Car Vibration Research Articles

Evaluation of ride quality in a passenger car with non-uniform tyre radial stiffness

This study is dedicated to examining the influence of varying radial stiffness along the circumference of tyres on a road vehicle ride quality and with a specific focus on aspects relevant to maintenance. Computer simulations employing a three-dimensional road-vehicle model, developed within commercial multi-body software, were conducted to explore the multifaceted factors influencing vehicle behaviour. These factors encompass road unevenness, driving speed, and the range of radial force variation resulting from harmonic changes in tire radial stiffness. Furthermore, simulation tests were carried out using a model of a diagnostic wheel balancing machine, which holds significance in vehicle maintenance practices. Measurements obtained from a passenger car equipped with standard tires with minimal non-uniformity, served as reference values for assessing the car's vibration levels. Additionally, selected scenarios were examined, involving vehicle with multiple wheels exhibiting non-uniform radial stiffness. The findings underscore that non-uniform radial stiffness can magnify the detrimental effects of road irregularities, potentially leading to amplified vibration levels and a heightened need for maintenance considerations.

Suppression of horizontal vibrations in high-speed elevators using active shock absorber to assist traditional damping systems

PurposeThis paper aims to design an active shock absorber scheme for use in conjunction with a passive shock absorber to suppress the horizontal vibration of elevator cars in a smaller range and shorter time. The developed active shock absorber will also improve the safety and comfort of passengers driving in ultra-high-speed elevators.Design/methodology/approachA six-degree of freedom dynamic model is established according to the position and condition of the car. Then the active shock absorber and disturbance compensation-based adaptive control scheme are designed and simulated in MATLAB/Simulink. The results are analysed and compared with the traditional shock absorber.FindingsThe results show that, compared with traditional spring-based passive damping systems, the designed active shock absorber can reduce vibration displacement by 60%, peak acceleration by 50% and oscillation time by 2/3 and is more robust to different spring stiffness, damping coefficient and load.Originality/valueThe developed active shock absorber and its control algorithm can significantly reduce vibration amplitude and converged time. It can also adjust the damping strength according to the actual load of the elevator car, which is more suitable for high-speed elevators.

Static and dynamic analysis of silicone/polyurethane embedded GFRP composite for magnetorheological elastomer

The current study focuses on the static and dynamic properties of GFRP composites embedded with a silicone(Si)/polyurethane(PU) blend used in automobile vibration dampening. Epoxy resin, glass fiber, and Si/PU blends of various compositions were used to create the hybrid composite specimens. For the present study, five different Si/PU blend compositions were considered to make five Si/PU embedded GFRP composite laminates were fabricated by hand layup method. The fabricated laminateswere cut to the standard sizes using water jet machining for mechanical and vibration testing. All tests were carried out in accordance with ASTM standards. Free Vibration test of five elastomeric composite specimens was carried out by impulse hammer method under fixed-free boundary condition. The current study found that the hybrid composite specimen with 0% Si and 100% PU elastomer has higher tensile strength, impact energy, and natural frequency than the other Si/PU blend elastomeric composite specimens.The better interfacial adhesion of PU rubber helps to transfer stress across interfaces more effectively and thereby enhancing the overall mechanical integrity of the composite laminate.

Lateral Vibration Control Strategy of High-Speed Elevator Car Based on Sparrow Search Optimization Algorithm

Aiming at the problems of inefficient mitigation of the lateral vibration of high-speed elevator cars, which results in low riding comfort, this paper introduces the electromagnetic active rolling guide shoes and incorporates the sky-hook damping control strategy into the high-speed elevator structure. On this basis, it adopts an optimization algorithm based on Sparrow Search Algorithm (SSA) to adjust the parameters of the lateral vibration controller, thereby reducing the amplitude of the lateral vibration and controlling it within the human comfort range. Specifically, this paper first incorporates electromagnetic active rolling guide shoes into the vibration reduction device of the high-speed elevator car. Based on the motion characteristics of lateral vibration, a mathematical model is established in which the sky-hook damping control strategy is introduced. Then, a simulation model is built, and the damping parameters of the controller are optimized using the SSA, resulting in effective control of the lateral vibration amplitude of the high-speed elevator car. Simulations demonstrate that the lateral vibration control model of the high-speed elevator car, optimized by SSA, achieves lower amplitudes within the frequency range of 1–2 Hz compared to the results obtained by the Genetic Algorithm (GA), demonstrating the effectiveness of SSA in optimizing the damping parameters of the car controller. Finally, the simulation results are compared with the measured data, and the research findings indicate that the proposed method for lateral vibration control of the car can effectively suppress the lateral vibration amplitude.

A New Approach to Selecting Optimal Parameters for the Sliding Mode Algorithm on an Automotive Suspension System

Stimuli from the road surface cause car vibrations. The suspension system ensures the vehicle’s stability and smoothness when moving. In this research, the author introduces the use of active suspension with a hydraulic actuator to improve the comfort of cars. Car oscillations are described based on a quarter-dynamics model with five state variables. Besides, the nonlinear system’s SM (sliding mode) control algorithm is used to control the system. The SM algorithm’s parameters are optimally selected using the multiple loop algorithm. The multiple loop algorithm allows the values to vary within a predefined limit and provides an optimal parameter based on the vehicle’s vibration conditions. This is a new point in the paper compared to previous studies. The output of the simulation problem includes displacements and accelerations of both the sprung and unsprung masses. In addition, the change of dynamics force at the wheel is also considered when evaluating the interaction between the wheel and the road surface. According to the paper’s results, the vehicle body’s acceleration and displacement values are strongly reduced when using the SM algorithm, compared with cars with only traditional suspension. In addition, the change in dynamics force at the wheel is not significant when using this algorithm. As a result, the car’s smoothness has been improved while the vehicle’s stability has not been lost. The phenomenon of “chattering” still occurs in some cases; however, its effect is negligible.

A novel approach with a fuzzy sliding mode proportional integral control algorithm tuned by fuzzy method (FSMPIF)

An automobile's vibration can be caused by stimulation from the road's surface. The change in displacement and acceleration values of the sprung mass is used to evaluate the automobile's vibration. Utilizing an active suspension system is recommended in order to attain an increased level of ride comfort. This article presents a novel strategy for regulating the operation of an active suspension system that has been put up for consideration. The PI (Proportional Integral) algorithm, the SMC (Sliding Mode Control) algorithm, and the Fuzzy algorithm served as the basis for developing the FSMPIF algorithm. The signal generated by the SMC algorithm is what is used as the input for the Fuzzy algorithm. In addition, the settings of the PI controller are modified with the help of yet another Fuzzy algorithm. These two Fuzzy methods operate independently from one another and in a setting that is wholly distinct from one another. This algorithm was created in a wholly original and novel way. Using a numerical modelling technique, the vibration of automobiles is investigated with a particular emphasis on two distinct usage situations. In each case, a comparison is made between four different circumstances. Once the FSMPIF method is implemented, the results of the simulation process have demonstrated that the values of displacement and acceleration of the sprung mass are significantly decreased. This was determined by looking at the values before and after implementing the new algorithm. In the first case, these figures do not surpass a difference of 2.55% compared to automobiles that use passive suspension systems. The second case sees these figures falling short of 12.59% in total. As a direct result, the automobile's steadiness and level of comfort have been significantly improved.

Influence of road quality and suspension stiffness on passenger vehicles oscillation in Viet Nam

In Viet Nam, passenger vehicles are used a lot in the transportation of passengers, suitable for circulation on small roads or rural roads. Meanwhile, these roads in our country are not complete, in many places, the road surface is not flat with high roughness. Therefore, when the vehicle is running on the road, it will vibrate, reduce motion smoothness, generate dynamic loads, damage some parts, and damage the road surface. The article presents the results of research on the influence of road surface quality on the vibration of passenger cars by building a dynamic model of the vehicle. The research results are to suggest the optimal stiffness of the passenger car suspension to minimize the transmissibility of oscillation from the rough pavement to the vehicle's body, and comfort for drivers and passengers.

Improving the Dynamic Response of Half-Car Model Using Modified PID Controller

This paper focuses on the vibration suppression of a half-car model by using a modified PID controller. Mostly, car vibrations could result from some road disturbances, such as bumps or potholes transmitted to a car body. The proposed controller consists of three main components as in the case of the conventional PID controller which is (Proportional, Integral, and Derivative) but the difference is in the positions of these components in the control loop system. Initially, a linear half-car suspension system is modeled in two forms passive and active, the activation process occurred using a controlled hydraulic actuator. Thereafter, the two systems have been simulated using MATLAB/Simulink software in order to demonstrate the dynamic response. A comparison between conventional and modified PID controllers has been carried out. The resulting dynamic response of the half-car model obtained from the simulation process was improved when using a modified PID controller compared with the conventional PID controller. Moreover, the efficiency and performance of the half-car model suspension have been significantly enhanced by using the proposed controller. Thus, achieving high vehicle stability and ride comfort.

ГРАФІЧНІ КОМП’ЮТЕРНІ ТЕХНОЛОГІЇ ПРОЕКТУВАННЯ НЕХАОТИЧНИХ МЕХАНІЧНИХ СИСТЕМ

  The application of technology for designing mechanical systems, which are based on elements of computer graphics, is considered. The work develops the themes of works where graphic computer technologies were used to study pendulum mechanical systems. Those. calculating the parameters of a mechanical system so that its pendulum oscillations become periodic (non-chaotic). For the development of research, it is necessary to apply computer graphic design technologies to other mechanical systems in order to provide their movements with technological not chaotic due to the selection of acceptable parameter values. The work uses the Lagrange method for conservative dynamical systems. To determine the approximate solution of the system of Lagrange equations of the second kind, it is necessary to coordinate the allowable values ​​of the system parameters with each other using the projection focusing method. These stages are carried out by graphical constructions in the environment of the maple package. Problems are solved as examples of the application of graphic technologies. 1. To develop options for ensuring the horizontal movement of the trolley due to non-chaotic oscillations of the pendulums associated with this trolley. Namely: a) two pendulums (on opposite sides of the cart); b) two pendulums under the cart; c) one spring pendulum under the cart. 2. Develop a method for calculating vehicle vibrations using the following example: a) railway car vibrations; b) oscillation of a trailer for the transport of dangerous goods. 3. Develop a method for determining the trajectory of the payload of a trebuchet machine for options: a) as a catapult for launching unmanned vehicles; b) as trebuchet with vertical movement of the counterweight. Keywords: computer graphics, Lagrange equation of the second kind, projection focusing method, trebuchet machine.

Vibration energy harvesting for cars: semi-active piezo controllers

Energy harvesting represents one of the recent challenging subjects related to vibration and control. The scale of energy harvesters and storage can involve a wide power range, and the scale of some milliwatt is the elective field of piezoelectric applications. This paper investigates the power frontiers of the piezoelectric-based harvesters applied to automotive units. The analysis, supported by experimental data, aims at estimating the upper bound of the specific power of this technology for powering small devices on board cars. Passive optimally tuned piezoelectric harvester and semi-active controlled ones are compared, based on a new control strategy named VFC-Variational Feedback Control, recently developed by the authors. This new technique makes it possible to increase the total energy storage drained from car vibrations. However, the real advantage for their use relies on a sharp balance between the harvested power and the costs for the additional hardware mass transport. Numerical simulations of circuitry and experimental vibration data provides references to assess the energy convenience in installing this type of devices on board.

Design and simulation of vehicle vibration test based on virtual reality technology

Abstract When a car is operating, the road roughness will cause it to vibrate. When this vibration reaches a particular threshold, the driver will get uncomfortable and fatigued, affecting the bearing system’s durability and longevity. The vehicle vibration virtual test system’s framework design and implementation approach is based on virtual reality (VR), and it is made up of a VR subsystem, a model subsystem, and a virtual instrument subsystem. A virtual car vibration test system based on VR is built, and the results of the virtual vehicle vibration test are reported. The findings indicate that the virtual test (VT) technology theoretical model pertains to the creation of VT systems for car vibration based on VR. Users may monitor the vehicle vibration as well as its time domain and frequency domain signals in three separate observation modes using the system.

Elevator Car Vibration Signal Denoising Method Based on CEEMD and Bilateral Filtering.

Elevator car vibration signals are important information to monitor and diagnose the operating status of elevators, but during the process of vibration signals acquisition, vibration signals are always inevitably disturbed by noise, which affects further research. Therefore, aiming at the vibration signal with noise, we propose a new vibration signal denoising method on the basis of complementary ensemble empirical mode decomposition (CEEMD) and bilateral filtering. Firstly, the collected original vibration signals are decomposed by the CEEMD into several inherent mode functions. Then, the false components are removed by determining the correlation coefficients of mode components, and then the noise-dominate components are denoised by bilateral filtering. Finally, the processed inherent mode functions are reconstructed to require the denoised signal. We test the method through simulation and practical application. The results indicate that the proposed method can efficaciously reduce the noise in the vibration signal of an elevator car.

Huber Kalman Filter for Wi-Fi Based Vehicle Driver's Respiration Detection

The use of breath detection in vehicles can reduce the number of vehicular accidents caused by drivers in poor physical condition. Prior studies of contactless respiration detection mainly targeted a static person. However, there are emerging applications to sense a driver, with emphasis on contactless methods. For example, being able to detect a driver's respiration while driving by using a vehicular Wi-Fi system can significantly enhance driving safety. The sensing system can be mounted on the back of the driver's seat, and it can sense the tiny chest displacement of the driver via Wi-Fi signals. The body displacement and car vibrations could introduce significant noise in the sensed signal. The noise then needs to be filtered to obtain the driver's respiration. In this work, the noise in the sensed signal is proposed to be reduced using a Huber Kalman filter to restore the original respiration curve. Through several experiments in terms of different drivers, different car models, multiple passengers, and abnormal breathing, we demonstrate the accuracy and robustness of the Huber Kalman filter in driver's respiration.

A study on psychoacoustics-based high-mileage automobile vibration and noise robustness evaluation modeling

A study on psychoacoustics-based high-mileage automobile vibration and noise robustness evaluation modeling

High-speed elevator car system semi-active horizontal vibration reduction method based on the improved particle swarm algorithm

As the field of modern high-rise buildings advances, the demand for the high-speed elevator increases. The high-speed elevator car vibration directly affects the riding comforts, among which the high-speed elevator car horizontal vibration has the most pronounced effect. Previous researches indicate that the semi-active vibration reduction method is an effective horizontal vibration reduction method for elevator car, which has the characteristics of low energy consumption, suitable for high-speed elevator, while its adaptability is relatively weak. To address the adaptability issue, we proposed a semi-active high-speed elevator car horizontal vibration reduction method based on the improved particle swarm algorithm. To verify the feasibility of the proposed method, it is applied with a magneto-rheological damper in the KLK2-type elevator from Canny Elevator Co, Ltd The horizontal vibration results are compared with ones of the passive vibration reduction method and other algorithm-based vibration reduction methods. The vibration reduction method proposed in this paper is superior to all other mentioned methods in terms of the peak-to-peak value and the A95 value of the vibration acceleration. The horizontal vibration acceleration performance of the HSEC is improved by about 70%.

Piezoelectric resonator design and analysis from stochastic car vibration using an experimentally validated finite element with viscous-structural damping model

Within the Vibration Piezoelectric Energy Harvesting (VPEH) framework, this paper investigates and designs an optimal piezoelectric harvester (PH) under stochastic real-time vibrations using a step-by-step guideline from an electrical and mechanical perspective. A stochastic-excitation high-order-shear-deformation finite element (FE) method, with experimental verifications, analyzed the trapezoid non-uniform piezoelectric resonator under random base vibration. The significance of the contact layer and proper viscous-structural combined damping model is reported for precise power estimation. Based on modal sensitivity, a fast and effective model-updating method for structural modulation is developed. Parametric studies of the optimum load–frequency and natural frequency-geometrical parameters relationships are investigated. Modeling results indicate that ignoring the contact-layer effect will create inaccuracies in the resonant frequency estimation. Besides, a combined viscous-structural damping model is mandatory for proper resonant power estimation. The matched resistance loading is slightly different under stochastic vibration than the harmonic analysis. The presented method is applied on a real-time stochastic vibration, i.e., car vibration. Electrical power of 1.32 mW with density of 495.92 µW/cm3 are produced by installing one PH undergoing random excitation from gravity-direction. This power can be enough to power a low-power autonomous wireless vibration sensor demonstrating the VPEH usage in autonomous sensors for future intelligent cars.

Powering the WSN Node for Monitoring Rail Car Parameters, Using a Piezoelectric Energy Harvester

Monitoring of railroad wagons is important for logistical processes, but above all for safety. One of the key parameters to be monitored is the temperature of the axle box and the bearings in the bogie. The problem with monitoring these parameters is the harsh environment and lack of power supply. In our research, we present a power supply system for a WSN node monitoring the bogie parameters. Knowing the operating conditions, we built a power supply system using a piezoelectric energy harvester. The harvester consists of three piezoelectric elements placed on a double arm pendulum beam. The circuit was modeled in the Comsol Multiphysics environment and then built and tested in laboratory conditions. After confirming energy efficiency, the system was tested on a freight car bogie during an 8 h trip. At typical car vibration frequencies (4–10 Hz), the system is able to generate 73 uW. Combined with an energy buffer of 1000 mAh (3.7 V), it can power a WSN node (based on the nRF5340 chip) for 13 years of operation.

IoT-based Lava Flood Early Warning System with Rainfall Intensity Monitoring and Disaster Communication Technology

A lava flood disaster is a volcanic hazard that often occurs when heavy rains are happening at the top of a volcano. This flood carries volcanic material from upstream to downstream of the river, affecting populous areas located quite far from the volcano peak. Therefore, an advanced early warning system of cold lava floods is inarguably vital. This paper aims to present a reliable, remote, Early Warning System (EWS) specifically designed for lava flood detection, along with its disaster communication system. The proposed system consists of two main subsystems: lava flood detection and disaster communication systems. It utilizes a modified automatic rain gauge; a novel configured vibration sensor; Fuzzy Tree Decision algorithm; ESP microcontrollers that support IoT, and disaster communication tools (WhatsApp, SMS, radio communication). According to the experiment results, the prototype of rainfall detection using the tipping bucket rain gauge sensor can measure heavy and moderate rainfall intensities with 81.5% accuracy. Meanwhile, the prototype of earthquake vibration detection using a geophone sensor can remove noise from car vibrations with a Kalman filter and measure vibrations in high and medium intensity with an accuracy of 89.5%. Measurements from sensors are sent to the webserver. The disaster mitigation team uses data from the webserver to evacuate residents using the disaster communication method. The proposed system was successfully implemented in Mount Merapi, Indonesia, coordinated with the local Disaster Deduction Risk (DDR) forum. Doi: 10.28991/esj-2021-SP1-011 Full Text: PDF

POSSIBLE OPTION FOR CALCULATING VEHICLE VIBRATIONS

Determination of the loads on the elastic elements of the car suspension is a necessary part of the overall calculation of the car as a complex technical system. Considerable attention is paid to this issue both in fundamental works on automobiles and in educational literature. The authors of works devoted to the problem of car vibrations, in most cases, vibrations are considered from the point of view the smoothness of the movement of the car, which is quite logical because the smoothness of the ride determines many indicators of movement and, first of all, the physical well-being of the driver and passengers as well as the safety of transported fragile goods. In this case, the car is considered as a system with several masses connected by elastic elements. This approach requires reducing the masses and stiffnesses of elastic elements to specific points of the vehicle structure, compiling several differential equations of mass motion and, accordingly, significantly complicates solving a problem that is not always required by specific design problems. This article presents a variant of calculating dynamic loads based on a single-mass dynamic system, in which the sprung masses are considered as a single mass concentrated in the center of mass of the body and resting on elastic suspension elements. The solution of the dynamic problem in this case is much simpler, and the results solving a problem that is not always required by specific design problems. This article presents a variant of calculating dynamic loads based on a single-mass dynamic system, in which the sprung masses are considered as a single mass concentrated in the center of mass of the body and resting on elastic suspension elements. The solution of the dynamic problem in this case is much simpler, and the results of the solution may well satisfy the requirements for the accuracy of calculations, since end obtaining specific formulas for the dynamic factor of the loads on the vehicle structure depending on the speed of the vehicle hitting an obstacle. In addition, knowledge of the maximum deformation of the elastic elements of the suspension makes it possible to optimally determine the required depth of the wheel arches of the car, to calculate the required stiffness of the elastic elements of the axles of the car in accordance with the parts of the weight of the entire car falling on them. Keywords: automobile, elastic elements, vibrations, loads.

Self-Loosening Failure Analysis Considering Vibration Frequency: Experimental Study for the Spare Tire Carrier

The testing stage involves ensuring a product is produced correctly to achieve the targeted performance. Testing is observed from the determination of looseness resistance for a spare tire carrier to ascertain its durability due to car vibration when driven on flat and bumpy roads to avoid road users' dangers. Therefore, this study was conducted to observe the spare tire carrier's working process and analyze the changes in torque and chain tension in the drive shaft by installing a strain gauge sensor on the chain link. Moreover, the change in strain was converted into tension using mathematical calculations based on test standards. Each component of the spare tire carrier was also analyzed to determine the factors affecting chain tension changes. The results showed that the torque change on the driveshaft was 7.79%, while chain tension was 7.14% on axis 1 and 7.25% on axis 2. Therefore, the spare tire carrier passed the test with the difference not exceeding 25%, which means the road's safety aspect is guaranteed for all the users. However, the new fact is self-looseness is initiated by the vibration due to the stationary engine rotation.