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A pneumatic cylinder driving polyhedron mobile mechanism

Wan DING, Sung-Chan KIM, Yan-An YAO

《机械工程前沿(英文)》 2012年 第7卷 第1期   页码 55-65 doi: 10.1007/s11465-012-0301-z

摘要:

A novel pneumatic cylinder driving polyhedron mobile mechanism is proposed in this paper. The mechanism is comprised of 5 tetrahedrons which includes a pneumatic cylinder in each edge. It locomotes by rolling and the rolling principle refers to the center of mass (CM) of the mechanism moved out of the supporting area and let it tip over through the controlling of the motion sequence of these cylinders. Firstly, the mathematical model is built to analysis the relation between the configuration and the CM of the mechanism. Then, a binary control strategy is developed to simplify and improve the control of this mobile mechanism. After that, dynamic simulation is performed to testify the analytical validity and feasibility of the rolling gaits. At last, a prototype is fabricated to achieve the rolling successfully to demonstrate the proposed concept.

关键词: mobile mechanism     polyhedron     cylinder    

Novel probabilistic rolling regular tetrahedron mechanism

Yonghan GUAN, Yan’an YAO, Chao LIU, Ruiming LI

《机械工程前沿(英文)》 2021年 第16卷 第2期   页码 363-378 doi: 10.1007/s11465-020-0628-9

摘要: With recent relevant publications on stochastic motion robots in , , and other journals, research on such robots has gained increasing attention. However, theoretical and applied research on stochastic motion in the field of robotics and mechanisms face many challenges due to the uncertainty of stochastic motion. Currently, a large gap remains in the research of stochastic motion mechanism. In this study, a novel mechanism that can conduct probabilistic rolling is proposed to reach a designated position and achieve overlying movement over a particular area. The mechanism consists of a regular tetrahedron frame, a central node, and four connecting linear actuators. According to mobility and kinematic analyses, the mechanism can implement probabilistic rolling. Each rolling gait has three probable rolling directions, and the mechanism rolls in one of the three directions in probability. A kinematic simulation is conducted, and a control method is proposed on the basis of the moving path analysis. Furthermore, the mathematical principle of probabilistic rolling is revealed in terms of probability theory and statistics. Lastly, a prototype is fabricated. To achieve the rolling function, the design of the linear actuators is improved, and the extension ratio is increased from 0.58 to 1.13. Then, tests are conducted. In a 4 m test site, the mechanism makes 11 moves to reach the target position and covers 29.25% of the site.

关键词: mobile mechanism     probabilistic motion     rolling mechanism     stochastic motion    

Design and locomotion analysis of two kinds of rolling expandable mobile linkages with a single degree

Yanlin HAO, Yaobin TIAN, Jianxu WU, Yezhuo LI, Yan-An YAO

《机械工程前沿(英文)》 2020年 第15卷 第3期   页码 365-373 doi: 10.1007/s11465-020-0585-3

摘要: This study presents two kinds of rolling robots that are able to roll by deforming their outer shapes with a single degree of freedom. Each robot is an essential multi-loop planar expandable linkage constructed by a concave outer loop and several inner parallelogram loops. In this study, the mechanical design of the robots is introduced. Dynamic rolling process is further analyzed on the basis of zero moment point method, and a morphing strategy is proposed to guarantee a stable dynamic rolling process. A novel passive rolling locomotion is also developed, which enables the robots to roll and stand on a slope. To verify the design, two prototypes are manufactured, wherein the dynamic and passive rolling locomotion are carried out.

关键词: rolling locomotion     expandable mechanism     mechanism design     zero moment point (ZMP) analysis    

A novel six-legged walking machine tool for

Jimu LIU, Yuan TIAN, Feng GAO

《机械工程前沿(英文)》 2020年 第15卷 第3期   页码 351-364 doi: 10.1007/s11465-020-0594-2

摘要: The manufacture and maintenance of large parts in ships, trains, aircrafts, and so on create an increasing demand for mobile machine tools to perform operations. However, few mobile robots can accommodate the complex environment of industrial plants while performing machining tasks. This study proposes a novel six-legged walking machine tool consisting of a legged mobile robot and a portable parallel kinematic machine tool. The kinematic model of the entire system is presented, and the workspace of different components, including a leg, the body, and the head, is analyzed. A hierarchical motion planning scheme is proposed to take advantage of the large workspace of the legged mobile platform and the high precision of the parallel machine tool. The repeatability of the head motion, body motion, and walking distance is evaluated through experiments, which is 0.11, 1.0, and 3.4 mm, respectively. Finally, an application scenario is shown in which the walking machine tool steps successfully over a 250 mm-high obstacle and drills a hole in an aluminum plate. The experiments prove the rationality of the hierarchical motion planning scheme and demonstrate the extensive potential of the walking machine tool for operations on large parts.

关键词: legged robot     parallel mechanism     mobile machine tool     in-situ machining    

Research and practice on system engineering management of a mobile payment project

Yongkai ZHOU, Hongfeng CHAI

《工程管理前沿(英文)》 2017年 第4卷 第2期   页码 127-137 doi: 10.15302/J-FEM-2017011

摘要: The popularization of the mobile internet has given rise to demand for flexible and convenient payment methods. For China, it is necessary to keep pace with or even lead the trend of innovation and development in the age of mobile payment. From the perspective of systems engineering, this paper introduces research and implementation of China UnionPay’s mobile payment project. The general requirements and core engineering problems of the mobile payment project are summarized based on analyses of the characteristics and engineering difficulties of this project. Integration of innovative technologies is introduced to resolve the contradiction between ease-of-use and security. A rapid iterative development process is adopted to improve the product release efficiency as well as the users' experience. The launch of the mobile payment project also opens the window to coordinating and upgrading the whole payment industry chains.

关键词: systems engineering     mobile payment     engineering management method     Mobile QuickPass     national information security     rapid iteration process     financial security     coordination and cooperation    

Motion control of multi-actuator hydraulic systems for mobile machineries: Recent advancements and future

Bing XU, Min CHENG

《机械工程前沿(英文)》 2018年 第13卷 第2期   页码 151-166 doi: 10.1007/s11465-018-0470-5

摘要:

This paper presents a survey of recent advancements and upcoming trends in motion control technologies employed in designing multi-actuator hydraulic systems for mobile machineries. Hydraulic systems have been extensively used in mobile machineries due to their superior power density and robustness. However, motion control technologies of multi-actuator hydraulic systems have faced increasing challenges due to stringent emission regulations. In this study, an overview of the evolution of existing throttling control technologies is presented, including open-center and load sensing controls. Recent advancements in energy-saving hydraulic technologies, such as individual metering, displacement, and hybrid controls, are briefly summarized. The impact of energy-saving hydraulic technologies on dynamic performance and control solutions are also discussed. Then, the advanced operation methods of multi-actuator mobile machineries are reviewed, including coordinated and haptic controls. Finally, challenges and opportunities of advanced motion control technologies are presented by providing an overall consideration of energy efficiency, controllability, cost, reliability, and other aspects.

关键词: motion control     electrohydraulic control     energy efficiency     mobile machineries    

A new efficient optimal path planner for mobile robot based on Invasive Weed Optimization algorithm

Prases K. MOHANTY,Dayal R. PARHI

《机械工程前沿(英文)》 2014年 第9卷 第4期   页码 317-330 doi: 10.1007/s11465-014-0304-z

摘要:

Planning of the shortest/optimal route is essential for efficient operation of autonomous mobile robot or vehicle. In this paper Invasive Weed Optimization (IWO), a new meta-heuristic algorithm, has been implemented for solving the path planning problem of mobile robot in partially or totally unknown environments. This meta-heuristic optimization is based on the colonizing property of weeds. First we have framed an objective function that satisfied the conditions of obstacle avoidance and target seeking behavior of robot in partially or completely unknown environments. Depending upon the value of objective function of each weed in colony, the robot avoids obstacles and proceeds towards destination. The optimal trajectory is generated with this navigational algorithm when robot reaches its destination. The effectiveness, feasibility, and robustness of the proposed algorithm has been demonstrated through series of simulation and experimental results. Finally, it has been found that the developed path planning algorithm can be effectively applied to any kinds of complex situation.

关键词: mobile robot     obstacle avoidance     Invasive Weed Optimization     navigation    

Output tracking control of mobile manipulators based on dynamical sliding-mode control

WUYuxiang, FENG Ying, HU Yueming

《机械工程前沿(英文)》 2007年 第2卷 第1期   页码 110-115 doi: 10.1007/s11465-007-0019-5

摘要: A dynamical sliding-mode controller is devised to track the output of mobile manipulators. During the investigation, firstly a reduced dynamic model considering the dynamics of the driving motor is developed for mobile manipulators. Then, the system is decomposed into four lower-dimensional subsystems by means of diffeomorphism and nonlinear input transformation. Moreover, a design method of the dynamical sliding-mode controller that is applied to the output tracking of mobile manipulators is proposed. The simulation results indicate that the dynamical sliding-mode controller can not only track the given trajectory correctly but also reduce the chattering of sliding-mode control system considerably.

关键词: lower-dimensional     nonlinear     trajectory     tracking     diffeomorphism    

Assessment of mobile and potential mobile trace elements extractability in calcareous soils using different

Mohsen Jalali, Ziba Hurseresht

《环境科学与工程前沿(英文)》 2020年 第14卷 第1期 doi: 10.1007/s11783-019-1186-4

摘要: DTPA and NH4OAc, HNO3 and EDTA, and MgCl2 and NH4NO3 had similar behavior. In NH4OAc, DTPA, and EDTA, the possibility of re-adsorption of trace elements is low. CaCl2 may be more suitable than other extracts in calcareous soils. Understanding trace elements mobility in soils, extracting agents, and their relationships with soil components, are essential for predicting their movement in soil profile and availability to plants. A laboratory study was conducted to evaluate extractability of cadmium (Cd), cobalt (Co), copper (Cu), nickel (Ni), and zinc (Zn) from calcareous soils utilizing various extracting agents to be specific CaCl2, DTPA, EDTA, HNO3, MgCl2, NaNO3, NH4NO3, and NH4OAc. Cluster analysis indicated that DTPA and NH4OAc, HNO3 and EDTA, and MgCl2 and NH4NO3 extracting agents yielded comparative values, whereas NaNO3 and CaCl2 have shown different behavior than other extracting agents for all studied trace elements. The speciation of extracted trace elements in solutions indicated that in the CaCl2, NaNO3, NH4NO3, and MgCl2 extracting agents most extracted Cd, Co, Ni, Zn, and part of Cu were as free ions and may be re-adsorbed on soils, leading to lower extractability, whereas, in the case of HNO3 extracting agent, the likelihood of re-adsorption of trace elements may be little. The results of speciation of trace elements using NH4OAc, DTPA, and EDTA extracting agents showed that Me-(Acetate)3–, Me-(Acetate)2(aq), Me(DTPA)3−, Me(EDTA)2−, and MeH(EDTA)– complexes dominated in solutions indicating that the extracted trace elements may not be re-adsorbed on soils, leading to higher extractability. The results of this study are useful for short and long-term evaluations of trace elements mobility and further environmental impacts.

关键词: Mobility     Calcareous soils     Extracting agents     Trace elements    

Analyzing the service availability of mobile cloud computing systems by fluid-flow approximation

Hong-wu LV,Jun-yu LIN,Hui-qiang WANG,Guang-sheng FENG,Mo ZHOU

《信息与电子工程前沿(英文)》 2015年 第16卷 第7期   页码 553-567 doi: 10.1631/FITEE.1400410

摘要: Mobile cloud computing (MCC) has become a promising technique to deal with computation- or data-intensive tasks. It overcomes the limited processing power, poor storage capacity, and short battery life of mobile devices. Providing continuous and on-demand services, MCC argues that the service must be available for users at anytime and anywhere. However, at present, the service availability of MCC is usually measured by some certain metrics of a real-world system, and the results do not have broad representation since different systems have different load levels, different deployments, and many other random factors. Meanwhile, for large-scale and complex types of services in MCC systems, simulation-based methods (such as Monte-Carlo simulation) may be costly and the traditional state-based methods always suffer from the problem of state-space explosion. In this paper, to overcome these shortcomings, fluid-flow approximation, a breakthrough to avoid state-space explosion, is adopted to analyze the service availability of MCC. Four critical metrics, including response time of service, minimum sensing time of devices, minimum number of nodes chosen, and action throughput, are defined to estimate the availability by solving a group of ordinary differential equations even before the MCC system is fully deployed. Experimental results show that our method costs less time in analyzing the service availability of MCC than the Markov- or simulation-based methods.

关键词: Service availability     Mobile cloud computing     Fluid-flow approximation     Ordinary differential equations    

Human power-based energy harvesting strategies for mobile electronic devices

Dewei JIA, Jing LIU

《能源前沿(英文)》 2009年 第3卷 第1期   页码 27-46 doi: 10.1007/s11708-009-0002-4

摘要: Energy problems arise with the proliferation of mobile electronic devices, which range from entertainment tools to life saving medical instruments. The large amount of energy consumption and increasing mobility of electronic devices make it urgent that new power sources should be developed. It has been gradually recognized that the human body is highly flexible in generating applicable power from sources of heat dissipation, joint rotation, enforcement of body weight, vertical displacement of mass centers, and even elastic deformation of tissues and other attachments. These basic combinations of daily activities or metabolic phenomena open up possibilities for harvesting energy which is strong enough to power mobile or even implantable medical devices which could be used for a long time or be recharged permanently. A comprehensive review is presented in this paper on the latest developed or incubating electricity generation methods based on human power which would serve as promising candidates for future mobile power. Thermal and mechanical energy, investigated more thoroughly so far, will particularly be emphasized. Thermal energy relies on body heat and employs the property of thermoelectric materials, while mechanical energy is generally extracted in the form of enforcement or displacement excitation. For illustration purposes, the piezoelectric effect, dielectric elastomer and the electromagnetic induction couple, which can convert force directly into electricity, were also evaluated. Meanwhile, examples are given to explain how to adopt inertia generators for converting displacement energy via piezoelectric, electrostatic, electromagnetic or magnetostrictive vibrators. Finally, future prospects in harvesting energy from human power are made in conclusion.

关键词: mobile electronic device     human power     energy harvesting     micro/miniaturized generator     battery     green energy    

Biomedical sensor technologies on the platform of mobile phones

Lin LIU, Jing LIU

《机械工程前沿(英文)》 2011年 第6卷 第2期   页码 160-175 doi: 10.1007/s11465-011-0216-0

摘要:

Biomedical sensors have been widely used in various areas of biomedical practices, which play an important role in disease detection, diagnosis, monitoring, treatment, health management, and so on. However, most of them and their related platforms are generally not easily accessible or just too expensive or complicated to be kept at home. As an alternative, new technologies enabled from the mobile phones are gradually changing such situations. As can be freely available to almost everyone, mobile phone offers a unique way to improve the conventional medical care through combining with various biomedical sensors. Moreover, the established systems will be both convenient and low cost. In this paper, we present an overview on the state-of-art biomedical sensors, giving a brief introduction of the fundamental principles and showing several new examples or concepts in the area. The focus was particularly put on interpreting the technical strategies to innovate the biomedical sensor technologies based on the platform of mobile phones. Some challenging issues, including feasibility, usability, security, and effectiveness, were discussed. With the help of electrical and mechanical technologies, it is expected that a full combination between the biomedical sensors and mobile phones will bring a bright future for the coming pervasive medical care.

关键词: biomedical sensor     pervasive technology     mobile phone     combined system     health management    

Emerging technologies to power next generation mobile electronic devices using solar energy

Dewei JIA , Yubo DUAN , Jing LIU ,

《能源前沿(英文)》 2009年 第3卷 第3期   页码 262-288 doi: 10.1007/s11708-009-0015-z

摘要: Mobile electronic devices such as MP3, mobile phones, and wearable or implanted medical devices have already or will soon become a necessity in peoples’ lives. However, the further development of these devices is restricted not only by the inconvenient charging process of the power module, but also by the soaring prices of fossil fuel and its downstream chain of electricity manipulation. In view of the huge amount of solar energy fueling the world biochemically and thermally, a carry-on electricity harvester embedded in portable devices is emerging as a most noteworthy research area and engineering practice for a cost efficient solution. Such a parasitic problem is intrinsic in the next generation portable devices. This paper is dedicated to presenting an overview of the photovoltaic strategy in the chain as a reference for researchers and practitioners committed to solving the problem.

关键词: photovoltaic conversion     energy harvesting     solar cell     maximum power point track algorithm     PV electricity storage     mobile/standalone PV application    

Development of mobile miniature natural gas liquefiers

Yanxing ZHAO, Maoqiong GONG, Haocheng WANG, Hao GUO, Xueqiang DONG

《能源前沿(英文)》 2020年 第14卷 第4期   页码 667-682 doi: 10.1007/s11708-020-0695-y

摘要: With increasing consumption of natural gas (NG), small NG reservoirs, such as coalbed methane and oil field associated gas, have recently drawn significant attention. Owing to their special characteristics (e.g., scattered distribution and small output), small-scale NG liquefiers are highly required. Similarly, the mixed refrigerant cycle (MRC) is suitable for small-scale liquefaction systems due to its moderate complexity and power consumption. In consideration of the above, this paper reviews the development of mobile miniature NG liquefiers in Technical Institute of Physics and Chemistry (TIPC), China. To effectively liquefy the scattered NG and overcome the drawbacks of existing technologies, three main improvements, i.e., low-pressure MRC process driven by oil-lubricated screw compressor, compact cold box with the new designed heat exchangers, and standardized equipment manufacturing and integrated process technology have been made. The development pattern of “rapid cluster application and flexible liquefaction center” has been eventually proposed. The small-scale NG liquefier developed by TIPC has reached a minimum liquefaction power consumption of about 0.35 kW·h/Nm . It is suitable to exploit small remote gas reserves which can also be used in boil-off gas reliquefaction and distributed peak-shaving of pipe networks.

关键词: natural gas     mobile miniature liquefiers     mixed refrigerant cycle     vapor liquid equilibrium     heat transfer    

Comparison of the performance of traditional advection-dispersion equation and mobile-immobile model

Haizhu HU,Xiaomin MAO

《农业科学与工程前沿(英文)》 2016年 第3卷 第3期   页码 241-248 doi: 10.15302/J-FASE-2016108

摘要: The traditional advection-dispersion equation (ADE) and the mobile-immobile model (MIM) are widely used to describe solute transport in heterogeneous porous media. However, the fitness of the two models is case-dependent. In this paper, the transport of conservative, adsorbing and degradable solutes through a 1 m heterogeneous soil column under steady flow condition was simulated by ADE and MIM, and sensitivity analysis was conducted. Results show that MIM tends to prolong the breakthrough process and decrease peak concentration for all three solutes, and tailing and skewness are more pronounced with increasing dispersivity. Breakthrough curves of the adsorbing solute simulated by MIM are less sensitive to the retardation factor compared with the results simulated by ADE. The breakthrough curves of degradable solute obtained by MIM and ADE nearly overlap with a high degradation rate coefficient, indicating that MIM and ADE perform similarly for simulating degradable solute transport when biochemical degradation prevails over the mass exchange between mobile and immobile zones. The results suggest that the physical significance of dispersivity should be carefully considered when MIM is applied to simulate the degradable solute transport and/or ADE is applied to simulate the adsorbing solute transport in highly dispersive soils.

关键词: solute transport     advection dispersion equation (ADE)     mobile-immobile model (MIM)     conservative solute     adsorbing solute     degradable solute     PHREEQC-2    

标题 作者 时间 类型 操作

A pneumatic cylinder driving polyhedron mobile mechanism

Wan DING, Sung-Chan KIM, Yan-An YAO

期刊论文

Novel probabilistic rolling regular tetrahedron mechanism

Yonghan GUAN, Yan’an YAO, Chao LIU, Ruiming LI

期刊论文

Design and locomotion analysis of two kinds of rolling expandable mobile linkages with a single degree

Yanlin HAO, Yaobin TIAN, Jianxu WU, Yezhuo LI, Yan-An YAO

期刊论文

A novel six-legged walking machine tool for

Jimu LIU, Yuan TIAN, Feng GAO

期刊论文

Research and practice on system engineering management of a mobile payment project

Yongkai ZHOU, Hongfeng CHAI

期刊论文

Motion control of multi-actuator hydraulic systems for mobile machineries: Recent advancements and future

Bing XU, Min CHENG

期刊论文

A new efficient optimal path planner for mobile robot based on Invasive Weed Optimization algorithm

Prases K. MOHANTY,Dayal R. PARHI

期刊论文

Output tracking control of mobile manipulators based on dynamical sliding-mode control

WUYuxiang, FENG Ying, HU Yueming

期刊论文

Assessment of mobile and potential mobile trace elements extractability in calcareous soils using different

Mohsen Jalali, Ziba Hurseresht

期刊论文

Analyzing the service availability of mobile cloud computing systems by fluid-flow approximation

Hong-wu LV,Jun-yu LIN,Hui-qiang WANG,Guang-sheng FENG,Mo ZHOU

期刊论文

Human power-based energy harvesting strategies for mobile electronic devices

Dewei JIA, Jing LIU

期刊论文

Biomedical sensor technologies on the platform of mobile phones

Lin LIU, Jing LIU

期刊论文

Emerging technologies to power next generation mobile electronic devices using solar energy

Dewei JIA , Yubo DUAN , Jing LIU ,

期刊论文

Development of mobile miniature natural gas liquefiers

Yanxing ZHAO, Maoqiong GONG, Haocheng WANG, Hao GUO, Xueqiang DONG

期刊论文

Comparison of the performance of traditional advection-dispersion equation and mobile-immobile model

Haizhu HU,Xiaomin MAO

期刊论文