Tolerance Requirements Research Articles

Manufacturing errors detection and visualization system for parts with complex internal cavity structural through industrial CT image

To address the challenge of detection and visualization manufacturing errors in part with complex internal cavity structures, this paper present a method based on industrial computed tomography (CT) image. First, a two-dimensional (2D) CT sequence slice images are obtained using fan-beam high energy industrial CT scanning, which is then reconstructed into a three-dimensional (3D) measurement model. The measurement 3D model is registered with the original design model, and the surface information of the part is obtained by segmenting the surfaces. The error between reference surface of original design model and test surface of measurement model is calculated. By comparing the error value with the tolerance, the detection result is obtained and analyzed. The developed software system enables areas that do not meet the tolerance requirements to be visualized. This method can detect manufacturing errors for part with complex internal cavity structures, such as planeness error, cylindricity error, verticality error, and parallelism error. This method provides a basis for assessing the manufacturing and processing quality of part with complex internal cavity structures.

Adaptive channel reservation multiple access protocol based on differentiated traffic guarantee

Ad Hoc network is widely used because of its distributed flexibility, in which nodes may generate different types of traffic, and some high-priority traffic requires lower delay and other Quality of service (QoS) requirements. However, as the load of traffic increases, the probability of conflict increases significantly, which makes it difficult to guarantee the requirement of these traffic. It is significant to design the efficient multiple access protocol to ensure the quality of different kinds of traffic. Channel reservation mechanism is an important method to ensure QoS. However, the existing channel reservation mechanism does not fine-adjust reservation parameters according to the QoS when dealing with various traffic differently, and the differentiation mechanism is rough. In addition, it is difficult to ensure the performance of common services when low-latency services are met. Therefore, a differentiated service guarantee adaptive reservation mechanism (DSGARM) to solve the above problems is proposed. The core idea of the protocol is to provide differentiated services in detail according to the delay tolerance requirements of each business. Absolute reservation mechanism is used to guarantee delay-sensitive services, and relative reservation mechanism is used to service relatively delay-insensitive services. In the protocol, a model is established to design an adaptive algorithm to quantitatively calculate reservation parameters that meet the delay requirements. On the premise of prioritized reservation for various services, appropriate reservation parameters can be adjusted according to network conditions to ensure the delay tolerance requirements of each type of service. The present work can be widely applied to scenarios with differentiated business requirements. The simulation results show the advantages of the present protocol and have great practical significance.

Individual Factors Modifying Postoperative Pain Management in Elective Total Hip and Total Knee Replacement Surgery.

Total hip and knee replacements are the most common orthopedic procedures performed due to osteoarthritis. Pain is an intrinsic symptom accompanying osteoarthritis, persisting long before surgery, and continuing during the preoperative and postoperative periods. Appropriate pain management after surgery determines the comfort, duration, and cost of hospitalization, as well as the effectiveness of postoperative rehabilitation. Individual differences in pain perception and tolerance in orthopedic patients remain an important research topic. Therefore, the aim of this study was to investigate the predictors of analgesic requirements (morphine, acetaminophen, and ketoprofen), including individual pain threshold and tolerance, body mass index (BMI), diabetes, and beliefs about pain control in patients undergoing elective hip or knee arthroplasty using a multilevel regression model (N = 147, 85 women, 62 men, 107 after hip replacement, and 40 after knee replacement). Results: Higher pain tolerance was associated with a lower dose of morphine per kg after surgery. Patients undergoing hip surgery received a lower dose of ketoprofen than patients undergoing knee surgery. The more the patient believed in personal pain control, the stronger the negative relationship between pain tolerance and morphine requirement. The lowest doses were given to patients with the highest pain tolerance and the greatest belief in personal control. Factors such as belief in pain control and pain tolerance should be considered in comprehensive postoperative pain management in orthopedic patients to reduce opioid doses and, thus, side effects.

Suitable Integral Sampling for Bandpass-Sampling Time-Modulated Fourier Transform Spectroscopy

For traditional Fourier transform (FTS), its integral sampling usually meets the Spectral Modulation Transfer Function (SMTF) criterion. However, for bandpass-sampling Fourier transform spectroscopy (BPS-FTS), based on our analysis, the integral sampling condition derived from the Spectral Modulation Transfer Function (SMTF) is excessively stringent. In other words, the interval of the integral sampling time that fulfills the tolerance requirements for the reconstructed spectrum is very narrow. There are numerous integration sampling time intervals outside this range that still meet the tolerance requirements for the reconstructed spectrum. In this paper, through theoretical modeling, we propose a method based on average |SMTF| as the selection criterion for the integration sampling time. Through simulation analysis, it is evident that the intervals and range of the integral sampling time obtained via this method are more accurate, ensuring the tolerance requirements of the reconstructed spectrum. Under these intervals, when conducting integral sampling on the interferogram, the spectral deviation of the reconstructed spectrum is minimal, and the Spectral Correlation Mapper (SCM) is nearly equal to one. This indicates that compared with the SMTF criterion in traditional FTS, this method is more suitable for the characteristics of BPS-FTS. The analysis in this paper can provide theoretical and simulation support for the implementation of BPS-FTS.

Development and Validation of an ADA-Tolerant Assay for Quantification of an Exatecan-Based ADC in Monkey Plasma.

The development of an anti-drug antibody (ADA)-tolerant pharmacokinetic (PK) assay is important when the drug exposure is irrelevant to toxicity in the presence of ADA. We aimed to develop and validate an ADA-tolerant assay for an exatecan-based antibody-drug conjugate (ADC) in monkey plasma. The assay tolerated 5.00 µg/mL of ADA at 12 µg/mL of ADC. Its accuracy and precision results satisfied the acceptance criteria. Furthermore, the assay was free from hook and matrix effects and exhibited good dilutional linearity. Additionally, the ADC in plasma samples was stable under different storage conditions. An ADA-tolerant ADC assay was configured with an anti-payload antibody for capture, and a drug-target protein combined with a horseradish peroxidase (HRP)-labeled antibody against a drug-target-protein tag for detection. Samples were firstly acidified to dissociate drug and ADA complexes, and to convert the carboxylate form to the lactone form of exatecan molecules; then, the ADAs in the samples were removed with a naked antibody-coated microplate. The treated samples were further incubated with coated anti-payload antibody and captured ADC molecules were quantified by the detection reagent. The developed assay was optimized and validated against regulatory guidelines. The assay met both methodological and sample-related ADA tolerance requirements, and was applicable to a nonclinical study in cynomolgus monkeys.

ANALYTICITY OF MARKOV PROCESSES FOR DESCRIPTION OF COEFFICIENT OF TECHNICAL READINESS OF GRAIN HARVESTERS COMBINES

The article presents the results of a study of the influence of operating conditions and modes on the technical condition of grain harvesters. The grain harvester gradually loses its performance during operation. To ensure stable operation of the fleet of agricultural machines, maintain its technical condition and increase operational reliability, technical control of grain harvesters is carried out. The analysis of the technical condition of combine harvesters showed that there remains a high percentage of defective combine harvesters, downtime for all types of repairs and the number of unplanned repairs. One of the main reasons for this condition is the low level of organization and quality of technical control, insufficient mechanization of technological processes. The basic element of the technological preparation of repair production is the development of a technological process that ensures the availability of a complete set of technological documentation at the enterprise for organizing and carrying out technical maintenance and repairs of traction rolling stock. During the development of technological processes of repair, the selection of technological operations and means of their technological equipment, normative documents of requirements for tolerances, clearances, forces of landings, pressings, threaded connections, processing quality, assembly accuracy, etc. is carried out. Technical conditions for the development of non-standard technological equipment are determined from the developed technological operations. As a target function, the rational periodicity of maintenance of grain harvesters was taken, namely, the rational time between services. The analysis of the results of known works on mathematical modeling and periodicity of repair and maintenance of complex technical systems based on Markov and semi-Markov processes allowed us to propose complex criteria as criteria for modeling the objective function: the functional of readiness, which is used to estimate the allowable time, and the functional of technical use, which allows determining the value of the optimal time between services of the combine harvester according to the technical parameter at the maximum point.

Damage Tolerance Behaviour of Stiffened Crown Panel of a Transport Aircraft Fuselage

Ever since the introduction of damage tolerance requirements in the aviation regulations, efforts continue to be made to prevent catastrophic failures due to damages present in the structure. It has also been realized that damage detection is the weakest link in the whole process of damage tolerance design to maintain continued airworthiness. The major components of the aircraft structure consist of both integral and riveted panels of sheets and stringers which are employed in fuselage skin panels, spar webs and stiffeners. In spite of all precautions, cracks or damages may arise in many of these primary structural members. These cracks cause stiffness degradation and reduce the total load-carrying capacity of the structure. In this paper, the damage tolerance behaviour of fuselage crown panel both integral and riveted stiffened panel configurations of Aluminium alloy 2024-T351 are studied using finite element based tools using crack growth analysis methods. The crack growth behaviour of both integral and riveted stiffened panels of aircraft fuselage having same geometrical configuration and subjected to uniformly distributed tensile loads is investigated. For this, a metallic stiffened panel with eight stringers, representative of crown panel of a transport aircraft fuselage is analysed with a centre skin crack propagating through the stringers. Stress intensity factors and fatigue crack propagation rates at the progressive crack tip of both types of the stiffened panels are computed by using Modified Virtual Crack Closure Integral (MVCCI) method. The stiffened panels fatigue crack growth rate was computed by using Paris law under constant amplitude fatigue loads. The analysis results show that integral stiffened panel causes higher stress intensity factor and less load bearing capability than riveted stiffened panel which has better damage tolerant capability in comparison to the integrally stiffened panel.

A model of hemodialysis after acute kidney injury in rats

BackgroundAcute kidney injury (AKI) is frequent among critically ill patients. Renal replacement therapy (RRT) is often required to deal with severe complications of AKI. This technique is however associated with side effects such as hemodynamic instability and delayed renal recovery. In this study, we aimed to describe a novel model of hemodialysis in rats with AKI and depict a dialysis membrane performance.MethodsEighteen Sprague–Dawley rats received 0.75% adenine-rich diet to induce AKI. After 2 weeks, nine underwent an arterio-venous extracorporeal circulation (ECC) (ECC group) for 2 h without a dialysis membrane on the circuit and nine received a hemodialysis session (HD group) for 2 h with an ECC circuit. All rats were hemodynamically monitored, and glomerular filtration rate (GFR) was measured by transcutaneous fluorescence after the injection of FITC-Sinistrin. Blood samples were collected at different time points to assess serum creatinine and serum urea concentrations and to determine the Kt/V. Sinistrin concentration was also quantified in both plasma and dialysis effluent.ResultsAfter 2 weeks of adenine-rich diet, rats exhibited a decrease in GFR. Both serum urea and serum creatinine concentrations increased in the ECC group but remained stable in the HD group. We found no significant difference in serum creatinine and serum urea concentrations between groups. At the end of experiments, mean serum urea was 36.7 mmol/l (95%CI 19.7–46.9 mmol/l) and 23.6 mmol/l (95%CI 15.2–33.5 mmol/l) in the ECC and HD groups, respectively (p = 0.15), and mean serum creatinine concentration was 158.0 µmol/l (95%CI 108.1–191.9 µmol/l) and 114.0 µmol/l (95%CI 90.2–140.9 µmol/l) in the ECC and HD groups, respectively (p = 0.11). The Kt/V of the model was estimated at 0.23. Sinistrin quantity in the ultrafiltrate raised steadily during the dialysis session. After 2 h, the median quantity was 149.2 µg (95% CI 99.7–250.3 µg).ConclusionsThis hemodialysis model is an acceptable compromise between the requirement of hemodynamic tolerance which implies reducing extracorporeal blood volume (using a small dialyzer) and the demonstration that diffusion of molecules through the membrane is achieved.

Targeting fidelity of pharmaceutical systems models by optimization of precision on parameter estimates

Quantitative models have gained momentum to drive the development of pharmaceutical processes. The assessment of the prediction fidelity of these models is key to provide interpretability of process phenomena and to enable decision-making. Evaluating parametric uncertainty is paramount when the focus is on systems models, which combine different sub-models together, and, thus, parameters related to previous units may strongly impact the prediction of one final output. A framework is proposed to assess reliability in model predictions, where the precision of parameter estimates is explicitly optimized to target pre-set tolerance requirements on process key performance indicators and product critical quality attributes. A direct compression systems model for the manufacturing of oral solid dosage products is used as a case study. Results show that the proposed methodology is effective at guaranteeing the target model fidelity and at quantifying the maximum acceptable uncertainty in the estimates of model parameters.

Impacts of PTL coating gaps on cell performance for PEM water electrolyzer

The anode porous transport layer (PTL) is a critical component of polymer electrolyte membrane (PEM) water electrolyzers, providing electrical conduction and water/oxygen transport to the anode catalyst layer. Platinum group metal (PGM) coatings are applied to titanium PTLs to prevent oxidation and preserve conductivity. To implement PEM water electrolysis on a large scale, it is essential to minimize the cost of mass-manufactured cell components while ensuring that defects in materials and components do not adversely affect the performance of the cell. In this study, we created gaps in the Pt coatings that are typically applied to PTLs to understand their effects on cell performance and inform on fabrication tolerances. The PTL coatings were fabricated by sputter deposition of Pt, intentionally leaving uncoated regions in either large patches or thin strips. For either geometry, the cell performance decreased with the increasing fraction of the uncoated regions. However, PTLs containing multiple thin uncoated strips caused a less severe performance effect than PTLs with continuous uncoated regions of the same relative total area. Through analysis of cell performance, impedance, and 3D charge transport modelling, we demonstrate that both the anode catalyst layer and membrane play a role in distributing current to mitigate the impact of coating defects at a short length scale. These results allow to draw conclusions about the tolerance requirements with regards to PTL coating uniformity in terms of both the size and total area of defects.

Tripogon loliiformis tolerates rapid desiccation after metabolic and transcriptional priming during initial drying

Crop plants and undomesticated resilient species employ different strategies to regulate their energy resources and growth. Most crop species are sensitive to stress and prioritise rapid growth to maximise yield or biomass production. In contrast, resilient plants grow slowly, are small, and allocate their resources for survival in challenging environments. One small group of plants, termed resurrection plants, survive desiccation of their vegetative tissue and regain full metabolic activity upon watering. However, the precise molecular mechanisms underlying this extreme tolerance remain unknown. In this study, we employed a transcriptomics and metabolomics approach, to investigate the mechanisms of desiccation tolerance in Tripogon loliiformis, a modified desiccation-tolerant plant, that survives gradual but not rapid drying. We show that T. loliiformis can survive rapid desiccation if it is gradually dried to 60% relative water content (RWC). Furthermore, the gene expression data showed that T. loliiformis is genetically predisposed for desiccation in the hydrated state, as evidenced by the accumulation of MYB, NAC, bZIP, WRKY transcription factors along with the phytohormones, abscisic acid, salicylic acid, amino acids (e.g., proline) and TCA cycle sugars during initial drying. Through network analysis of co-expressed genes, we observed differential responses to desiccation between T. loliiformis shoots and roots. Dehydrating shoots displayed global transcriptional changes across broad functional categories, although no enrichment was observed during drying. In contrast, dehydrating roots showed distinct network changes with the most significant differences occurring at 40% RWC. The cumulative effects of the early stress responses may indicate the minimum requirements of desiccation tolerance and enable T. loliiformis to survive rapid drying. These findings potentially hold promise for identifying biotechnological solutions aimed at developing drought-tolerant crops without growth and yield penalties.

Consequence analysis, layer of protection analysis, and bow‐tie as strategies to prevent accidents

AbstractThis article discusses some accidents and uses consequence analysis as well as layer of protection analysis (LOPA) and bow‐tie to establish the best approach for safely controlling the process to avoid loss of containment due to overfilling. Four accidents and their aftermaths are examined, considering current investigations. Consequence analysis was used with 12 products to demonstrate how to determine the level of protection of the systems to reduce the likelihood of containment loss due to overflow. Finally, LOPA and bow‐tie were used to ensure that the systems have adequate protection at an acceptable level of risk tolerance and will be correctly maintained throughout their life cycle. The analyses indicated that an independent layer of protection with safety integrity level 2 was required to achieve the risk tolerance requirement of <10−4/year, which is a known and widely accepted frequency when an accident has the potential to result in a fatality. Furthermore, a study of degradation factors and controls was performed to enhance the reliability of all the components that interfere with the frequency of the top event. This will improve process safety throughout the system's lifecycle, and the results will also be input for safeguards audits.

On Solving Concurrent Process Problem in Process-Oriented Programs

Prevailing portion of the factories and manufacturers are controlled by programming microcontrollers in the modern world. And the portion keeps growing which is closely tied to processes of the Fourth Industrial Revolution. Precisely, with an idea of fully automated manufactures to help humans to make less decisions and make them faster. Or to exclude humans from the decision making process at all. Due to that, there is a need for the controlling algorithms which should react to the different events, be aware of the external world and be tolerant to both internal and hardware failures. There is a process-oriented paradigm which was developed in Institute of Automation and Electrometry SB RAS and suits perfectly for automatization of such algorithms. This is achieved by splitting the algorithm into huge amounts of the small parallel processes highly tied to the elements of the real world. Which is how real processes on real manufactures work. This is where the conflicts during concurrent programming appear. And because there is a fault tolerance requirement there is a need to solve those conflicts. This work presents the analysis of already existing solutions to the conflicts during concurrent programming with the goal of either reusing those solutions in process-oriented programming or adapting them to it. As a result, there is an answer on how effective the process-oriented paradigm is in solving those kinds of conflicts and how fault tolerant those programs are.

Stomach-partitioning versus conventional gastrojejunostomy for unresectable gastric cancer with gastric outlet obstruction: A propensity score matched cohort study

BackgroundStomach partitioning gastrojejunostomy (SPGJ) was introduced to deal with delayed gastric emptying (DGE). This study aimed to compare the short- and long-term outcomes of SPGJ versus conventional gastrojejunostomy (CGJ). MethodThis cohort study analyzed 108 patients who underwent gastrojejunostomy for unresectable gastric cancer: 70 patients underwent SPGJ, and 38 patients underwent CGJ between 2018 and 2022. Propensity score-matched (PSM) analysis was used to balance the baseline characteristics. ResultsAfter PSM, there were 26 patients in each group. SPGJ group had significantly lower incidence of DGE (3.8% vs. 34.6%), vomiting (3.8% vs. 42.3%), and prokinetics requirement (11.5% vs. 46.2%). SPGJ group had significantly shorter time to solid diet tolerance (4.1 days vs. 5.7 days) and postoperative hospital stay (7.7 days vs. 9.3 days). There was no significant difference in relapse reinterventions, gastric outlet obstruction (GOO) recurrence, conversion surgery, and survival outcomes. ConclusionsSGPJ was associated with lower rate of DGE, prokinetics requirement, and shorter time of solid diet tolerance compared to CGJ in the treatment of unresectable gastric cancer patients with GOO.

3D-Simulation of Heat Flow in Indexable Drilling

In machining, the heat flow into the workpiece during the cutting process is often a major concern. The temperature rise can lead to substantial residual stresses or elastic in-process deformations which may result in the dimensional tolerance requirements being violated. In the present study a modelling strategy is developed for determination of the heat load during indexable drilling. The heat load on the workpiece is determined from 3D thermomechanical Coupled Eulerian Lagrangian analyses of orthogonal turning for various chip thicknesses and cutting speeds. The determined heat load is then transferred to a 3D transient heat transfer analysis of the indexable drilling process for the determination of the temperature field. Thereby, this modelling technique avoids the complex cutting process that is performed in real cutting simulations and thereby reducing the computational complexity of the problem considerably. The simulated temperatures are compared with experimentally measured temperatures and some conclusions are drawn regarding the modelling approach.

Ultra-wide angle panoramic imaging system based on a multiplexed reflective surface.

We propose an ultra-wide angle panoramic imaging system based on a multiplexed reflective surface, which consists of a panoramic head unit (PHU) and the relay lens group. The multiplexed reflective surface is applied in the PHU to reflect light from glass and air for imaging, obtaining the front and rear view channels, respectively. With a field of view (FoV) of 360∘×(35∘-120∘) and an f-number of four, this system has good image quality and relative illumination in the FoV. In addition, it has loose tolerance requirements and a diameter ratio of 7.2, reducing the difficulty of manufacturing and assembly. This optical system architecture provides a promising solution for panoramic perception over a wider FoV.

Conceptual Definition of A New Very-Light-Jet Aircraft Configuration

Israel Aircraft Industries (IAI) is a world leader in the design and manufacturing of business aircraft. IAI has developed and introduced to the market several biz-jets (Westwind I and II, Astra-AKA Gulfstream G-100, and Galaxy- AKA Gulfstream G-200). All these aircraft have been in the midsize and recently "super-midsize" category. During the last two years, IAI has been evaluating a new aircraft design, the ProJet that belongs to the new, emerging category of "very-light jets" (VLJ). This lightweight twin turbofan aircraft is characterized by its small size and low target price, compared to existing IAI designs. The ProJet will be certificated to FAR23 normal category requirements, including single pilot operation. The ProJet exploits newly developed technologies and capabilities, such as: new, small and efficient turbofan engines; advanced low cost and sophisticated avionic systems; advanced low cost mechanical and electrical systems; rapid and efficient development and production methods. All these attributes will provide the capability of introducing a very low cost aircraft into the emerging new VLJ market sector. The ProJet is a twin turbofan, low wing, T-tail airplane utilizing an all-metal airframe; designed in accordance with damage tolerance requirements. It features a comfortable pressurized cabin with optimized seating for 6 occupants, including 2 pilots, and excellent performance. The ProJet will have a VFR range of 1200nm, a cruise ceiling of 41,000ft, and a cruise speed of 365kt. It will take-off and land on runways shorter than 3000ft. Generous allowance for baggage stowage is provided in the pressurized internal baggage compartment, and in the external rear baggage compartment. The ProJet flight deck features an all-glass cockpit with an integrated avionics package, designed for ease of operation and reduced workload. Composite materials are utilized in flight control surfaces and secondary structures. Two FADEC controlled turbofan engines mounted on the upper aft fuselage supply the ProJet power. Each engine generates about 1300 pounds static installed thrust at ISA +10°C.

Enhancing EDM Machining Precision through Deep Cryogenically Treated Electrodes and ANN Modelling Approach.

The critical applications of difficult-to-machine Inconel 617 (IN617) compel the process to be accurate enough that the requirement of tight tolerances can be met. Electric discharge machining (EDM) is commonly engaged in its machining. However, the intrinsic issue of over/undercut in EDM complicates the achievement of accurately machined profiles. Therefore, the proficiency of deep cryogenically treated (DCT) copper (Cu) and brass electrodes under modified dielectrics has been thoroughly investigated to address the issue. A complete factorial design was implemented to machine a 300 μm deep impression on IN617. The machining ability of DCT electrodes averagely gave better dimensional accuracy as compared to non-DCT electrodes by 13.5% in various modified dielectric mediums. The performance of DCT brass is 29.7% better overall compared to the average value of overcut (OC) given by DCT electrodes. Among the non-treated (NT) electrodes, the performance of Cu stands out when employing a Kerosene-Span-20 modified dielectric. In comparison to Kerosene-Tween-80, the value of OC is 33.3% less if Kerosene-Span-20 is used as a dielectric against the aforementioned NT electrode. Finally, OC's nonlinear and complex phenomena are effectively modeled by an artificial neural network (ANN) with good prediction accuracy, thereby eliminating the need for experiments.

Differential contribution of nitrifying prokaryotes to groundwater nitrification

The ecophysiology of complete ammonia-oxidizing bacteria (CMX) of the genus Nitrospira and their widespread occurrence in groundwater suggests that CMX bacteria have a competitive advantage over ammonia-oxidizing bacteria (AOB) and archaea (AOA) in these environments. However, the specific contribution of their activity to nitrification processes has remained unclear. We aimed to disentangle the contribution of CMX, AOA and AOB to nitrification and to identify the environmental drivers of their niche differentiation at different levels of ammonium and oxygen in oligotrophic carbonate rock aquifers. CMX ammonia monooxygenase sub-unit A (amoA) genes accounted on average for 16 to 75% of the total groundwater amoA genes detected. Nitrification rates were positively correlated to CMX clade A associated phylotypes and AOB affiliated with Nitrosomonas ureae. Short-term incubations amended with the nitrification inhibitors allylthiourea and chlorate suggested that AOB contributed a large fraction to overall ammonia oxidation, while metaproteomics analysis confirmed an active role of CMX in both ammonia and nitrite oxidation. Ecophysiological niche differentiation of CMX clades A and B, AOB and AOA was linked to their requirements for ammonium, oxygen tolerance, and metabolic versatility. Our results demonstrate that despite numerical predominance of CMX, the first step of nitrification in oligotrophic groundwater appears to be primarily governed by AOB. Higher growth yields at lower ammonia turnover rates and energy derived from nitrite oxidation most likely enable CMX to maintain consistently high populations.

Optimization Design and Experimental Study of Space High-precision Gripper

To meet the requirements of large tolerance, high precision, soft capture and high reliability of space gripper, a three finger end effector is developed. The gripper adopts a three fingered gripper configuration, which needs to be used together with the corresponding capture adapter. It is characterized by stable grip, high precision, large clamping force, large tolerance and strong correction ability. A 6-DOF microgravity equivalent device is innovatively designed, which adopts the combination of ball bearing and reverse counterweight. In this paper, a ground capture calibration platform is built to fully test the capture accuracy of the gripper. Considering the disturbance of capture load, carrying platform and other factors to capture, the capture stiffness of the gripper is tested and the capture stiffness curve is obtained. Both tests have verified the feasibility and effectiveness of the design.