China Mechanical Engineering

Select

Industrial Engineering and Lean Management for Smart Manufacturing

QI Ershi, HUO Yanfang, LIU Hongwei

China Mechanical Engineering 2022, 33 (21): 2521-2530. DOI: 10.3969/j.issn.1004-132X.2022.21.001

Abstract （1518）

PDF （4622KB）（1085）

Save

This paper reviewed the development routes of developed countries such as the United States， Japan， and Germany since the emergence of industrial engineering for more than 100 years， discussed the regular characteristics of enterprise management innovation， and drew the conclusion that smart manufacturing also needed IE/LM to provide management support. According to the smart manufacturing project cycle， the functions of IE/LM in smart manufacturing engineering were analyzed from the perspectives of basic preparation， scheme selection， and integration development. The framework of lean smart management system for smart manufacturing transformation of Chinese enterprises was given， and the improvement ideas and methods of smart-lean integration were explained based on a case. Finally， some key technologies of smart manufacturing management facing transformation and upgrading of Chinese enterprises were presented based on the actual needs of China.

Reference | Related Articles | Metrics

Select

China Mechanical Engineering 2022, 33 (05): 1-.

Abstract （321）

PDF （126975KB）（1066）

Save

Related Articles | Metrics

Select

Research Review of Error Compensation Technology for Ultra-precision Machining

CHEN Qidi, HU Xiaolong, LIN Min, SUN Xiaoxia, ZHANG Tao, ZHOU Zhixiong

China Mechanical Engineering 2023, 34 (03): 253-268. DOI: 10.3969/j.issn.1004-132X.2023.03.001

Abstract （1758）

PDF （8557KB）（529）

Save

Ultra-precision machining technology was a key technology in high-end manufacturing fields. At present, ultra-precision machining has entered the nano scale. Mastering the key technology of ultra-precision machining error control, ensuring and improving the machining accuracy of CNC machine tools, become a hot research point to improve the machining and manufacturing levels. This paper systematically summarized the research status and development trend of ultra-precision machining error compensation technology, and focused on the geometric errors, force induced errors, thermal induced errors and their compensation methods, which had the greatest impact on ultra-precision machining. Then, a series of problems of ultra-precision machining in geometric error separation, cutting force, thermal induced error measurement and compensation were deeply discussed, and it is further pointed out that the ultra-precision machining error compensation technology should also pay attention to the development direction of high efficiency, high precision, generalization, modularization, intelligence and flexibility.

Reference | Related Articles | Metrics

Select

A Circular Target Stability Detection Method Based on Deep Learning Image Super-resolution

CUI Haihua, XU Zhenlong, YANG Yapeng, MENG Yayun, WANG Baojun

China Mechanical Engineering 2021, 32 (23): 2861-2867. DOI: 10.3969/j.issn.1004-132X.2021.23.010

Abstract （441）

PDF （5820KB）（527）

Save

In order to improve the recognition rate and location accuracy of circular targets under the conditions of long-distance and large deflection angle， a circular target stability detection method was proposed based on deep learning image super-resolution. The multi-angle and multi-distance image sets were constructed through a hybrid data set of real images and synthetic images， the pixel loss and perceptual loss were used to improve the loss function of image super-resolution model， so the super-resolution reconstruction of images might be realized and the image details of target contours might be enriched. By using the pretrained super-resolution model， the images were reconstructed. Finally， traditional detection algorithm was used to recognize and locate the circular targets. The experimental results show that the circular target recognition rate is increased by 40%， and the target location accuracy is increased by 8.47%.

Reference | Related Articles | Metrics

Select

Research Status and Prospect of CMG Technology

REN Yinghui, ZHOU Jiaheng, LI Wei, ZHOU Zhixiong, LI Chenfang

China Mechanical Engineering 2021, 32 (18): 2143-2152. DOI: 10.3969/j.issn.1004-132X.2021.18.001

Abstract （673）

PDF （6455KB）（506）

Save

At present, the CMG technology was widely applied in fields of optics and semiconductors manufacturing, because it might achieve ultra-precision, high quality and low damage processing for hard-brittle materials such as monocrystalline silicon and quartz glass through chemo-mechanical synergistic processes. Current CMG research status around material removal mechanism, grinding processes and compound processes was reviewed, and these existing problems for related researches were summarized. Factors affecting the quality and processing efficiency of CMG were discussed furtherly. The analyses show that revealing the mechanism of CMG from the perspective of solid-solid phase chemical reaction and chemo-mechanical synergistic effect is helpful to innovate feasible methods to improve the processing efficiency of this technology from the perspectives of material removal mechanism, grinding tool structure design and compound processing development. Furthermore, the probable development trend of CMG technology in the direction of diversified processing materials, more complicated structure processing, multi-energy field compound processing, and related intelligent machining databases were forecasted.

Reference | Related Articles | Metrics

Select

Bearing Fault Diagnosis Method Based on Small Sample Data under Unbalanced Loads#br#

HE Qiang, TANG Xianghong, LI Chuanjiang, LU Jianguang, CHEN Jiadui

China Mechanical Engineering 2021, 32 (10): 1164-1171,1180. DOI: 10.3969/j.issn.1004-132X.2021.10.004

Abstract （836）

PDF （6051KB）（503）

Save

Aiming at the problems that the bearing vibration signals were easily disturbed by unbalanced load and the small number of bearing fault samples, a bearing fault diagnosis method based on WGAN-GP and SeCNN was proposed. The bearing vibration signals were processed by short-time Fourier transform to get the time-spectrum samples that were easy to be processed by WGAN-GP, which were divided into training set, validation set and test set. Then the training set was inputted into WGAN-GP for adversarial training, new samples were generated with similar distribution to the training samples, and added to the training set to expand the training set. The expanded training set was input into SeCNN for learning, and the trained model was applied to the test set and output the fault recognition results. The analysis of the CUT-2 platform unbalanced load bearing data was carried out, and the experimental results show that the proposed method may accurately and effectively classify the bearing faults.

Reference | Related Articles | Metrics

Select

Two-way Fluid-Solid Coupling Simulation and Experimental Research of Sealing Rings Based on MpCCI Method

GONG Ran, ZHANG Zhenyu, CHENG Zhigao, XU Yi, ZHANG He

China Mechanical Engineering 2021, 32 (14): 1639-1646. DOI: 10.3969/j.issn.1004-132X.2021.14.001

Abstract （622）

PDF （5466KB）（496）

Save

To predict the fluid-solid coupling characteristics of sealing systems in transmission of heavy-duty off-road vehicles, the stress state of sealing rings in small confined spaces and the flow characteristics in flow fields of rotating sealing gaps were taken into account, and then the numerical models of two-way fluid-solid coupling for sealing systems were established and the solving methods were presented. The multi physics code coupling tool MpCCI was combined with FLUENT and Abaqus to carry out the numerical calculations of two-way fluid-solid coupling of rotary sealing systems. According to the fluid-solid coupling calculations, the flow states of oil in flow fields of rotary sealing gaps were obtained. The effective characteristics of sealing ring deformations on the leakage of rotary sealing systems and the friction torques of sealing rings were studied. The influences of transmission system working conditions on sealing ring performances were explored by two-way fluid-solid coupling dynamic simulation. Experimental investigations were performed in sealing performance test rig for sealing rings of vehicle transmission systems. Comparisons of numerical and experimental results show a good consistency of their change rules, which verifies the correctness of sealing fluid-solid coupling numerical models and calculation results.

Reference | Related Articles | Metrics

Select

Solution of Inverse Kinematics for 6R Robots Based on Combinatorial Optimization Algorithm#br#

JI Yangzhen, HOU Li, LUO Lan, LUO Pei, LIU Xubin, LIANG Shuang

China Mechanical Engineering 2021, 32 (10): 1222-1232. DOI: 10.3969/j.issn.1004-132X.2021.10.011

Abstract （496）

PDF （1672KB）（491）

Save

In order to solve the problems of multiple solutions, low accuracy and poor generality in inverse kinematics, a combinatorial optimization algorithm was proposed to solve the inverse kinematics for all kinds of 6R industrial robots. The kinematics models of the robot were established according to the classical D-H method. The objective function of the inverse kinematics was constructed by minimizing the pose errors with the principle of motion stability, and its fitness function was designed by linear weighing-sum method. An improved whale optimization algorithm for inverse kinematics was developed by using four methods including chaotic mapping initializing population, nonlinear updating of convergence factor, adaptive inertia weight and simulated annealing strategy. The combinatorial algorithm took the results of the whale optimization algorithm as the initial value, and then the inverse kinematics solution satisfying the accuracy requirements was iterated by the Newton-Raphson numerical method. The results of simulation experiments indicate that the performance of the improved whale optimization algorithm is greatly enhanced. Compared with the direct use of whale optimization algorithm for inverse kinematics, the combinatorial optimization algorithm has the advantages of faster solution speed, better stability and ultra-high accuracy, which also proves that the proposed algorithm is feasible and effective for inverse kinematics problems.

Reference | Related Articles | Metrics

Select

Digital Transformation Mode and Strategy of SMEs in China

WANG Baicun, ZHU Kailing, XUE Yuan, BAI Jie, ZANG Jiyuan, XIE Haibo, YANG Huayong,

China Mechanical Engineering 2023, 34 (14): 1756-1763. DOI: 10.3969/j.issn.1004-132X.2023.14.013

Abstract （671）

PDF （5220KB）（489）

Save

Promoting the digital transformation of SMEs was of great significance for Chinas manufacturing industries to improve quality and increase efficiency. SMEs were facing problems in digital transformation, such as high cost, fuzzy path, talent shortage, and lacking analytical framework and reference paradigm for digital transformation. The key factors to achieve digital transformation were clarified by building an analytical framework for SMEs digital transformation herein. Through case studies, 4 basic path models of digital transformation of SMEs were summarized and proposed. Based on the above researches, targeted suggestions were proposed for SMEs digital transformation in China, so as to promote the digital and intelligent development of SMEs.

Reference | Related Articles | Metrics

Select

Overview of Micro Friction to Macro Dynamics for Bolted Connections

CAO Junyi, LIU Qinghua, HONG Jun

China Mechanical Engineering 2021, 32 (11): 1261-1273. DOI: 10.3969/j.issn.1004-132X.2021.11.001

Abstract （689）

PDF （7675KB）（487）

Save

As a typical mechanical assembly method, bolted connections played an important role in the design and operation of key mechanical equipment in the field of aerospace, military weapons, energy and chemical equipment and transportation industry. Moreover, due to the introduction of the nonlinear factors of stiffness and damping by bolted connections, new challenges in performance predictions and operation reliability were come into being to propel us to comprehensively understanding the characteristics of bolted connections from interface micro friction to macro structural dynamics. Therefore, the micro-macro dynamics of bolted connections reviewed and the fractal characterization modeling, statistical summation modeling and Iwan modeling methods of bolt joint friction constitutive model were summarized. Several experimental benchmarks for testing the friction energy consumption of bolted connections in the world were analyzed in detail. The latest research progresses of nonlinear modeling, parameter identification, numerical simulation and structural health monitoring in the macro dynamics of bolted connections were discussed, and the development trend of this field was prospected.

Reference | Related Articles | Metrics

Select

Research and Applications of Condition Monitoring and Predictive Maintenance of Marine Diesel Engines

CHEN Dongmei, ZHAO Siheng, WEI Chengyin, CHEN Yajie

China Mechanical Engineering 2022, 33 (10): 1162-1168. DOI: 10.3969/j.issn.1004-132X.2022.10.004

Abstract （548）

PDF （3080KB）（487）

Save

Based on the four dimensions of thermal-pressure parameters， lubricant oil conditions， vibrations and cylinder pressures， data acquisition and feature extraction were carried out， and a method for diesel engine condition monitoring was proposed based on OCSVM anomaly detection algorithm and Fisher discriminant analysis. The CUSUMMR was used for parameter trend detection and the D-S evidence theory and weight of evidence method were used for multi-source information fusion. the RUL(remaining useful life) of diesel engine lubricating oil was predicted by LSTM. The Paper solves the problems such as low early warning rate， poor adaptability of the model under diesel engine dynamic conditions.

Reference | Related Articles | Metrics

Select

State-of-the-art of Key Maritime Rescue and Salvage Equipment and Technology

ZHAO Jiechao, JIN Hao, CHEN Jian, PAN Changcheng, ZHANG Yingxiang, WANG Jiwu, WENG Datao

China Mechanical Engineering 2022, 33 (04): 432-451,458. DOI: 10.3969/j.issn.1004-132X.2022.04.007

Abstract （751）

PDF （3281KB）（481）

Save

To promote the modernization of the national emergency management systems and capabilities， combined with the current development of maritime emergency rescue capabilities in China， the key issues exposed in some typical maritime emergency rescue cases in recent years were deeply analyzed， and the conclusion that “systematic construction” was the core issue that urgently needed to be strengthened in the construction of Chinese maritime rescue and salvage equipment and technology was pointed out. From the perspective of the land-sea-air-space integrated， aiming at the four major Chinese rescue and salvage missions of life rescue， environmental rescue， property rescue， and emergency rescue and salvage， this paper systematically divided the key equipment technology of maritime rescue and salvage into 7 types according to the dimensions of space-based， air-based， water surface， and underwater. Aiming at the current development of each type of key equipment technology， the Delphi method， brainstorming method and bibliometric method were used to carry out research and judgment on the development of key maritime rescue and salvage equipment and technology. The results of the study selected 13 key equipment technologies that require urgent attention from the 7 categories of key equipment technologies. Meanwhile， the current challenges faced by each key equipment technology were systematically analyzed， and recommendations for the development goals and core construction tasks in the next 5~15 years were given as well.

Reference | Related Articles | Metrics

Select

Fault Diagnosis Method of Wind Turbine Gearboxes Mixed with Attention Prototype Networks under Small Samples

YU Haoshuai, TANG Baoping, ZHANG Kai, TAN Qian, WEI Jing

China Mechanical Engineering 2021, 32 (20): 2475-2481. DOI: 10.3969/j.issn.1004-132X.2021.20.010

Abstract （558）

PDF （4907KB）（469）

Save

The scarcity of labeled fault sample data of wind turbine gearboxes in some wind farms seriously reduced the accuracy of fault diagnosis. To solve this issue, a fault diagnosis method based on mixed self-attention prototype networks under small samples was proposed. First, the vibration signals were mapped to the fault feature measurement space through the prototype networks. Then, the position self-attention mechanism and channel self-attention mechanism were used for matrix fusion to construct a mixed self-attention module, which established the global dependence of the original vibration signals and obtained more discriminative characteristic information to learn the measurement prototypes of wind power gearboxes in various health states. Finally, the trained metric classifier was adopted to identify the faults of the wind turbine gearbox under the condition of small samples. Experimental results show that the fault diagnosis method of the mixed self-attention prototype networks may achieve high-precision fault diagnosis of wind turbine gearboxes on different scales of small sample datasets.

Reference | Related Articles | Metrics

Select

Research Progresses on Surface Integrity of Bearing Grooves

WANG Dongfeng, YUAN Julong, WANG Yanshuang, CHENG Yongjie, LYU Binghai

China Mechanical Engineering 2022, 33 (18): 2143-2160. DOI: 10.3969/j.issn.1004-132X.2022.18.001

Abstract （570）

PDF （5702KB）（464）

Save

Improving the surface integrity of bearing grooves was an important solution to solve technical problems such as low reliability life, high friction power consumption and unstable vibrations and noises of bearings. On the basis of comprehensive research of generalized surface integrity by domestic and foreign scholars, the definition and connotation of characteristic parameters of bearing groove surface integrity were proposed, and the significance of characteristic parameters and the influence mechanism on bearing performance were expounded. The influences of different processing processes such as forging, turning, heat treatment, grinding and ultra-precision on the surface characteristic parameters of bearing raceways were analyzed in details, and the corresponding control measures were given. The new technologies, new processes, and new methods for improving surface integrity were briefly introduced. Finally, the summary and prospect of improving the surface integrity of bearing grooves were made to provide some references for improving the contact fatigue lifes of bearings.

Reference | Related Articles | Metrics

Select

Health Status Assessment of Hydraulic Pumps Based on Multi-sensor Information Fusion and Multi-grained Cascade Forest Model

SHAN Zenghai, LI Zhiyuan, ZHANG Xu, HUANG Yixiang, LI Yanming, LIU Chengliang, ZHANG Xuan

China Mechanical Engineering 2021, 32 (19): 2374-2382. DOI: 10.3969/j.issn.1004-132X.2021.19.013

Abstract （375）

PDF （6055KB）（462）

Save

The health status assessment of hydraulic pumps was of great significance to the operating state monitoring of engineering equipment. The existing methods based on vibration signal analysis had single data source and low reliability， therefore a method was proposed for evaluating the health status of hydraulic pumps based on multi-sensor information fusion and multi-grained cascade forest. The pressure， temperature， flow and other signals of the hydraulic pumps were collected under different working hours through the test system， and the time-domain features of the signals were extracted to form preliminary features. Multiple classifiers were used to obtain the category probability vectors of the preliminary features， and the results were stitched with the important features selected by the random forest model to form the final features， and then the multi-grained cascade forest was used to evaluate the health status.The testing results show that the classification precision of the proposed method may still reach 99.5% when the training ratio is only 5%， which may effectively improve the accuracy of hydraulic pump health assessment.

Reference | Related Articles | Metrics

Select

Research Progresses of Superhydrophobic Surface Processing Technology and Abrasion Resistance

HUANG Yun, HUANG Jianchao, XIAO Guijian, LIU Shuai, LIN Ouchuan, LIU Zhenyang

China Mechanical Engineering 2024, 35 (01): 2-26. DOI: 10.3969/j.issn.1004-132X.2024.01.001

Abstract （313）

PDF （50387KB）（453）

Save

The abrasion resistance of currently prepared superhydrophobic surfaces is generally poor, which limite the applications in various fields. Studied results found that micro-nano structure and low surface energy were the key factors to achieve superhydrophobic properties. Firstly, based on the mechanism of superhydrophobic surface, the superhydrophobic surface texture was summarized, aiming to solve the wear-prone challenge of micro-nano structures by optimizing the surface texture. Secondly, the superhydrophobic surface processing technology was summarized, and measures to reduce surface energy were analyzed in terms of cost and efficiency which might provide ideas for expanding the superhydrophobic surface processing system. Then, the means of analyzing the abrasion resistance of superhydrophobic surfaces were concluded in detail and the methods of improving the abrasion resistance of superhydrophobic surfaces were described. Finally, the future development prospects of abrasion resistant superhydrophobic surfaces was prospected, with a view to promote the large-scale applications of superhydrophobic surfaces in engineering.

Reference | Related Articles | Metrics

Select

Research Status Analysis of Adhesively Connection Technology in Aerospace Industry#br#

GUO Lei, LIU Jianhua, ZHANG Jiapeng, LI Xiayu, ZHANG Xiumin, XIA Huanxiong

China Mechanical Engineering 2021, 32 (12): 1395-1405. DOI: 10.3969/j.issn.1004-132X.2021.12.002

Abstract （525）

PDF （5219KB）（452）

Save

Aiming at current inadequate researches of adhesive assembly technology in aerospace products, especially in precision electromechanical products in China, the application types for adhesive connection technology in aerospace and application characteristics of ultra-high/low temperature resistance, sealing, versatility, stability/low creep, and low volatility were briefly introduced. Research improvement of mechanism, key processes, static/dynamic mechanics properties, and fatigue and aging characteristics of adhesive bonding were summarised and analysed. Finally, development tendencies of the aerospace adhesive technology in the aspects of process parameter quantization, dynamic mechanics property investigation, and advanced adhesive equipment were pointed out.

Reference | Related Articles | Metrics

Select

State-of-the-art on MQL Synergistic Technologies and Their Applications

YANG Jianzhang, WANG Chengyong, YUAN Yaohui, YUAN Songmei, WANG Xibin, LIANG Cile, LI Weiqiu

China Mechanical Engineering 2022, 33 (05): 506-528. DOI: 10.3969/j.issn.1004-132X.2022.05.001

Abstract （628）

PDF （22261KB）（441）

Save

MQL technology had the advantages of low cutting fluid consumption and high lubrication efficiency. However, there were more problems such as inadequate lubrication and low cooling performance under the specific conditions. MQL synergistic technology, such as cryogenic air or liquid carbon dioxide et.al. which combines the advantages of cooling and lubrication, might effectively solve the machining problems of difficult-to-cut materials. The latest research of principle, key devices and technology applications of various types of MQL synergistic technology were summarized. The performance of various devices and their parameter regulation characteristics were analyzed in details. Combining with the applications and the mechanism of MQL synergistic technology, the machinability in titanium alloy, nickel alloy, stainless steel and other difficult-to-cutting materials were analyzed. In addition, a sustainable analysis of various types of MQL synergistic technology was provided. The purpose is to provide technical support and reference for the engineering applications of clean cutting technologies.

Reference | Related Articles | Metrics

Select

Contact States of Workpiece-Abrasive Particles-Polishing Pad in Cemented Carbide CMP Processes

MAO Meijiao, XU Qing, LIU Jingli, YUAN Julong, LI Min, HU Zihua

China Mechanical Engineering 2021, 32 (17): 2074-2081. DOI: 10.3969/j.issn.1004-132X.2021.17.008

Abstract （432）

PDF （6792KB）（439）

Save

Theoretical analysis of the contact states among workpiece， abrasive particles and polishing pads was carried out based on the theory of elastoplastic mechanics， the depth of the abrasive particles pressed into the workpieces under each contact states was calculated， and the mathematical model of the critical conditions of the contact states was established， and the verification experiments were conducted. The research results show that in the cemented carbide CMP processes， there are three forms of non-contact state， partial contact state， and full contact state among workpiece， abrasive particles and polishing pads. The depth of the abrasive particles pressed into the cemented carbide workpieces in the three contact states is mainly affected by the polishing load， the size of the abrasive particles and the hardness of soft layer of workpiece， and the critical conditions of each contact states are determined by the characteristics of the polishing pad， the mass fraction of abrasive particles， and the polishing load. The experimental results show that the established mathematical model is credible.

Reference | Related Articles | Metrics

Select

Vehicle Tracking of Information Fusion for Millimeter-wave Radar and Vision Sensor

HU Yanping, LIU Fei, WEI Zhenya, ZHAO Linfeng

China Mechanical Engineering 2021, 32 (18): 2181-2188. DOI: 10.3969/j.issn.1004-132X.2021.18.006

Abstract （504）

PDF （4596KB）（422）

Save

In order to improve accuracy of vehicle forward collision prevention warning system on road environment perception, a vehicle tracking method of information fusion for millimeter-wave radar and vision sensor was proposed. An algorithm to eliminate radar jamming targets was proposed to reduce processing time of jamming targets. A symmetric detection algorithm was proposed to detect radar target ROI (region of interest) symmetrically and reduce lateral position errors of radar target ROI. In order to improve the tracking accuracy, a KCF-KF combined filtering algorithm was proposed to track and fuse vehicles. Actual vehicle tests show that the method may effectively track vehicle position information, and the tracking accuracy of X and Y coordinates in pixel coordinate system is more than 97.34% and 95.19% respectively.

Reference | Related Articles | Metrics

Select

Evolution of Concept of Machine Composition from the 19th Century to Modern Time

ZHANG Ce, YANG Tingli, LIU Jianqin

China Mechanical Engineering 2023, 34 (10): 1135-1139. DOI: 10.3969/j.issn.1004-132X.2023.10.001

Abstract （423）

PDF （2405KB）（422）

Save

With increasing of productivity and development of machines， the concept of “machine composition” also evolved. The requirements of modern society for machines were gradually increasing， and complex machines came from the transformation of traditional machines. Understanding the evolution of machines was a necessary process for the transformation of traditional machines. Marx first described the composition of machines in his Das Kapital， which coincided with the start of the Second Industrial Revolution. However， within only a few years， the control system joined a machine， and Marxs “concept of machine composition” began to be broken through. In the second half of the 20th century， in the Third Scientific and Technological Revolution， the concept of mechatronics emerged， and electronic technology， control technology and sensor technology were integrated into mechanical systems. The evolution processes of the concept of machine composition were explained through the history of the development of machines herein. By analyzing the evolution of the concept of machine composition， a more accurate definition of modern mechanical systems was put forword. It may enlighten people， increase their understanding of the machine itself， which has guiding significance for modern mechanical product designers.

Reference | Related Articles | Metrics

Select

Research on Flexible Job-shop Scheduling Problems with Integrated Reinforcement Learning Algorithm

ZHANG Kai, BI Li, JIAO Xiaogang

China Mechanical Engineering 2023, 34 (02): 201-207. DOI: 10.3969/j.issn.1004-132X.2023.02.010

Abstract （528）

PDF （4473KB）（402）

Save

The flexible job-shop scheduling problems were transformed into a Markov decision process， and an algorithm D5QN integrated with 5 kinds of deep Q-network (DQN) optimizations was proposed. In the constructing of Markov process， a set of features was extracted to describe the states， and 3 sets of actions were designed by composite rules. The rewards were mapped by direct and indirect methods. The proposed algorithm was compared with the algorithms based on rules， meta-heuristic， and other reinforcement learning， which verifies the proposed algorithm may further decrease the calculating time， and have feasibility and effectiveness.

Reference | Related Articles | Metrics

Select

Gear Fault Diagnosis Based on Deep Learning and Subdomain Adaptation

JIE Zhenguo, WANG Xiyang, GONG Tingkai

China Mechanical Engineering 2021, 32 (22): 2716-2723. DOI: 10.3969/j.issn.1004-132X.2021.22.008

Abstract （459）

PDF （3700KB）（398）

Save

Aiming at the insufficient labeled fault data in real cases, a method was proposed based on deep learning and subdomain adaptation. The domain-shared one dimensional CNN was first used to extract transferable features from the fault data. Then, the multi-kernel local maximum mean discrepancy was used to measure the distribution discrepancy of the learned transferable features relevant subdomains, and the measured distribution discrepancy was added to the objective function for training. Finally, the trained model was used to identify the health conditions of the target domain. The results show that the proposed method may achieve high accuracy in the case of target domain data without label.

Reference | Related Articles | Metrics

Select

Research Status of Key Technologies for Energy Management System of Marine Hybrid Propulsion Systems

SUN Xiaojun, SONG Enzhe, YAO Chong

China Mechanical Engineering 2022, 33 (04): 469-481,495. DOI: 10.3969/j.issn.1004-132X.2022.04.010

Abstract （631）

PDF （4818KB）（388）

Save

In the face of energy shortage and strict emission regulations， the use of new hybrid power system would become an important direction of ship development in the future. Firstly， the challenges were analyzed by the shipping industries， and the advantages and necessity of marine hybrid power were expounded. The topology and implementation framework of energy management systems were presented. Secondly， the research status of energy management strategy was analyzed, and the development route of hybrid system multi energy coupling energy management strategy was put forward. The challenges faced by the research and development of energy management strategies for marine hybrid power systems were explored ， and the future development trends and in-depth research directions were looked forward. The paper provides the research and development directions for the green and intelligent development of marine hybrid powers.

Reference | Related Articles | Metrics

Select

Improved Genetic Programming Algorithm for RCMPSP

CHEN Haojie, DING Guofu, ZHANG Jian, YAN Kaiyin

China Mechanical Engineering 2021, 32 (10): 1213-1221. DOI: 10.3969/j.issn.1004-132X.2021.10.010

Abstract （423）

PDF （1266KB）（386）

Save

Aiming at the lack of optimization ability for priority rule scheduling, an improved hyper-heuristic genetic programming algorithm for the RCMPSP was proposed to evolve better priority rules. By analyzing the existing priority rules, a normalized attribute set and a top-level discriminant coding method for multi-project scheduling were constructed, and the NSGA-Ⅱ virtual fitness allocation method was applied to evaluate the population for achieving multi-objective optimization. A diversity population updating method was designed to enhance the search ability and avoid the defects that the traditional genetic programming was easy to fall into local optimum. The validity and feasibility of the proposed method were verified by the calculation experiments based on benchmark data set PSPLIB and the aircraft assembly line production instance.

Reference | Related Articles | Metrics

Select

Scale Optimization of Humanoid Robotic Arms Based on Kinematic Performance Analysis

SUN Peng, LI Yanbiao, ZHANG Cong, SHAN Xiaohang, YUE Yi, WEI Baochen

China Mechanical Engineering 2022, 33 (19): 2331-2340. DOI: 10.3969/j.issn.1004-132X.2022.19.007

Abstract （445）

PDF （10626KB）（378）

Save

Aiming at the problems that the coupling effect of multi-joint series mechanisms on the kinematic performance of the end-effector， the kinematic characteristics of series-parallel hybrid mechanisms were analyzed， and a multi-parameter plane model was proposed to realize visualized design. Based on screw theory， the kinematics transfer matrices of serial and parallel joints were established respectively， and the corresponding performance indexes were set up. According to the multi-parameter plane model， the coupling relationship among parameter scale， orientation workspace， and performance indexes were further revealed through a three-dimensional visualization graphics. Finally， the values of parameters， the range of high-quality orientation workspace， and the distribution of indexes were confirmed. The results show that the global performance indexes of the shoulder and wrist joints are as 0.78 and 0.67， respectively， and the global condition number of the elbow joint is as 2.38. The hybrid configuration has functions similar to that of the human arm joints， and gives full play to the comprehensive advantages of series and parallel mechanisms.

Reference | Related Articles | Metrics

Select

Construction Method of Virtual-real Drive Systems for Robots in Digital Twin Workshops

LIU Huailan, ZHAO Wenjie, LI Shizhuang, YUE Peng, MA Baorui

China Mechanical Engineering 2022, 33 (21): 2623-2632. DOI: 10.3969/j.issn.1004-132X.2022.21.011

Abstract （521）

PDF （2935KB）（376）

Save

For the current problems for complex modeling and long development cycle of virtual entities such as industrial robots in digital twin workshop construction， a modular construction method of virtual-real drive systems for industrial robots in digital twin workshops was proposed， which divided the virtual-real drive systems into an interaction layer for setting model parameters and a control layer for designing configurations according to functional requirements， and then abstracted the physical industrial robots， etc. into a simulation model from coupling single functional atomic model. The modular and hierarchical approach to building virtual-reality drive systems may quickly and effectively realize the modeling of digital twin virtual entities such as industrial robots, as well as the simulation of industrial robots operating in virtual space and the simultaneous operation of virtual-reality.

Reference | Related Articles | Metrics

Most Download articles