Principle and Experimental Verification of Novel Dual Driving Face Rotary Ultrasonic Motor

Existing rotary ultrasonic motors operating in extreme environments cannot meet the requirements of good environmental adaptability and compact structure at same time,and existing ultrasonic motors with Langevin transducers show better environmental adaptability,but size of these motors are usually big due to the radial arrangement of the Langevin transducers.A novel dual driving face rotary ultrasonic motor is proposed,and its working principle is experimentally verified.The working principle of the novel ultrasonic motor is firstly proposed.The 5th in-plane flexural vibration travelling wave,excited by the Langevin transducers around the stator ring,is used to drive the rotors.Then the finite element method is used in the determination of dimensions of the prototype motor,and the confirmation of its working principle.After that,a laser Doppler vibrometer system is used for measuring the resonance frequency and vibration amplitude of the stator.At last,output characteristics of the prototype motor are measured,environmental adaptability is tested and performance for driving a metal ball is also investigated.At room temperature and 200 V(zero to peak) driving voltage,the motor’s no-load speed is 80 r/min,the stalling torque is 0.35 N·m and the maximum output power is 0.85 W.The response time of this motor is 0.96 ms at the room temperature,and it decreases or increases little in cold environment.A metal ball driven by the motor can rotate at 210 r/min with the driving voltage 300 V(zero to peak).Results indicate that the prototype motor has a large output torque and good environmental adaptability.A rotary ultrasonic motor owning compact structure and good environmental adaptability is proposed,and lays the foundations of ultrasonic motors’ applications in extreme environments.

Mode switching control strategy of dual motors coupled driving on electric vehicles

Based on analyzing the structure and working principle on electric vehicles （EVs） with dual motors coupled by planetarY gears, the control strategy of mode switching was proposed. The power interruption problem on EVs with automatic mechanical transmission （AMT） shifting was resolved. Based on the speed-torque characteristics of the planetary gears and the principle of the auxiliary motor＇ s zero speed braking, control features of mode switching were introduced. The mode shifting between the main motor mode and dual motors coupled driving were studied. Matlab/Simulink was adopted as a platform to develop the simulation model of EVs with dual motors drive system and 3 gears AMT. Simulation results demonstrated that the power interruption of dual motors drive system was solved during mode switching. The power requirements of EVs were satisfied, too.

Reliability Analysis on Repairable System with Dual Input Closed-Loop Feedback Link Considering Shutdown Correlation Based on Goal Oriented Methodology

Goal oriented( GO) methodology is a kind of success oriented system reliability analysis method and has been used widely.The repairable system with dual input closed-loop feedback link( DICLFL) considering shutdown correlation didn't make reliability analysis accurately based on existing GO methodology. So, a reliability analysis method used to deal with DICLFL considering shutdown correlation is provided based on GO methodology.Firstly, a new operator, which is used to describe DICLFL considering shutdown correlation,whose number is 1,is created and named as Type 9C operator. And then,the formulas of type 9C operator are derived based on Markov process theory. Finally,the new method presented in this paper is adopted to conduct the reliability analysis of an electro-hydraulic servo speed control system. The analysis result is compared with those of Monte Carlo simulation and fault tree analysis( FTA). The comparison results show that this new reliability analysis method based on GO methodology is feasible and meaningful for reliability analysis of repairable systems with DICLFL considering shutdown correlation.Meantime,it will be useful for more other applications.

Experiments and Simulation of Thermal Behaviors of the Dual-drive Servo Feed System

The machine tool equipped with the dual-drive servo feed system could realize high feed speed as well as sharp precision. Currently, there is no report about the thermal behaviors of the dual-drive machine, and the current research of the thermal characteristics of machines mainly focuses on steady simulation. To explore the influence of thermal characterizations on the precision of a jib boring machine assembled dual-drive feed system, the thermal equilibrium tests and the research on thermal-mechanical transient behaviors are carried out. A laser interferometer, infrared thermography and a temperature-displacement acquisition system are applied to measure the temperature distribution and thermal deformation at different feed speeds. Subsequently, the finite element method （FEM） is used to analyze the transient thermal behaviors of the boring machine. The complex boundary conditions, such as heat sources and convective heat transfer coefficient, are calculated. Finally, transient variances in temperatures and deformations are compared with the measured values, and the errors between the measurement and the simulation of the temperature and the thermal error are 2 ~C and 2.5 pm, respectively. The researching results demonstrate that the FEM model can predict the thermal error and temperature distribution very well under specified operating condition. Moreover, the uneven temperature gradient is due to the asynchronous dual-drive structure that results in thermal deformation. Additionally, the positioning accuracy decreases as the measured point became further away from the motor, and the thermal error and equilibrium period both increase with feed speeds. The research proposes a systematical method to measure and simulate the boring machine transient thermal behaviors.

Analysis and Design of Conjugate Cam Shedding Mechanism with Dual Driving Shafts

The principle of conjugate cam shedding mechanism forthe outside tappets with dual driving shafts is discussed,and its design conditions and parameters are studied,giving the results of practical calculations finally.

Dual Instinct and Structural Theories: DSM-5-TR

The genetic based Dual Instinct Theory is determined by evolutionary history. Aggression is required for survival and sex for propagation of species. Aggressive and sexual drive derivatives with their corresponding defence mechanisms are combined with biologically based stages of infant/child development and the functional entity of Structural Theory. This model of human nature is the applied to the diagnostic categories of DSM-5-TR. Objectives: To follow the innate Dual Instinct Theory from life to death and through Artificial Intelligence;connect it with biological stages of development of the Structural Theory and illustrate its manifestations in DSM-5-TR classifications. Method: Review of selected published literature. Applying the principle of focus and cognition of informed clinical observation of innate drive derivatives in conjunction with The Structural Theory. Both theories are functional entities with no structures involved. Sigmund Freud’s biologically based stages of development;oral, anal, genital pubic, adult, and geriatric along with a variety of unconscious, automatic, and persistent defense mechanisms are selectively folded into diagnosis listed in the manual.

Genetic algorithm and particle swarm optimization tuned fuzzy PID controller on direct torque control of dual star induction motor

This study presents analysis, control and comparison of three hybrid approaches for the direct torque control (DTC) of the dual star induction motor (DSIM) drive. Its objective consists of combining three different heuristic optimization techniques including PID-PSO, Fuzzy-PSO and GA-PSO to improve the DSIM speed controlled loop behavior. The GA and PSO algorithms are developed and implemented into MATLAB. As a result, fuzzy-PSO is the most appropriate scheme. The main performance of fuzzy-PSO is reducing high torque ripples, improving rise time and avoiding disturbances that affect the drive performance.

Combined Estimation of Vehicle Dynamic State and Inertial Parameter for Electric Vehicles Based on Dual Central Difference Kalman Filter Method

Distributed drive electric vehicles(DDEVs)possess great advantages in the viewpoint of fuel consumption,environment protection and traffic mobility.Whereas the effects of inertial parameter variation in DDEV control system become much more pronounced due to the drastic reduction of vehicle weights and body size,and inertial parameter has seldom been tackled and systematically estimated.This paper presents a dual central difference Kalman filter(DCDKF)where two Kalman filters run in parallel to simultaneously estimate vehicle different dynamic states and inertial parameters,such as vehicle sideslip angle,vehicle mass,vehicle yaw moment of inertia,the distance from the front axle to centre of gravity.The proposed estimation method only integrates and utilizes real-time measurements of hub torque information and other in-vehicle sensors from standard DDEVs.The four-wheel nonlinear vehicle dynamics estimation model considering payload variations,Pacejka tire model,wheel and motor dynamics model is developed,the observability of the DCDKF observer is analysed and derived via Lie derivative and differential geometry theory.To address system nonlinearities in vehicle dynamics estimation,the DCDKF and dual extended Kalman filter(DEKF)are also investigated and compared.Simulation with various maneuvers are carried out to verify the effectiveness of the proposed method using Matlab/Simulink-CarsimR.The results show that the proposed DCDKF method can effectively estimate vehicle dynamic states and inertial parameters despite the existence of payload variations and variable driving conditions.This research provides a boot-strapping procedure which can performs optimal estimation to estimate simultaneously vehicle system state and inertial parameter with high accuracy and real-time ability.

Opening up under Dual Circulation

China’s mega-scale market has become a significant engine of the world economy.The contribution rate of its economic growth to the world has averaged more than 30 percent during the past seven years,ranking first in the world.According to Kristalina Georgieva,managing director of the International Monetary Fund,the Chinese economy has always been a momentous driving force for global growth,and its sound and steady development is of great importance to the world.

“科教+产教”双驱动融合的计算机类研究生创新人才培养模式探索

面对传统科教与产教中计算机类研究生培养存在的耦合性不足,该文探索“科教+产教”双驱动融合视域下计算机类研究生创新人才培养模式。该模式从思想转变和理念建设、体系构建和规划、资源保障和人才培养三个层面提出总体框架,并针对性地提出多条具体举措,充分诠释“科教+产教”双驱动融合的教育理念,最后阐明所提出的创新人才培养模式的两点特色。研究成果能够在促进教育发展、推动科技创新的同时,成就更多适应新时代计算机类产业需求的高素质创新人才。

“主动面向、科教融合、双轮驱动”——工程管理专业新工科改革与引领的探索实践

面对国家战略需求以及新一轮科技革命和产业变革所带来的严峻挑战,工程管理专业建设正面临转型升级的迫切需要。西安建筑科技大学工程管理专业始终坚持改革探索与自我革新,在新工科背景下,努力探索工程管理专业改造升级路径、人才培养模式、课程体系建设、创新体系建设、平台建设和机制体制设计;坚持“主动面向”,以国家重大战略需求和科技创新的双轮驱动为导向,拓展专业内涵,加速科教融合,积极探索和重构专业课程体系;创新“精课程、微课堂”的课程建设和教学模式;开发“工程管理云专业”平台,大力推动“2+X”创新体系建设,构建“师生成长共同体”。为探索和形成工程管理专业发展的新模式、新路径、新体系提供重要支撑和经验借鉴。

Transient Analysis and Control Strategies for a Quad-lnverter Multiphase Multilevel Motor Drive in Faulty Conditions

In this paper, post-fault-tolerant control strategies for quad-inverter multiphase-multilevel induction motor drives are investigated. More specifically, four standard two-level three-phase VSIs （voltage source inverters） supplying the open-end windings of a dual three-phase induction motor is considered, quadrupling the power capability of a single VSI with given voltage and current ratings. In healthy conditions, the control algorithm is able to generate multi-level voltage waveforms, equivalent to the ones of a three-level inverter and to share the total motor power among the four dc sources in each switching period. This sharing capability is investigated under post-fault operating conditions, when one VSI must be completely insulated due to a severe failure on it. In this case, the conversion power unit can operate with a reduced power rating by a proper modulation of the remaining three VSIs. The whole ac motor drive has been numerically implemented, and the effectiveness of the proposed control strategies under healthy and post-fault operating conditions have been proved.

考虑道路识别的四驱电动汽车再生制动策略

为了充分利用路面附着条件分配再生制动力,提高制动能量回收率,根据双电动机四驱结构电动汽车复合制动系统的特点,对其制动能量回收控制策略进行了研究.分析了驱动轮与地面附着特性,设计了道路识别器来计算每个轮胎与当前路面之间的峰值附着系数,并使用模糊控制策略确定每个车轮与8种道路的滑移率和附着利用率的相似输入.根据双电动机外部特性的制动力分配关系,提出了使更多制动能量回馈给电池的策略.结果表明:制动强度为0.3时,能量回收率为65.55%,具有较高的回收效率.

无人船载监控系统的设计与开发

为了满足无人船实时通信和远程操控需要,综合利用计算机、传感器及无线通信等技术,设计一种无人船载监控系统,实现了对无人船的实时监测、控制与实时通信。设计一种双驱动独立控制方案,实现了无人船遥控器控制与计算机控制的相互分离,可提高无人船运行操控的安全性与可靠性。提出采用插件式软件架构,将易变动的功能模块以插件的方式动态加载至系统框架中,加快了开发速度,降低了系统的耦合程度,提高了系统的可扩展性,并利用插件动态加载与卸载方法,实现了插件功能的动态加载与在线升级,提高了系统应对任务多样化的能力。

农业职业教育赋能乡村振兴的人才培养困境与推进策略

文章从农业职业教育创新育人的视角,分析了农业职业教育发展中面临的人才匮乏、综合素养不高,产教难融、科创动力不足,体系不全、育人模式滞后等困境问题;基于“项目+平台”,探索了“文化引领、‘双融’驱动、校村合作”的人才培养路径;构建了“耕读立德、产才融合、多元协同”的创新育人模式。以期为农业职业教育赋能乡村振兴培育创新型农业技术技能人才,提供推进策略。

信息类专业课程思政与混合式教学改革研究——以韶关学院为例

以信息类专业的课程现状为研究对象,从政策视角着力推进课程思政与混合式教学双驱模式的建设,不仅要在意识上加强教育,学校层面重视,还要培养兼具专业知识与思政知识、熟练运用新的教学方法与模式的教师资源。同时分别设计了课程思政与混合式教学双驱模式改革具体实施方案,提出了双驱模式实施过程中的具体措施,希望能为其他工科专业教育提供启示,并促进教育信息化发展。

基于YOLOv7-DCA的疲劳检测方法研究

针对疲劳检测中小尺度检测效果不佳和实时性差等问题,以矿井提升机司机疲劳检测为目标,对YOLOv7的结构进行精简并且基于AIoU(Area Intersection over Union)损失函数优化预测框与验证框的回归过程.在模型中引入双通道注意力机制实现小尺度特征的信息增强,通过融合眨眼频率、闭眼时长和打哈欠时长来判断司机的状态.实验结果表明,本文方法对疲劳检测精度达到98.85%,检测速度达到70 FPS,与其他算法相比,本文算法具有更好的准确性和实时性.

双驱动射频负氢离子源匹配网络设计与实验研究

随着磁约束聚变实验装置对中性束注入器的输出束流强度与脉冲时间的要求越来越高,开展高功率大面积射频离子源的研究迫在眉睫。为了实现大面积、高密度均匀等离子体放电,基于多驱动射频离子源的设计是当前的发展趋势,而阻抗匹配网络是射频功率源将最大功率输送至线圈并耦合至等离子体的关键,故对其结构设计和调谐特性的研究是不可或缺的。基于前期在单驱动射频离子源的研究基础上,结合双驱动射频离子源的放电需求,开展了双驱动阻抗匹配网络优化结构的设计与分析,通过实验中对匹配网络的调谐,成功实现了140 kW高功率和25 kW/1 000 s长脉冲的稳定运行。随后在等离子体稳定放电的基础上研究了两个驱动器之间的功率分配均匀性问题,实验结果表明了该匹配网络的优化设计合理可行,上下驱动器的射频功率分配基本均匀。

基于定子电流和电磁转矩双信号融合的齿轮故障智能诊断

在电机驱动的齿轮传动系统中,电机本体具有传感器的特性,因此可以通过电机的定子电流、电磁转矩信号来进行齿轮故障分析,由于受转速和负载转矩的影响,使得故障诊断结果的准确率较低。针对此问题,提出一种基于双信号融合与反向传播神经网络相结合的齿轮故障诊断方法。对电机齿轮传动系统一体化建模,进行电机齿轮传动系统联合仿真。对齿轮的不同故障进行模拟,得到电机侧定子电流和电磁转矩的故障信号,采用双树复小波变换来分析齿轮故障频段信号,提取故障特征量,建立了丰富的齿轮故障样本库。搭建反向传播神经网络并提出改进的自适应学习率算法,实现了对齿轮断齿、磨损故障的精确分类。为了验证所提方法的有效性,搭建齿轮故障试验平台,对相应齿轮故障进行诊断。结果表明,所提方法能够在不同转速和负载转矩条件下准确辨识齿轮的故障类型,相较于只采用定子电流和电磁转矩中一种信号对齿轮进行故障诊断,该方法准确率更高。

双元创新驱动的中小企业人力资源共享服务模式研究

新发展理念是实现我国经济高质量发展的指导思想,中小企业作为国民经济和社会发展的重要力量,其管理模式的创新和发展至关重要。为了促进中小企业人力资源共享服务模式转变,文章采用文献分析法和系统分析法,分析中小企业人力资源管理转型过程中存在的问题,基于双元创新驱动角度对中小企业人力资源共享服务模式转变给出建议,有效解决中小企业在人力资源共享服务模式转型中存在的问题,为我国中小企业共享发展提供助力。