Recent Patents on Engineering - Volume 16, Issue 1, 2022

Background: Crop straw is a valuable renewable biological resource. In this study, a mobile straw granulator was designed to fully and efficiently use crop straw. The key crushing mechanism device of the mobile straw granulator was also designed in detail. Method: The first three natural frequencies and vibration modes of the roller crusher were obtained by applying ANSYS-Workbench software to the modal analysis of the roller crusher. Results: The lowest natural frequency of the roller crusher was 165.83 Hz, which was higher than its working frequency of 30 Hz, whichwould not cause resonance. The three factors and three levels were tested using the average resistance of the blade as an index, edge angle, thickness, and the end width of the blade as the test factors. Conclusion: The optimum parameter combination obtained by software analysis is blade edge angle of 30°, blade thickness of 8 mm, and blade width of 75 mm. With this parameter combination, the blade power consumption is the smallest, the service life is the largest, and the crushing effect is the best.

According to the universal one-dimensional consolidation equation introduced by Gibson, the governing equation with the excess pore water pressure as the control variable is derived, and the Fourier series solution under the boundary condition of single-sided drainage is deduced in detail by the standard mathematical and physical method. It verifies the correspondence between the analytical solution and the numerical solution from a theoretical point of view. Using this analytical solution, the nonlinear distribution of the excess pore pressure along the depth direction is obtained, and the traditional small strain consolidation is compared in terms of the average consolidation degree and the final settlement. In the project, the one-dimensional consolidation theory established by Terzaghi is obviously no longer applicable to the foundation built on saturated soft clay with a compressive amount of 80%, so the research on the large strain theory began. The purpose of this article is to give a detailed derivation process of the differential equation with excess pore pressure as the control variable in the analytical theory of one-dimensional nonlinear large-strain consolidation, and verify it based on calculation examples, hoping to provide suitable theoretical basis for large-deformation foundations. This article mainly uses detailed formula derivation and standard mathematical and physical methods to derive the Fourier series solution of the consolidation differential equation according to the boundary conditions of single-sided permeable water and compare and verify the analysis according to an example of calculation. Based on Gibson's general equation of consolidation and its theory, the detailed derivation process of differential equations with excess pore water pressure as the control variable is given. According to the example, the image shows the distribution of excess pore pressure with depth, and comparative analysis of large and small strains. If all other conditions are the same, when mv1=1 MPa-1, it can be calculated according to the large and small strains, but when mv1≥3MPa-1, for the soil that should be calculated according to large strain, it is unreasonable to calculate according to small strain. Therefore, the calculation error of the two methods is very large, so it is necessary to distinguish the large and small strains.

Background: As an important method of remanufacturing, laser cladding can be used to obtain parts with specific shapes by stacking the materials layer by layer. The formation mechanism of laser cladding determines the “Staircase effect”, which makes the surface quality hardly meet the dimensional accuracy of the parts. Therefore, the subsequent machining must be performed to improve the dimensional accuracy and surface quality of cladding parts. Methods: In this paper, chip formation, cutting force, cutting temperature, tool wear, surface quality, and optimization of cutting parameters in the subsequent cutting of the laser cladding layer are analyzed. Scholars have expounded and studied these five aspects, but the cutting mechanism of laser cladding needs further research. Results: The characteristics of the cladding layer are similar to that of difficult-to-machine materials, and the change of parameters have a significant impact on cutting performance. Conclusion: The research status of subsequent machining of cladding layers is summarized, mainly from the aspects of chip formation, cutting force, cutting temperature, tool wear, surface quality, and cutting parameters optimization. Besides the existing problems and further developments of subsequent machining of cladding layers have been pointed out in this paper. These efforts are helpful in promoting the development and application of laser cladding remanufacturing technology.

The security of information is the major problem faced in today’s digital environment. Biometric Systems help in achieving high-end security at precise performance requirements for various applications. This paper surveys the present multimodal and unimodal biometric-based authentication systems which are in use, and their future possibilities. The authentication techniques that can identify the individual using unique features of the human such as face, fingerprint, DNA, speech, and iris are discussed. Different recognition systems for new biometric traits such as voice, gait, and lip moment are also focused. This paper also focuses on the information security of biometric systems and their performance requirements.

Cr12MoV hardened steel is widely used in the manufacturing of stamping die because of its high strength, high hardness, and good wear resistance. As a kind of mainstream cutting technology, high-speed machining has been applied in the machining of Cr12MoV hardened steel. Based on the review of a large number of literature, the development of high-speed machining of Cr12MoV hardened steel was summarized, including the research status of the saw-tooth chip, cutting force, cutting temperature, tool wear, machined surface quality, and parameters optimization. The problems that exist in the current research were discussed and the directions of future research were pointed out. It can promote the development of high-speed machining of Cr12MoV hardened steel.

Background: Bearing has been widely used in automotive, aerospace, electronics industry and other fields. Its pre-tightening technology is one of the most critical technologies. It has an important influence on the accuracy, speed, stiffness and temperature rise of the spindle. Proper pre-tightening force can eliminate bearing clearance and improve machining accuracy and efficiency of machine tools. Therefore, the development trend of bearing pre-tightening mechanism has been paid more and more attention. Objective: In order to improve the processing efficiency and processing accuracy of the bearing system, the structure and function of the bearing pre-tensioning device are continuously enhanced. Methods: This paper retraces various current representative patents relative to the mechanism of bearing pre-tightening. Results: Through the investigation of a number of patents of bearing pre-tightening devices, the principles and effects of different bearing pre-tightening devices are classified and reviewed. Besides, the future development trend of bearing pre-tightening devices is discussed. Conclusion: The optimization of the bearing pre-tightening device is conducive to improving processing efficiency and quality. A controllable pre-tightening force is the research direction, and more related patents will be invented in the future.

Background: The development of deep learning technology has promoted the industrial intelligence, and automatic driving vehicles have become a hot research direction. As to the problem that pavement potholes threaten the safety of automatic driving vehicles, the pothole detection under complex environment conditions is studied. Objective: The goal of the work is to propose a new model of pavement pothole detection based on convolutional neural network. The main contribution is that the Multi-level Feature Fusion Block and the Detector Cascading Block are designed and a series of detectors are cascaded together to improve the detection accuracy of the proposed model. Methods: A pothole detection model is designed based on the original object detection model. In the study, the Transfer Connection Block in the Object Detection Module is removed and the Multi-level Feature Fusion Block is redesigned. At the same time, a Detector Cascading Block with multi-step detection is designed. Detectors are connected directly to the feature map and cascaded. In addition, the structure skips the transformation step. Results: The proposed method can be used to detect potholes efficiently. The real-time and accuracy of the model are improved after adjusting the network parameters and redesigning the model structure. The maximum detection accuracy of the proposed model is 75.24%. Conclusion: The Multi-level Feature Fusion Block designed enhances the fusion of high and low layer feature information and is conducive to extracting a large amount of target information. The Detector Cascade Block is a detector with cascade structure, which can realize more accurate prediction of the object. In a word, the model designed has greatly improved the detection accuracy and speed, which lays a solid foundation for pavement pothole detection under complex environmental conditions.

Background: Thin-walled parts of aluminum alloy are easy to occur in machining deformation due to the characteristics of thin wall, low rigidity, and complex structure. Objective: To reduce and control the machining deformation, it is necessary to select reasonable machining parameters. Methods: The influence of milling parameters on the milling forces, milling temperature, and machining deformation was analyzed through the established model based on ABAQUS. Then, the corresponding empirical formula was obtained by MATLAB, and parameter optimization was carried out as well. Besides, a lot of patents on machining thin-walled parts were studied. Results: The results showed that the prediction error of milling forces is about 15%, and 20% of milling temperature. In this case, the optimized milling parameters are as follows: ap=1 mm, ae=0.1 mm, n=12 000 r/min, and f=400 mm/min. It is of great significance to reduce the machining deformation and improve the machining quality of thin-walled parts.

Background: In the whole design process of modular fuel tank, there are some unreasonable phenomena. As a result, there are some defects in the design of modular fuel tank, and the function does not meet the requirements in advance. This paper studies this problem. Objective: Through on-the-spot investigation of the factory, a mechanical design process model is designed. The model can provide reference for product design participants on product design time and design quality, and can effectively solve the problem of low product design quality caused by unreasonable product design time arrangement. Methods: After sorting out the data from the factory investigation, computer software is used to program and simulate the information input of mechanical design process, and the final reference value is obtained. Results: This mechanical design process model is used to guide the design and production of a new project, nearly 3 months ahead of the original project completion time. Conclusion: This mechanical design process model can effectively guide the product design process, which is of great significance to the whole mechanical design field.