Recent Patents on Engineering - Volume 17, Issue 3, 2023

Background: Manipulator is widely used in the manufacturing industry because it can imitate some movements of human hands, and replace human hands to complete some high-risk and heavy labor or carry out man-machine cooperation. Flexible soft manipulator made of flexible materials is a new field of the manipulator. Investigation of the material and driving mode of the flexible soft manipulator is helpful to improve the flexibility and force position control when grasping objects. Therefore, researchers pay more and more attention to the development trend of the flexible soft manipulator. Objective: In order to optimize the driving mode and materials of a flexible soft manipulator, pneumatic- driven flexible soft manipulator and variable stiffness flexible soft manipulator are developed. Methods: This paper summarizes the selection, classification and introduction of patents related to pneumatic drive and variable stiffness in the flexible soft manipulator. Results: Through the investigation of various patents on flexible soft manipulators, the main existing problems in flexible soft manipulators, such as small grasping range and insufficient driving force, are summarized and analyzed. In addition, the development trend of flexible soft manipulators is also discussed. Conclusion: The optimization of the driving mode and materials of the manipulator is beneficial to improve the driving force and grasping force. More related patents will be invented in the future.

Background: In China, there are more than 2 million patients with hand function impairment caused by trauma and stroke each year. Since the hand is an important sensory and motor organ of the human body, the loss of hand function seriously affects people's daily activities and work. The current hand function rehabilitation robots are mainly rigid. The rigid robot has the problems of fixed rehabilitation track, high rigidity, and poor comfort. To solve this series of problems, soft hand function rehabilitation robots have been vigorously developed. Objective: To introduce the classification, advantages and disadvantages, and development trend of existing soft hand rehabilitation robots. To provide for other researchers to understand its development status and future development trends. Methods: The various products and patents of soft hand rehabilitation robots are summarized, and the structural features, merits, and demerits of typical soft hand rehabilitation robots are introduced. Results: By analyzing a variety of soft hand function rehabilitation robots, the characteristics and the current problems of soft hand function rehabilitation robots are determined, the development trend of soft hand function rehabilitation robots has been prospected, the current research status of soft hand function rehabilitation robots are discussed and the prospects are carried out. Conclusion: Because the rate of increase in patients with hand function loss is much greater than that of rehabilitation physicians, many patients cannot receive timely and effective treatment. Therefore, hand function rehabilitation robots have received people’s attention. Compared with rigid rehabilitation robots, soft hand function rehabilitation robots have diverse rehabilitation trajectories, high comfort, and low rigidity, so it is very necessary to develop soft hand function rehabilitation robots. In the future, soft hand function rehabilitation robots will inevitably develop towards simplification of structure, more comfortable wearing, economical, diversified functions, better curative effect, and safer development.

Background: At present, with the rapid development of technology in medical treatment and rescue, how to reduce the operational complexity caused by limited space has become one of the hot topics. For example, in search and rescue, it is difficult for people to enter these high-risk areas due to various restricted geographic environments. During some medical treatment processes, minimally invasive surgery is difficult to operate on because of its small incision. In order to solve these problems, a kind of Wire-Driven Flexible Robot Manipulator (WDFRM) has been developed. The WDFRMs have better flexibility and greater degrees of freedom (DOF) than the traditional rigid manipulators and play an important role in these extreme operation fields. Objective: The paper aims to report the latest progress in the studies of the WDFRMs, and provides a reference for readers in this field. Methods: By summarizing various productions and patents related to the WDFRMs, the structural characteristics, differentiations, and applications of the WDFRMs are proposed. Results: Different types of WDFRMs are compared, analyzed, and classified according to their structural characteristics and supporting mode. The technical problems of the WDFRMs are pointed out, and the future development direction of this research field is predicted. Conclusion: According to their structural characteristics, the research shows that WDFRMs can be divided into Wire-Driven Serpentine Flexible Robot Manipulators (WDSFRMs) and Wire-Driven Continuum Flexible Robot Manipulators (WDCFRMs). WDFRMs will have more applications in medical treatment, rescue, and military affairs. The structure, stiffness, and accuracy of the WDFRMs still need to be improved continuously.

Background: The high-speed motorized spindle system is the main component and the most significant heat source of high-precision CNC machine tools in mechanical processing. Plenty of research shows that 60%~80% of the machining accuracy error comes from the thermal deformation of each part in automated manufacturing. Therefore, it is urgent to study the control method of thermal error for motorized spindle systems. Objective: Some valuable conclusions are drawn through the introduction and discussion of thermal error control methods for motorized spindles in recent years, and we prospect the future research and development of thermal error control methods for motorized spindles. Methods: The patents and papers based on the control methods of thermal error for motorized spindles are studied. The advantages and disadvantages of thermal error control methods and their research status are summarized. Results: With the urging of social as an essential part of CNC machine tools, we cannot ignore the thermal error of high-speed motorized spindles. To improve the machining accuracy, increase efficiency and prolong life, etc., all need a motorized spindle with excellent thermal dynamic performance. Conclusion: We analyze the structural characteristics and the primary heat sources of high-speed motorized spindles, and review a mass of patents and papers related to the motorized spindle thermal error control methods for investigation. By comparing these papers, some valuable conclusions are drawn to predict the future research and development of thermal error control methods for the motorized spindle.

Background: Roller bearing is a widely used component in modern machinery. It has the advantages of small friction, low starting torque, high rotation accuracy, less power loss, and high efficiency. The researches on the structure and working principle of new type roller bearings are conducive to improving the performance of bearings. Therefore, it is necessary to analyze and summarize the recent research. Objective: By summarizing the research on roller bearings in recent years, some valuable conclusions are obtained to predict the future development of roller bearings and provide a reference for researchers in related fields. Methods: This paper summarizes the representative patents related to roller bearings, including bearings with tapered rollers, cylindrical rollers, spherical rollers, and needle rollers. The advantages and disadvantages of these roller bearings are discussed. The influences of the special structure of these bearings on their performances are analyzed. Results: The existing problems are summarized through the analyses of the patents related to roller bearings. New patents of roller bearing to be developed in the future are expected. Conclusion: Optimizing the roller bearing structure improves the accuracy and reliability of the whole equipment. It is necessary to continually improve the roller bearings' structure according to the actual working conditions, especially simplifying the bearing structure. More and more novel bearings will be invented in the future.

Background: Only a fraction of the produced social media data is usable in mental health assessment. So the problem of sufficient training data for deep learning approaches arises. Data sufficiency can be presented in terms of number of users or the number of posts per user. Objective: We examine the data need of machine learning and deep learning models for a practical system and let researcher choose best fitting models depending on the dataset type available with them. We perform distinct experiments to find the effect of these issues on depression classification by various approaches. Methods: We explored various machine learning and deep learning techniques on various data set versions, taken from Twitter and Reddit, with varying numbers of users and posts per user. Diagnosed and control users are taken in different ratios to assess the impact of an imbalanced dataset. Results: The results reveal that SVM achieved 68% accuracy in depression classification for 70 users each from diagnosed and control group. It decreases for 150 users from each group, but then regains performance for 350 and 550 users from each group. Whereas Naive Bayes got 64% for the same dataset fragment (1). We observed that accuracy decreases for 150 diagnosed users, but then regains performance for 350 and 550 users. However from deep learning algorithms, HAN and BiLSTM perform better, compared to other algorithms, as the imbalance ratio increases. Conclusion: We found, mainly, that classification accuracy increases with the number of users, number of posts per user and imbalance in the number of diagnosed versus control users. We also found that posts from Reddit have better accuracy compared to tweets.