VUTS (Czechia)

Abstract Aiming at the challenges of high energy consumption, low integration, and insufficient stability in the drive systems of ultra-high-speed air-jet looms, a drive and control in-tegrated software/hardware architecture for a “three-in-one” system (mainshaft drive motor, warp motor, and take-up motor) is constructed. A multi-axis (main shaft, warp shaft, and take-up shaft)coupled drive model with multiple spatiotemporal character-istics and nonlinear mathematical properties is established. Amethod for multi-axis electromechanical parameter monitoring and information fusion is proposed. An intel-ligent drive andcontrol integrated controller is developed to achieve real-time moni-toring and diagnosis of the operating status of the multi-axiselectromechanical system, as well as vector control and field-weakening control. This enhances the efficiency of the loomdrive system and reduces power consumption.In addition, in response to the low efficiency and poor consistency of manualfabric quality inspection in the textile in-dustry, this paper proposes an intelligent fabric quality inspection system based onthe improved YOLOv8n algorithm. By constructing a dataset containing seven types of typical fabric defects, the structure ofthe original model was optimized. Experimental results show that the improved YOLOv8n achieves a mAP_0.5 of 98.4% infabric defect detection tasks and a reasoning speed of 156 FPS, which is more than 20 times faster than traditional detectionmethods. Practical deployment tests show that the system can stably identify defects such as broken warp and weft yarns,stains, and loose weft over 0.3mm, with a false detection rate of less than 0.15%, meeting the real-time quality in-spectionrequirements of textile production lines. This research provides an effective technical solution for the intelligence of textilemachinery and has been successfully applied to the RFJA36 series looms of Shandong Rifa Textile Machinery Co., Ltd.

Warp-knitted spacer fabrics are featured by a 3d integral structure consisting of two warp-knitted fabric layers, which are kept on distance by vertical threads. This structure enables the realization of several functions like mechanical cushioning, permeability for air and moisture, and thermal insulation. Due to these functions, spacer fabrics can be used as moisture and thermal-regulating functional components in various sewing products, whereby compression stability is essential for the functionalities mentioned above. These can also be influenced locally by stitching. A numerical tool is preferred to compute the mechanical properties in an accurate way, taking into account the varying sewing parameters. This study's objective is to extend the macroscopic material law for spacer fabrics through numerical analysis of experimental data. For this purpose, 3d samples stitched at varying intervals were tested by a compression test. A regression analysis was applied to predict the compressive stress for each structure. The research steps included representing and approximating the coefficients and potencies for the experimental curves as explicit functions of the distance between the stitch lines. An effective contact model for spacer fabrics with stitches was developed, which is to be expressed in the form of seam distance in terms of the effective compression of the spacer fabrics. Thus, in the future, it will be much easier to predict the effective properties for selected semi-analytical applications with such materials.

Many-objective optimization problems are challenging for the majority of extant multi-objective evolutionary algorithms to solve because they are unable to strike a balance between diversity and convergence in the high-dimensional objective space. Therefore, for many-objective evolutionary optimization, this paper proposes a vector angle-based and I_SDE⁺ indicator selection strategies. Using these two strategies, the worst individual are repeatedly removed from the population through environmental selection. More specially, the first one is aimed at finding any two individuals that have the smallest vector angle, which indicates that they are looking in the same research direction. The latter considers the individuals with poor convergence and diversity, which are eliminated according to the value of I_SDE⁺ indicator one by one. Experimental results revel that the proposed algorithm obtains competitive advantages on various benchmark problems with up to 10 objectives, when the proposed algorithm is compared with several state-of-the-art many-objective algorithms.

The article considered the effective issues of preparing a set of quality of special clothes for express delivery courier service, strengthening corporate culture and promoting the brand. The special uniform of the employees ensures the reputation and reliability of the service companies, which increases the professional image of the service. A special uniform, made of textured materials mixed with corporate colors, allows customers to immediately identify the field of service, increases its recognition in this field and the loyalty of its work. In the preparation of express delivery courier clothing sets, mixed textured materials were selected and the wear resistance, non-cracking and friction resistance properties of the various materials package met the specified index requirements, the state technical regulatory committee analyzed the standard indicators in the test samples. The multi-functional express delivery courier clothing set prepared according to the requirements of modern fashion has the importance of creating a new composition of the suit in new constructive and artistic solutions for each season, making the transformation of the courier clothing according to the function impossible. On the basis of the above-mentioned factors, courier clothing is transformed according to the service. A set of clothes prepared with reflective elements ensures the safety of the courier (front waist, back waist, sleeves, trouser seams). Courier's special work clothes made from a package of mixed textured materials, express delivery set is easy to service and meets operational requirements, its shape allows comfortable operation in any weather without hindering movement and extends the service life.

This article describes measurement of the internal screw thread by the camera system. Especially thread handedness detection is focused. For this purpose, a geometric transformation on camera image was used, followed by the FFT method to detect thread direction. Possible issues of the measurement precision are also discussed.

Braided structures are widely used in numerous contexts including everyday practice. In most cases, rope ends are knotted to form various types of loops or tie them to rigid body parts; however, knots take up space that may not be available in some application scenarios, thus making them unsuitable for certain purposes. Hence, this paper introduces first development steps of a method for the numerical simulation of rope ends connected by sewing stitches.

The functional prototype of the CNC machine will be created by the reconstruction of the existing SIG CF2 machining center. Including the development of a new single purpose control system based on HW and SW components from OMRON, which results in faster, more efficient and easier to operate and service than the old control method. This also involves the replacement of the individual drives of the interpolation and positioning axes, the necessary external encoders and the machining spindles, together with following structural and mechanical changes. This makes it possible to achieve higher accuracy and speed during machine working movements. The new system also required unavoidable intervention in the electrical installation, its reorganization and replacement of the old nonfunctional components. All modifications are summarized in detailed documentation. The paper describes the current state of renovation of the machine, which will then be able to be involved in the ongoing serial production of radial and axial cams, either as a backup or as a replacement for one of the existing SIG machines at the research institute.