Base Frame Research Articles

Calibration of a dual-robot collaborative system for drilling tasks on spacecraft core cabins

Purpose This study aims to propose a calibration method to enhance the positioning accuracy in dual-robot collaborative operations, aiming to address the challenge of drilling hole spacing errors in spacecraft core cabin brackets that require an accuracy of less than 0.5 mm. Design/methodology/approach Initially, the cooperative error of dual robots is defined. Subsequently, an integrated model is constructed that encompasses the kinematic model errors of the dual robots, as well as the establishment errors of the base and tool frames. A calibration method for optimizing the cooperative accuracy of dual robots is proposed. Findings The application of the proposed method satisfies the collaborative drilling requirements for the spacecraft core cabin. The average cooperative positioning error of the dual robots was reduced from 0.507 to 0.156 mm, with the maximum value and standard deviation decreasing from 1.020 and 0.202 mm to 0.603 and 0.097 mm, respectively. Drilling experiments conducted on a core cabin simulator demonstrated that after calibration, the maximum hole spacing error was reduced from 1.219 to 0.403 mm, with all spacing errors falling below the 0.5 mm threshold, thus meeting the requirements. Originality/value This paper addresses the drilling accuracy requirements for spacecraft core cabins by using a calibration method to reduce the cooperative error of dual robots. The algorithm has been validated through experiments using ER 220 robots, confirming its effectiveness in fulfilling the drilling task requirements.

Design and development of an IoT-based trolley for weighing the patient in lying condition.

An immobile patient cannot be weighed on a stand-on weighing machine, i.e., a bathroom scale. They have to get weighed while lying, which is not easy. The main objective of this research is to design a medical apparatus that measures the patient's weight in a lying condition. To achieve this the apparatus is designed as a stretcher to carry the patient in and around the hospital. The stretcher has four load cells to measure the patient's weight; it can bear a weight of 500 kg and has a self-weight of 20 kg. A Microcontroller unit (MCU) is embedded into the apparatus to weigh the patient lying on it. The stretcher comprises the top frame, middle frame, and base frame. The top frame can be detached and mounted back to the middle frame; this will help the medical personnel shift the patients from a medical bed. The middle frame is a plate structure where the four load cells are mounted at the corners of the lower plate. The upper plate functions as a pressure plate on the load cell. The base plate has four heavy-duty wheels that can bear the load. The middle frame and base frame, together, form a single structure, giving mobility to the structure. A control panel is employed with reset, tare, and on-off buttons to control the embedded platform. The LCD panel on the side of the apparatus shows the weight when the patient is placed on top of the apparatus. A prototype trolley equipped with a wireless data logging system was tested on 10 healthy participants. The device accurately measured weight within ±50 g across a scale range of 2-140 kg, with data captured every 30 s over a 5-min testing period. Wireless communication was successfully demonstrated over a 100-m range. The important add-on feature of this work is the apparatus is connected to the internet, transforming it into an IoT-based medical device.

Drivers for Nominating First Women Executives: Empirical Evidence From Japanese Firms

Prior research on women in executive positions (WiE) has focused exclusively on the consequences of WiE by addressing how women executives influence firm strategy and performance, whereas little is known about the antecedents of WiE. However, to gain a comprehensive understanding of the overall impact of women executives on the firm, it is worthwhile to identify the triggers that prompt firms to appoint women executives for the first time. In this study, we have attempted to identify the antecedents of first appointments of women to executive teams (FAWE). On the basis of a theoretical frame incorporating the think crisis–think female perspective into the punctuated equilibrium model, we consider FAWE as the process of the transformational reform of an organization and examine the roles of three factors—firm performance (i.e., ROA and aspirational performance), environmental changes (i.e., industry dynamism, industry munificence, and industry complexity), and new CEO appointments—as antecedents of FAWE. We conducted a panel logistic regression analysis using 20 years of panel data (2000–2019) for Japanese listed firms. Our findings demonstrate that (1) poor firm performance (ROA and aspirational performance) was significantly related to the likelihood of FAWE in the subsequent year, and (2) a new CEO appointment was significantly related to the likelihood of FAWE in the subsequent year, whereas (3) hypotheses regarding environmental changes (industry dynamism, industry munificence, and industry complexity) were not confirmed. Implications for researchers and practitioners are discussed, along with the study’s limitations and suggestions for future research.

Qualitative Analysis of the State of Apprenticeship Training in Abeokuta South Local Government

This study examined the state of apprenticeship training in Abeokuta South Local Government. It examines the attitude of relevant stakeholders towards apprenticeship training; the level of apprenticeship training and factors that influence apprenticeship training in Abeokuta South Local Government. Conceptually, the paper briefly explained the overview of apprentice, factors influencing apprenticeship training and cognitive learning theory served as the basis of theoretical frame. The paper revealed that the attitude of the stakeholders especially the trainer and the trainee are positive however, need more commitment from the government, the trainer and the trainee. More so, the paper revealed that there was high level of apprenticeship decline in the society. Finally, majority of the respondents mentioned poverty, high learning fee, internet fraud, peer group’s influence, etc as factors affecting apprenticeship training. However, this paper recommends that all the stakeholders should be deliberate and commited in their goals of ensuring a viable apprenticeship system for the teeming youth in the country.

Comparative study of seismic performance between fixed base and base-isolated regular RC frames (G+21 floors) using SAP 2000

Comparative study of seismic performance between fixed base and base-isolated regular RC frames (G+21 floors) using SAP 2000

Improved Metallic Thermal Protection Systems for Reentry Vehicles: Thermomechanical and Impact Considerations

A design for a metallic thermal protection system (TPS) panel made of SS304 stainless steel was developed to withstand a simulated aerodynamic heating rate of 7.1 W/cm2. The TPS panel, which comprised an outer sandwich structure, thermal insulation material, stand-off brackets, and an interior base frame, faced challenges from its thermomechanical and impact properties. These challenges were addressed through a combined analytical and numerical approach, optimizing the design parameters, namely, deflection, low-velocity impact peak load, and weight balance, to enhance the performance of the sandwich structure. The results indicated consistency between the analytical and numerical models, effectively predicting deflection and initial peak load for the TPS design. The proposed TPS design was then manufactured and evaluated through both experimental and numerical analysis to assess its thermomechanical behavior. The underlying structure of the TPS panel remained within specified temperature limits, and the exterior sandwich structure demonstrated acceptable levels of impact energy. The experiment confirmed the feasibility of the TPS panel design, with no significant damage observed after 10 simulated flight missions. This study not only validates the proposed analytical method for initial TPS development stages but also confirms the viability of a SS304 stainless-steel TPS panel design for high thermal-stress environments, marking a significant step in advancing thermal protection technology.

Wind influence numerical simulations on stadium structures in RWIND module of the DLUBAL RFEM software

This paper examines the effect of wind load on the stadium building, designed as a possible replacement for the stadium in the city of Mariupol, which was destroyed as a result of hostilities. The problems of using domestic standards in the design of stadium structures are considered. The approach of European regulatory documents to taking into account the effect of wind influence is considered. An analysis of previous scientific studies concerning the determination of aerodynamic parameters for stadium structures has been carried out. An analysis of the domestic regulatory document regulating the collection of wind loads showed the need for additional research into the aerodynamic parameters for stadium structures. Using a special RWIND module as part of the Dlubal RFEM software package, numerical modeling was used to simulate the wind flow flowing around the model of the stadium building, which best corresponded to the adopted design decisions, as if it were carried out in a real wind tunnel. A project was considered for an ellipsoidal stadium, the configuration of the stands and the covering of which is a full bowl with an incomplete covering. The covering over the stadium stands is designed in the form of a canopy formed by cantilever flat steel trusses. The basis of the stadium building frame is made up of vertical steel frames with a rigid connection of nodes, to the central post of which cantilever trusses of the canopy are attached. The result of theoretical testing of the stadium model was distribution diagrams of aerodynamic coefficients, the maximum values of which were used to further determine the values of wind pressure on these structures. An analysis of the research results was was carried out. The use of numerical simulation tools for wind flows made it possible to increase the complexity of the system both at the level of the design solution and at the level of the calculation model. Analysis of the design solution allowed us to competently select the necessary design solutions for load-bearing structures, taking into account the requirements of current design standards and Eurocode 1 regulations.

Two-step calibration of 6-DOF industrial robots by grouping kinematic parameters based on distance constraints

The positioning accuracy of industrial robots is critical for their applications, which can be improved through calibration. This paper proposes a two-step calibration method for six-degree-of-freedom (6-DOF) industrial robots to reduce couplings of their modified Denavit-Hartenberg (MD-H) model parameters during optimization processes of kinematic calibration. In this method, a distance error model is established based on the distance constraints, and the MD-H model parameters of the industrial robots are identified group by group using the Levenberg-Marquardt (LM) algorithm. To determine the optimal MD-H model parameter grouping, the different grouping strategies are simulated and analyzed. In the proposed method, the coordinate system transformation between the measurement frame and the robot base frame can be avoided based on the distance error model, thereby reducing the errors introduced by the coordinate system transformation during the calibration process. Finally, the proposed two-step calibration method is verified through an experiment. The experimental result shows that the distance/positioning accuracy on the robot end-effector is improved from 0.602 mm/2.7317 mm to 0.151 mm/0.717 mm after calibration. The presented study may be beneficial for improving performance of industrial robots.

T–01M TESTER ADAPTATION FOR WEAR DEBRIS COLLECTIONAND ANALYSIS

The article describes the need to collect and analyse data on stereological features of car tire and brakesystem friction material wear products, as required under new European Union regulations and by the projectto expand the existing T–01M tester with a separation chamber and equipment enabling their capture. Thestructure of the chamber is described and the conditions for measuring the average diameter of particlesemitted by the tested contacts are presented. The basic task of the additional chamber is to separate thesurroundings of the tested friction node from environmental influences and to enable the capture of wearproducts to measure stereological features and analyse their chemical composition. A unidirectional filteredair flow towards the friction node is provided in the separation chamber in order to limit the deposition of wearproducts on the tester components. Mounting the separation chamber does not require any interference in thestructure of the T–01M tester, because it is mounted on a sealed base frame screwed to the station plate. Thechamber is equipped with holders for mounting a replaceable filter at the air inlet and a removable cycloneparticles separator with a container for wear debris collected.

Investigation of the effects of beam oscillations in electron beam–welded S1100M TMCP steel

The development of thermomechanically controlled processed (TMCP) high-strength steel (HSS) has significantly contributed to designing and developing the intricate structural components. It has broader applications in the cranes and lifting process industry (base frame, crane jibs, and crane columns), trailers, agricultural and forestry machinery, earth-moving equipment, etc. However, the development of new-grade steels with higher tensile strength led to higher requirements for welded joints, and the associated weldability issues have inspired detailed studies on electron beam welding (EBW) with different beam oscillations. Beam oscillation application with EBW processes improves the welding efficiency, weld quality, weld geometry, keyhole, etc., affecting the welded joints mechanical and microstructural properties. Thus, the present study investigates the impact and comparison of various beam oscillations on the microstructural and mechanical properties of EB-welded S1100M steel. The influence of welding parameters on the microstructure of welded joints was analyzed using a scanning electron microscope (SEM) and electron backscattered diffraction (EBSD). The analysis focused on evaluation of grain sizes, morphologies, distributions, and crystallographic orientations of different phase constituents in fusion zone (FZ) and heat-affected zone (HAZ). The mechanical properties were analyzed using hardness, tensile, and Charpy V-notch impact tests. The texture in the FZ is typically random, while the HAZ typically exhibits a strong rolling texture. In general, the cooling rate in EBW is very fast, possibly resulting in a fine-grained structure and reduced formation of coarse second-phase particles in the weld zone. The elliptical beam oscillation showed the highest hardness in HAZ 450 HV10. Elliptical beam oscillation slightly improves the welded joint’s tensile strength, and the impact test showed mixed fracture behavior.

Clinical evaluation of a stereotactic system for single-stage deep brain stimulation surgery under general anesthesia: technical note.

Conventional frame-based stereotactic systems have circumferential base frames, often necessitating deep brain stimulation (DBS) surgery in two stages: intracranial electrode insertion followed by surgical re-preparation and pulse generator implantation. Some patients do not tolerate awake surgery, underscoring the need for a safe alternative for asleep DBS surgery. A frame-based stereotactic system with a skull-mounted "key" in lieu of a circumferential base frame received US FDA clearance. The authors describe the system's application for single-stage, asleep DBS surgery in 8 patients at their institution and review its workflow and technical considerations. Eight patients underwent DBS lead insertion and IPG implantation in a single surgical preparation under general anesthesia using the system. Postoperative CT imaging confirmed lead placement. Eight patients underwent implantation of 15 total leads targeting the ventral intermediate nucleus (4 patients), globus pallidus internus (GPi; 3 patients), and subthalamic nucleus (STN; 1 patient). Intraoperative microelectrode recording was conducted for GPi and STN targets. Postoperative CT imaging revealed a mean ± SD radial error of 1.24 ± 0.45 mm (n = 15 leads), without surgical complications. The stereotactic system facilitated safe and effective asleep, single-stage DBS surgery, maintaining traditional lead accuracy standards.

Case of Marital Therapy Using I-ATTACH: An Indian Model of Marital Therapy Intervention

ABSTRACT The following case study demonstrates the potential of a culturally sensitive, integrated model of marital therapy intervention designed and developed using data from and research done in India. This integrated approach utilizes humanistic-existential approaches as the base frame of reference and techniques from the approaches falling within the theoretical frame of systemic and social constructionist approaches have been assimilated into it. The model is called the Indian model for Attunement To Tackle Active Conflict And Helplessness with married couples (I-ATTACH). This case demonstrates the application of the approach with a couple married for 2 years who saw an escalation of marital problems leading to talks of separation post the birth of their child 6 months ago. The couple completed both pre-treatment and post-treatment assessment measures that included a self-reported standardized questionnaire, a 5 point scaled questionnaire designed by the authors and a semi-structured questionnaire to assess for the couple’s assessment regarding the effectiveness of the intervention. After the pre-treatment assessment, the couple engaged in 16 joint and 2 individual intervention sessions of I-ATTACH. A description of the model and the stage-wise progress of the couple is discussed and the assessment data presented for both pre-treatment and post-treatment.

Wide-angle beam scanning from binary amplitude-modulated conformal meta-surface dense array with precise beam granularity

We propose a binary amplitude-modulated conformal meta-surface with every meta-element capable of functioning as the leaky wave passage or the null radiating spot through dynamically tuning the PIN diodes over the meta-elements with ON or OFF states. In particular, the staggered arrangement of the meta-elements forms a dense radiating array with 0.1 wavelength periodicity and every radiating patch consists of dual hourglass shaped slots stacked over the coupled feed of substrate integrated waveguide slits. Such a design, on the basis of binary amplitude-modulated conformal meta-surface frames, can achieve wide-angle steerable fan-beam scanning, while possessing the precise beam direction with less than one tenth of the 3 dB beamwidth. Thus, this should pave the way for building up more advanced contemporary conformal wireless communication systems over different platforms.

Ocena zwłoki rejestracji zamrożonej ramki na podstawie wartości napięcia sieci pojazdu

Assessment of frozen frame recording delay on the basis of vehicle power voltage Freeze frames are recorded at a changeable delay dependent on the system in which they were recorded, type of failure or vehicle operation parameters. This delay is sometimes difficult to assess, which makes it difficult for the reconstructionists to qualify the data from the frozen frame as useful in the process of event reconstruction. In the paper a method of assessing the recording delay of a frozen frame based on the vehicle power voltage is proposed.

Undisciplining the study of religion: critical posthumanities and more-than-human ways of knowing

ABSTRACT Recent discussions about other-than-human agency and relationality across species and lifeforms are closely tied to theoretical reconsiderations within, and beyond, the humanities. Scholars in the study of religion have only reluctantly picked up these considerations. Theoretical work that includes nonhuman animals in conceptualisations of religion often still operates in binary structures of nature/culture and body/mind. The author reviews recent naturalistic approaches to concepts of religion and combines them with discussions in critical animal studies and biosemiotics, as well as with Karen Barad’s theory of agential realism, which forms the basis of a robust analytical frame of nonhuman agency. The author proposes a critical posthumanities study of religion, transforming and ‘undisciplining’ the humanities into a form of scholarly engagement that creates a transversal field of knowledge, consisting of human and other-than-human intra-actions—a study of religion that intentionally leaves behind the regimes of mastery and exploitation that are still operative today.

Oscillating Saw Calibration for Mandibular Osteotomy Robots

Accurate oscillating saw tool calibration is an important task for mandibular osteotomy robots to perform precise cutting operations. However, in contrast to traditional tool calibration which just calibrates the tool center position (TCP) or the tool feed axis, both the position and the plane orientation of the saw should be carefully calibrated. Therefore, aiming at this problem, in this paper, we propose a method to carry out oscillating saw calibration by employing an optical stereo vision tracking system. At first, hand–eye calibration is conducted to ascertain the spatial pose of the vision frame within the manipulator’s base frame. Subsequently, employing a probe, the positions of the sawtooth points on the oscillating saw plane are captured within the vision frame. These positions are then translated to the manipulator’s end-effector frame using the positional elimination algorithm proposed in this paper. Finally, the pose of the oscillating saw plane within the manipulator’s end-effector frame is extrapolated from the positions of the three sawtooth points. The result shows that the position errors of the points on the oscillating saw plane are within 0.25 mm and the variance of the plane normal direction is 1.93∘ in the five experiments. This approach enables accurate calibration of the oscillating saw plane’s position and orientation within the manipulator’s end-effector frame. Furthermore, it mitigates the necessity of continual adjustments to the joint angles of the manipulator as required by the “six-point method”. However, this approach is hinged upon the availability of precision-oriented 3D positioning equipment.

Performance Analysis and Testing of Spiral Quantitative Fertiliser Distributors in Orchards

This study designed two levels of quantitative fertilizer distribution to investigate precision fertilization applications in orchards in South Xinjiang, China, which have vast rows and narrow plant spaces. The machine comprised a base frame, a ditching device, a fertilizing apparatus and an earth-covering device. The design parameters of the flow stabilization screw, conveyor screw and single-ring fertilizer quantity were summarised using theoretical analysis. The single-ring fertilizer quantity of the conveyor screw was verified via an experiment by combining EDEM software. Three-factor and three-level Box–Behnken tests were conducted using the spiral rotation speed of the conveyor, advancing of the speed and the opening degree of fertilizer outlet as the test factors and using the coefficient of variation (CV) of uniformity as the test index—thus obtaining the optimal working parameters. The simulation test results revealed that the single-ring fertilizer quantity of the fertilizing apparatus was 145.6 g, fulfilling the design requirements. The prototype testing results showed that the CV of uniformity was 6.521% when the spiral rotation speed of the conveyor, the opening degree of the fertilizer outlet and the advancing speed were 66 RPM, 42% and 2.7 km/h—thus meeting the needs of precision fertilization operations. The two designed levels of the quantitative fertilizer distributors were applied to fertilization processes in orchards with wide-row spaces and narrow plant spaces in South Xinjiang, China and were able to effectively carry out the precision fertilization applications. These data could also provide references for the optimization of spiral quantitative fertilizer distributors.

Performance Analysis and Testing of a Multi-Duct Orchard Sprayer

A multi-duct orchard sprayer is designed in this paper to address the problem of low droplet coverage during plant protection in walnut orchards in South Xinjiang, China. This spray comprises a base frame, a pesticide tank, an air delivery system, a copying base frame and a drive system. Effects of the sprayer structure on the flow field were simulated using computational fluid dynamics. Operation parameters were optimised using the response surface analysis and validated using a field test. The results demonstrated that five jet tubes in the simulation design could fulfil the design requirements of GB/T 32250.3-2022. The upper, middle and lower droplet coverages were 74.92%, 90.01% and 69.9%, respectively, when the sprayer’s advancing speed, the angle of jet tubes and the nozzle diameter were 0.53 m/s, 70.27° and 0.81 mm, respectively. The machine can effectively enhance the spraying efficiency and droplet coverage of each canopy during plant protection operations in the new walnut orchards of South Xinjiang, China, and provide references for designing and optimising fruit tree spraying machinery.

AISI 4130 and E250BR alloy steels chassis structural analysis and performance comparison

A base frame, also known as a skid and it is one of the most important parts of an automotive vehicle. It is a structural member made up of small cross members and long side members. Frame takes the entire load and vibration of the vehicle, so it should be strong enough. In this paper, the 3D modeling and analysis of ISMC C-section and ISMB I- section is caried out using Creo parametric software as per IS: 808.1989. There are four base frames developed (2 frame with C-section and 2 frames with I-section). E250BR and AISI 4130 alloy steel material are assigned to C and I-section base frames. The base frames are designed for a 40kN load capacity and load is uniformly distributed over the entire span of frame. Bending stress and deflection are calculated analytically as well as using FEA to determine strength of frames. For the deflection calculation, Macaulay’s method is used with both side overhang beams. The flexural rigidity equations are used to find the bending stress. Finally, the comparison of all base frames is done. Result shows that for the same load carrying capacity minimum deflection occur at ISMB I-section base frame. Also, stresses generated in I-section and C-section base frame for both materials are same. Material E250BR perform better than AISI 4130 alloy steel in deformation. So, performance of material E250BR is better than that of AISI 4130 alloy steel.

Ear reconstruction stage I: Minor modifications in sculpting the auricle support using the 7th and 8th costal cartilages

BackgroundThe verisimilitude of the reconstructed auricle and its long-term stability largely depends on the framework sculpting. This study described three kinds of minor modifications based on Firmin’s way of sculpting the auricle framework and reported the clinical outcomes achieved with them. MethodsWe conducted a retrospective study of congenital microtia patients undergoing detail-improved auricular reconstruction from June 2016 to June 2020. The three kinds of minor modifications included: (1) fabricating the base frame using the 7th costal cartilage, (2) fabricating the helix and the antihelix complex using the 8th costal cartilage, and (3) fabricating the helix using the combination of the 8th and 9th costal cartilage. ResultsNinety-eight patients (aged 9–27 years, 62.2% male) were included. Ninety-five patients (97.0%) adopted minor modifications 1, 2, and 3 patients (3.0%) adopted minor modifications 1, 2, and 3. All patients achieved an excellent auricle appearance and a well-laid foundation for subsequent operations. During the follow-up period, 89 patients (90.8%) were satisfied with the reconstructed auricles, 6 (6.1%) complained of hypertrophic scars in the retroauricular sulcus or pigmentation in the skin graft area, and 3 (3.1%) developed surgery-related complications. ConclusionsThree minor modifications of the auricle framework sculpting can make more satisfactory use of cartilage and adjust with the flexibility of the reconstructed auricle in different situations, making it similar to the contralateral auricle, thus, improving patients’ satisfaction.