Recent Patents on Engineering - Volume 14, Issue 1, 2020

The Internet of Things (IoT) is a novel technology that has opened doors to the new level of interaction between the things. This has resulted in an enhancement in the quality of life and optimized use of various resources. IoT uses various technologies related to networking, sensing, databases and artificial intelligence to enhance the lifestyle and makes business processes simpler. In the IoT based systems, the number of devices contributing to a particular application is very large, spreading to a large geographical area at various locations. The device can be considered as a resource used by a service in the application layer. IoT service is the most important entity. The real-world things generate data by perceiving the environment in large quantity and store it in the distributed databases or cloud databases. This manuscript analytically and statistically categorizes and analyze the current research techniques on the service discovery and selection in the IoT, published between 2010 and 2018. It finds that the discovery among a huge number of services requires fast, scalable and dynamic service discovery mechanism over the Internet. Once the services are discovered, the next step is to select the most appropriate service. This paper includes a comprehensive analysis of the discovery and selection of services in IoT. A patent related to service and discovery have been also discussed which would be beneficial in identifying the research gap to make the system more efficient.

Background: Portable life support system is used in the battlefield, disaster and in other special circumstances such as in space exploration, and underground survey to give the wounded a life support. The most dangerous period for the injured is the first hour after an injury, which is a crucial time for treatment. If the patient's vital signs were stabilized, more than 40% of the injured could be saved. The staff can efficiently complete the task if they get effective and stable vital signs during the operation. Therefore, in order to reduce the risk of disaster and battlefield mortality to improve operational safety and efficiency, it is necessary to study the portable life support system. Objective: The study aimed to provide an overview of recent portable life support system and its characteristics and design. Methods: This paper introduces the patents and products related to a portable life support system, and its characteristics and application. Results: This paper summarizes five kinds of portable life support systems which are box type, stretcher type, bed type, backpack type and mobile type. Moreover, the characteristics of different portable life support systems are analyzed. The paper expounds the problems of different types of portable life support systems and puts forward improvement methods to solve the problems. Finally, the paper points out the future development of the system. Conclusion: Portable life support system plays an increasingly important role in health care. In terms of the structure, function and control, further development and improvements are needed, along with the research on portable life support system.

Design patent is deemed as a superb competitive tool in the design industry. The author of this study delineates a co-opetition type of relationship of design patent with patent, trademark, and copyright to assist designers to construct a correct core concept of design patent quickly. The investigator proposed five key judgment factors based on infringement identification, and they are (1) literal infringement, (2) doctrine of equivalence, (3) points of novelty test, (4) prosecution history estoppel, and (5) prior art limitation. They can help designers clearly identify the legal right and scope of their design. Lastly, the author proposed three new competitive tools for a design patent, and they are (1) partial design patent, (2) computer-generated icons and graphic user interface, and (3) derivative design patent. Using these three new design patent tools will enable designers to effectively expand their design patent rights and maximize design benefits for their companies.

Background: Particle Reinforced Metal Matrix Composites (PRMMCs) are widely used because of the higher specific strength, better dimensional stability, lower thermal expansion coefficient, better wear and corrosion resistance. However, the existence of reinforcing particles makes it hard to machine. The main manifestations are as follows: severe tool wear, easy generation of debris tumors in processing, and many defects on the machined surface, etc. These seriously limit its wider application. The Finite Element Method (FEM) has been widely applied in the research of PRMMCs machining according to recent patents, which can improve the efficiency and reduce the cost of research. Therefore, it is necessary to carry out a deep research for the processing technology of PRMMCs. Methods: In this paper, the latest research progress of finite element simulation of cutting PRMMCs was summarized. The key technologies of finite element simulation, including constitutive model, geometric model, friction model between chip and tool, fracture criterion and mesh generation, are comprehensively analyzed and summarized. The application in the specific processing methods was discussed, such as turning, milling, grinding, ultrasonic vibration grinding and drilling. The existing problems and development direction of the simulation of PRMMCs cutting are also given. Besides, a lot of patents on finite element simulation for PRMMCs machining were studied. Results: Finite element model for the actual composition determines the accuracy of finite element simulation. Through the secondary development of finite element software, a more realistic finite element model of Particle reinforced metal matrix composites can be established. Conclusion: Finite Element Method (FEM) provides a new approach for the study of mechanism of Particle reinforced metal matrix composites machining. Quantitative analysis and prediction of micro- details in cutting can be realized.

Background: Ankle joint, as one of the important joints supporting the weight of human body, is vulnerable to injury in daily physical exercise and sports because of its special growth location and anatomical composition. The rehabilitation period of traumatic ankle is relatively long, especially in the later period of recovery. In order to relieve the clinical symptoms such as swelling and pain caused by ankle trauma, the rehabilitation of the ankle should be actively carried out by means of rehabilitation equipment. Thus, the ankle rehabilitation cycle can be minimized largely and the rehabilitation efficiency can be improved greatly. Objective: Through the summary of the latest literature on ankle rehabilitation devices, readers will be familiar with the research progress and difficulties in this field, and the reference for the followup study in this direction is provided. Methods: The structural characteristics and applications of the ankle rehabilitation devices are introduced in the paper. The latest patents and articles related to ankle rehabilitation device are compared and analyzed. Results: The ankle rehabilitation devices are classified according to the structure characteristics, driving mode and training function. The advantages and disadvantages of various devices are pointed out, and the future development direction of this research field is predicted. Conclusion: Studies show that remarkable improvements have been achieved on the ankle rehabilitation equipment. In the future, the structural optimization, new materials, control strategy, new type actuators, and rehabilitation evaluation of ankle rehabilitation devices should be further studied.

Background: Structural damage identification is a very important subject in the field of civil, mechanical and aerospace engineering according to recent patents. Optimal sensor placement is one of the key problems to be solved in structural damage identification. Methods: This paper presents a simple and convenient algorithm for optimizing sensor locations for structural damage identification. Unlike other algorithms found in the published papers, the optimization procedure of sensor placement is divided into two stages. The first stage is to determine the key parts in the whole structure by their contribution to the global flexibility perturbation. The second stage is to place sensors on the nodes associated with those key parts for monitoring possible damage more efficiently. With the sensor locations determined by the proposed optimization process, structural damage can be readily identified by using the incomplete modes yielded from these optimized sensor measurements. In addition, an Improved Ridge Estimate (IRE) technique is proposed in this study to effectively resist the data errors due to modal truncation and measurement noise. Two truss structures and a frame structure are used as examples to demonstrate the feasibility and efficiency of the presented algorithm. Results: From the numerical results, structural damages can be successfully detected by the proposed method using the partial modes yielded by the optimal measurement with 5% noise level. Conclusion: It has been shown that the proposed method is simple to implement and effective for structural damage identification.

Background: Reliability analysis for the systems with masked data had been studied by many scholars. However, most researches focused on a system that is either series or parallel only, and the component in the system is mainly exponential or Weibull. In engineering practice, it is often seen that the structure of a system is a combination of series and parallel system, and other types of components are also used in the system. So it is important to study the reliability analysis of hybrid systems with modified Weibull components. Objective: For the hybrid system with masked data, the constant stress partial accelerated life test is performed under type-II progressive hybrid censoring. These data from life test are used to estimate unknown parameters and reliability index of system. The research results will not only provide theoretical basis and reference for system reliability assessment but also favor the patents on partial accelerated life test. Methods: Maximum likelihood estimates of unknown parameters are investigated with the numerical method. The approximate confidence intervals, and bootstrap confidence intervals for parameters are constructed by the asymptotic theory and the bootstrap method, respectively. Results: Maximum likelihood estimations of unknown parameters and reliability index of system are derived. The approximate confidence intervals and bootstrap confidence intervals for unknown parameters are proposed. The performance of estimation of unknown parameters and reliability index are evaluated numerically through Monte Carlo method. Conclusion: The performance on maximum likelihood estimation method is effective and satisfying. For the confidence intervals of parameters, bootstrap method outperforms the approximate method.

Background: In recent years, many patents have been dedicated to increasing the rated power factor of generators. However, hydro-generators often encounter uncontrollable factors, such as dry season, power network adjustment, and so on, resulting in low power factor operation. In other words, the generator is often in a low power factor operating state. In order to provide data reference for power plant in regulating power factor, it is necessary to analyze the performance of generator in low power factor operation. Objective: The performance of the generator is analyzed when the power factor decreases, and the influence of low power factor operation on the generator is obtained. Methods: Taking a 24MW bulb tubular turbine generator as an example, a 2D transient electromagnetic field model is established. The correctness of the model is verified by comparing the test data and the simulation data. The torque, eddy current loss and air gap flux density of the generator under different power factor are calculated. Results: When the power factor deceases from 0.99 to 0.85, the air gap flux density increases from 0.713 T to 0.749 T, the torque ripple increases from 150.5 kNm to 179.9 kNm, and the rotor eddy current loss increases from 17.48 kW to 18.15 kW. Conclusion: The results show that the torque ripple and eddy current loss will increase with the decrease of power factor when the generator lagging phase operation. The torque ripple and eddy current loss increase by 3.8 % and 1 % respectively with the power factor decrease by 0.02 % with power factor between 0.99 and 0.85.

Background: Highly-inclined and horizontal wells have been widely used for the development of mature oilfield, marine oilfield, and low permeable oilfield. During drilling operations, cutting particles will accumulate in the low side of wellbore and cuttings bed may be formed, which may lead to high drag and torque, stuck pipe, and other drilling problems. We reviewed the patents about cutting bed cleaning tool. Objective: The goal of this work is to determine the incipient motion velocity or rate to re-suspend and remove the cutting particles. Methods: In this study, the random distribution function of particles is introduced to determine the percentage of incipient particle motion, and the mechanical models for rolling and lifting method considering the net gravity, drag force, lift force, additional mass force, adhesive force and flow pressure gradient force are developed to predict the incipient motion velocity or rate. Also, the model has been verified by published experimental data. Results: The critical particle size of incipient motion rate is approximately 1 mm. The incipient motion rate decreases as the height of cuttings bed decreases, and the minimum flow rate that prevents the bed formation may be estimated when bed height is small enough. Also, increasing wellbore inclination or fluid density has a positive effect on incipient motion rate, but increasing particle density or percentage of incipient particle motion has an adverse effect. Conclusion: This study may provide a guideline for designing hydraulic parameters and sand washing in the highly-inclined and horizontal wells, thereby contributingin economic production.

Background: In recent years, sudden deaths of primary and secondary school students caused by sports activities have drawn great attention in education and medical circles. It is necessary for schools to monitor the physical condition of the students in order to reasonably set the duration of their physical activity. At present, the physical condition monitoring instruments used in various hospitals are expensive, bulky, and difficult to operate, and the detection process is complicated. Therefore, existing approaches cannot meet the needs of physical education teachers on campus for detecting the physical condition of students. Methods: This study designs a portable human-physiological-state monitoring and analysis system. Real-time communication between a wearable measurement device and a monitoring device can be ensured by real-time detection of the environment and power control of the transmitted signal. Results: From a theoretical point of view, the larger the number of segments M, the more significantly the reduction of false alarm probability. The simulation results also show this fact. Compared with the conventional early warning mechanism, the probability of a false alarm for the proposed system is lower, and the greater the number of segments, the faster its reaction speed. Conclusion: The portable monitoring system of student physical condition for use in physical education of primary and middle school students proposed in this paper ensures real-time monitoring of the members within the system in an open environment, and further proposes an early warning mechanism for combining multiple vital sign parameters. In addition, the proposed system functions faster; the average early warning time required is only one-quarter of that of the conventional system.

Background: The wind turbine is divided into a horizontal axis and a vertical axis depending on the relative positions of the rotating shaft and the ground. The advantage of the choke wind turbine is that the starting torque is large and the starting performance is good. The disadvantage is that the rotation resistance is large, the rotation speed is low, the asymmetric flow occurs when the wind wheel rotates, the lateral thrust is generated, and the wind energy utilization rate is lowered. How to improve the wind energy utilization rate of the resistance wind turbine is an important issue to be solved by the wind power technology. Objective: The nautilus isometric spiral wind turbines studied in this paper have been introduced and analyzed in detail, preparing for the further flow analysis and layout of wind turbines, improving the wind energy utilization rate of wind turbines, introducing patents of other structures and output characteristics of its generator set. Methods: Combined with the flow field analysis of ANSYS CFX software, the numerical simulation of the new wind turbine was carried out, and the aerodynamic performance of the new vertical axis wind turbine was analyzed. The mathematical model and control model of the generator were established by the maximum power control method, and the accuracy of the simulation results was verified by the measured data. Results: The basic parameters of the new wind turbine tip speed ratio, torque coefficient and wind energy utilization coefficient are analyzed. Changes in wind speed, pressure and eddy viscosity were investigated. Three-dimensional distribution results of wake parameters such as wind speed and pressure are obtained. By simulating the natural wind speed, the speed and output current of the generator during normal operation are obtained. Conclusion: By analyzing the wind performance and power generation characteristics of the new wind turbine, the feasibility of the new wind turbine is determined, which provides reference and reference for the optimal design and development of the wind turbine structure.

Background: The study of kerosene fuel for gasoline engines is of great significance to the supply, management, storage and transportation of military fuel, as well as its safety. Small aviation two-stroke kerosene engine fuel injection controller is the key technology of kerosene engines. It is very important to improve the performance of kerosene engine by controlling the air-fuel ratio accurately. Objective: The initial injection pulse spectrum was firstly obtained by numerical calculation in the absence of kerosene injection pulse spectrum, and then the injection controller was designed based on the initial injection pulse spectrum. Methodology: Firstly, a numerical model of the whole engine was established by using BOOST software. The air mass flow data of the inlet was obtained through numerical calculation. The amount of initial engine fuel injection was calculated according to the requirements of air-fuel ratios in each working condition, from which an initial injection pulse spectrum was obtained. Then, based on Free scale 16-bit embedded micro-controller MC9S12DP512, a kerosene engine fuel injection controller was developed, together with the circuit was also designed. According to the initial fuel injection pulse spectrum, a two-dimensional interpolation algorithm was developed by using assembly language and C language mixed programming, and the anti-electromagnetic interference ability of the controller was further enhanced. Finally, the accuracy of the initial injection pulse spectrum and the performance and reliability of the injection controller of the kerosene engine were verified by the kerosene engine bench test. Conclusion: The experimental results show that the numerical model was accurate, and the development time of the injection controller was shortened by using the numerical model to calculate the initial injection pulse spectra. The developed controller was stable and reliable, which can meet the control requirement.