Simulation Bench Research Articles

Blade tip clearance measurement method based on blade tip timing without the once per revolution sensor

Abstract The rotor blade tip clearance (BTC) of an aeroengine is a critical parameter that significantly impacts its performance and safety. Accurately determining dynamic BTC has been a focal point of research in experimental testing. Among the effective measurement methods for dynamic BTC, the laser triangulation method based on blade tip timing (BTT) stands out. However, this method typically relies on an once-per-revolution (OPR) sensor for rotor speed and blade serial number information during measurement, leading to increased installation and maintenance costs as well as additional measurement uncertainties. In response to this challenge, this paper presents two signal processing method that eliminate the need for an OPR sensor. The first method, referred to as "none OPR method 1," closely follows the measurement principles of the traditional method but employs a skewed dual light probe (SDLP) signal to extract rotational speed information, thus obviating the need for an OPR sensor. The second method, "none OPR method 2," introduces a novel data processing approach that enables BTC determination without any source of rotor speed information. Both methods utilize dynamic and static BTC matching techniques to identify blade serial numbers and achieve BTC measurement without an OPR sensor on a simulated rotor experimental bench. Comparative analysis with traditional method BTC measurements reveals that, under stable rotor speeds, all methods achieve similar levels of accuracy and repeatability errors within 0.025mm. However, when dealing with variable speed conditions, the traditional method's accuracy is significantly affected. None OPR method 1 mitigates the impact of rotor speed changes to some extent, while none OPR method 2 remains unaffected by such changes. Importantly, both none OPR methods demonstrate the capability to measure blade-by-blade tip clearances akin to the traditional method.

Gerontological Simulation Lab: Process Mapping a New Virtual Ward for the Nursing Home Liaison Service

Abstract Background Simulation-based training is an increasingly accepted way for multidisciplinary teams to learn together. Its use in geriatric departments around Ireland is increasingly visible. The application of simulation to pathway and process development however is less common. We decided therefore to deploy a simulation lab to test a new virtual ward platform for local nursing homes. Methods We developed, in partnership with a digital provider, a piece of software that could enable the efficient and safe operation of a virtual ward. Our simulation was conducted in two phases. Phase 1 involved bench simulation of the platform in order to identify any obvious software issues. Phase 2 involved the development of two simulated patient scenarios that would specifically test the operation of the pathway. Nursing staff from our local nursing homes and specialist MDT members from our own department were invited to the Sim lab in order to work through the developed scenarios. Results Bench simulation of the software during phase 1 identified three significant limitations to the software developed. These were resolved before progressing to phase II testing. The simulated scenarios at our lab worked well and participants shared positive feedback regarding the pathway and technology. They found the software easy to navigate, practical and agreed unanimously to its future use. There were further minor technical issues identified that have been fed back to the software company for resolution. The simulation facilitated training using the “live” system for both the staff at our nursing homes and our own team members. Conclusion The simulation lab proved to be an ideal environment for testing both our new virtual ward pathway and the digital technology developed for its enablement. It facilitated the creation of a comprehensive process map and ensures that all stakeholders had a clear understanding of the new pathway.

Research on The Influence of Continous Damping Control Shock Absorber on Frequency Response Function of Spindle Coupled Road Simulation Test Bench

When the semi-active suspension is tested based on the 6-DOF spindle coupled road simulation test bench, the traditional test method is no longer applicable, because the continous damping control shock absorber of the original vehicle controller cannot be used and the overall nonlinear of the system is stronger. At present, there are few related engineering applications in the industry. This paper introduces the current reproduction technology of semi-active suspension on the 6-DOF spindle coupled road simulation bench and researches the difference of the system frequency response function by excitation of continous damping control shock absorber with different control current.

Performance evaluation of endoscopic ultrasonography needles: Experimental study.

Background and study aims The relative procedural performance of needles for endoscopic ultrasound-guided fine-needle aspiration/biopsy (EUS-FNA/B) is unclear. The present study therefore compared six types of 22-gauge FNA/B needles using a bench simulator. Methods Resistance forces during needle puncture and removal, needle tip damage before and after procedure, leakage after puncture of mucinous cyst models, the shape of the puncture surface at the puncture site, amounts of samples extracted, ranges of needle deflection angles, and needle deformation after multiple procedures were compared using six types of needles. Results Maximum resistance forces during puncture and removal were highest for ProCore needles and lowest for Expect needles. None of the needles had damage after puncturing. SharkCore needles showed the highest amount of leakage, whereas FNA needles showed no leakage. The puncture tracts of FNA needles remained in the form of a flap at the puncture site, whereas FNB needles broke off the target material creating a hole. The target material removed was supplemented within the puncture needle. TopGain needles produced significantly larger samples than ProCore, EZShot3 Plus, and Expect needles. FNB needles produced larger and more core samples than FNA needles. EZShot3 Plus needles had the highest range of needle deflection angle using an elevator device and the lowest needle deformation after 20 punctures at full endoscopic angle and a full elevator. Conclusions The performance of the six needles differed in various ways. Understanding the characteristics of each needle may allow for selection of the appropriate needle for each situation.

Thermal characterization of cylindrical roller bearings based on thermal-structural coupling approach

High-speed running bearings generate a large amount of heat, which has a significant impact on the accuracy of machine tool feeding system. In this paper, by applying the bearing proposed statics and local heat source method, considering the combined surface contact thermal resistance and lubricant viscous temperature characteristics of the influence of the thermal network method to determine the main thermal characteristics of the shaft system parameters, the establishment of the transient thermal equilibrium equations, in the iterative process of the shaft system temperature field and deformation of the coupling; through the solution, the bearing temperature field and the transient change of the thermal parameters of the characteristics of the bearing, analyze the working conditions and structural parameters of the bearing transient thermal characteristics curve; using the finite element method coupled field simulation and test bed test, to verify the theoretical model is reasonable. The influence of working conditions and structural parameters on the transient thermal characteristic curve of the bearing is analyzed. The reasonableness of the theoretical model is verified by using the finite element method coupled field simulation and test bench test. After in-depth analysis: no matter the initial clearance or the change of rotational speed and load, it will lead to the change of thermal equilibrium temperature of the bearings, and will produce heat-induced load. Therefore, by choosing the appropriate clearance, improving the viscosity of lubricant, and enhancing the air convection, the heat generation and thermal deformation can be effectively reduced, which provides an important method to support the optimization of the bearing structure and the design of thermal balance.

Ex-vivo Aortic Root Simulator Bench Model for Investigation of Aortic Annular Rupture During TAVI Procedures

Ex-vivo Aortic Root Simulator Bench Model for Investigation of Aortic Annular Rupture During TAVI Procedures

Deviation of drive torque and rotational speed of a wind turbine drivetrain between test bench and wind turbine simulations

Wind turbines are a major contributor to a clean and independent energy mix in the future and therefore need to have as little downtime as possible. Downtime can be minimised by increasing the robustness of the wind turbine. The drivetrain is one of the major contributors of downtime in wind turbines. One way of increasing the robustness of wind turbine drivetrains is extensive drivetrain testing and loop-back optimization of the design and control. On the drivetrain test bench torque and other wind loads are applied. To ensure that the drivetrain reaction to the loads is the same as of the erected wind turbine the accuracy of the application of the loads needs to be sufficient. Only if the reaction loads of the drivetrain are similar to the rotor loads of the erected wind turbine a robustness increase can be achieved via the loop-back optimization after the tests. This paper therefore quantifies the deviations occurring in torque and rotational speed of the hub between the erected wind turbine and the test bench for a specific wind turbine. To do so the results of a test bench simulation are compared to results of an aerodynamic simulation of the wind turbine. For the investigated wind turbine drivetrain, the deviation in drive torque increases slightly with higher windspeeds. The torque values are maximum 2 % higher at the wind turbine compared to the rated torque. The rotational speed values are represented very well regarding the time series as well as the occurring frequencies. The speed values deviate maximum 0.5 % compared to the rated speed. The deviations are a result of differences in an underestimation of the drivetrain efficiency in the aerodynamic simulation and the inertia of the drivetrain on the test bench and wind turbine. Since the deviations are small the abstraction losses at the test bench regarding torque and speed are acceptable.

A rolling bearing fault diagnosis method based on interactive generative feature space oversampling-based autoencoder under imbalanced data

With the rapid development of railroads and the yearly increase in the scale of operation, the safe operation and maintenance of rail trains have become particularly important. Among them, deep learning-based bearing fault diagnosis methods have attracted more and more attention in rail train operation and maintenance. However, rail trains usually operate normally. Collecting complete fault data for deep learning model training is often difficult. Such scenarios with a large difference between the number of normal data and fault data usually affect the performance of fault diagnosis models. Here, an interactive generative feature space oversampling-based autoencoder (IGFSO-AE) is proposed to realize fault sample generation under imbalanced data. First, the original vibration signal is converted into a semantically stable amplitude–frequency signal by fast Fourier transform and input into the autoencoder; second, the order of the hidden layer space features of the autoencoder is randomly exchanged, and the interactive sample generation learning strategy trains the autoencoder; then, interpolation oversampling is used to interpolate samples in the hidden layer space where the Euclidean distance between samples is large, and is input into the decoder, the generated samples are mixed with the original samples to form a new training set, which is used to train the intelligent fault diagnosis model and output the diagnosis results. Finally, the performance of the proposed method is evaluated using the publicly available bearing dataset and the bogie-bearing fault simulation bench in our lab. The experimental results show that IGFSO-AE can generate diverse samples with incremental information and exhibits robustness and superiority in different imbalanced proportions of data.

Application of Transcatheter Electrosurgery in Structural Heart Interventions: A Report of Three Different Techniques

Transcatheter electrosurgery is a novel technique to traverse or cut tissue, within blood-filled spaces, using alternating current directed by guidewires and catheters. We report the first series of transcatheter electrosurgery procedures in Asia including transcaval access for transcatheter aortic valve implantation, intentional aortic leaflet laceration to mitigate the risk of coronary occlusion in transcatheter aortic valve implantation and intentional laceration of anterior mitral valve leaflet to mitigate the risk of left ventricular outflow tract obstruction. These procedures are potentially valuable in Asian patients because of their smaller body build compared to Caucasians posing a higher risk of coronary or left ventricular outflow tract obstruction during transcatheter valve implantation. There is a need to adopt transcatheter electrosurgery in Asia to treat more surgically inoperable patients, including proper simulation training, bench training and clinical proctorship.

Development of high-speed and precision metering device with gradient-feeding and control seed for soybean planting

High-speed and precision planting was employed to improve the yields of soybean seeds. However, most mechanical seed metering devices had a lower quality index under high-speed. In this study, a high-speed and precision metering device with gradient-feeding (GF) and control-seed (CS) for soybean planting was designed to improve the quality index at high speeds. GF was designed to make soybean seeds rapidly enter seed cells. CS prevented soybean seed that was to be released from being cleared during the clearing stage. Firstly, the range of working parameters of it was determined by theoretical analysis, which included the angle of guiding-slope (α), the angle of seed-control (θ), and mutation height (∆H). Then, orthogonal center combination tests with three-factor and five-level were carried out to determine the corresponding quality index and miss index with different working parameters. The optimal working parameters were determined by regression equations between the quality index and the miss index. The high-speed and precision metering device with GF and CS was thus manufactured based on these optimal working parameters. The simulation test and bench test of it were carried out with different forward speeds of the planter. The results showed that the optimal angle of guiding-slope (α), angle of seed-control (θ), and mutation height (∆H) were 18.06°, 136.67°, and 2.77 mm, respectively. In the bench test, all quality indices were higher than 95.00%, and all miss indices were lower than 3.00% when the forward speed of the planter was 4 - 16 km/h. The results of the bench test were consistent with the results of the simulation test, with an average relative error of 2.33%. High-speed and precision metering device with gradient-feeding (GF) and control-seed (CS) can realize precision planting at high speeds.

Effect of construction method and bench height on particle size segregation during waste rock disposal

ABSTRACT Waste rock segregation and heterogeneity can increase the hydrogeotechnical and geochemical instability of waste rock piles, but characterising segregation quantitatively in the field is difficult because of the large dimensions of these structures. In this study, a discrete element model (PFC3D) was calibrated on two real cases and used to simulate the flow behaviour of waste rock during disposal. The effect of the construction method, the bench height, and additional factors (e.g. mine truck payloads and push velocities) on particle segregation was investigated. Segregation degree and relative particle diameters of waste rock at different locations in the pile were compared to propose practical solutions and reduce segregation and heterogeneity during deposition. Results indicated that simulated bench heights and mine truck payloads had limited effect on segregation. A smaller proportion of large particles in the original waste rock can increase segregation. Lateral disposal and increasing the push velocity tend to reduce segregation.

Development of personalized non-invasive ventilation masks for critically ill children: a bench study

BackgroundObtaining a properly fitting non-invasive ventilation (NIV) mask to treat acute respiratory failure is a major challenge, especially in young children and patients with craniofacial abnormalities. Personalization of NIV masks holds promise to improve pediatric NIV efficiency. As current customization methods are relatively time consuming, this study aimed to test the air leak and surface pressure performance of personalized oronasal face masks using 3D printed soft materials. Personalized masks of three different biocompatible materials (silicone and photopolymer resin) were developed and tested on three head models of young children with abnormal facial features during preclinical bench simulation of pediatric NIV. Air leak percentages and facial surface pressures were measured and compared for each mask.ResultsPersonalized NIV masks could be successfully produced in under 12 h in a semi-automated 3D production process. During NIV simulation, overall air leak performance and applied surface pressures were acceptable, with leak percentages under 30% and average surface pressure values mostly remaining under normal capillary pressure. There was a small advantage of the masks produced with soft photopolymer resin material.ConclusionThis first, proof-of-concept bench study simulating NIV in children with abnormal facial features, showed that it is possible to obtain biocompatible, personalized oronasal masks with acceptable air leak and facial surface pressure performance using a relatively short, and semi-automated production process. Further research into the clinical value and possibilities for application of personalized NIV masks in critically ill children is needed.

Functional Data Analysis of Hand Rotation for Open Surgical Suturing Skill Assessment.

This study explores the application of functional data analysis (FDA) to hand roll velocity during radial suturing on the SutureCoach bench simulator for evaluating open suturing performance. By treating temporal sensor data as mathematical functions, FDA provides a holistic view of the dynamic changes in hand roll, offering comprehensive assessments that are easily interpretable and clinically relevant. Cluster analysis was performed on hand roll profiles from 96 subjects, categorized into advanced surgeons, trainee surgeons, and novices. Functional k-means, using dynamic time-warping to align curves, were used to partition the data into two preset numbers of clusters (3 and 6). Both clustering models (3-cluster and 6-cluster) effectively clustered performance into groups with distinct characteristics and levels of skill (evident from visual inspection of cluster centroids). The relationship between cluster membership and suturing skills was corroborated using proxy measures of skill: expert global rating scale ratings, clinical status and expertise, and simulator-derived metrics. The findings of this study offer valuable insight into essential components of suturing skill and can improve the autonomy and efficiency of simulation-based suturing training. The clinical relevance of our results is immediately pertinent to the field of surgical skill assessment, where FDA-based methods could potentially be employed for objective feedback and training.

Influência da posição do sensor de sementes da semeadora em diferentes velocidades de trabalho

ABSTRACT: The uniformity of seed distribution and sowing speed directly impact crop quality and productivity. This experiment assessed how the position of the sowing monitoring sensor influences the distribution of cotton seeds using a pneumatic meter at different operating speeds. The experiment employed a completely randomized two-factor factorial design on a static simulation bench. The first factor involved the sensor installation sites (upper, middle, and lower portions of the conductor tube and conveyor belt), while the second factor encompassed simulated speeds of 3.0, 5.0, 7.0, 9.0, and 11.0 km/h. Parameters such as frequency of double, flawed, and acceptable spacing, coefficient of variation, and precision index were measured based on five replications of 250 consecutive spacing. The results indicated that the sensor’s placement significantly influences reading accuracy. Optimal results were observed when the sensor was positioned at the final portion of the conductor tube, providing more accurate seed deposition, and facilitating decision-making.

Vehicle Headlight Halo Simulation of Presbyopia-Correcting Intraocular Lenses.

This optical bench study was designed to evaluate and compare the halos generated by presbyopia-correcting intraocular lenses (PCIOLs) and monofocal intraocular lenses (IOLs), with or without lens decentration, using an optical bench to simulate the headlight of a distant vehicle in mesopic conditions. Halos generated by six nondiffractive and 10 diffractive IOLs with different dioptric add powers were evaluated using a high dynamic range bench system. Halo intensities were compared by assessing the area under the measured intensity profile curve to compute the relative halo magnitude (RHM). Nondiffractive PCIOLs produced smaller and less intense bench halo images than diffractive ones. RHM measurements ranged from 964 to 1896. Monofocal IOLs produced lower RHM values, whereas diffractive PCIOLs generated higher ones. When decentered by 0.5 mm with respect to the system aperture, more obviously asymmetric halo image profiles were observed in diffractive compared with nondiffractive PCIOLs. Simulated bench halos of nondiffractive PCIOLs are smaller and less intense than those of diffractive PCIOLs. Additional clinical studies assessing standardized patient-reported outcomes measures are required to correlate these bench results with patient satisfaction. This study contrasts the design-related simulated bench halos of nondiffractive and diffractive PCIOLs, aiming to elucidate their impact on halo perception.

Response Analysis and Stator Optimization of Ultrahigh-Speed PMSM for Fuel Cell Electric Air Compressor

For the requirement of the complex dynamic performance for the fuel cell vehicle (FCV), the wide operation range and rapid dynamic response ability are essential to the fuel cell electric air compressor, which are limited by the output torque of the permanent magnet synchronous motor (PMSM) commonly used in FCV. The purpose of this study is to improve the output torque of the stators and its rapid dynamic response capacity of PMSM using the mathematical model, multi-objective optimization and experimental validation. Firstly, a mathematical model of speed regulation response of ultra-high speed PMSM is established, which provides a basis for taguchi legal sub-optimization in this study. Secondly, stator parameters were selected as optimization variables based on Taguchi method, and the optimal combination of optimization variables was selected with the maximum electromagnetic torque, minimum cogging torque, minimum stator copper loss and minimum stator iron loss as optimization objectives. Finally, the effectiveness of the optimization method is verified by simulation analysis and bench test. At the target speed of 110652rpm, 124364rpm and 146876rpm, the overall response times before optimization are 1.9386s, 2.3902s, and 2.7844s. Respectively, the overall response times after optimization are 1.8604s, 2.2856s, and 2.6132s. The speed response time after optimization is 0.0782s, 0.1046s and 0.1712s less than before optimization, respectively.

Study on cavitation fault features of centrifugal pumps based on principal component analysis

The centrifugal pump plays a key role in the ship water supply system, and cavitation is a common fault mode that leads to poor efficiency of centrifugal pumps. To select valid features as the criteria of cavitation fault diagnosis, we calculate RMS, peak factor, kurtosis factor, wave factor of raw data, and the data after empirical mode decomposition (EMD). Although the raw features can be obtained, they were still in a high-dimensional space and contain a lot of redundant information. So, Principal Component Analysis (PCA) method was used to decrease dimensions and extract sensitive features. As a case study, the data were obtained from a centrifugal pump fault simulation bench, and a variety of cavitation states were observed in the experiment. And a six-dimensional sensitive feature vector was determined through data analysis.

Design and Experimental Analysis of Straw Suction Unit on Straw Cover Weight Detection Machine

In response to the issues of high cost, limited detection accuracy, and significant measurement errors inherent in conventional manual techniques used to measure straw cover weight under the conservation tillage method, a dedicated straw cover weight detection machine was developed in the current study. This machine included a critical straw suction device that utilizes negative pressure to collect straw within a defined area. The efficiency of straw collection is affected by suction chamber structural parameters and transport pressure. With crushed corn straw as the research subject, the theoretical calculation of straw suspension velocity was used to determine the wind duct diameter, perform the initial design of the suction chamber structure, and select the appropriate fan. After conducting preliminary experiments, single-factor optimization tests, and orthogonal rotation experiments, we analyzed the flow field distribution patterns and identified the critical parameters for the straw cover weight suction unit. We found that the fan should operate at a speed of 2900 r/min, the diameter of the straw outlet should be 200 mm, the vertical height of the suction chamber should be 536 mm, and the bottom diameter of the suction chamber should be 800 mm. The optimization results were validated through simulation tests and bench tests, yielding an average near-ground airflow velocity of vj = 9.03 m/s and an average outlet airflow velocity of vo = 34.27 m/s, meeting the basic requirements of the suction unit. This study could provide a new approach and technical support for the automated detection of straw cover weight in conservation tillage areas.

Design and Simulation Test of the Control System for the Automatic Unloading and Replenishment of Baskets of the 4UM-120D Electric Leafy Vegetable Harvester

This study designed a control system for the automatic unloading and replenishment of baskets based on the cooperative detection of photoelectric sensors and pressure sensors based on analyzing the structure of the 4UM-120D electric leafy vegetable harvester. The goal of this study was to increase the operation efficiency of leafy vegetable harvesters and decrease the work intensity of operators. A control system for the automatic unloading and replenishment of baskets based on the cooperative detection of a photoelectric sensor and pressure sensor was designed and constructed after an analysis of the operating principle and system components of automatic basket unloading and basket replenishment control at the rear of the harvester. The bench test results showed that the bottom photoelectric sensor and top photoelectric sensors 1 and 2 on the touch screen were not lit and the pressure sensor value was displayed as −0.00075531 kg, after pressing the system start button on the touch screen. On the touch screen, only the basket feeding motor was on: the transverse conveyor motor and the basket unloading motor were not, indicating that there was no collection basket on the unloading basket conveyor belt at this time and that the basket feeding motor was conveying an empty basket to the unloading basket conveyor belt. At 26 s, on the touch screen, only the top photoelectric sensor 2 was not on: the top photoelectric sensor 1 and the bottom photoelectric sensor were on and the pressure sensor value was shown as 1.38488 kg. Only the transverse conveyor motor lit up on the touch screen, the basket unloading motor and the basket feeding motor did not light up, indicating that the leafy vegetables temporarily stored in the transverse conveyor belt started to fall into the collection basket at this time and had not yet reached the expected capacity of the collection basket. At 43 s, the bottom photoelectric sensor and top photoelectric sensors 1 and 2 were lit on the touch screen and the pressure sensor value was shown as 2.37229 kg. On the touch screen, only the basket unloading motor lit up: the transverse conveyor motor and the basket feeding motor were not lit up, indicating that the collection basket capacity had reached the expected capacity at this time and the unloading was in progress. At 83 s, the bottom photoelectric sensor and top photoelectric sensors 1 and 2 were not lit on the touch screen and the pressure sensor value was displayed as −0.0040102 kg. On the touch screen, only the basket feeding motor lit up: the transverse conveyor motor and the basket unloading motor did not light up, indicating that the collection basket with the expected capacity had been unloaded to the ground, and the basket feeding motor was transporting empty baskets to the basket unloading conveyor belt. Through bench simulation tests, it was determined that the control system for the automatic unloading and replenishment of baskets based on the cooperative detection control strategy of the photoelectric sensor and pressure sensor reduced the probability of misjudgment and misoperation and improved system performance. This was conducted with the probability of system misjudgment and misoperation serving as the main evaluation index. The simulation results demonstrated that the control system for the automatic unloading and replenishment of baskets based on a photoelectric sensor and pressure sensor cooperative detection control strategy could be error-free judgment and avoid misoperation, effectively improving the stability, accuracy, and rapidity of the system. The study’s findings could suggest a strategy to lessen the workload of operators and increase the operational effectiveness of harvesters for leafy vegetables.

Importance of optimal rewiring guided by 3-dimensional optical frequency domain imaging during double-kissing culotte stenting demonstrated through a novel bench model

The usefulness of optical frequency domain imaging (OFDI) guidance on two-stenting at left main bifurcation has not been evaluated. Here, we used a novel bench model to investigate whether pre-defined optimal rewiring with OFDI-guidance decreases acute incomplete stent apposition (ISA) at the left main bifurcation segment. A novel bench simulation system was developed to simulate the foreshortening and overlapping of daughter vessels as well as left main bifurcation motion under fluoroscopy. Double-kissing (DK) culotte stenting was performed using the novel bench model under fluoroscopy with or without OFDI-guidance. In the OFDI-guidance group, if the guidewire did not pass through the pre-defined optimal cell according to the 3-dimensional OFDI, additional attempts of rewiring into the jailed side branch were performed. The success rate of optimal jailed side branch rewiring after implantation of the first and second stent under OFDI-guidance was significantly higher than that under only angio-guidance. After completion of the DK-culotte stenting, the incidence and volume of ISA at the bifurcation segment in the OFDI-guidance group was significantly lower than that in the angio-guidance group. Online 3-dimensional OFDI-guided DK-culotte stenting according to a pre-defined optimal rewiring point might be superior to only angio-guided rewiring for reducing ISA at the bifurcation.