Recent Patents on Petroleum Pipe Inspection Gauge in China

Background: With a great growing demand for petroleum, the amount of petroleum pipe is also increasing, and petroleum pipe blockage has become a severe problem in China. It is necessary to clean and inspect the petroleum pipe regularly. But the current petroleum pipe in-spection gauge can very easily block the petroleum pipe ,while the cleaning efficiency is poor. Therefore, the anti-blocking capacity and high-efficiency cleaning ability of the petroleum pipe inspection gauge has been paid more and more attention. Objective: By analyzing and discussing the patents of petroleum pipe inspection gauges in China in recent years, the future design of petro-leum pipe inspection gauge has been provided and some valuable conclusions have been summarized to solve the current problems of pipe inspection gauge. Methods: This paper studied and compared various representative patents relevant to the petroleum pipe inspection gauge. Results: By summarizing a large number of patents about petroleum pipe inspection gauges in China, the anti-blocking capacity or cleaning efficiency of those patents are analyzed and compared, and the further development tendency of petroleum pipe inspection gauges has been discussed. Conclusion: The problems of easy blocking for petroleum pipe inspection gauge and poor cleaning efficiency are still exist. It is still the main development trend for the study on anti-blocking capacity and the improvement of cleaning efficiency. The future work can be focused on pigging technical cooperation, new materials, power source and intelligent control.

Research on Orbit Assembly Strategy of Large-scale Space Truss Structure

Background: With the rapid development of spatial technology and mankind's continuous exploration of the space domain, expandable space trusses play an important role in the construction of space station piggyback platforms. Therefore, the study of the in-orbit assembly strategy for space trusses has become increasingly important in recent years. The spatial truss assembly strategy proposed in this paper is fast and effective, and it is applied for the construction of future large-scale space facilities effectively. Objective: The four-prismatic truss periodic module is taken as the research object, and the assembly process of the truss and the assembly behaviors of the spatial cellular robot serving for on-orbit assembly are expressed. Methods: The article uses a reinforcement learning algorithm to study the coupling of truss assembly sequence and robot action sequence, then uses a q-learning algorithm to plan the strategy of the truss cycle module. Results: The robot is trained through the greedy strategy and avoids the failure problem caused by assembly uncertainty. The simulation experiment proves that the Q-learning algorithm of reinforcement learning used for planning the on-orbit assembly sequence of the truss periodic module structures is feasible, and the optimal assembly sequence with the least number of assembly steps obtained by this strategy. Conclusion: In order to address the on-orbit assembly issues of large spatial truss structures in the space environment, we trained the robots through greedy strategy to prevent failure due to the uncertainty conditions both in the strategy analysis and in the simulation study.Finally, the Q-learning algorithm in reinforcement learning is used to plan the on-orbit assembly sequence in the truss cycle module, which can obtain the optimal assembly sequence in the minimum number of assembly steps.

Review of Subdivision Schemes and their Applications

Background: Subdivision surfaces modeling method and related technology research gradually become a hot spot in the field of computer-aided design(CAD) and computer graphics (CG). In the early stage, research on subdivision curves and surfaces mainly focused on the relationship between the points, thereby failing to satisfy the requirements of all geometric modeling. Considering many geometric constraints is necessary to construct subdivision curves and surfaces for achieving high-quality geometric modeling. Objective: This paper aims to summarize various subdivision schemes of subdivision curves and surfaces, particularly in geometric constraints, such as points and normals. The findings help scholars to grasp the current research status of subdivision curves and surfaces better and to explore their applications in geometric modeling. Methods: This paper reviews the theory and applications of subdivision schemes from four aspects. We first discuss the background and key concept of subdivision schemes. We then summarize the classification of classical subdivision schemes. Next, we show the subdivision surfaces fitting and summarize new subdivision schemes under geometric constraints. Applications of subdivision surfaces are also discussed. Finally, this paper gives a brief summary and future application prospects. Results: Many research papers and patents of subdivision schemes are classified in this review paper. Remarkable developments and improvements have been achieved in analytical computations and practical applications. Conclusion: Our review shows that subdivision curves and surfaces are widely used in geometric modeling. However, some topics need to be further studied. New subdivision schemes need to be presented to meet the requirements of new practical applications.

Numerical analysis of Johnson-Cook damage model parameters effects on the cutting simulation of AISI 1045

Background: Failure model is the important basis for the research of material failure and fracture, and plays an important role in the finite element simulation of metal cutting. Johnson-Cook damage model is widely used to predict the failure of many materials. Its damage evolution is controlled by five parameters Objective: In order to decrease the cost of damage parameters identification and find out the damage parameters which have great influence on the simulation results. This work can provide an assistance in the optimization and selection of constitutive model parameters. Methods: Suitable Johnson-Cook damage model parameters, which can be used in the metal cutting simulation of AISI 1045 steel, are selected by comparing the simulation results and the experiments results. The cutting process of AISI 1045 steel is simulated by changing the Johnson-Cook damage parameters in the ABAQUS/Explicit. Results: The relevance of cutting force, feed force, cutting temperature, and deformation coefficient with five Johnson-Cook damage parameters are determined. Conclusion: The finite element simulation results show that the Johnson-Cook damage model parameters D2 and D3 have the biggest impact on the cutting simulation of AISI 1045 steel. Meanwhile, different Johnson-Cook damage parameters would take different changes to the simulation results

A Review of the Research on the Influencing Factors of Lubrication Performance for Sliding Bearings

Background: Sliding bearing is a kind of bearing that works under sliding friction, which has the characteristics of stable operation, safety and reliability and noiseless. With the technological progress of the machinery industry, modern machinery and equipment is developing in the direction of high speed and heavy load, its power is getting higher and higher, and the working environment is getting worse, so plain bearings are more and more widely used. Objective: In order to improve the lubricating performance of sliding bearings, the influencing factors of lubricating performance of sliding bearings are summarized and commented. Methods: The research progress and achievements at home and abroad are summarized from three aspects: influencing factors of lubrication performance of radial sliding bearings, thrust sliding bearings and influencing factors of lubricating oil on lubrication performance of sliding bearings, which provides reference for the future development of sliding bearings. Results: The study discusses the experimental method, simulation process and experimental results of the factors affecting the lubrication performance of sliding bearing. Conclusion: The texture, deformation, surface morphology of oil cavity, eccentric load and flow state of sliding bearings all affect the lubricating performance of sliding bearings, and lubricating oil also affects the lubricating performance of sliding bearings.

Recent Patents on Mechanical Structure of 3D Printer

Background: 3D printing technology is widely applied in transportation, industrial equipment, medical, aerospace, and civil industry due to its characteristics of material saving, no model manufacturing, and machinability of complex parts. The mechanical structure of 3D printer mainly includes 3D printer head structure and working platform and plays a major role in the machining efficiency and processing accuracy of the 3D printer. Thus, increasingly attention has been paid to the current trends of the mechanical structure of 3D printers. Objective: To meet the increasing requirements of 3D printing processing efficiency and precision, the mechanical structure of 3D printers, such as 3D print head structure and working platform, needs to be carefully studied, and a feasible mechanical structure of 3D printers should be proposed. Methods: This paper studies various representative patent related to the mechanical structure of 3D printer, analyzes the mechanical structure of 3D printer, and studies the perfect mechanical structure of 3D printer. Results: Through summarizing a lot of patents about the mechanical structure of 3D printers, the main current existing problems such as platform jitter and machining error are summarized and analyzed, a new mechanical structure of 3D printers is proposed. Moreover, the development tendency of the mechanical structure of 3D printers in the future is discussed. Conclusion: The optimization of the mechanical structure of 3D printer is conducive to increasing the machining efficiency and processing accuracy in the 3D printing process. More relevant patents about working platform and 3D printer head will be invented in the future

Current status and future perspectives of active knee joint rehabilitation device

Background: Today, living standards and medical technology are improving, and the aging global population is increasing. Moreover, more and more older adults are suffering from knee diseases. This will seriously affect patients’ daily life and their mental state. In many studies, repetitive physical exercises and motor activities in real-world environments have been shown to help improve knee muscle strength and restore damaged nerves. Therefore, physical knee therapy is very necessary. The use of rehabilitation training devices for movement therapy has shown great potentia Objective: The structural features, functions and development status of the knee rehabilitation training device are introduced Method: This review explores the structure and function of various current knee rehabilitation devices based on structural and kinematic properties of the knee joint in relation to requirements of physical knee rehabilitation. This paper aims to present a systematic guideline and to outline a reference for future designers of rehabilitation devices. Results: By analyzing the structure and movement of the knee joint and combining the strategies of physical knee rehabilitation, movement requirements during knee rehabilitation training are concluded. According to the structure, drive form, transmission mode and rehabilitation environment of knee rehabilitation devices, the devices are classified and compared; some typical features are summarized; some current problems are analyzed; and the future trends and development directions of rehabilitation devices are discussed. Conclusion: Current rehabilitation equipment has a variety of structures and functions, but a good balance between weight and volume is hardly maintained. The protection of the body needs to be further improved. Many knee rehabilitation devices are only concepts, not physical objects, and lack clinical trial data. Power sources and drives are large and heavy, which can compress the knee joint and place a burden on the patient. Strong and light-weight materials should be chosen to assist knee rehabilitation. It will be a good development in the future

Research on Dynamic Obstacle Avoidance Method of Manipulator Based on Binocular Vision

Background: With the development of robotics, more and more robots are used in manufacturing. However, in actual work, safety accidents happen to robots from time to time. How to ensure the safe operation of robots in a limited and complex working environment is the key to improve robot technology. Therefore, it is of great significance to study the dynamic obstacle avoidance of robots in complex environment for improving the intelligence and safety of robots, and the application of human-robot collaboration. Objective: The primary purpose of this paper is to improve the traditional artificial potential field method, including he disadvantages that the improved target is inaccessible and easily plunged into local optimal solution of the drawback of the improved method, second. Secondly, the background difference method based on binocular vision and Kalman filtering algorithm, and the environmental map containing the static and dynamic obstacles is obtained. After obtaining the position information of static and dynamic obstacles, the robot arm can make good use of the improved artificial potential field method to plan its own trajectory, thus realizing the dynamic obstacle avoidance of the robot arm in complex environment. Methodology: The background difference method and the Kalman filtering algorithm based on binocular vision were introduced to track the dynamic obstacles, and the improved artificial potential field method for path planning was applied to the dynamic obstacle avoidance path planning of the manipulator. Finally, the simulation and experimental results show that under the complex environment with dynamic obstacles exist, robot arm can realize independent dynamic obstacle avoidance. Results: By using background difference method and Kalman filtering algorithm to track the target in real time, the result showed that the target could be detected and tracked well. By improving the defect that the traditional artificial potential field method is easy to fall into local optimum, the improved algorithm can well realize the dynamic obstacle avoidance of the manipulator. Conclusions: For the development requirements of the industrial robots in the future, this paper based on binocular vision, which can make the manipulator realize more intelligent industrial production activities in complex working environment, meet the needs of future industrial development, and make this technology play an important role in production activities.

A Review of designing freeform optical surfaces by the Monge–Ampère equations

Background: The equations of Monge–Ampère type which arise in geometric optics is used to design illumination lenses and mirrors. The optical design problem can be formulated as an inverse problem: determine an optical system consisting of reflector and/or refractor that converts a given light distribution of the source into a desired target light distribution. For two decades, the development of fast and reliable numerical design algorithms for the calculation of freeform surfaces for irradiance control in the geometrical optics limit is of great interest in current research. Objective: The objective of this paper is to summarize the types, algorithms and applications of Monge–Ampère equations. It helps scholars to grasp the research status of Monge–Ampère equations better and to explore the theory of Monge–Ampère equations further. Methods: This paper reviews the theory and applications of Monge–Ampère equations from four aspects. We first discuss the concept and development of Monge–Ampère equations. Then we derive two different cases of Monge–Ampère equations. We also list the numerical methods of Monge–Ampère equation in actual scenes. Finally, the paper gives a brief summary and an expectation. Results: The paper gives a brief introduction to the relevant papers and patents of the numerical solution of Monge–Ampère equations. There are quite a lot of literatures on the theoretical proofs and numerical calculations of Monge–Ampère equations. Conclusion: Monge–Ampère equation has been widely applied in geometric optics field since the predetermined energy distribution and the boundary condition creation can be well satisfied. Although the freeform surfaces designing by the Monge–Ampère equations is developing rapidly, there are still plenty of rooms for development in the design of the algorithms.

Recent Patents on Third Generation Bearing Testing Machine

Background: Bearing testing machine is the key equipment for bearing design, theoretical research and improvement, and it plays an important role in the performance of bearing life, fatigue, vibration and working temperature. With the requirements of aerospace, military equipment, automobile manufacturing and other industrial fields of the bearing are becoming higher and higher. There is an urgent need for high-precision and high-efficiency bearing testing machines to monitor and analyze the performance of bearings. Objective: By analyzing the recent patents, the characteristics and existing problems of the current bearing testing machine are summarized to provide references for the development of bearing test equipment in the future. Methods: This paper reviews various representative patents related to the third generation bearing testing machines. Results: Although the structure of bearing testing machines is different, the main problems in the structure and design principle of bearing testing machine have been summarized and analyzed, and the development of trend and direction of the future bearing testing machine have been discussed. Conclusion: Bearing testing machines for health monitoring of bearing life cycle is of great significance. The current bearing testing machine has basically achieved the monitoring and analysis However, due to the emergence of new types of bearings, further improvement is still needed. With the development of testing technology towards intelligent and big data-driven direction, bearing testing machine is moving towards the type of cloud computing and large-scale testing.