Search Results (11)

This paper presents a design method for a continuous tension detection sensor based on a cantilever beam structure and compensates for the temperature drift of a SAW sensor based on a neural network algorithm. Firstly, a novel cantilever beam roller structure is proposed to significantly enhance the sensitivity of the transmission of silk thread tension to a SAW tension sensor. Secondly, to improve the sensitivity of the SAW tension sensor, the COMSOL finite element method (FEM) is employed for simulation to determine the optimal IDT placement. An unbalanced split IDT design is utilized to suppress potential parasitic responses. Finally, the designed sensor is tested, and a GA-PSO-BP algorithm is employed to fit the test data for temperature compensation. The experimental results demonstrate that the temperature sensitivity coefficient of the data optimized by the GA-PSO-BP algorithm is reduced by an order of magnitude compared to the raw data, with reductions of $6.0409\times {10}^{-3}{°C}^{-1}$ and $3.0312\times {10}^{-3}{°C}^{-1}$ compared to the BP neural network and the PSO-BP algorithm, respectively. The average output error of the optimized data is reduced by 5.748% compared to the sensor measurement data, and it is also lower than both the BP neural network and the PSO-BP algorithm. It provides new design ideas for the development of tension sensors. Full article

Rice membrane-covered cultivation offers notable agronomic advantages, including effective weed suppression and improved moisture retention. However, current mechanized approaches remain constrained by high labor requirements, low operational efficiency, and the inherent fragility of biodegradable membranes. To address these limitations, this study integrates a high-speed synchronous membrane-covering device, governed by a PSO-Fuzzy PID control algorithm, into a conventional rice transplanter. This integration enables precise coordination between membrane-laying and transplanting operations. The mechanical properties of the membranes were analyzed, and a tension evaluation model was developed considering structural parameters and roll diameter variation. Experimental tests on three biodegradable membranes revealed an average thickness of 0.012 mm, a longitudinal tensile force of 0.57 N, and a tensile strength of 2.85 N/mm. The PSO algorithm was employed to optimize fuzzy PID parameters (K = 5.3095, K_p = 10.6981, K_i = 0.0100, K_d = 8.2892), achieving adaptive synchronization between membrane output speed and transplanter travel speed. Simulation results demonstrated that the PSO-Fuzzy PID reduced rise time by 53.13%, stabilization time by 90.58%, and overshoot by 3.3% compared with the conventional PID. In addition, a dedicated test bench for the membrane-covering device was designed and fabricated. Orthogonal experiments determined the optimal parameters for the speed-measurement system: a membrane pressure of 5.000 N, a roller width of 28.506 mm, and a placement angle of 0.690°. Under these conditions, the minimum membrane-stretching tension was 0.55 N, and the rotational speed error was 0.359%. Field tests indicated a synchronization error below 1.00%, a membrane-width variation rate below 1.50%, and strong anti-interference capability. The proposed device provides an effective solution for intelligent and fully mechanized rice transplanting. Full article

During the temper rolling process, scratch defects on the lower surface of the steel strip caused by the tension measuring roller are a critical issue that affects the resulting product quality. Previous research has been limited to analyzing the mechanism and influencing factors of scratch generation, and has lacked a systematic design solution for analyzing and addressing scratch defects. This study deeply analyzed the mechanism of scratch formation, and it was determined that the fundamental cause lies in the relative sliding between the steel strip and the tension measuring roller. Specifically, the driving torque of the steel strip on the tension measuring roller is insufficient to overcome its total rotational resistance torque. This study identified the strip wrap angle, roller sleeve outer diameter, and wall thickness as key structural parameters that influence this torque balance. In optimizing the structural parameters of the tension measuring roller, this research had two main goals: eliminating scratch defects and avoiding strip warpage defects. To achieve this, a strip warpage calculation model and a scratch verification model were established. These were combined with structural connection safety verification. Based on these analyses, the optimal structural parameter combination was determined. This combination includes a roller sleeve outer diameter of 500 mm, a roller sleeve wall thickness of 20 mm, and a wrap angle of 30°. The consistent results that were obtained from theoretical analysis, finite element simulation, and actual production trials demonstrate that the optimized structural parameters of the tension measuring roller can effectively prevent relative sliding between the steel strip and the tension measuring roller, completely eliminating scratch defects on the lower surface of the steel strip and significantly improving product quality. This provides a reliable solution for the scratch problem in temper rolling. This solution also reduces scrap rate and production costs. Furthermore, it meets the strict surface quality demands of high-end applications. This leads to improved production efficiency and customer satisfaction. Ultimately, this method enhances product competitiveness and promotes industry technological progress. Full article

Given the need for versatile joining processes, form-fit joining is gaining increasing importance. Although it has known limitations and complexity, roller hemming remains widely used due to its flexibility. Here, the novel Incremental Sheet Forming (ISF) hemming technique has the potential to expand the range of applications and process limits. It has already proven effective in preliminary works for joining comparatively small radii without wrinkles and cracks. However, a deeper understanding of the dominant material flow and deformation mechanism during forming is required to fully exploit its potential. This study aims to conduct a detailed examination of this technology through experimental and numerical investigations. Strain measurements on convex and concave hems provide insights into the material flow. A comparison of the forming mechanism for both processes is made using straight hems. The results show that ISF hemming has a favorable material flow for compensating cracks and wrinkles in curved hems. Additionally, it induces strains across the entire hem area, reaching higher values than those achieved with roller hemming. One reason for this is the forming mechanism, which combines tension, compression and shear, whereas roller hemming primarily involves bending and compression of the hemming radius. Full article

The parameters of the roll characteristics of a large-scale round bale machine were collected in real time to investigate the bale rolling mechanism. This investigation develops a set of adaptable and highly integrated data acquisition systems for the bale rolling performance parameters of large-type round bale machines. A rolling experiment is conducted using sunflower straw as the material, and the power consumption and radial tension of the roller-round bale machine during the bale rolling process are studied. In the grass core formation stage, the round bale machine’s torque need was minimal, the radial tension of the bale remained nearly constant, and the bale chamber was primarily filled with loose sunflower straw. The motor torque and the straw bale’s radial tension both showed a tendency of gradual increase when the round bale machine was in the grass-filling stage. The motor torque and bale radial tension displayed a roughly linear trend of rapid rise as the sunflower straw continued to enter the rolling bale chamber; this was when the round bale machine was in the compressed bale rolling stage. When the power consumption of the round bale machine was measured using the data acquisition system during the test bench empty run and core-creation stage, the energy consumption comparison analysis produced a relative error of 5.8%. During the stage of bale rolling and compression, the data acquisition system monitored the power consumption of the round bale machine. The relative error was 9.5%. The data acquisition system of the round bale machine test bed has an accuracy of 90.5%–94.2% when measuring the machine’s power consumption, indicating that it is a stable and efficient system. This study provides a foundation for further research on intelligent the roller-round bale machine. Full article

In a punch-bending machine, wire products are manufactured for a wide range of industrial sectors, such as the electronics industry. The raw material for this process is flat wire made of high-strength steel. During the manufacturing process of the flat wire, residual stresses and plastic deformations are induced into the wire. These residual stresses and deformations fluctuate over the length of the semi-finished product and have a negative effect on the final product quality. Straightening machines are used to reduce this influence to a minimum. So far, the adjustment of a straightening machine has been performed manually, which is a lengthy and complex task even for an experienced worker. This inevitably leads to the use of inefficient straightening strategies and causes high rejection rates in the entire production process. Due to a lack of sensor information from the straightening operation, application of modern feedback control methods has not been practicable. This paper presents a novel design for a straightening machine with an integrated, precise straightening force measurement. By simultaneously monitoring the position of the straightening rollers, state variables of the straightening operation can be derived. Additionally, a tension control for feeding the flat wire is introduced. This is implemented to mitigate the disturbing effects caused by irregularities in the wire-feeding process. In the results of this article, the high precision of the developed force measurement design and its possible applications are shown. Full article

Aiming to solve the problem of knot-tripping failure caused by severe wear between the spherical roller and planar cam of the knotter, this paper first establishes a calculation model of the spatial cam contour surface. The knot-tripping mechanism in the knotter is designed as a line-contact curved-surface cam mechanism, with the cutter arm swinging in accordance with sinusoidal acceleration. The design significantly reduces the contact stress between the cam and the roller, compared to the original knot-tripping mechanism. Additionally, it eliminates the impact between the spherical roller and the planar cam. Based on the Archard model, the calculation model for cam-roller wear in the knot-tripping mechanism has been derived and utilized for wear calculation. The wear test results of the knot-tripping mechanism with an aluminum cam show that the curved cam has a wear amount that is 43%, 56%, 46%, and 37% lower than that of the planar cam after tying the knot 200 times, 600 times, 1300 times, and 2000 times, respectively. Under the condition that the twine tension is set to 120 N, and the rotation speed of the fluted disc is 60 rpm, the deviations between the calculated value and the measured value of the wear amount of the curved cam are 9.48%, 6.01%, 7.27%, and 9.95%, respectively. This validates the accuracy of the spatial cam wear model and the correctness of the curved cam design. Full article

This paper deals with research on the operational process monitoring of a pipe conveyor for the needs of online diagnostics. The aim of this research is to verify the possibility of identifying the selected pipe conveyor’s failures in its straight section during operation (a missing roller in the idler housing, absent material on the conveyor belt) with the use of a discrimination method. This is an attempt to implement digital transformation with the aim of verifying its possibilities and limitations. The basis for discrimination is a continuous measurement and evaluation of measured values of contact forces in certain rollers’ positions in the hexagonal idler housing. Within this research, eight different measurement regimes were implemented. The use of the method was verified with simulated data using the trace table. We aimed to create prerequisites for online monitoring, which, based on digital transformation, will be deployed to control a transport system. The measurement was realized with the maximum tension force of 28,000 N. From the measurements, a decision-making algorithm was proposed to identify selected failures in the pipe conveyor operation with the use of the discrimination method. Within the algorithm, classifying criteria were determined, in the range of 57 N ÷ 251 N. The results confirm the method’s suitability for its practical assurance of pipe conveyors’ failure-free operation, as the failures were always identified sufficiently in advance, thanks to which, in practice, there was no further damage to the diagnosed devices. Full article

Roll-to-plate nanoimprinting with flexible stamps is a fabrication method to pattern large-area substrates with micro- and nanotextures. The imprint consists of the preferred texture on top of a residual layer, of which the thickness and uniformity is critical for many applications. In this work, a numerical model is developed to predict the residual layer thickness (RLT) as a function of the imprint parameters. The model is based on elastohydrodynamic lubrication (EHL) theory, which combines lubrication theory for the pressure build-up in the resin film, with linear elasticity theory for the elastic deformation of the roller material. The model is extended with inextensible cylindrical shell theory to capture the effect of the flexible stamp, which is treated as a tensioned web. The results show that an increase in the tension of the web increases the effective stiffness of the roller, resulting in a reduction in the RLT. The numerical results are validated with layer height measurements from flat layer imprints. It is shown that the simulated minimum layer height corresponds very well with the experimental results for a wide range of resin viscosities, imprint velocities, and imprint loads. Full article

During long-distance running, athletes are exposed to repetitive loads. Myofascial structures are liable to long-term work, which may cause cumulating tension within them. The aim of this study was to evaluate the acute effect of self-myofascial release on muscle flexibility in long-distance runners. The study comprised 62 long-distance, recreationally running participants between the age of 20 and 45 years. The runners were randomly divided into two groups: Group 1 (n = 32), in which subjects applied the self-myofascial release technique between baseline and the second measurement of muscle flexibility, and Group 2 (n = 30), without any intervention. The self-myofascial release technique was performed according to standardized foam rolling. Assessment of muscle flexibility was conducted according to Chaitow’s proposal. After application of the self-myofascial release technique, higher values were noted for the measurements of the following muscles: piriformis, tensor fasciae latae muscles and adductor muscles. Within the iliopsoas and rectus femoris muscles, lower values were observed in the second measurement. These changes were statistically significant (p < 0.05) within the majority of muscles. All these outcomes indicate improvement related to larger muscle flexibility and also, an increase in range of motion. In the control group (Group 2), significant improvement was observed only in measurements for the iliopsoas muscles. The single application of self-myofascial release techniques with foam rollers may significantly improve muscle flexibility in long-distance runners. Based on these results, the authors recommend the self-myofascial release technique with foam rollers be incorporated in the daily training routine of long-distance runners, as well as athletes of other sport disciplines. Full article

Pathein suspension bridge situated in Pathein City in the south of Myanmar has shown various symptoms of damage, and the safety of the bridge is questionable. The authorities concerned reported that the bridge has undergone severe deterioration since its construction, involving the towers’ inclination, excessive deflections, bearing failure, heavy corrosion of main cables and hangers, hangers’ inclination, and slippage of clamps. The deformed shape of the stiffening girder was found to be unusual, with maximum deflection nearer to the towers; however, in a single span bridge, such as Pathein Bridge, the maximum deflection is expected to be at mid-span. This paper will explain the possible reasons for the unusual excessive deformations in the stiffening girder and bearing failure. The tension force of hangers was estimated based on vibration measurements, and the distribution of hangers’ tension force along the bridge’s span was found to be non-uniform with low-tension force in hangers closer to the towers. The non-uniform distribution of the hangers’ tension force is possibly due to shortcomings of the design of the cable system. The towers’ inclination has caused the road level to drop down; however, the unusual deformations in stiffening girder are attributed to the non-uniform distribution of the tension force in the hangers. Low-tension force in the hangers near the towers caused the bearing to carry excessive force, which eventually caused the bearing to fail; the bearing was rehabilitated by adding steel rollers. Full article