A mathematical model of the system was established based on the pressure drop principle and validated by a bench test. Damping characteristics and the energy harvesting capability are studied via simulations. Results show that the EH-HIS has considerable asymmetric and tunable damping characteristics that can meet the allowable range of most passenger vehicles. When the external resistance increases from 5 to 25 \begin{document}$ \mathrm{\Omega } $\end{document}, the corresponding equivalent damping coefficient decreases from 7558 to 3134 N·s·m−1. The energy harvesting capability analysis shows that maximum energy harvesting power is achieved when the external resistance is equal to the internal resistance. Furthermore, the average harvesting power can reach 875.9 W under the excitation of 2 Hz (frequency) 30 mm (amplitude).

This paper introduces a finite-time generalization of Lyapunov modal contributions (LMC) – a technique for energy-based selective modal analysis. The main focus is a case study involving a system with physically meaningful squared output and considering its unforced movement as transferring excessive energy towards its environment. This problem statement leads to LMCs estimating energy transfers measured in joules. The results facilitate solutions to several issues that occur in applications of methods based on Gramian spectral decomposition.

A novel parameter identification method was proposed for vehicle suspensions subjected to performance degradation. The proposed method does not require the measurement of the stiffness and damping coefficients of suspensions. Instead, it uses vehicle states to calculate the stiffness and damping coefficients based on an efficient multibody model and inverse dynamics. First, a full-vehicle system was modelled using a semirecursive multibody formulation, and the dynamic properties of suspensions, chassis frame, and tires were considered. Second, dynamic simulations on a bumpy road were performed, and vehicle state data were collected. A deep neural network (DNN) model, whose inputs and outputs were vehicle states and suspension parameters, was developed. The DNN model can estimate the stiffness and damping coefficients based on vehicle states measured by sensor networks. The parameter identification was achieved by deep learning of the relationship between vehicle states and suspension parameters in a given maneuver. Finally, the model accuracy was investigated in terms of different DNN inputs, data samples, and hidden layers. The results showed that the DNN model predicts accurate stiffness and damping coefficients in real time. This maneuver-based parameter identification method can be used for the condition-based monitoring or fault diagnosis of vehicle suspensions subjected to performance degradation. [ABSTRACT FROM AUTHOR]

The key request for a vehicle suspension system is vibration control and decreasing the actual inertia forces. This ensures ride comfort for the crew and influences the fatigue level of the driver and overall driving safety. Implementing semi-active damping control in the vehicle suspension allows for adjusting the damping process in the vehicle for minimum acceleration applied to the seats, driver, and passengers. In order to implement theoretical analysis, we used a mathematical full-car model in Simulink/MATLAB. As the load, we added simulations of various artificially generated road profiles. The damping coefficient of the semi-active suspension system was optimized for maximum comfort level for a driver only. Results from the full-car simulation process deliver a graph of the output accelerations showing kinematic excitation from road deformities under various locations of vehicle load positions. [ABSTRACT FROM AUTHOR]

This paper concerns a hybrid vibration reduction system (HVRS) equipped with a linear electrodynamic motor (LM). The objective of the study was to implement the HVRS in a scaled vehicle suspension and reveal the benefits of its application in the system. First, a mathematical model of a quarter-vehicle suspension with the HVRS was formulated. Next, the dynamic similarity method was employed to conduct numerical simulations of the passive vibration reduction system (PVRS). Subsequently, an algorithm for HVRS controlling was developed. Then, the system was investigated experimentally under deterministic and random excitations. The results confirmed the effectiveness and applicability of the proposed HVRS. [ABSTRACT FROM AUTHOR]

The advantages of the proposed dual-mode magnetic suspension are it having a high level of safety and a compact structure compared with the previous studies. However, the structure parameters can affect the energy harvesting of the suspension system. Therefore, this paper aims to analyze the energy-harvesting characteristics of the proposed dual-mode magnetic suspension. Firstly, the structure and working principle of the proposed suspension are introduced. Then, the influences of the various parameters for the actuator on the energy regeneration characteristics are analyzed by the finite element method, such as the magnetic ring, the fixed plug thickness, the heat dissipation, and the air gap, and the actuator parameters are defined by the orthogonal analysis method. Furthermore, the numerical results of the energy harvesting are calculated. Finally, the vibration experimental setup is manufactured, and the simulation analysis is verified by the experiment. The results demonstrate that the excitation amplitude is 3.1 mm, the frequency is 18 Hz, and the maximum induced EMF is 8.8 V. Additionally, compared with passive suspension, the energy harvesting of the proposed suspension has been verified in the laboratory, which lays the foundation for the design and analysis of the dual-mode magnetic suspension in a real vehicle. [ABSTRACT FROM AUTHOR]

This paper introduces a finite-time generalization of Lyapunov modal contributions (LMC) – a technique for energy-based selective modal analysis. The main focus is a case study involving a system with physically meaningful squared output and considering its unforced movement as transferring excessive energy towards its environment. This problem statement leads to LMCs estimating energy transfers measured in joules. The results facilitate solutions to several issues that occur in applications of methods based on Gramian spectral decomposition. [ABSTRACT FROM AUTHOR]

Abstract A novel absorber, which is equivalent to a spring and a damper, is developed and the corresponding equivalent formulae of stiffness coefficient and damping coefficient are derived. The key component of the absorber is the circular array of multi‐section U‐shaped piezoelectric coupled beams (MUPCBs) which can alleviate harmful vibration of various devices by converting the vibration energy into electrical energy. As an example, the absorber is used in a quarter vehicle suspension system, and its properties of energy harvesting and vibration attenuation are studied using the computational model of dual‐mass iteration method. The dual‐mass model includes two sprung masses (body mass and wheel mass) which are linked by the absorber. The effects of some important factors, such as the piezoelectric coupling section (PCS) length, the PCS substrate thickness, the force arm length of the MUPCB, the speed of vehicle and the class of road surface on the root mean square (RMS) of the output power, are discussed. The research results show that half of the amplitude of the harmful vibration can be attenuated and a power up to 254.3 W can be realized by the absorber made of MUPCBs in the quarter vehicle suspension computational case. This research provides a feasible piezoelectric absorber suitable for various devices by transferring the vibration energy into electricity to attenuate the harmful vibration and achieve the energy recycling application.

Vehicle stability during cornering on horizontal road curves is a risky stage of travel because of additional factors acting. The main stability factor is centrifugal force, which depends on road curve sharpness and is very sensitive to driving speed usually controlled by the driver. However, the counterforce is produced at tire-road interaction, where different pavement types and states cause a wide variation of tire contact forces and vehicle stability. In the paper, the part of vehicle suspension performance while moving on a sharp horizontal road curve with different levels of pavement roughness was simulated by 14 degrees of freedom vehicle model. The model was built in MATLAB/Simulink software with available pavement roughness selection according to ISO 8608. The influence of variable suspension damping available in modern vehicles on risky cornering is analysed when a vehicle reaches the edge of the pavement with its specific roughness. Critical parameters of vehicle stability depending on road curvature, pavement roughness and driving speed are selected to assess the solutions for safe cornering.

This paper provides a comprehensive understanding of the amplitude- and frequency-dependent characteristics of rubber springs. The dynamic nonlinear inelasticity of rubber is a key academic problem for continuum mechanics and a bottleneck problem for the practical use of rubber structures. Despite intensive efforts witnessed in industrial applications, it still demands an unambiguous constitutive model for dynamic nonlinear inelasticity, which is known as the Payne effect. To this end, three types of rubber springs (shear-type (ST), compression-type (CT) and shear-compression-combination-type (SCCT)) were tested with amplitude and frequency sweeps in different conditions. We investigated and present changes in dynamic stiffness and loss factor with amplitude, frequency and the hysteresis loops of different rubber springs. We also propose a hypothesis and research strategy to study a constitutive model involving multiple factors of hyperelasticity, the Mullins effect, viscoelasticity and the Payne effect, which we hope will provide new ideas for the establishment of a constitutive equation. [ABSTRACT FROM AUTHOR]

Summary: As a classical control model, the skyhook damper configuration can be used to adapt to changes in road conditions rather than that in load conditions. Conversely, as a newly developed control model, the skyhook inerter configuration can be used to adapt to variation of load conditions but not that of road conditions. In order to solve or at least reduce the conflict between load and road adaptability, a double‐skyhook configuration that combines a skyhook inerter and a skyhook damper is proposed in this paper to adapt to changes in both road and load conditions. Two semi‐active means to realize the double‐skyhook configuration are investigated separately; one is using two mutually independent devices (a semi‐active inerter and a semi‐active damper); the other is using a semi‐active device combining an adjustable inerter and an adjustable damper. Three control strategies—the independent double‐skyhook control, the inertance‐based double‐skyhook control, and the damping‐based double‐skyhook control—are proposed for the devices to approximate the skyhook inerter and damper. To simulate the skyhook inertance and damping forces realistically, a model of the combined semi‐active device is established and verified by a prototype test. Numerical simulations based on such a model are performed to demonstrate the effectiveness of these strategies and to achieve the desired load and road adaptabilities. As a consequence, the semi‐active suspensions with the double‐skyhook controls can offer a much smoother and more constant ride quality than the suspensions with the single‐skyhook (skyhook inertance and skyhook damping) controls and the passive suspension, which effectively demonstrates the necessity and benefit of introducing the double‐skyhook control to vehicle suspension. [ABSTRACT FROM AUTHOR]

Neither the separate skyhook damping nor the skyhook inertance control strategy can adapt to the variations of both road and load conditions simultaneously. To address this issue, this work proposed a novel ideal multi-hook system by combining the skyhook inerter and hybrid damper, with both of their coefficients optimized. The proposed system can achieve road holding without sacrificing ride comfort. Depending on whether the inerter and damper were adjusted independently or together, this ideal multi-hook was realized semi-actively in two different control models with three different control strategies, i.e., independent, inertance-based and damping-based control. The effects of these strategies were compared and analyzed. The simulation results show that compared with passive suspension, the root mean square value of body acceleration of the three kinds of multi-hook suspension decreases by more than 40% under different loads and by more than 28% on the roads of Classes A, B and C. Compared with the skyhook damping suspension, the dynamic wheel load of the multi-hook suspensions is reduced by more than 27.5%, proving that the semi-active suspension system with multi-hook control guarantees handling stability under various road and load conditions while ensuring ride comfort. [ABSTRACT FROM AUTHOR]

The advantages of the proposed novel magnetic energy-harvesting suspension (MEHS) are high safety, compact structure and convenient maintenance, compared with the previous studies. However, the force generated by the energy harvester with harvesting energy can affect the motion of the mechanical system. Therefore, this paper aims to analyze the ride comfort and road handling of the MEHS, and investigates the dynamic performance of the MEHS. Firstly, the structure and the working principle of the MEHS are illustrated and introduced, and the dynamic mechanism of the quarter-vehicle with the MEHS is revealed and investigated. Secondly, the effects of the electromechanical coupling coefficient and external load resistance on the dynamic performance are investigated by numerical calculation. An experimental setup is established to verify the dynamic performance of the proposed MEHS. According to the experimental results, the dynamic performance of the suspension is contradictory with the increase of the external load resistance at the periodic frequency 7 Hz. And compared with the passive suspension, the dynamic performance of the MEHS is changed at various excitations, in which the sprung displacement and relative dynamic load of the tire of MEHS at the periodic frequency 3.3 Hz are reduced by 39.45% and 41.18%, respectively. Overall, the external load resistance of the proposed MEHS can be utilized to realize the variable damping of the suspension system and reduce the effect of vibration on the suspension system at the resonance frequency. And the dynamic performance has been verified in the laboratory, which lays the foundation for the dynamic analysis in a real vehicle.

In this article, a magnetorheological (MR) damper fault diagnosis algorithm is proposed. Recently, various studies have been proposed fault diagnosis methods for this damper system, however, these methods use a displacement sensor in addition to the two accelerometers mounted on the commercial vehicle. The use of this sensor configuration limits the application of the algorithm proposed so far to commercial vehicles. In order to overcome this limitation, this article proposes an MR damper fault diagnosis algorithm that uses only two accelerometers. Based on these sensors, the states of the vehicle suspension system are estimated by a Takagi–Sugeno (T-S) fuzzy unknown input observer. This observer scheme can estimate the states of the damper even under conditions affected by damper hysteresis and unknown road elevation. Using the Lyapunov stability theorem, the stability of the proposed observer with an unmeasured premise variable is verified. In addition, a support vector machine (SVM) classifier is used to determine damper condition without empirically set thresholds. In this article, a fault flag is generated by data-driven machine learning algorithms, reducing the design effort while at the same time achieving optimal performance. The proposed algorithm is verified using a quarter-car test rig and test results confirm that the proposed algorithm exhibits robust performance in various road conditions. Consequently, the MR damper fault diagnosis algorithm proposed in this article can reduce the effort in designing a diagnosis algorithm while using inexpensive production sensors applied to a vehicle. [ABSTRACT FROM AUTHOR]

This work introduces an algorithm integrated from two component signals called fuzzy sliding mode control (FSMC). This aims to ensure both road holding and ride comfort criteria rather than just one, as mentioned in previous articles. These mentioned criteria are guaranteed based on the design of membership functions and fuzzy rules, while the stability of the sliding mode framework is evaluated through the Lyapunov function. Simulations are performed in the MATLAB-Simulink interface, with four cases corresponding to different road types. According to the calculation results, the displacement and acceleration values of the sprung mass are the smallest once the FSMC method is used to control automotive suspension. In the last case, the wheel can be separated from the road if the automobile has only a passive suspension system or an active suspension system controlled by the proportional integral derivative (PID) algorithm. However, this does not happen when the FSMC algorithm is applied. As a result, the vehicle’s road holding and ride comfort can be ensured in many conditions. [ABSTRACT FROM AUTHOR]

The key request for a vehicle suspension system is vibration control and decreasing the actual inertia forces. This ensures ride comfort for the crew and influences the fatigue level of the driver and overall driving safety. Implementing semi-active damping control in the vehicle suspension allows for adjusting the damping process in the vehicle for minimum acceleration applied to the seats, driver, and passengers. In order to implement theoretical analysis, we used a mathematical full-car model in Simulink/MATLAB. As the load, we added simulations of various artificially generated road profiles. The damping coefficient of the semi-active suspension system was optimized for maximum comfort level for a driver only. Results from the full-car simulation process deliver a graph of the output accelerations showing kinematic excitation from road deformities under various locations of vehicle load positions.

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The current design of vibration energy recovery system for vehicle suspension does not analyze the vibration of the vehicle under different road conditions, resulting in the system's low energy recovery ratio, low recovery efficiency, and low energy utilization. Therefore, in this paper, the vibration energy recovery system of vehicle suspension based on ultrasonic sensors is proposed. The ultrasonic sensor is used to obtain the vibration information of the vehicle, and the vibration of the vehicle on the smooth and uneven roads is analyzed according to the obtained information. According to the analysis results, the design of the vibration energy recovery system for vehicle suspension is completed through four parts: the IGBT module, the control system, the direct thrust controller, and the energy management controller. The experimental results show that the system designed by the proposed method has a large energy recovery ratio, high recovery efficiency and high energy utilization rate. [ABSTRACT FROM AUTHOR]

The suspension systems are designed to provide good performance in terms of comfort and maneuverability and to satisfy other requirements such as fatigue strength. This study focuses on the leaf springs, a classic mechanism; leaf springs are still being extensively used in several types of vehicles because of their high load capacity and low manufacturing and maintenance costs. Its dynamic behavior assesses stationary nonlinear preload state components to provide considerable added value to this suspension type. This assessment considers the contact condition of the suspension's components and the large deflections and tightening torques observed in the whole assembly. Furthermore, the components of the non-suspended mass subsystems, such as tires, shock absorbers, and stabilizer bars, are characterized according to the simplified models for reducing their computational cost. In addition, a commercial test vehicle is used for simulating the complete system using three-dimensional modeling for describing its most relevant components in terms of their mass and rigid connection. The vehicle is additionally analyzed using multibody system simulations (MBS) coupled with the finite element method (FEM) in an implicit nonlinear transient environment using the ANSYS APDL solver. This dynamic simulation is parameterdriven for obtaining the experimental design and determining the optimal suspension stiffness and damping features required for transporting suitable load sizes. [ABSTRACT FROM AUTHOR]

A novel absorber, which is equivalent to a spring and a damper, is developed and the corresponding equivalent formulae of stiffness coefficient and damping coefficient are derived. The key component of the absorber is the circular array of multi‐section U‐shaped piezoelectric coupled beams (MUPCBs) which can alleviate harmful vibration of various devices by converting the vibration energy into electrical energy. As an example, the absorber is used in a quarter vehicle suspension system, and its properties of energy harvesting and vibration attenuation are studied using the computational model of dual‐mass iteration method. The dual‐mass model includes two sprung masses (body mass and wheel mass) which are linked by the absorber. The effects of some important factors, such as the piezoelectric coupling section (PCS) length, the PCS substrate thickness, the force arm length of the MUPCB, the speed of vehicle and the class of road surface on the root mean square (RMS) of the output power, are discussed. The research results show that half of the amplitude of the harmful vibration can be attenuated and a power up to 254.3 W can be realized by the absorber made of MUPCBs in the quarter vehicle suspension computational case. This research provides a feasible piezoelectric absorber suitable for various devices by transferring the vibration energy into electricity to attenuate the harmful vibration and achieve the energy recycling application. [ABSTRACT FROM AUTHOR]

This paper concerns the performance analysis of a fractional-order vehicle mechatronic ISD suspension with parameter perturbation. A dynamic model of the vehicle mechatronic ISD suspension based on a fractional-order electrical network is constructed. The superiority of the vibration isolation performance of the fractional-order ISD suspension is demonstrated, and the dynamic performance of the suspension is analyzed considering perturbation of parameters. Results show that the inertance has an important role when the frequency is above 10³ Hz, and the fractional inductance order and fractional capacitance order have significant impact in the frequency range of 10−2 Hz to 10² Hz. [ABSTRACT FROM AUTHOR]