Power equipment vibration visualization using intelligent sensing method based on event-sensing principle

Vibration measurements can be used to evaluate the operation status of power equipment and are widely applied in equipment quality inspection and fault identification.Event-sensing technology can sense the change in surface light intensity caused by object vibration and provide a visual description of vibration behavior.Based on the analysis of the principle underlying the transformation of vibration behavior into event flow data by an event sensor,this paper proposes an algorithm to reconstruct event flow data into a relationship correlating vibration displacement and time to extract the amplitude-frequency characteristics of the vibration signal.A vibration measurement test platform is constructed,and feasibility and effectiveness tests are performed for the vibration motor and other power equipment.The results show that event-sensing technology can effectively perceive the surface vibration behavior of power and provide a wide dynamic range.Furthermore,the vibration measurement and visualization algorithm for power equipment constructed using this technology offers high measurement accuracy and efficiency.The results of this study provide a new noncontact and visual method for locating vibrations and performing amplitude-frequency analysis on power equipment.

Adaptive and distance-driven power control scheme in mobile ad hoc networks

In order to save the energy and reduce the latency of the end-to-end transmission in mobile ad hoc networks an adaptive and distance-driven power control ADPC scheme is proposed by means of distance research in random geometrics. Through mathematical proof the optimal number of relay nodes and the optimal location of each node for data transmission can be obtained when a distance is given.In the ADPC first the source node computes the optimal number and the sites of the relay nodes between the source and the destination nodes.Then it searches feasible relay nodes around the optimal virtual relay-sites and selects one link with the minimal total transmission energy consumption for data transmission.Simulation results show that the ADPC can reduce both the energy dissipation and the end-to-end latency of the transmission.

Mobile Jammer-Aided Secure UAV Communications via Trajectory Design and Power Control

To further promote the achievable average secrecy rate for UAV-ground communications, a UAV-aided mobile jamming strategy was proposed in this paper. Specifically, an additional cooperative UAV is employed as a mobile jammer to transmit the jamming signal to help keep the source UAV closer to the ground destination, thus establishing more favorable legitimate link and enhancing the secrecy performance. We aimed to maximize the achievable secrecy rate by jointly optimizing the trajectories and transmit power of both source UAV and jammer UAV. To solve the considered non-convex optimization problem, we presented a block coordinate descent based iterative algorithm to address a sequence of approximated convex problems for the optimized parameter block by block to find a local optimal solution. Numerical results verify that the proposed algorithm can achieve significant secrecy rate gain compared to all the benchmark schemes.

Online Computation Offloading and Trajectory Scheduling for UAV-Enabled Wireless Powered Mobile Edge Computing

The unmanned aerial vehicle(UAV)-enabled mobile edge computing(MEC) architecture is expected to be a powerful technique to facilitate 5 G and beyond ubiquitous wireless connectivity and diverse vertical applications and services, anytime and anywhere. Wireless power transfer(WPT) is another promising technology to prolong the operation time of low-power wireless devices in the era of Internet of Things(IoT). However, the integration of WPT and UAV-enabled MEC systems is far from being well studied, especially in dynamic environments. In order to tackle this issue, this paper aims to investigate the stochastic computation offloading and trajectory scheduling for the UAV-enabled wireless powered MEC system. A UAV offers both RF wireless power transmission and computation services for IoT devices. Considering the stochastic task arrivals and random channel conditions, a long-term average energyefficiency(EE) minimization problem is formulated.Due to non-convexity and the time domain coupling of the variables in the formulated problem, a lowcomplexity online computation offloading and trajectory scheduling algorithm(OCOTSA) is proposed by exploiting Lyapunov optimization. Simulation results verify that there exists a balance between EE and the service delay, and demonstrate that the system EE performance obtained by the proposed scheme outperforms other benchmark schemes.

Power Consumption Characteristics Research on Mobile System of Electrically Driven Large-Load-Ratio Six-Legged Robot

The electrically driven large-load-ratio six-legged robot with engineering capability can be widely used in outdoor and planetary exploration.However,due to the particularity of its parallel structure,the effective utilization rate of energy is not high,which has become an important obstacle to its practical application.To research the power consumption characteristics of robot mobile system is beneficial to speed up it toward practicability.Based on the configuration and walking modes of robot,the mathematical model of the power consumption of mobile system is set up.In view of the tripod gait is often selected for the six-legged robots,the simplified power consumption model of mobile system under the tripod gait is established by means of reducing the dimension of the robot’s statically indeterminate problem and constructing the equal force distribution.Then,the power consumption of robot mobile system is solved under different working conditions.The variable tendencies of the power consumption of robot mobile system are respectively obtained with changes in the rotational angles of hip joint and knee joint,body height,and span.The articulated rotational zones and the ranges of body height and span are determined under the lowest power consumption.According to the walking experiments of prototype,the variable tendencies of the average power consumption of robot mobile system are respectively acquired with changes in duty ratio,body height,and span.Then,the feasibility and correctness of theory analysis are verified in the power consumption of robot mobile system.The proposed analysis method in this paper can provide a reference on the lower power research of the large-load-ratio multi-legged robots.

Computation Rate Maximization in Multi-User Cooperation-Assisted Wireless-Powered Mobile Edge Computing with OFDMA

In the era of Internet of Things(Io T),mobile edge computing(MEC)and wireless power transfer(WPT)provide a prominent solution for computation-intensive applications to enhance computation capability and achieve sustainable energy supply.A wireless-powered mobile edge computing(WPMEC)system consisting of a hybrid access point(HAP)combined with MEC servers and many users is considered in this paper.In particular,a novel multiuser cooperation scheme based on orthogonal frequency division multiple access(OFDMA)is provided to improve the computation performance,where users can split the computation tasks into various parts for local computing,offloading to corresponding helper,and HAP for remote execution respectively with the aid of helper.Specifically,we aim at maximizing the weighted sum computation rate(WSCR)by optimizing time assignment,computation-task allocation,and transmission power at the same time while keeping energy neutrality in mind.We transform the original non-convex optimization problem to a convex optimization problem and then obtain a semi-closed form expression of the optimal solution by considering the convex optimization techniques.Simulation results demonstrate that the proposed multi-user cooperationassisted WPMEC scheme greatly improves the WSCR of all users than the existing schemes.In addition,OFDMA protocol increases the fairness and decreases delay among the users when compared to TDMA protocol.

Resonant-Inductive Wireless Power Transfer for Autonomous Mobile Robots

Due to the increasing commercial interest in autonomy and sustainability,this paper reviews and presents a comprehensive summary of the resonant-inductive power transmission(RPT)technology for autonomous mobile robots.It outlines historic and recent research activities in wireless power transmission,covering the fundamental operation of microwave,capacitive and inductive power transfer technologies,state-of-the-art developments in RPT for high-power applications,current design and health standards,technological drawbacks,and possible future trends.In this paper,coupling-enhanced pad designs,adaptive tuning techniques,compensation network designs,and control techniques are explored.Major design issues such as coupling variation,frequency splitting,and bifurcation are reviewed.The difference between maximum power transfer and maximum energy efficiency is highlighted.Human exposure guidelines are summarized from documentations provided by the Institute of Electrical and Electronics Engineers(IEEE)and the International Commission on Non-ionizing Radiation Protection(ICNIRP).Other standards like WPC’s Qi and Airfuel design standards are also summarized.Finally,the possible trends of the relevant research and development,particularly dynamic charging,are discussed.The intention of this review is to encourage designs that will relieve robot operators of the burden of frequent manual recharging,and to reduce downtime and increase the productivity of autonomous mobile robots in industrial environments.

Novel Technological Developments with Impacts on Perspectives for Mobile Nuclear Power Plants

New research developments suggest that nuclear reactors using fusion may enter the market sooner than imagined even for mobile applications, like merchant ship propulsion and remote power generation. This article aims at pointing such developments and how they could affect nuclear fusion. The method is enumerating the main nuclear reactors concepts, identifying new technological or theoretical developments useful to nuclear field, and analysing how new recombination could affect feasibility of nuclear fusion. New technologies or experimental results do not always work the way people imagine, being better or worse for intended effects or even bringing completely unforeseen effects. Results point the following designs could be successful, in descending order of potential: aneutronic nuclear reactions using lattice confinement, aneutronic nuclear reactions using inertial along magnetic confinement, hybrid fission-lattice confinement fusion, and fission reactions.

Performance of joint dual links dynamic power control and smart antenna for TDMA/TDD cellular mobile communications

Interference cancellation is made available by using smart antenna at cellular base stations. Well distributed cumulative probability of signal to interference plus noise power ratio appears to be vital for cellular mobile multimedia communications. A scenario of dual links dynamic power control combined to a solution of smart antenna is proposed to adjust the instant transmission power in terms of the disparity from the favorite range. Simulation results show that this method is quite effective to improve the cumulative distribution probability performance. Meanwhile, accompanying low power consumption is also obtained at both base stations and mobile stations.

A Multi-mode Electronic Load Sensing Control Scheme with Power Limitation and Pressure Cut-off for Mobile Machinery

In mobile machinery,hydro-mechanical pumps are increasingly replaced by electronically controlled pumps to improve the automation level,but diversified control functions(e.g.,power limitation and pressure cut-off)are integrated into the electronic controller only from the pump level,leading to the potential instability of the overall system.To solve this problem,a multi-mode electrohydraulic load sensing(MELS)control scheme is proposed especially considering the switching stability from the system level,which includes four working modes of flow control,load sensing,power limitation,and pressure control.Depending on the actual working requirements,the switching rules for the different modes and the switching direction(i.e.,the modes can be switched bilaterally or unilaterally)are defined.The priority of different modes is also defined,from high to low:pressure control,power limitation,load sensing,and flow control.When multiple switching rules are satisfied at the same time,the system switches to the control mode with the highest priority.In addition,the switching stability between flow control and pressure control modes is analyzed,and the controller parameters that guarantee the switching stability are obtained.A comparative study is carried out based on a test rig with a 2-ton hydraulic excavator.The results show that the MELS controller can achieve the control functions of proper flow supplement,power limitation,and pressure cut-off,which has good stability performance when switching between different control modes.This research proposes the MELS control method that realizes the stability of multi-mode switching of the hydraulic system of mobile machinery under different working conditions.

Mobile user forecast and power-law acceleration invariance of scale-free networks

This paper studies and predicts the number growth of China＇s mobile users by using the power-law regression. We find that the number growth of the mobile users follows a power law. Motivated by the data on the evolution of the mobile users, we consider scenarios of self-organization of accelerating growth networks into scale-free structures and propose a directed network model, in which the nodes grow following a power-law acceleration. The expressions for the transient and the stationary average degree distributions are obtained by using the Poisson process. This result shows that the model generates appropriate power-law connectivity distributions. Therefore, we find a power-law acceleration invariance of the scale-free networks. The numerical simulations of the models agree with the analytical results well.

A Power Line-delivered and Lamp-based Broadband Mobile Communication System

A new mobile communications network architecture is proposed to solve four existing bottlenecks that restrict the rapid development of mobile communications,as well as to meet the development demands of future broadband mobile communications. The architecture introduces the Information Lamp (IL),a novel device carrying out transceiver function,as the access point,besides providing light. It fulfills information interaction between the access points and radio access network through the power line (or fiber). The new system,supported by core technologies such as multi-antenna based distributed space-time signal processing and distributed radio resource management,integrates the wired and wireless networks to provide high-speed and high-quality mobile communication services.

Manufacture and Export of Complete Power Equipment

Through construction during over four decades, remarkable achievements have been made by China’s manufacturing industry of complete sets of power equipment. During the Seventh Five-Year Plan period, over RMB2 billion and several hundred million US dollars were invested in the introduction

Development of welding technology of hydroelectric power equipment

Hydroelectric power equipment consists of a hydro-turbine and a hydrogenerator whose weldments have the features of complicated construction and large bulk as well as some parts operating under water. With the increase of unit rating of the hydroelectric power equipment, the application field of high strength steel and dissimilar steel has been enlarged. What to be introduced in this paper is the development of the welding technology of large hydroelectric generating equipment in China since the 1970s, and the development orientation of its welding construction and procedure in the future.

Shanghai Electric (Group) Corp.- The pioneer of Power Equipment Manufacturing in China

Shanghai Electric (Group) Corporation (SEC) is a large-scale industrial enterprise group in China engaged in design and manufacturing of power generation equipment, power transmission and distribution equipment and heavy machinery equipment. SEC is separately catalogued in the program of the State Planning Commission. Based on its main economic norms, SEC is listed as one of the 500

基于MobileNet的电力设备图像识别

针对全社会用电量需求的增大所引起的电力输送和用电安全与人力维护的成本较高等问题,借助图像增强技术与深度学习技术实现对电力设备图像的识别与分析。首先,利用图像增强技术完成对电力设备图像集的扩充和增强;其次,搭建MobileNet卷积神经网络完成对电力设备图像进行数据训练与识别。最终实验表明,MobileNet的运行速度为0.02 s一张图片,检测率可达到96%,该方法适用于图像特征较明显、大量重复检测的电力设备检测场景。

基于MOBILE6.2的北京市出租车排放污染物分析

利用MOBILE6.2模型计算了2000年、2005年及2008年北京市出租车的排放因子,同时,计算了北京市出租车2005年更换部分旧车以及2008年更换全部旧车以后,相对于2000年污染物的降低总量。结果表明,排放污染物随更换车型大大下降。HC排放物的总量下降了1779.4T,CO排放物的总量下降了13304.3T,NOx排放物的总量下降了684.4T。2008年完成出租车全部更换后,相对于2000年,HC排放物的总量下降3097.9T,CO排放物的总量下降17483.5T,NOx排放物的总量下降了1211.8T。同时,还估算了2000年和2008年其他类型机动车的排放因子及污染物的排放总量,并计算了各车型对排放的贡献率。

基于Windows Mobile的固定资产条码管理系统的设计与实现

随着智能移动设备技术的发展,智能移动设备广泛应用于固定资产的管理工作中。本文以高职院校固定资产条码管理系统为例,讨论了基于Windows Mobile的固定资产条码管理系统的功能设计与实现。

Windows Mobile电源管理分析与实现

阐述基于Windows Mobile的嵌入式系统中系统软件层次的低功耗设计。在基于PXA270处理器的手机平台上具体实现了Windows Mobile的电源管理功能,即与PXA270处理器的低功耗模式相结合,实现了Suspend/Resume模型,以及设备驱动和应用程序中电源管理,最后对系统工作在典型电源状态的功耗数据做了测量。数据表明,与未采用电源管理的系统相比,电源管理模块能使系统更高效合理地使用电池电量,有效地降低系统运行过程中的功耗。