Wheel Assembly Research Articles

Optimization of a roller coaster bogie considering fatigue life

This study explores the effectiveness of fatigue-life constrained topology optimization in roller coaster engineering, a previously unexplored field. Emphasizing the importance of fatigue life considerations, the research focuses on key components of roller coasters: the wheel assemblies. By integrating stress–life fatigue constraints, such an approach can lead to longer lasting and more efficiently designed roller coaster components. Multiaxial fatigue topology optimization using the method of moving asymptotes gradient-based optimization is examined to address the complex loading experienced by these bogies given a substantial load-time history in the high-cycle fatigue region. Using a validated optimization methodology, this study aims to reduce the bogie volume in selected domains while ensuring structural integrity and potentially extending service life. The optimization process successfully reduces the number of designable elements, resulting in decreased global volume and mass, and the results quantifiably demonstrate the impact of applying high-cycle fatigue constraints on the bogie’s performance.

Design and Optimization of Rear Wheel Assembly in All-Terrain Vehicle

Abstract: Suspension is one of the automobile's critical subsystems. Isolating the driver from the shocks of the road is the ultimate purpose. The need of sufficient wheel travel, lateral stability, load transmission, and driver comfort are elements of secondary functions. The study details the design and improvement of an ATV's braking and rear wheel suspension systems. The vehicle was designed under the terms of rules framed by the SAE Organization. The suspension provides the most effective achievable camber, caster, toe, anti-dive, Roll Center, and improvements since it is made for tough terrain. Additionally, there are also calculations, mounting considerations, and shock absorber presented. A prime instance of a commercial software package that studies suspension geometry is Lotus Shark. With the commercial program ANSYS WOKRBENCH, different suspension components are subjected to finite element analysis. All knuckle tests were performed on aluminium alloys 7075 and Hub EN24.

Experimental analysis of noise disturbances generated by reaction wheel

Abstract Microvibrations originating from onboard disturbance sources can lead to a range of issues, including a decrease in satellite pointing accuracy, image distortion and blurring. Therefore, reaction wheels emerge as the primary sources of disturbance noise. This paper employs an experimental approach based on the real dynamics of rotating reaction wheel assembly, closely simulating on-orbit configurations to measure noise responses transferred to the satellite structure. An assessment of noise response behaviour, incorporating a comprehensive understanding of the factors influencing the levels, was conducted on a proto-flight satellite for three reaction wheels. Initially, reaction wheel assemblies underwent individual iterative balancing to reduce mass deviations. Subsequently, amplitude-time responses at different rotational speeds of reaction wheel assemblies (RWA) disturbance noise were measured. The experimental results demonstrate that each individually balanced reaction wheel generates independent perturbation noise level due to manufacturing imperfections. Hence, the necessity of wheels testing for accurate prediction and mitigation of disturbance levels is crucial, especially for payloads sensitive to microvibrations. Furthermore, increasing wheel speeds proportionally amplify disturbance noise levels. Therefore, implementing an optimised mission attitude control profile with lower rotation speeds of reaction wheels effectively reduces microvibration levels which minimises risks to payload performance and reduce power consumption.

Research on Running Performance Optimization of Four-Wheel-Driving Ackerman Chassis by the Combining Method of Quantitative Experiment with Dynamic Simulation

The wheeled chassis, which is the carrying device of the existing handling robot, is mostly only suitable for flat indoor environments and does not have the ability to work on outdoor rugged terrain, greatly limiting the development of chassis driven handling robots. On this basis, this paper innovatively designs a four-wheel-driving Ackerman chassis with strong vibration absorption and obstacle surmounting capabilities and conducts performance research and optimization on it through quantitative experiments and dynamic simulation. Firstly, based on the introduction of the working principle and structure of the four-wheel-driving Ackerman carrier chassis, a multi-sensor distributed dynamic performance test system is constructed through the analysis of the chassis performance evaluation index. Then, according to the quantitative operation experiment of the chassis, the vibration and acceleration characteristics of the chassis at different positions of the chassis, the amount of slip and straightness of the chassis under different running distance, and the operating characteristics of the chassis under different road conditions and different damping springs conditions were analyzed respectively, which verified the rationality of the chassis design. Finally, by constructing the chassis dynamics simulation model; the influence law of chassis structure; and performance parameters such as chassis wheelbase, guide rod structure, and parameters, wheel friction coefficient and assembly error on the dynamic characteristics of the chassis is studied, and the optimal structure of the four-wheel-driving Ackerman chassis is determined while it is verified based on the simulation results. The research shows that the four-wheel-driving Ackerman chassis has good vibration performance and stability and has strong adaptability to different roads. After optimization, the vibration performance, stability, amount of slip, and straightness of the chassis structure are significantly improved, and the straightness is reduced to 0.399%, which is suitable for precise carriage applications on the chassis. The research has important guiding significance for promoting the development and application of wheeled chassis.

NEDD1 overexpression increases cell proliferation, tumor immune escape, and drug resistance in LUAD.

Background: Neural Precursor Cell Expressed Developmentally Down-Regulated Protein 1 (NEDD1) serves as a crucial factor in promoting cellular mitosis by directly facilitating wheel assembly and daughter centriole biogenesis at the lateral site of parent centrioles, ultimately driving centrosome replication. The amplification of centrosomes and the abnormal expression of centrosome-associated proteins contribute to the invasion and metastasis of non-small cell lung cancer cells. However, the specific mechanism by which NEDD1 contributes to the progression of lung adenocarcinoma (LUAD) remains unexplored. Therefore, the objective of this study is to uncover the role played by NEDD1 in LUAD. Methods: To verify the expression of NEDD1 in pan-carcinoma. The feasibility of NEDD1 as a prognostic marker for LUAD in TCGA and GEO databases was verified. Subsequently, Cox proportional hazard regression analysis was used to screen the prognostic factors of LUAD, so as to analyze the correlation between prognostic factors and NEDD1 expression. For another, NEDD1-related genes were screened for pathway enrichment analysis to verify their possible functions. In addition, the expression of NEDD1 in LUAD was verified by qPCR and IHC, then siRNA was used to construct NEDD1-knocked lung cancer cells for subsequent cytobehavioral experiments. Finally, the distribution of NEDD1 in single-cell samples was revealed, and then the correlation between its overexpression and LUAD immune escape and drug resistance was analyzed. Results: LUAD exhibits upregulation of NEDD1, which in turn promotes the proliferation, migration, invasion, and epithelial-mesenchymal transition of lung cancer cells, thereby contributing to a poor prognosis. Furthermore, the overexpression of NEDD1 is closely associated with immune escape and drug resistance in LUAD. Conclusion: NEDD1 serves as a reliable prognostic marker for LUAD, and its upregulation is associated with increased immune escape and drug resistance. Given these findings, NEDD1 holds potential as a novel therapeutic target for the treatment of LUAD.

Model of the turboprop engine reduction gear tooth harmonic spectral component

The width of spectral components in rotary machines is determined by the frequency modulation of the carrier from the rotor speed deviation in the stationary operation mode. It was shown that, for the tooth spectral component, it is not enough to take into account this factor only. The analysis of publications and the studies performed show that it is also determined by the effect of many other factors: process-related ones (errors in manufacturing and assembly of gear wheels), operation mode parameters (rpm, temperature, transmitted load); design-related factors (flexibility of drive parts; modification of the tooth face), as well as uneven wear of tooth flanks. Using the planetary gearbox of a turboprop engine as an example, the structure of the tooth spectral component width in function of the analyzed influencing factors was considered. Based on the vibration statistics for eighteen gearboxes in overhauled engines, the choice of a ratio for the spectral component width of a frequency modulated process was justified. This choice showed readings closest to the corresponding experimental data. For the vibration of ten gearboxes with different degrees of tooth flank wear, the corresponding dependence of the width on the wear is presented. A mathematical model for the tooth spectral component width in overhauled and newly manufactured gearboxes as the product of the constant coefficient with the deviation dispersion sum from the considered factors was proposed. The same dependence was also given for gearboxes with wear when adding the dispersion from wear to the dispersion sum. It was demonstrated that, for the presented case of the maximum wear, its fraction in the total width was about 50%, whereas the fraction of the frequency modulation from the operating system of adjusting relative rotor speed constancy in the stationary engine operation mode was equal to half of all the other factors.

Identification of reaction wheel assembly disturbances based on variable modal frequencies

Micro-vibrations of the reaction wheel assembly (RWA) can have a negative impact on spacecrafts’ attitude control, surveillance, and measurement. Evaluating the micro-vibration magnitude during the design stage is possible by establishing an accurate dynamic model of the RWA disturbance characteristics and identifying the relevant parameters. Doing so can provide references for spacecraft design and development, ultimately leading to more efficient and effective spacecraft operations. However, the conventional methods of modeling and identifying the RWA and of predicting the distribution and magnitude of the disturbing force/torque are limited, as it relies on stable and constant modal frequencies. In the development mission of a satellite, a specific scenario is found that the modal frequency of the RWA changes with speed. This study proposes a novel modeling and parameter identification method for the RWA disturbances based on variable modal frequencies and is advantageous in this scenario. The RWA’s dynamic model is considered a covariant system related to the rotational speed. Additionally, frequency-domain and time-domain models have been established for the RWA’s translational and swinging motions. Simultaneously, the identification method of the model parameters is developed, which involves identifying the harmonic factors, the variable modal frequencies, and the amplitude coefficients. Finally, the method is validated by numerical simulations and experiments. The results indicate that the proposed method offers excellent identification performance, surpassing conventional methods in model accuracy and identification performance. This achievement holds significant reference value in the micro-vibration suppression and optimization design of spacecraft.

Attitude Control and Parameter Optimization: A Study on Hubble Space Telescope

Abstract In this work, we build a satellite attitude Proportional-Integral-Derivative (PID) controlled system by using the Hubble Space Telescope (HST) parameters as a reference and tune its controller parameters using various tuning methods. First, we give the equations for the motion of a satellite. We elaborate the control structure as controller, actuator, dynamics, and kinematics subsystems and construct an external disturbance model. We use a reaction wheel assembly used in the HST with the same configuration as the actuator. We evaluate the performance of the linearization by comparing it with the nonlinear model output. By working on the linearized model, we tune the PID controller parameters using two different methods: “Model-Based Root Locus Tuning” and “Genetic Algorithm Based Tuning”. First, we obtain the controller parameters by manipulating the poles on the root locus plot of the linearized system. In addition, we use genetic algorithms to find the optimized controller values of the system. Finally, we compare the performances of the two methods based on their cost function values and find that the Genetic Algorithm-based tuned parameters are more fruitful in terms of the cost function value than the parameters obtained by the Root Locus-based tuning. However, it is found that the Root Locus-based tuning performs better in disturbance rejection.

Microvibration simulation of reaction wheel ball bearings

Microvibrations on board satellites are a well-known problem affecting their pointing accuracy by inducing oscillations to the line-of-sight. Fast rotating devices, such as reaction wheel assemblies (RWAs) are a major cause of these onboard mechanical disturbances. Imbalances in the flywheel, as well as imperfections in the ball-bearing components yield low-amplitude vibrations that are transmitted to the satellite structure, adversely affecting the performance of sensitive onboard instruments. This research focuses on the RWA’s ball bearing microvibration frequency and amplitude characterization. This is achieved by introducing specific geometry imperfections on the ball bearing rotating elements. In addition, variables such as the ball bearing preload, the number of balls and their dimensions are altered to understand how the bearing microvibration changes in order to minimize it. Finally, available physical microvibration test data is used to compare and cross-correlate the microvibration waterfall plots obtained from the transient FEA of the parametrized bearing models introduced herein. This work provides a better understanding of the relation between the main structural ball bearing parameters and the microvibration disturbances emitted by the RWA to minimize its mechanical noise.

Tuned mass damper on spacecraft reaction wheel assembly

Considering the wide frequency range and time-varying characteristics of reaction wheel assembly (RWA) micro-vibrations, an embedded tuned mass damper (TMD) was proposed herein to reduce the influence of the RWA micro-vibration effect on spacecraft. First, dynamics model of the RWA and a mechanical model of the angular contact ball bearing were constructed, and the time-varying characteristics of the RWA were theoretically analyzed. Based on single- and multiple-degree-of-freedom vibration absorption dynamics models, it was shown that the TMD could be applied to the vibration suppression of the RWA’s multi-modal and time-varying state by changing the design parameters of the TMD. Based on the RWA single-degree-of-freedom equivalent dynamics model, the effects of the TMD natural frequency and damping on the displacement amplitude ratio of the RWA were analyzed, and the sensitivities of the RWA resonance peak amplitude and resonance frequency to the two parameters were analyzed by the Sobol sensitivity analysis method. Then, according to the analysis results, the structural design of the TMD in the RWA was guided, and a test platform was built to obtain the RWA micro-vibration data. Finally, a normalized amplitude-frequency response identification algorithm was used to eliminate the effects of non-linearities in the experimental data and to identify the RWA dynamics in a time-varying state, thus obtaining the RWA amplitude–frequency response curve and verifying the results of the theoretical analysis. Theoretical and experimental data showed that the addition of a TMD structure with variable damping and stiffness within the RWA allowed for micro-vibration suppression for arbitrary modes and improved the RWA vibration characteristics. This could provide convenience for different specifications of RWA vibration suppression as well as reference for further research on the effective application of TMDs in RWAs.

Development of a New Test-Rig for Wheel–Rail Contact Experiments under Large Slip Conditions

In order to further theoretical and experimental research on adhesion recovery, an innovative new test-rig for wheel–rail contact experiments under large slip conditions was developed. The wheel-on-ring category of test-rig was determined to preserve surface conditions on rail. A scale factor of 1/4 and a circling diameter of 2 m were adopted considering the power limit in the laboratory and wheel–rail contact similarity. The test-rig consisting of wheel assemblies, ring track, gearbox, motors and sprinkler system was specially designed for motor decoupling and precise slip control. Then, the accuracy of slip under PID control was verified by simulation and experimental validation. Thereafter, experimental observations with different speeds, axle loads and surface contaminants showed the potential of the new test-rig for exploring adhesion recovery under various surface conditions.

A General Method to Obtain the Frequency Response Function from the Disturbance Source to the Sensitive Payload

Microvibrations are one of the main factors contributing to platform jitter and a decline in pointing stability and precision. Among various disturbance sources, reaction wheel assembly (RWA) is one of the most significant ones and has drawn the interest of numerous scholars. How to evaluate the influence of the disturbances of RWA on the pointing accuracy of a spacecraft is an arduous task because it involves multiple disciplines. The acquisition of the frequency response function (FRF) from the disturbance source to the sensitive payload is one of the most crucial stages in integrated modeling. Direct measurement of the FRF in the six directions is challenging because of the restricted room for RWA installation in a spacecraft, particularly in small satellites. In this paper, a general method based on the Hv algorithm to obtain the FRF is presented. This method only needs the RWA, itself, as an excitation source. Then, in order to acquire the FRF, we use an optical remote-sensing satellite as the research object. The peak positions of FRF obtained by different RWAs are basically the same, while the amplitudes are slightly different, indicating that this method is effective. This method takes into consideration the coupling between the RWA and the spacecraft, making it possible to multiply the RWA disturbance measured at a fixed interface with the FRF, to determine the image motion of the sensitive payload.

Design and acoustic tests of the ATHENA WFI filter wheel assembly development model towards TRL5

The filter wheel (FW) assembly (FWA), developed by the CBK Institute, is one of the critical subsystems of the wide field imager (WFI) instrument on board the Advanced Telescope for High Energy Astrophysics—mission of the ESA Cosmic Vision 2015-25 space science program (launch scheduled around 2035). The instrument has to collect soft x-rays with very high quantum efficiency, thus WFI requires extremely thin optical blocking filter (OBF). Due to its thickness (∼150 nm) and large area (∼170 mm × 170 mm) needed to achieve a 40 ′ × 40 ′ instrument field of view, the filter is extremely vulnerable to acoustic loads generated during Ariane 6 rocket launch. On the other side, FW mechanism has to provide high overall reliability, so it is more favourable to launch the instrument in atmospheric pressure (without vacuum enclosure for filter protection). Design efforts of the FW subsystem were focused on two issues: providing maximal possible sound pressure level suppression and smallest possible differential pressure across the OBF, which should prevent filters from damaging. We describe the design of a reconfigurable acoustic-demonstrator model (DM) of WFI FWA created for purposes of acoustic testing. Also, the acoustic test campaign is described: test methodology, test criteria, and results discussion and its implication on future FWA design. In general, tests conducted with the FWA DM showed that current design of WFI is feasible and the project can be continued without introducing a vacuum enclosure, which would significantly increase system complexity and mass.

Prototype Design of E-BMX 2000 Watt Electric Motorcycle

Limited supplies of fossil fuels such as gasoline, diesel and LPG resulting in vehicles that use internal combustion would be abandoned and replaced by electric vehicles. There have been many coverages that have reviewed the advantages of electric vehicles, where the advantages of electric vehicles include simple mechanical components, relatively low pollution, low noise levels, and could become a solution for future vehicles for an environmentally friendly life. This study aims to design and build a motorcycle prototype, a work which includes the design and manufacture of a BMX type motorcycle frame powered by a 2000 watt BLDC motor power, and testing the performance of the prototype using dynotest and compared to conventional motorcycles to compare the performance characteristics of both motorcycle. The frame is designed using Solidworks, then manufactured by cutting, bending, drilling, welding, and painting process. Mechanical components include frames that use mild steel pipes with diameter of 1.5 inches and thickness of 1.2 mm. Other mechanical components use components available on the market, such as headsets, front forks, disc brakes, hydraulic caliper brakes, and wheel assemblies. The electrical components used are 48V 2000-watt QS Motor, 60V 15 Ah Lithium battery, Yuyangking 80A controller and electric gas throttle with voltage indicator. The results of the dynotest show that the maximum torque reaches 204 NM (roller) which is achieved at 976 rpm. The maximum speed reaches 69.7 Km/hour. The range of the single-charged battery could cover a distance of 30 km. The characteristic of 2000 Watt E-BMX is very powerful at low revs and stable at high revs, shown by achieving maximum torque at low RPM. To save battery life, it is necessary to limit the remaining voltage, which is done at 55 Volts, so that the battery do not completely run out. It could be concluded that electric motorcycle developed in this study is suitable for use in urban areas (paved tracks or light off-road) with determined mileage and the path travelled, and battery management is needed so the battery does not run out in the middle of a trip.

Validation of the New Small Wheel Micromegas sectors for the phase 1 upgrade of the muon forward spectrometer of the ATLAS experiment at CERN

The ATLAS experiment is currently upgrading the first muon station in the high-rapidity region with the New Small Wheels (NSW), based on large-size resistive Micromegas (MM) technology and small-strip Thin Gap Chambers (sTGC). The NSW system is going to be installed in the ATLAS underground cavern during the LHC long shutdown 2 (2021) to enter in operation for Run3 (starting in the first months of 2022). 128 Micromegas quadruplets, each composed by four measurement layers two to three square meters in size, are needed to build the two New Small Wheels, covering a total active area of about 1280 m2. The construction of all MM modules, carried out in France, Germany, Italy, Russia and Greece, is completed. Their mechanical integration into sectors, the installation of on-detector services and electronics, for the first NSW is also completed, along with all validation and acceptance tests. The preparation of the second NSW is very well advanced. The advanced status of the project, in view of the imminent installation of the two NSW in ATLAS by the fall of 2021 will be reported. Micromegas detector construction and integration into sectors is presented, together with results obtained with cosmic rays data during the validation tests and the impressive steps of the wheel assembly completion.

СОЗДАНИЕ ЦИФРОВОГО ДВОЙНИКА ПРОЦЕССА СБОРКИ РАБОЧЕГО КОЛЕСА КОМПРЕССОРА

A digital dual compressor wheel assembly process has been developed to predict the angular rotations of the blade assembly rotating as it rotates. The calculated angles characterize the tension in the joints of the end flanges of the blades. At the input of a digital double sequence of data on geometry deviations with control of operations on parts. During the implementation, the random forest method was used, the study of which was carried out on a set of calculated experiments performed in the ANSYS environment using the element model of the assembled impeller. The experimental results show that the calculation error does not exceed 15 minutes of arc.

DoE-FEM Based Design Optimization of Hub and Spindle

A significant portion of the wheel assembly's safety is determined by the performance of the spindle and hub. In conventional designs, weight-to-strength ratio, connection configuration, etc., have barely been optimized. The purpose of this paper is to apply an optimization process through the design of experiments (DoE) concept to hub and spindle designs. To achieve better efficiency, lighter materials are targeted for use in a 3-wheel solar-powered vehicle. Using FEM analysis, both designs were statically analysed. Using Taguchi method, experiments were designed for both maximum safety and minimum weight, subjected to geometrical boundary constraints with regard to maximum safety and minimum weight. Each part was evaluated based on its impact on performance and safety. Both spindle and hub have been optimized to provide a reliable factor of safety and light weight.

THE FUNCTIONAL DEPENDENCE OF THE 3D PRINTED PARTS BY THEIR TRIBOLOGICAL AND THERMAL CHARACTERISTICS

The popularity of bio - based thermoplastic materials with applications in a variety of industries, including consumer goods, automotive, medical equipment, and so on, has grown significantly in recent years. This increase in the market for biodegradable materials is closely related to the growing concerns of both users and industry, especially in relation to replacing the conventional or non-biodegradable polymeric products on a widespread scale. This study examined the tribological performance (friction coefficient) and wear of biodegradable polymers PLA, HD PLA Green, and Impact PLA Gray in various meteorological testing conditions on a simulation stand that replicate the operation mode of worm-worm wheel assembly as part of the drive mechanism of car wipers. The Impact PLA Gray sample had the greatest average value of a wear coefficient and wear resisting during simulation and best on testing. The lowest performance has been recorded by the PLA sample because its melting temperature is the lowest, thus affecting its resistance to friction and wear. Regarding the possibility of practical use of the worm wheel in the proposed assembly, it is recommended only to use at negative temperatures, below -10°C.

Ride Comfort Analysis of Motor Vehicles using Analytical and Experimental Procedures

The occupants of an automobile are subjected to varying levels of vibration, which may not affect them consciously, but passively these are found to contribute to lower back pain, dizziness and discomfort amongst other health hazards when exposed for a chronic period. The primary source of these vibrations apart from the ones originating from the engine, are transmitted from the road during tire road interaction. The effect of this is felt by the occupants via the seat, foot rest, back rest and steering wheel of a four wheeler and the handlebar, footrest and seat in case of a two wheeler. The international standards such as ISO 2631-1:1997 for whole body are followed by vehicle manufacturers for ensuring ride comfort in terms of vibration transmissibility to the occupants. The ride comfort of a vehicle is influenced by the natural and force transfer characteristics of the tire wheel assembly and the suspension system. The objective of the current work is to use analytical models for finding natural frequencies of sprung and unsprung mass and henceforth determining the trend of vibration amplitude influenced by parameters like damping, mass and stiffness values through a forced response analysis. Subsequently, experiments are conducted to measure the real time vibration levels at aforementioned human interaction points. This helps to correlate the analytical study with the experimental outcomes.

Biochemical Blood Sensing Platform With CMOS Image Sensor and Software-Based Wavelength Filter

A fully integrated biochemical sensing platform is developed for blood diagnostics. The biochemical analyses of blood include the enzymatic reaction of the sample with a reagent that produces a colorimetric variation of solutions. The developed platform focuses on providing software solutions to the hardware dependencies in the existing analyzers by replacing the physical optical filter wheel assembly with software-based wavelength filtering. The experiments are performed to sense these variations with the developed image acquisition platform and the software-based wavelength filtering unit. The machine learning approach is used to train the system to predict unknown concentrations using the experimentally generated dataset. To verify the usability of the developed platform, the sensing of glucose, albumin, and cholesterol was carried out in the linear range from 10 to 400 mg/dL, from 1 to 8 g/dL, and from 10 to 800 mg/dL with a limit of detection (LOD) of 2.8 mg/dL, 0.64 g/dL, and 3.14 mg/dL, respectively. The results obtained are matching with the commercial biochemistry analyzer. The system is tested thoroughly, and the results show that the developed blood sensing platform is reliable, portable, and accurate due to the minimization of hardware moving parts, and offers extreme flexibility of operation due to software solutions, facilitating numerous blood analysis all-in-one instruments.