Recent Patents on Mechanical Engineering - Volume 9, Issue 3, 2016

Background: Masticatory robot is a bionic robot, which is the product of the combination of medical technology and robot technology, to simulate human chewing movement. It can be mainly used for rehabilitation training of patients with occlusal disorders, and detecting the texture of food. Objective: To provide an overview of recent masticatory robots and introduce their respective characteristics and development. Method: This paper reviews various representative patents related to masticatory robot. The structural characteristics, control characteristics, applications of the typical masticatory robots are introduced. Results: The differences of different types of masticatory robots are compared and analyzed, and the structural characteristics are concluded. The main problems in its development are analyzed, the development trend is foreseen, and the current and future research of the patents on masticatory robot is discussed. Conclusion: Masticatory robot has important practical significance, and plays an important role in promoting the technology innovation in medical and food industries. And further improvements are needed in the aspects of authenticity, intelligence and security of the masticatory robot. More patents on masticatory robot should be invented.

Background: Tribological system is a complex nonlinear system. In recent years, for outstanding ability of analyzing nonlinear problems, the Artificial Intelligence (AI) has been widely applied in tribology. Objective: The purpose of this study is to provide an overview of AI and its developments, and to introduce and analyze how AI technologies are applied to solve complex nonlinear tribological problems. Methods: In this study, the applications of AI in tribology were analyzed from three aspects: design of tribological systems, development of friction materials, and monitoring and diagnosis of friction and wear behaviors. The research methods and progress of AI in tribology were summarized as follows: design tribological system; design and optimize formula of friction materials; analyze typical tribological performance parameters such as friction coefficient, friction heat and wear rate; monitor and diagnose friction states and wear forms. Results: In order to improve the efficiency and effectiveness of AI in solving tribological problems, current development and applications of AI in tribology are provided specifically. Conclusion: AI technologies are greatly beneficial to solve complex and nonlinear tribological problems. Owing to that various AI technologies have their advantages and shortcomings, combinations of different AI technologies must be more effective in solving tribological problems. In this article, various patents have been discussed.

Background: Electrospinning technology is a simple and effective method for the production of polymer nanofibers. The electrospinning machine is the carrier of the spinning process, mainly includes high power voltage source, generating device and collecting device. Objective: To meet the increasing requirement of spinning parameters and efficiency, the mechanical structure of the machine is constantly being improved. Method: This paper reviews various representative patents related to electrospinning machine. Results: The differences of different types electrospinning machines are compared and analyzed and the characteristics are concluded. The main problems in its development are analyzed, the development trend is foreseen, and the current and future developments of the patents on electrospinning machine are discussed. Conclusion: The optimization of the electrospinning machine structure improves the efficiency of spinning and the electrospinning condition. For further enhancement, more patents on electrospinning machine should be invented.

Background: Wheel plays an important role in many different areas, such as the wheeled mobile robot which is now widely used in planetary exploration, industrial production, household appliances and training aid appliances. In some occasions, wheeled mobile robot is required to turn in a zero radius, thus various omnidirectional wheels including ball wheel, Mecanum wheel, orthogonal wheel and Rover wheel are proposed by researchers. Objective: To evaluate a wheeled mobile robot, mobility and loading capacity are two factors meanwhile wheel is one of the key factors that makes difference on the mobility and loading capacity of wheeled mobile robot. The purpose of this paper is to study mobility and loading capacity of different kinds of omni-directional wheels. Method: This paper reviews various representative patents, productions and papers related to omnidirectional wheels. Their structures and working principles are introduced, compared and analyzed. Results: Current and future developments of the omni-directional wheels are finally provided and discussed. Conclusion: Developing an omni-directional wheel which can be used in common at anywhere is impractical. It is effective and reasonable to develop modified omni-directional wheels based on above four kinds of wheels to satisfy different requirements for the wheeled mobile robot.

Background: With the development of high-speed and high-precision rotating machinery, the rotor usually needs to work at very high speeds and the huge unbalancing vibration of rotor may be caused by a tiny unbalancing mass. To reduce the unbalance of rotor, a suitable dynamic balancing method should be designed for different rotor systems. In this article, various patents have been discussed. Objective: The typical dynamic balancing methods and technologies are summarized and analyzed so as to provide some references for dynamic balancing design and application. Method: To make it easier to design the proper balancing measure for actual rotating mechanical system, the dynamic balancing methods for rotor are classified as workpiece dynamic balance, assembling dynamic balance, field dynamic balance and online dynamic balance according to the balancing time of rotor. Results: The principle of all kinds of dynamic balancing method is given firstly, and then advantages, disadvantages and future developments about each balancing method are reviewed in the paper. Conclusion: Corresponding to these balancing methods, the online dynamic balancing method is recommended.

Background: Generally, the functionality of reconfigurable antennas is achieved by changing the topological structure controlled by RF switches. Compared with traditional antennas, reconfigurable antennas have many advantages, such as multi-function, small size, light weight, good diversity. Therefore, reconfigurable antennas will be an important part in MIMO systems, cognitive radio systems and future communication systems. Objective: This paper mainly focuses on the reconfigurable antennas based on RF MEMS switches. In this paper, various recent patents are also presented and discussed. Method: Firstly, the working principle and classification of reconfigurable antennas based on RF switches are introduced. Reconfigurable antennas can be grouped into four categories: frequency reconfigurable antennas, pattern reconfigurable antennas, polarization reconfigurable antennas and compound reconfigurable antennas. Secondly, the research status of RF MEMS switches is presented and the advantages of the RF MEMS switches are summed up. Moreover, the applications of RF MEMS switches in the related four kinds of reconfigurable antennas are introduced, respectively. Results: At last, the current and future developments of patents and academic papers in reconfigurable antennas are discussed.

Background: In recent years, as microcellular plastics have been used in different economic and life fields, microcellular injection molding machine has been paid more and more attention and been developed into various structures. Objective: The purpose of this article is to provide an overview of the supercritical fluid injecting system, mixing, and nucleating equipment of the microcellular injection molding, and explain how the technologies influence the product's quality and application. Methods: The paper reviews various patents and research developments about supercritical fluid injecting system, mixing, and nucleating equipment of microcellular injection molding machine, and analyses their effects on cell diameter, weight reduction, and product appearance. Results: Current and future developments of the injection apparatus, nozzle, and mold apparatus of microcellular injection molding are finally provided to improve the microcellular injection molded product's quality. Conclusion: The considerable attention has been paid on the microcellular injection technology. The recent patents and technologies have provided help to apply microcellular injection molding in a wider range, however how to inject physical agent into resin melt, mix them, and form fine cell structure is still difficult. For further enhancement, more devices should be invented in order to solve or simplify the above difficulties.

Background: Natural fibres are getting substantial attention as reinforcement in polymer composites. However, they are commonly recognised to have poor compatibility with polymers. Hence, it is important to enhance the interfacial bonding of natural fibres. Recent patents have highlighted several alternatives to improve the interfacial characteristics. Objective: In this study, the interfacial shear strength of untreated and 10wt% sodium hydroxide (NaOH) treated bamboo fibre reinforced polyester composites was investigated. Method: The bamboo fibre length was fixed at 7mm in both cases. The interfacial shear strength was measured through single fibre pull-out test (SFPT) and subsequently analysed using Weibull distribution plot. Results were also compared with the data from literature. Finally, scanning electron micrographs (SEM) were captured to analyse the debonded surfaces of both matrix and fibre. Results: Results showed that the interfacial shear strength of the treated fibre was improved by almost three fold higher than the untreated fibre. In addition, Weibull analysis revealed that the Weibull moduli were similar for both untreated and treated fibres. This suggested that surface impurities were formed on the treated fibre due to the damage induced by sodium hydroxide. Furthermore, scanning electron micrographs showed that alkalisation has modified the fibre surface morphology and improved the overall surface quality for better interfacial bonding. Conclusion: In conclusion, alkali treatment is a potential method to improve the interfacial characteristics of bamboo fibre in unsaturated polyester. Recent patent suggested that coating with bacterial cellulose is a green technique for better interfacial bonding behaviour.

Background: The medium and heavy plate surface defects can be divided into two categories. One is the defects without the depth changes. Such defects are called closed defects. The other is the defects with the depth changes. Such defects are called open defects. Objective: The purpose of this study is to provide an efficient patent for the open defects detection of medium and heavy plate. Method: A defects detection patent is proposed based on the theory of color photometric stereo. A single multi-spectral line scan camera with a white line light source is used to obtain the image of the medium and heavy plate surface. The determination algorithm for open defects is presented and the image processing algorithm is also studied. Results: The possibility of the presented patent is verified through industrial application experiments in a steel plant. Experimental results show that the patent can realize online detection for the medium and heavy plate surface open defects promptly and accurately. Conclusion: The defects with the depth changes are called the open defects. The patent proposed in this paper provides a new way of surface open defects inspection based on machine vision.

Background: It is better to consider the formation of coal and rock nonlinear complex system dynamics role in the cutter, using nonlinear dynamics theory and methods, in order to study rocks and coal cutter picks nonlinear dynamical systems effectively. Some patents have been discussed in this article. Objective: The purpose of the article is to study the characteristics of cutting load, especially the load characteristics of different cutting material parameters for the coal seam with coal and rock interface cutting. Method: The phase space was reconstructed by cutting load test data, through which the strange attractor phase diagram of cutting load was obtained. Moreover, this method can describe the load characteristics of cutting conditions above well. Based on determining the embedding dimension, the cutting load correlation dimensions and Lyapunov exponents of different working conditions were obtained. Results: Analyses show that the value ranges of correlation dimension and Lyapunov exponents are in accord with the chaotic characteristics, which proves that the single pick cutting system has chaotic characteristics; the corresponding value has some variation. In the scope of this study, different cutting conditions can be distinguished by these values. Finally, the cutting system characteristics can be studied by taking the complexity as measure standard, and it can be obtained that the complexity of cutting system will increase with the cutting object variation, which provides guidance significance for the system chaotic characteristics study. Conclusion: The similarities and differences of coal seam with coal and rock interface, homogeneous coal seam and homogeneous rock seam can be seen by the above contrast.