Recent Patents on Engineering - Current Issue

Due to the difficulty of obtaining the real dataset of paired underwater images, it is urgent to build an unsupervised underwater image enhancement network.

To address the problem, a novel underwater image enhancement based on Retinex decomposition and Unsupervised Generative Adversarial Network (RUGAN) is proposed.

A color correction module is proposed considering the different color distortions of underwater images. Further, considering the human visual perception mechanism, the RUGAN network, which is similar to U-Net, is constructed using the characteristics of underwater imaging and Retinex decomposition. Based on Retinex decomposition and the characteristics of underwater imaging, the RUGAN network similar to U-Net is constructed. The reflectance image and illumination image are obtained. The reflectance image with a better effect is taken as the enhancement result. Unlike the previous supervised methods, RUGAN adopts clear air images and distorted underwater images as training. RUGAN adopts the underwater image of the color correction module as pseudo-ground truth to achieve an unsupervised effect.

The superiority of RUGAN network is further supported by extensive experiments that compared it with more methods.

The RUGAN performs well both subjectively and objectively.

With the continuous progress of electronic information technology, people have begun to study the combination of electronic information technology and hydraulic technology to achieve more accurate and flexible control. Electro-hydraulic servo technology was thus developed. Much attanetion has been paid to electro-hydraulic servo valve, a key component of electro-hydraulic servo technology.

The number of stages of the electro-hydraulic servo valve, the structure form of the electro-hydraulic servo valve hydraulic front stage, the feedback form of the electro-hydraulic servo valve, the output form of electro-hydraulic servo valve, and the control algorithm based on the application of electro-hydraulic servo valve are analyzed and commented respectively. Combined with associated patents, the research direction and hot topics of electro-hydraulic servo valves are analyzed.

The electro-hydraulic servo valves were briefly classified; and then the problems of different types of valves were discussed in depth.

By analyzing the problems of electro-hydraulic servo valves, the problems of how to improve the control accuracy, response speed, anti-interference ability, service life and cost reduction of electro-hydraulic servo valves are analyzed comprehensively, and the future development prospect of electro-hydraulic servo valves is predicted and outlooked.

Analyzing and discussing the existing hot issues of electro-hydraulic servo valves helps to update and change the electro-hydraulic servo valves, and makes corresponding references for the subsequent research of electro-hydraulic servo valves.

As the ecological environment deteriorates, manufacturing and construction, as major industries that consume energy and cause environmental degradation, urgently need a new technology that is more efficient and sustainable. 3D printing has become a suitable choice for the manufacturing and construction industries to solve sustainability problems and environmental pollution problems due to its lower material consumption and no need for templates.

Through the analysis of the research status of sustainable improvement of 3D printing materials, scattered research is reviewed, valuable conclusions are extracted from representative studies, and future research directions are predicted.

Researches on sustainable improvement of 3D printing materials are compared and summarized, sustainable materials that can be used to replace existing materials are described, and the performance changes of samples after material improvement are summarized.

By tracking the impact of the substitution of various sustainable materials on the sample, the main problems in the current study are analyzed, including the degradation of sample performance and increased cost. On the premise of solving the above problems, the sustainable improvement of 3D printing materials in the future is prospected.

Improving the sustainability of 3D printing materials can help improve the environmental benefits of 3D printing. Therefore, this patent article has compared and summarized previous studies, described the available sustainable materials, and summarized the impact of various types of material substitution on samples. Considering the shortcomings of existing research, a more comprehensive evaluation of sample performance, specific quantitative assessment of environmental benefits, and expansion of indicators for evaluating environmental benefits are the key research directions in the future.

With the continuous progress of technology and the development of shield enterprises, higher requirements are put forward for speed estimation and system stability in the sensorless control system of induction motors in shield machines.

In order to solve the problems of velocity observation error and sliding mode vibration of the induction motor velocity observation method based on sliding mold observer, an improved super-helical sliding mold observer is proposed by combining the currently known invention patents and the information based on the induction motor control.

The open square of the current error value is introduced into the continuous function of the sliding variable of the observer, and two different functions are used in the boundary layer to replace the sign function, which reduces the sliding mode noise and vibration problems, and the stability of the observer is proved by the Lyapunov stability theory. After that, a phase-locked loop alternative model-referenced adaptive algorithm is used as the rotational speed observation link, which solves the problem that the conventional model-referenced adaptive algorithm relies on the current-modeled magnetic chain observer.

The improved super-helical sliding mode observer and phase-locked loop control method effectively reduce the system vibration and speed estimation error of the motor under different speeds and loading conditions, and the observed currents are smoother, which improves the stability of the system. Simulation and experimental results under different working conditions show the effectiveness of the proposed method.

The method was proposed to optimize the warpage and volume shrinkage of the blade of a plant protection unmanned aerial vehicle (UAV) during injection molding. The influence of molding defects on the geometric parameters of airfoil was analyzed from two aspects of blade geometry structure and molding process based on blade element theory. This paper focuses on reducing the warpage and volume shrinkage of the blade in the production process and improving molding quality through moldflow analysis and calculation.

The purpose of this patent study was to combine injection molding CAE with orthogonal test and response surface method to reduce product warpage and volume shrinkage, improve dimensional accuracy and production efficiency, and combine fluid dynamics simulation experiments to prove the experiment's reliability.

The optimization method of injection molding process parameters was proposed based on the orthogonal test and response surface method, combining the principles of aerodynamics mathematics and polymer injection molding. The Taguchi experiment was designed with melt temperature injection time and mold temperature pressure holding time as the optimization variable. The Box-Behnken Design (BBD) experiment was designed, and the response surface model was established with Design-Expert software to analyze the mapping relationship between process parameters and warpage and volume shrinkage. Moldflow software was used for flow analysis on the basis of analysis by response surface method, and the deformed parts were analyzed by computational fluid dynamics (CFD) with ANSYS software to prove the reliability of the calculation process.

The warpage and volume shrinkage of the product can be significantly reduced based on the orthogonal test and response surface model. The aerodynamic performance of the blade can be improved by optimization injection molding, making the actual production of the blade close to the original design blade model to the greatest extent and reducing the actual production trial and error cost.

An optimization method of the injection molding process of the UAV rotor was proposed based on the response surface method and blade element theory. Through the systematic design and optimization of injection molding parameters, the molding quality and performance of the rotor can be improved, which provides a new way to optimize the dynamic components of mass-produced UAVs.

As the pace of human conquest of space continues to accelerate, the number of spacecraft carrying out various activities in space continues to increase, so that the available orbital space continues to decrease, the amount of space debris continues to increase, and thus the probability of orbiting spacecraft being impacted by space debris is also increasing. Research on the development of protective structures in the current state is conducive to improving the protection performance of spacecraft protective structures against space debris, reducing the occurrence of spacecraft disintegration events and spacecraft collision events, and may also promote the development of many fields through the development of new technologies.

Through the latest application and development of spacecraft, the advantages and disadvantages of various protection structures are summarized, and the development trend of academic and aerospace protection engineering is analyzed.

Through the latest representative patent research methods for spacecraft space debris, research content, and creative structure, the principle and characteristics of the protective structure are demonstrated.

By comparing the application of different spacecraft space debris protection structures, the existing problems of the current protection structures are listed, and the potential development paths and research topics are put forward.

The development of aerospace, military, and other industries benefit from the development of protective structures, and the composite spacecraft space debris protection structures have broad development prospects.

Hip suffering is a serious concern for human health, which may be caused by arthritis, accidents, and childhood disorders; hence, man-made joints are the only option for restoring the function of natural hips and ensuring a comfortable life. To design an effective hip joint is a challenging task; there are myriads of novel designs continuously patented over the last two decades.

The finite element approach was utilized in this extensive investigation to assess self-mated polymer-based biomaterials (PTFE, UHMWPE, and PEEK) with different boundary conditions. The numerical analysis was performed to find the stress intensity and deflection of the femoral head and the acetabular components; the evaluation was done critically with a 10-node quadratic tetrahedron element and different mesh intensities.

The detailed outcome showcases that the bare PEEK mated GO-PEEK has good load resistance and is affected by minimum stress and deflection, which is quantified at 20.89% less than the PTFE with GO-PEEK (M3) combination. This stress and deflection are quite higher than those of metal implants (Ti6Al4V) but comparatively more prominent materials for human cortical bone.

This investigation proved the polymer-on-polymer combination effectively eliminates stress shielding and metal ion emission, reducing revision surgery and elevating implant longevity. Therefore, it was identified that PEEK-based polymer composites are the best-suited alternative substance for hip repair applications.

In recent years, observers have been crucial for controlling quadruped crawling robots, especially for feed-forward compensation in complex terrains. However, their tracking performance in continuous convex terrains requires optimization.

In order to improve the mobility of quadruped crawling robots by reducing posture adjustment time in continuous convex terrain, a finite-time observer with integration elements and optimized gait planning is proposed.

First, a buffer phase is introduced into the tripod gait planning to adapt to terrain changes, and the velocity error of the robot's center of mass is analyzed. Second, a coupled robot dynamics model is developed and the disturbance component structure is derived to ensure accurate estimation of the system state, especially in maintaining stability in the face of external disturbances. Finally, the auxiliary variable of the observer is based on the velocity error, with disturbance estimation terms combining power and sign functions, and the cumulative error is introduced by integrating the adjustment functions to improve the tracking performance.

The proposed observer reduces the maximum estimation error at knee and hip joints by 0.63 and 0.425 degrees, respectively, compared to a non-integrated observer. The integral of the absolute error during leg swing is 17.44% to 35.04% of the latter's, and the integral of the squared deviation error is 1.90% to 8.38%. These results demonstrate that the proposed observer can track the state information of the robot with greater accuracy.

The proposed finite-time observer significantly improves motion control for robots in continuous convex terrain and offers insights for enhancing stability in complex environments, which is expected to address the challenges of other robotic manipulator systems in overcoming the effects of external disturbances.

Lower limb-assisted exoskeleton robots have gained wide attention today because of their practicality, complete functions, and advanced technology.

By analyzing the current research status and key technology classification of lower limb-assisted exoskeleton robots and thinking about the future development direction of lower limb-assisted exoskeleton robots, the feasibility of future development is proposed to provide a reference for the readers.

This patent paper systematically describes the classification and development history of lower limb-assisted exoskeleton robots, introduces the working principles of various types of lower limb-assisted exoskeleton robots, summarizes the current research status of lower limb-assisted exoskeleton robots through a study of patents and journals, analyzes the critical technologies of active/passive lower limb-assisted exoskeleton robots, and outlooks their future development direction.

Through the research and analysis of active and passive exoskeleton robots, both of them have their shortcomings to be improved. Although exoskeleton robots at this stage have been able to be applied, there are still many problems such as insufficient endurance and poor structural flexibility.

Finally, based on the analysis and comparison of the current situation and key technologies of active/passive lower limb-assisted exoskeleton robots, the future development trend of lower limb-assisted exoskeleton robots is predicted, and it is believed that the ultimate development trend is the exoskeleton robots with the combination of rigid and flexible structure and active-passive assistance mode.