Approach for Cost Determination of Electro-Mechanical Equipment in Ror Shp Projects

Electricity is one of the most widely used forms of energy. Being a renewable source of energy small hydropower is considered as an environment—friendly and cheap source of electricity. The installation cost of the small hydropower project depends mainly on two parts—civil works and electromechanical equipment. One of the most important element on the recovery of a small hydro-power plant is the electromechanical equipment (turbine-alternator). The present paper intends to develop a correlation to determine the cost based on the cost influencing parameters as power and head using three different methods, namely;sigma plot method, linest method and logest method. An attempt has also been made to identify the best correlation among the three models closer to the actual cost of electro-mechanical equipment as collected from recently developed projects.

An Improved Solov2 Based on Attention Mechanism and Weighted Loss Function for Electrical Equipment Instance Segmentation

The current existing problem of deep learning framework for the detection and segmentation of electrical equipment is dominantly related to low precision.Because of the reliable,safe and easy-to-operate technology provided by deep learning-based video surveillance for unmanned inspection of electrical equipment,this paper uses the bottleneck attention module(BAM)attention mechanism to improve the Solov2 model and proposes a new electrical equipment segmentation mode.Firstly,the BAM attention mechanism is integrated into the feature extraction network to adaptively learn the correlation between feature channels,thereby improving the expression ability of the feature map;secondly,the weighted sum of CrossEntropy Loss and Dice loss is designed as the mask loss to improve the segmentation accuracy and robustness of the model;finally,the non-maximal suppression(NMS)algorithm to better handle the overlap problem in instance segmentation.Experimental results show that the proposed method achieves an average segmentation accuracy of mAP of 80.4% on three types of electrical equipment datasets,including transformers,insulators and voltage transformers,which improve the detection accuracy by more than 5.7% compared with the original Solov2 model.The segmentation model proposed can provide a focusing technical means for the intelligent management of power systems.

Fuzzy Comprehensive Judgment on the Mechanical Equipment Bid Sheet

The reasonable model of fuzzy comprehensive judgment is found by means of the theory and method of multi-level fuzzy judgment on the basis of the judging index system of mechanical equipment bid sheets. The scientific method is supplied for the judging bids, the key chain of the judging process of the mechanical equipment bid sheet. All factors are considered, especially quantitative factors or qualitative factors in the process of judgment.

Preface for Special Issue on“Key Mechanical Problems of Marine Energy Development Equipment”

There are abundant energy reserves such as oil,natural gas,hydrate,and wind energy in the ocean.Countries around the globe are competing to advance their marine energy development technologies.The exploitation of marine resources relies on cutting-edge industrial equipment.After decades of R&D endeavors,China has obtained most of the key technologies for the design,production,testing,and field application of marine energy development equipment(Xie and Zeng,2021).

Vibration Analysis and Fatigue Assessment of Floors.Part II:Mechanical Equipment

Floors subjected to mechanical equipment loads frequently present problems associated with excessive vibration which can cause human discomfort or even reduce the structure service life.In this context,this work aims to develop an analysis methodology in order to assess the fatigue performance of steel-concrete composite floors,when subjected to vibrations induced by mechanical equipment.The studied structural model corresponds to a steel-concrete composite floor spanning 10 m by 10 m,with a total area of 100 m^(2).The numerical model developed for the dynamic analysis adopted the usual mesh refinement techniques present in finite element method(FEM)simulations implemented in the ANSYS program.The investigated floor dynamic response was calculated through the consideration of the dynamic loadings imposed by the mechanical equipment,simulated based on the use of harmonic forces applied on the concrete slabs.Furthermore,the dynamic structural response was performed considering several scenarios for the positioning of the equipment,in order to verify the occurrence of excessive vibration.The fatigue assessment is based on a linear cumulative damage rule through the use of the Rainflow-counting algorithm and S-N curves from traditional design codes.The results of this investigation indicated that the equipment position affects directly the floor dynamic structural response and also significantly influences the structure service life.

Effects of Sowing Depth and Sowing Equipment on Growth and Yield of Mechanized Sowing Maize

Taking Zhongyu 3 as the experimental variety,this paper analyzed the effects of different sowing depths(5 cm and 8 cm)and sowing equipment(ZHSB-10 medium-sized sowing machine and 2B-2 small sowing machine)on the growth,yield and components of yield of mechanized sowing maize,to provide references for mechanized maize production in southwest ecological zone.The results showed that the germination rate,plant height uniformity,and most agronomic traits of maize plant were higher at the sowing depth of 5 cm;with the growth of the maize,the effects of the sowing depth on agronomic traits of maize gradually declined;the effects of the sowing depth on the empty stalk rate,double ear rate,lodging rate,and lodging and stem broken rate were smaller;the sowing depth of 5 cm could increase the yield of mechanized sowing maize and most yield traits of maize.Different sowing machines had smaller effects on the germination rate,plant height uniformity,and agronomic traits of all growth stages,empty stalk rate,double ear rate,lodging rate,lodging and stem broken rate,yield,and components of yield of mechanized sowing maize.

Mechanical solution for a mechanical problem:Tennis elbow

Lateral epicondylitis is a relatively common clinical prob lem, easily recognized on palpation of the lateral protu berance on the elbow. Despite the "itis" suffix, it is no an inflammatory process. Therapeutic approaches with topical non-steroidal anti-inflammatory drugs, cortico steroids and anesthetics have limited benefit, as would be expected if inflammation is not involved. Other ap proaches have included provision of healing cytokine from blood products or stem cells, based on the recog nition that this repetitive effort-derived disorder repre sents injury. Noting calcification/ossification of tendon attachments to the lateral epicondyle(enthesitis), dry needling, radiofrequency, shock wave treatments and surgical approaches have also been pursued. Physi ologic approaches, including manipulation, therapeuti ultrasound, phonophoresis, iontophoresis, acupuncture and exposure of the area to low level laser light, ha also had limited success. This contrasts with the benefi of a simple mechanical intervention, reducing the stres on the attachment area. This is based on displacemen of the stress by use of a thin(3/4-1 inch) band applied just distal to the epicondyle. Thin bands are required as thick bands(e.g., 2-3 inch wide) simply reduce mus cle strength, without significantly reducing stress. Thi approach appears to be associated with a failure rateless than 1%, assuming the afflicted individual modifies the activity that repeatedly stresses the epicondylar attachments.

Environment Adaptability Evaluation for Buffering Airbag of Heavy Equipment During Airdrop Landing

Aimed at the difficulties in analyzing the buffer characteristics of airbag system by using thermodynamic or experimental method only,the finite element method was used to establish nonlinear models for heavy equipment and its airbag system.The models' efficiency and correctness were validated by using on-site experiment data in vehicle airdrop landing.The simulation results agree very well with the experiment results.Then,the environment adaptability of airbag system of heavy equipment under high-altitude condition was studied by using the models.Finally,some solutions were given to solve the overturn problem in the landing.

Configuration and Maintenance Management of Highway Engineering Machinery and Equipment

Firstly,this paper analyzes the necessity of highway engineering construction machinery and equipment management,discusses the configuration management of highway engineering machinery and equipment,and then puts forward the problems existing in the management and maintenance of highway engineering machinery construction equipment.Finally,the management and maintenance measures of highway engineering machinery construction equipment are discussed in a targeted manner.

Application of Transfer Learningin Mechanical Equipment Intelligent Diagnosis:Literature Review

Accelerating the process of intelligent manufacturing and the demand for new industrial productivity,the operating conditions of machinery and equipment have become ever more severe.As an important link to ensure the stable operation of the production process,the condition monitoring and fault diagnosis of equipment have become equally important.The fault diagnosis of equipment in actual production is often challenged by variable working conditions,large differences in data distribution,and lack of labeled samples,etc.Traditional fault diagnosis methods are often difficult to achieve ideal results in these complex environments.Transfer learning(TL)as an emerging technology can effectively utilize existing knowledge and data to improve the diagnostic performance.Firstly,this paper analyzes the trend of mechanical equipment fault diagnosis and explains the basic concept of TL.Then TL based on parameters,TL based on features,TL based on instances and domain adaptive(DA)methods are summarized and analyzed in terms of existing TL methods.Finally,the problems faced in the current TL research are summarized and the future development trend is pointed out.This review aims to help researchers in related fields understand the latest progress of TL and promote the application and development of TL in mechanical equipment diagnosis.

煤矿掘进机机电设备故障诊断与维护

针对煤矿掘进机机电设备传统故障诊断方法效率较低、故障识别较为困难、潜在故障无法及时发现等问题,本文对煤矿掘进机机电设备故障诊断与维护技术进行研究。在分析了掘进机关键结构常见故障和监测方法的基础上,提出了煤矿掘进机故障监测与智能诊断系统,完成硬件系统选型和软件控制系统设计,实现了对掘进机机电设备运行状态实时监控和远程运维,转被动维护为主动维护,提高了设备运行可靠性,降低了设备维护成本,提高了机电设备故障诊断效率。经安装调试后表明:当掘进机关键部位出现异常现象时可准确识别,并且故障响应时间仅为1.28 s,故障发现率达97.8%,对潜在故障准确识别和判断,智能诊断系统极大提高了设备故障诊断效率,故障排除时间降低为97.3%。

基于可编程逻辑控制器的煤矿综采组合开关结构设计

针对有效、统一控制煤矿综采工作面多种采煤设备为目的,设计基于可编程逻辑控制器的煤矿综采工作面配套组合开关结构。该开关结构分为主控制电路、次控制电路,两种电路均与液晶显示模块相连。通过液晶显示模块的界面将电路状态反馈给管理人员,两种控制电路主要通过可编程逻辑控制器和继电器、信号提醒、保护回路相连,分别完成电源供应、警报信息提醒、采煤设备连接状态管理。实验结果表明,在过载、漏电工况中可用电气互锁的方式保证采煤机状态不出现异常变化,完成异常采煤设备的统一管理,最高节能比例达到11.2%,最低节能比例也能达到7.8%,由此证明设计的方法具有一定研究价值。

Digital monitoring for heavy duty mechanical equipment based on fiber Bragg grating sensor

The digital monitoring principle and technologies for heavy duty mechanical equipment based on fiber Bragg grating (FBG) technology are introduced in this paper. The fundamentals of new-style FBG sensing technology, including the photorefractive effect of FBG, the physical formation, and the relation between optical properties and grating parameters, are investigated. The plaster, encapsulation and distribution planning of FBG sensor (FBGS), which is used to monitor heavy duty mechanical equipment under abominable environment and extreme conditions, are also studied. In addition, theoretical and experimental researches on the strain, temperature, displacement, and stress transmission characteristics between FBGS and detection interface are presented. The principle and method for temperature compensation in non-uniformity temperature field are described in detail as well. Comparing with the traditional sensing monitoring techniques, the application of FBGS technology on digital monitoring and diagnosis for heavy duty mechanical equipment has a number of significant technical advantages and will make a new breakthrough in this field.

A novel combination belief rule base model for mechanical equipment fault diagnosis

Due to the excellent performance in complex systems modeling under small samples and uncertainty,Belief Rule Base(BRB)expert system has been widely applied in fault diagnosis.However,the fault diagnosis process for complex mechanical equipment normally needs multiple attributes,which can lead to the rule number explosion problem in BRB,and limit the efficiency and accuracy.To solve this problem,a novel Combination Belief Rule Base(C-BRB)model based on Directed Acyclic Graph(DAG)structure is proposed in this paper.By dispersing numerous attributes into the parallel structure composed of different sub-BRBs,C-BRB can effectively reduce the amount of calculation with acceptable result.At the same time,a path selection strategy considering the accuracy of child nodes is designed in C-BRB to obtain the most suitable submodels.Finally,a fusion method based on Evidential Reasoning(ER)rule is used to combine the belief rules of C-BRB and generate the final results.To illustrate the effectiveness and reliability of the proposed method,a case study of fault diagnosis of rolling bearing is conducted,and the result is compared with other methods.

Research on Microcrack Extension Mechanism of SiCp/Al in the Machining Process

The generation and development of microcracks of SiCp/Al materials in the machining process were researched, and the forming causes and mechanism of the cut surface morphology for ap=0.2 mm or ap=0.4 mm and at 2 m/min～10 m/min were systematically analyzed. The supporting and "floor"roles of aluminum are wake at a shallower cutting depth and a lower speed, the SiC particles are shed under the role of cutting force, and the microcrack size of cut surface is larger. With the increase in the cutting depth and the cutting speed, the cutting temperature increases, the supporting and "floor" roles of aluminum are enhanced, the shedding and fracture of the reinforcement particles are flexible under the action of the cutting force, the fracture of cutting transforms from brittle to ductile, and the expansion of microcrack on the entire surface tends to balance with a smaller size. A curve between the cutting force and the cutting speed was plotted, a microcrack form of the cut surface was given, and some theoretical basis is provided for the mechanical processing and the surface quality.

多尺度熵方法在机械故障诊断中的应用研究进展

机械设备状态监测与故障诊断的关键是故障特征的表征与提取,采用基于熵及相关方法建立的非线性动力学指标能够提取蕴藏在振动信号中的非线性故障特征信息。自熵方法引入以来,通过不断修改和改进来提高熵估计的准确性,多尺度熵进一步拓展了时间序列其他尺度上包含的复杂度信息,其在设备状态监测与故障诊断中得到广泛应用。本文对单一尺度熵及多尺度样本熵、多尺度模糊熵、多尺度排列熵和多尺度散布熵等多尺度熵方法在机械智能故障诊断中的应用进行综述,总结不同方法的特点优势与不足;针对多变量数据处理问题,综述由单变量推广到多变量的多元多尺度熵的应用发展过程。最后结合多尺度熵相关方法在机械智能故障诊断中面临的问题与挑战,对未来发展方向进行展望,即在工业大数据应用、故障机理、可解释性角度构建基于熵的深度学习模型。

基于扎根理论的超学科科研协同机制研究——以中国重大装备制造为例

以解决重大问题为导向的超学科研究,成为大科学时代推动我国基础研究走向世界前沿、解决国家重大战略问题和行业“卡脖子”问题的新引擎。以我国十万空分压缩机、碳纤维复合材料切削、大型全断面掘进装备制造为案例,结合扎根理论和半结构化访谈方法,遵循超学科研究主体协同—问题凝练—知识整合概念模型,对我国超学科科研协同机制进行探索性研究。结果发现:超学科科研协同包括3条路径:①超学科关键问题凝练,在实践问题、重大问题的基础上,提炼关键实践难题和关键技术难题,最终寻找关键科学问题,从根本理论层面解决重大问题;②超学科主体协同,通过建立由不同学科主体、不同组织主体等多元、多层次主体参与的超学科团队,建立成员间互信和共识,推动协同研究不断深入;③超学科多元知识整合,以学科知识、非学科知识等多种类型知识聚合为基础,通过知识转化、知识体系重构实现知识整合再创新,并涌现出一系列创新成果,同时需要资源、制度、文化3个超学科科研协同的保障条件,并形成超学科科研协同机制“三棱锥”模型。

PLC技术的造纸机械设备自动控制系统设计与研究

新型造纸公司依托于高科技实现了生产流程的机械化和自动化,造纸行业的生产效率和效益都得到了提升。PLC技术在工业自动化生产中应用广泛,在造纸机械设备的应用有利于提高造纸设备的自动化运转,同时有助于提高产品的质量,节约产品的人力成本和时间成本等。对PLC技术进行了简要介绍,并讨论了其在造纸机械设备的应用的形式以及自动化设计系统的设计等,为造纸行业的进一步发展提供更多的技术支撑。

丘陵山区机械化灌溉现状与发展思考

针对目前丘陵山区机械化灌溉装备与技术单一,适应性差,缺少绿色化、智能化的灌溉模式等一系列问题,系统阐述了目前相关研究的现状和未来的发展趋势;全面了解目前丘陵山区机械化灌溉水平是后续开展相关研究的关键.通过分析目前丘陵山区机械化灌溉的现状,适应丘陵山区机械化发展的要求,在机械化灌溉方面从国家政策入手到丘陵分区,结合丘陵山区的灌溉特点、目前的灌溉现状和相关经济因素进行了系统的总结.根据中国丘陵山区的国情以及相关政策,对丘陵山区机械化灌溉提出了相应的建议.可为未来丘陵山区机械化灌溉改造提供参考,补齐丘陵山区机械化灌溉装备与技术的短板,还可提高对丘陵山区机械化灌溉方面的重视,提升丘陵山区农业的灌溉水平,促进农业跨领域深度联合,推动农业可持续和现代化发展.

基于OBE理念的机械装备设计课程思政教学与实践

为培养符合就业市场需求,具有较强机械装备设计知识和能力,爱国、诚信、勇于担当素质的新工科创新性人才,对机械装备设计课程内容与教学方法进行改革与实践。基于OBE理念将传统以加工制造装备为主的教学内容拓宽到不同行业领域,设计典型机械装备案例并融入思政元素;利用图片、视频等资源与学生展开交流与互动,充分发挥学生的主动性;指导学生针对实际生产问题提出机械装备设计目标,自由成组开展创新设计;构建综合考勤、作业、讨论,及小组设计成果师生评价结果的考核方法。实践结果表明,机械装备设计课程教学在各毕业要求指标点达成度评价超过0.89,达到了课程的建设目标。