Table of contents

We gratefully acknowledge the presence of all participants on the 2021 International Conference on Mechanical Automation and Electronic Information Engineering (MAEIE 2021), which was successfully held in Zhuhai from 24th to 26th September, 2021. MAEIE 2021 aimed to provide a platform for experts and scholars, engineers and technicians, and R&D personnel to share scientific research results and cutting-edge technologies, understand academic development trends, broaden research ideas, strengthen academic research and discussion, and promote cooperation in the industrialization of academic results. MAEIE 2021 focused on professional fields such as Mechanical Integration, Artificial Intelligence, Intelligent Information Processing, Information Engineering, etc.

About 80 participants from academic, high-education institutes and other organizations took part in the conference. The conference model was divided into two sessions, including oral presentations and keynote speeches. In the first part, some scholars, whose submissions were selected as the excellent papers, were given 15 minutes to perform their oral presentations one by one. Then in the second part, keynote speakers were each allocated 30-45 minutes to hold their speeches.

In the keynote presentation part, we invited 12 professors as our keynote speakers. The first keynote speaker, Prof. Junlong Chen, IEEE Fellow, from South China University of Technology, China. The second keynote speaker, Prof. Guoliang Chen, from Shenzhen University, China. The others keynote speaker as follow: Prof. Anhui Liang, Shandong University of Science and Technology, China; Prof. Weijia Jia, IEEE Fellow, ACM Fellow, Beijing Normal University - Hong Kong Baptist University United International College, China; Prof. Nong Xiao, from Sun Yat-sen University, China; Prof. Yutong Lu, Sun Yat-sen University, China; Prof. Young Liang, Macau University of Science and Technology, China; Prof. Jianxin Wang, IEEE Senior Member, from Central South University, China; Prof. Xiaofeng Zhu, University of Electronic Science and Technology of China; Prof. Yang Yue, Nankai University, China; Prof. Li Na, from Xi' dian University, China; Assoc. Prof. Zhengtian Fang, from University of Macau, China. They had outstanding research in Mechanical Automation and Electronic Information Engineering and other related area.

The proceedings present a selection of high-quality papers submitted to the conference by researchers from universities, research institutes, and industry. All papers were subjected to peer-review by conference committee members and international reviewers. The papers were selected based on their quality and their relevance to the conference. The proceedings present recent advances in the fields of Mechanical, Force and Tactile Sensors, Industrial Tribology, Machine Vision, Algorithm and Data Structure and others related research.

I would like to express special gratitude to members of the conference committee and organizers of the conference. I would also like to thank the reviewers for their valuable time and advice which helped in improving the quality of the papers selected for presentation at the conference and for publication in the proceedings. Finally, I want to thank the authors, the members of the organizing committee, the reviewers, the chairpersons, sponsors, and all other conference participants for their support of MAEIE 2021.

The Committee of MAEIE 2021

List of Committee member are available in this pdf.

All conference organisers/editors are required to declare details about their peer review.

Therefore, please provide the following information:

• Type of peer review: Double-blind

• Conference submission management system: AI Scholar System

• Number of submissions received: 96

• Number of submissions sent for review: 89

• Number of submissions accepted: 48

• Acceptance Rate (Number of Submissions Accepted/Number of Submissions Received X 100): 50%

• Average number of reviews per paper: 2

• Total number of reviewers involved: 35

• Any additional info on review process:

• Step 1. Each of selected paper will be reviewed by two/three professional experts in the related subject area.

• Step 2. Review Reports received from the experts will be judged by one of the editors either Review Reports are logical or not?

• Step 3. If not logical, then editor can assign new reviewer or can also judge at his/her own.

• Step 4. If logical, then Review Reports will be sent to authors to modify the manuscript accordingly.

• Step 5. Authors will be required to revise their papers according to the points raised.

• Step 6. Revised version will then be evaluated by the editor for the incorporation of the points raised by the reviewers.

• Step 7. Then the editor will send the revised manuscript to the reviewers again for re-evaluation.

• Step 8. If the reviewers approve the revise version of the manuscript, then will be accepted for publication.

• Contact person for queries:

Xuexia Ye

publication@keoaeic.org

AEIC Academic Exchange Information Centre

The longitudinal vibration of the bottom drill string is violent and the law is complex during the deep well drilling. The vibration of the drill string brings many adverse effects on the drilling pipe fracture and bit trampoling. Generally speaking, the effective way to control the vibration of drill string is to install damping device in bottom hole. The research group proposes a device that uses the longitudinal vibration energy of the deep well drill string to modulate the impact dynamic load, which converts the vibration energy of the downhole drill string that is not conducive to drilling into the mechanical impact energy that improves the rock breaking capacity of the bit. The impact load modulation device can use the drill string to apply the "mechanical WOB" and the differential pressure between the upper and lower piston to produce the "hydraulic WOB", The simulation results show that the adjustable range of output load is 2 ~ 7T, and the change of each time is about 2T. The modulation law of impact load under the influence of longitudinal vibration of drill string and different parameters is analyzed. Through ground experiment and simulation, the damping performance and speed-up effect of the modulation device are compared and analyzed, and the impact load output characteristics of the device are analyzed, which provides a thinking for the design of damping and pressurization tools.

This paper studies the measurement technology of heat transfer coefficient of building envelope, explores the main factors affecting the measurement of heat transfer coefficient, uses ANSYS Icepak software to simulate the steady-state heat transfer property measurement platform model, and establishes the virtual prototype of the product. The product design based on Icepak replaces the test on the physical prototype with the simulation on the virtual prototype, We should reduce or even cancel the manufacturing of physical prototype, shorten the R & D process, and cut R & D costs with the improvement of design quality. Through the comparison and analysis with the experimental data of the offline detection platform, the feasibility of using Icepak to simulate the equipment is proved. The software is used to simulate the ther-mal environment in the hot box. Through comparison and analysis, the most uniform upper wi-nd steady-state thermal environment scheme is found.

This paper proposes an integrated simulation method of the performance and reliability for aerospace electromechanical products, which can obtain the reliability parameters of the product through digital simulation, so as to guide the design of the product, taking into account the factors that affect the reliability in the design stage. This method is based on a multidisciplinary performance simulation model, comprehensively considers the failure mode and failure mechanism of the product. Through the method of DESIGN OF EXPERIMENT(DOE), the key design parameters and disturbance factors are combined and designed as input, the performance response surface model, the performance and reliability integrated simulation model are constructed in turn. Taking a typical aerospace electromechanical product solar wing drive mechanism as an example, the engineering application verification is carried out, and the response surface has a high matching degree with the sampling point, which can meet the engineering application.

In order to solve the problem of abrupt curvature change at the connection between arcs and straight lines in circle-line-circle (C-L-C) combined parallel parking paths, curvature optimization was carried out by using a cycloid curve, and the trajectory curvature and heading Angle were made to meet the pose requirements of parallel parking. By establishing the kinematics model state equation and taking the optimized C-L-C trajectory as the reference trajectory, the error model was obtained. The model predictive controller based on the error model was designed, and the effectiveness of the path planning and model predictive controller was verified on Carsim and Matlab/Simulink co-simulation platform.

Aiming at the path tracking problem of the AGV transfer platform of an Optical module installing and calibrating system, this paper designs a pure pursuit control strategy in which the preview distance changes adaptively according to the current speed of AGV and the curvature of the reference path. Firstly, AGV kinematics model and pure pursuit model are established according to the geometric relationship. Then fitness function is established with tracking deviation and steering stability, and Particle swarm optimization (PSO) algorithm is used to optimize the preview distance of pure pursuit model of AGV under various working conditions. During the tracking process, AGV selects the optimal preview distance according to the curvature of the reference path and the current speed. The simulation experiment results show that the improved pure pursuit control strategy containing curvature information of reference path can improve the adaptability of AGV when it is tracking complex path, guaranteeing tracking accuracy and steering stability.

Aiming at the problem that the exiting human skeleton-based action recognition methods cannot fully extract the relevant information before and after the action, resulting in low utilization efficiency of skeleton points, we propose a two-layer LSTM (long short term memory) network with attention mechanism. The network has two layers, the first LSTM network is used for skeleton coding and initialization of system storage units and the second LSTM network integrates attention mechanism to further process the data of the first layer network. An algorithm is designed to assign different weights to skeleton points according to the importance of human body, which greatly increases the recognition accuracy. Action classification is accomplished by multiple support vector machines. Through training and testing, the average recognition rate of 98.5% is achieved on KTH dataset. The experimental result shows that the proposed method is effective in human behavior recognition.

The force supple control method of robotic arm has been widely researched internationally for many years, and its specific use varies according to the structure of the robotic arm, the location of the sensor, the working space environment, and other factors. Based on the force control principle and control method of the space robot arm, this paper adopts the position-based Cartesian spatial impedance control and proposes an effective forcesmoothing control method after pre-processing the feedback signal of the six-dimensional force sensor installed at the end of the space robot arm with the coordinate system conversion. In addition, the proposed position-based Cartesian spatial impedance control method is modeled and simulated to analyze the effect of each control element on the force-following control effect, to find out the control conditions that can optimize the force-position control effect, and finally to optimize the impedance parameters. This study aims to promote the rapid development of the field of robotic arm control.

This paper studies the influence of the material quality in the vibrating plate and the relative height difference of the leaf springs on the stability of the worktable, i n order to obtain the disturbance law; firstly, the control variable method is adopted an d the Ansys workbench software is used to determine the quality of different materials on the worktable under static force. Secondly, the deformation of the beam and the cr ossbeam was compared by a simulation test. The results showed that the heavier the m aterial, the greater the deformation of the upper beam and the smaller the deformation of the crossbeam. Finally, the harmonic response method was used to study the effect of the height difference of the leaf spring on the deformation of the beam and the cro ssbeam of the worktable. The results show that the greater the height difference, the s maller the impact on the stability of the workbench.

Based on the work tasks and positioning characteristics of indoor robots, the environment is divided into grids, and wireless sensors are used to detect obstacles, and the density of obstacles in each grid is given. At the same time, the path planning algorithm is combined to realize the optimal path planning of indoor robot. The simulation results show that the wireless sensor network can realize the obstacle density detection, so that the robot can achieve fast optimal path planning and reach the target point.

RF (Radio Frequency) connector has been extensively applied in the field of communication for it is a key device of transmitting microwave signals. If he RF connector end is designed improperly in dimension, a clearance will be observed after inserting, resulting in an abnormal phenomenon in the voltage standing wave ratio (VSWR) of the RF connector. This paper studied the influence of the inserting clearance of RF connector on the voltage standing wave ratio through theoretical analysis and performance simulation. Moreover, the solution to the abnormal voltage standing wave ratio was also proposed. At last, the abnormal phenomenon of voltage standing wave ratio of the connector in the inserting process was handled by means of carrying out optimization design and test validation on the RF connector.

With the development and popularization of UAVs, illegal UAV accidents occur frequently. The complex signal environment in the city brings difficulties to detect UAV signal. In order to detect the UAV signal in the complex environment, this paper proposes a UAV detection algorithm based on the difference of power dispersion in time. Firstly, the algorithm performs short-time Fourier transform on the signal to obtain the time-frequency matrix. Secondly, The fixed frequency interference in the matrix is filtered by the local adaptive threshold. Finally, the UAV image transmission signal is detected by the discrete difference in time between image transmission signal and WiFi. Simulation results show that the algorithm can detect UAV signal under constant frequency interference and WiFi interference.

With the development of science and technology, self-driving automobile will become increasingly available in the future, and our lives will become more convenient with them. Autocar is in an area of robotics, belonging to the service field. It can be used to make our lives better and reduce the cost of human driving the car, thus will have a great effect on human's life. However, people do not understand the mechanism of self-driving quite clearly, it is necessary to present some basic operating process and related algorithms of the automatic cars. Meanwhile, in order to show how a self-driving car could control itself using various sensors and algorithms, which is also the basic idea of the automobile company to make a new autocar. Different sensors that are able to detect the behavior of the self-driving cars are used in this paper to fit in different algorithm that follows the principles of motion and robotics. It is concluded that the car could theoretically drive safely, and could avoid crashing to other cars, people or barriers with the safety algorithm. Also, the car could follow the traffic rules properly and plan the most efficient route to get to the final location.

Aiming at the premature convergence problem of particle swarm optimization (PSO) due to the loss of population diversity in the late stage of search, this paper improves the traditional PSO and proposes the elite mean deviation induction strategy, which improves the convergence speed and accuracy of PSO. The experimental results show that the convergence speed and accuracy of the improved PSO are improved. The effectiveness of the improved algorithm is proved.

As con-rod is a critical component in an engine, its reliability overwhelmingly directly affects the performance of the whole diesel engine. The fretting wear of con-rod bushing mainly occurs on the contact surface with con-rod small end and con-rod small end cap. In the proposed study, the contact process of con-rod small end, con-rod small end cap and bushing under maximum combustion pressure condition was analyzed, and the distribution of contact pressure and friction stress was analyzed. Then the orthogonal simulation test was designed. According to the contact mechanics theory, the interference amount and friction coefficient of the contact surface were taken as the test factors, and the maximum contact pressure and friction stress under the maximum combustion pressure condition were taken as the objective functions. The influence of the test factors on the objective function was analyzed, and the most reasonable interference amount and friction coefficient were found, so as to slow down the fretting wear of the con-rod bushing.

Stiffness evaluation can improve the reliability and safety of combined machinery, which is often used to evaluate the performance of combined machinery. In order to study the stiffness evaluation method and rapid matching of mechanical composite structure, the composite machinery composed of high-power diesel is taken as the research object. The results show that the error between test mode and calculation mode is no more than 10%, indicating the reliability of finite element simulation model; two characterization methods of static stiffness and dynamic stiffness are determined, and the analysis methods of two characterization methods of combined machinery are discussed one by one. Taking the combined machinery of body, main bearing cap and oil pan as the research object, the overall stiffness characterization data of three parts are obtained one by one; finally, the principles of mechanical combination Stiffness Evaluation and rapid matching are summarized. This study provides a reference for Stiffness Evaluation and rapid matching of combined mechanical structures.

In order to improve the performance of the refrigeration system, researchers have introduced nano-refrigerant and nano-lubricating oil into the latest development of airconditioning system. However, explaining the role of nano-particles based on the physical phenomena affecting the vapor compression refrigeration system (VCRS) has been limited in experiments. Therefore, this paper reviews the mechanism of using nano-refrigerant and nano-lubricating oil to improve the performance of VCRS, discusses the compression work of the refrigeration system using nano-refrigerant and nano-lubricating oil and VCRS performance parameters such as COP and COF, and relates them to the overall performance of the system. The results show that the main factors affecting the performance of VCRS are heat transfer enhancement, refinement of the characteristics of cold oil mixture and improvement of tribological properties. The influence of nano-refrigerant and nano-lubricating oil on heat transfer, cold oil mixture and tribological properties of VCRS improves the overall performance of VCRS. Therefore, nano-refrigerant and nano-lubricant are expected to be the best choice to improve the efficiency of VCRS.

For the low-voltage transformer district with distributed generations (DGs), the traditional theoretical calculation method of line loss is not applicable. This paper presents a novel clustering method for line loss data of transformer district with DGs, which combined an improved Cuckoo Search algorithm and K-Means clustering algorithm. Firstly, the influence factors of line loss are screened based on the maximum information coefficient, and the line loss index system is established. Secondly, an improved cuckoo search clustering algorithm is proposed to cluster the sample data set to reduce the dependence on the initial clustering center. Finally, the simulation results of 410 samples from a certain area with photovoltaic power supply show the accuracy and effectiveness of the proposed method. The simulation results show that the proposed method is accurate and effective.

A novel control strategy of synchronous compensators and converters is proposed to increase the ability of line commutated converter (LCC) based HVDC systems to successfully recover from commutation failures (CFs). The dynamic var support is one of the most important factors, which impact the commutation process. Many synchronous compensators have been implemented to enhance the transient voltage stability for improving the CF recovery performance. However, the traditional automatic voltage regulator (AVR) of synchronous compensator may not be suitable for the commutation voltage support, because the transient var demand of converters during the CF recovery is neglected. In our work, the voltage control will be adaptively adjusted, depending on the state of converters. Case studies based on simulations in PSCAD/EMTDC show that the proposed strategy can improve the performance of fault recovery from CF.

A miniaturized analog load-checking relay protection test device is developed in this paper, in which a high-precision wireless phase volt-ampere test device is configured. This device, characterized by intelligence and ease of operation, realizes the detection of the transformation ratio, polarity, phase, etc. of the secondary wiring of the transformer in the smart substation merging unit and the conventional substation. It meets the testing requirements of smart substations, and can test bus differential protection, line protection, and various protections such as main transformer differential.

The existing technology of automatic classification and recognition of welding negative images by computer is difficult to achieve a multiple classification defect recognition while maintaining a high recognition accuracy, and the developed automatic recognition model of negative image defect cannot meet the actual needs of the field. Therefore, the convolutional neural network (CNN)-based intelligent recognition algorithm for negative image of weld defects is proposed, and a B/S (Browser/Server) architecture of weld defect feature image database combined with CNN is established subsequently, which converted from the existing CNN by the migration learning method. It makes full use of the negative big data and simplifies the algorithm development process, so that the recognition algorithm has a better generalization ability and the training algorithm accuracy of 97.18% achieved after training. The results of the comparison experiments with traditional recognition algorithms show that the CNN-based intelligent recognition algorithm for defective weld negatives has an accuracy of 92.31% for dichotomous defects, which is significantly better than the traditional recognition algorithm, the established recognition algorithm effectively improving the recognition accuracy and achieving multi-category defect recognition. At the same time, the CNN-based defect recognition method was established by combining the image segmentation algorithm and the defect intelligent recognition algorithm, which was applied to the actual negative images in the field with good results, further verifying the feasibility of CNN-based intelligent recognition algorithm in the field of defect recognition of welding negative images.

Bluetooth Low Energy (BLE) is an innovative technique that was firstly employed in Bluetooth 4.0 and is being applied in the Bluetooth 5.0 and 5.2 technologies. Bluetooth 5.0 and 5.2 technologies are now widely used in all kinds of electronic communication equipment (e.g., PCs, tablets, smartphones, wearable devices). BLE has the capacity to minimize the power consumption and equipment cost in the low-power devices, which becomes a competitive scheme among the huge number of standard wireless transmission techniques already existing in everyday life for a large number of applications. As one of the available solutions in wireless transmission, Bluetooth technology equipped with the BLE module is very suitable for developing internet of things (IoTs) technology, which is gaining more and more interest. This paper briefly introduces the modulation and encoding of the BLE standard in the physical layer (PHY). The applications of cyclic redundancy check (CRC) in BLE are then presented. Moreover, the main characteristics, including the maximum reachable range, transmission latency, and power consumption of BLE, are also introduced.

Aiming at the defects of difficult to establish fault diagnosis models caused by the small scale of liquid rocket engine test data, imbalanced categories and high fault coupling, the fault diagnosis platform with 10 fault diagnosis models are developed for fault diagnosis, covering K-nearest neighbor (KNN) model, optimized KNN model, logistic regression (LR) model, optimized LR model, support vector machine model, K-means model, decision tree model, neural network model, random forest model and light-GBM model. The prediction accuracies of these models are validated based on the experimental data. Among these models, the light-GBM model provide the best prediction accuracies, and 5 models have the prediction accuracy larger than 98%.

Utility function of packet is often used to decide how to replicate packet in DTN networks. But this method has more uncertainty and relies on a single performance metric. For this problem, in order to reduce the impact of a single metric uncertainty, multiple utility metrics are introduced in the new algorithm. A packet replication probability calculation method based on entropy weight is designed. By calculating the entropy weight of each metric, the algorithm obtains the replication probability of each packet and takes the probability as the priority of packet replication. Because of considering the two metrics of packet expected transmission delay and node encounter possibility, the algorithm effectively reduces the influence of encounter time distribution problem and direction prediction problem in the original algorithm, and reduces the uncertainty of utility function. Simulation results show that the algorithm reduces the packet replication number and the average delay, improves the successful packet delivery rate. The overall performance of the network is further improved.

Nowadays, laser communication has received great achievements owing to its advantages, e.g., large channel capacity, easy miniaturization of communication system and strong anti-interference ability in different conditions. Pulse position modulation (PPM), as an important modulation technology in laser communication system that transmit signal with lower power, is attracting much attention. However, the performance of the modulation scheme highly depends on the bandwidth of transmission. To remedy this defect of PPM, the multipulse position modulation (MPPM) scheme is proposed to increase the accuracy and bandwidth limit. This modulation scheme has stronger anti-interference ability than PPM. Therefore, there has been rising interest in studying the characteristics of the multi-PPM. In this article, we developed an appropriate mathematical model to represent a PPM transmission, analyzed the spectrum of the transmission and characterized the bandwidth of this transmission. Compared with benchmarks of MPPM scheme, its performance has been discussed. According to the analysis, MPPM strongly increases band-utilization efficiency, however PPM has a better bit error rate (BER) performance than MPPM.

After the oblique aerial photography technology is used to collect the stereo image, it is necessary to use the relative orientation method to check the image parameters. After the rectification process is completed, the 3D software is used to draw the 3D model to meet the subsequent application requirements. The author of this paper analyzes the difficulty of the matching and aerial photography, including affine transformation cannot successful transformation, influence there covered phenomenon and characteristic finishing is difficult, the combination of fundamental matrix tilt aerial photography as a method of relative orientation, through the study of oblique aerial photography based matrix as precision control points, its aim is to continuously optimize tilt aerial photography as the content, improve the use value of collation results.

In this paper, voltage equalization, corona prevention and noise reduction are studied by using finite element calculation method and multi-objective optimization algorithm for UHV substation, series compensation circuit, transmission line, DC valve hall and outdoor field. The calculation model of multi parameter and multi-objective optimization design is established, the optimal configuration parameters of voltage equalizing structure are obtained, the electric field distribution uniformity and structure rationalization are realized, the corona discharge is effectively restrained, the key technology of voltage equalizing and anti corona is solved, the cost is reduced, the efficiency is improved, and a simulation calculation and optimization design platform with independent intellectual property rights is formed. The research results have been successfully applied to UHV projects in China.

Aiming at the problems such as limited transmission distance of traditional temperature data, complex wiring and aging line, ZigBee wireless network is introduced into the temperature acquisition system of the intaglio printing machine oven, which makes the whole system easy to operate and simple, and greatly improves the transmission distance of temperature signal. The composition of the temperature monitoring system and the hardware circuit of the ZigBee master node are described, including DC 5 V power supply circuit and USB interface power supply circuit, the connection circuit between the RADIO frequency board and the backboard, to realize the construction of the network and the wireless reception of temperature data. To realize the construction of the network and wireless reception of temperature data. It combines ZigBee wireless communication technology to complete real-time transmission of multi-point temperature data, realize real-time LCD display of multi-point temperature data collected by DS18B20, and realize ZigBee networking function based on ZigBee protocol stack.

Aiming at the complex dynamic changes of inter-satellite link signals, this paper proposes a low-complexity method to calculate dynamic parameters of inter-satellite link signals so as to simulate inter-satellite link signals with complex dynamic characteristics. Based on the precise ephemeris, the algorithm is used to calculate the transmission delay and Doppler frequency of the signals in an inertial frame of reference by using iteration and interpolation. The calculation result is compared with the result obtained by using the simulation software of the global navigation system. It is found that the error of the transmission delay is at the nanosecond level and the error of Doppler frequency is at the Hertzian level. Therefore, the dynamic signal simulation accuracy can meet the requirements of load testing and verification of inter-satellite links. The algorithm is simple to implement.

Aiming at the problem of the small aperture of the traditional MIMO radar with virtual degrees of freedom, this paper designs a high degree of freedom space-limited MIMO radar. Both the transmitting and receiving elements of this radar adopt a sparse array structure. Array composition, the receiving array element is composed of a single array element and a uniform linear array. The number of virtual array elements can be realized by using array elements. Compared with the traditional sparse array MIMO radar with the same number of elements, the designed space-limited sparse array MIMO radar has a larger aperture. Experimental simulations verify the superiority of the space-limited MIMO radar angle estimation.

Pulse-Position Modulation (PPM) is a modulation method that only makes every pulse in the carrier pulse sequence change with time but without changing the shape and amplitude of the pulse signal. In this paper, a PPM system is designed. Firstly, an appropriate mathematical model is established to represent PPM transmission, and the shape of the pulse signal is designed. After that, we write the code and add a white Gaussian noise channel. Then the transmission process is simulated and visualized. At last, the error rate of the scheme is analyzed and discussed through MATLAB simulation then compared with other modulation methods. The goal of this paper is to study PPM by designing a PPM system fully. Besides, our method is compared with other modulation methods to understand the advantages and disadvantages of PPM. This may help other scholars to design and research the PPM system.

In order to improve the testability design level of radar equipment, achieve rapid detection and isolation of faults, and reduce the life cycle cost of the system, a testability analysis method of radar equipment based on correlation model is proposed. The basic process of correlation model modeling is introduced. On this basis, the optimization method of test points for fault detection and isolation and the generation method of fault diagnosis strategy are analyzed. The effectiveness of the proposed method is verified by applying it to radar transmitting subsystem.

With the improvement of vehicles automation, autonomous vehicles become one of the research hotspots. Key technologies of autonomous vehicles mainly include perception, decision-making, and control. Among them, the environmental perception system, which can convert the physical world's information collection into digital signals, is the basis of the hardware architecture of autonomous vehicles. At present, there are two major schools in the field of environmental perception: camera which is dominated by computer vision and LiDAR. This paper analyzes and compares the two majors schools in the field of environmental perception and concludes that multi-sensor fusion is the solution for future autonomous driving.

Contemporarily, the Internet of Things (IoT) is recently a newly emerging technology for connecting small devices into a platform; the IoT has been an increasingly demanded front-edge technology in terms of connecting different devices using information transmission and storage technology. To adapt to the small capacities of device batteries, Bluetooth Low Energy is adopted as the protocol of communication. However, the existing standards do not have a suitable and specific error correction method. As there is no ideal information transmission channel, there must be errors that occurred during message transmission. The performance and capacity of error correction become decisive factors in evaluating how efficient the IoT communication system performs. This article uses convolutional coding—a better-performing coding scheme than block coding—to correct errors in information transmission and reception on Internet of Things devices. It is better competent to control and correct bit errors in information transmission. To achieve this goal, convolutional coding algorithms devised by Dr Justin Coon at the University of Oxford have been referred to. By simulation using MATLAB, it has been found that the error rate is enhanced significantly for high Signal-to-Noise Ratio (SNR) in convolutional codes compared to uncoded messages.

With the development of network and communication technology in modern society, WiFi technology has become an indispensable part of people's lives. WiFi shows its future application prospects with its wireless portability and multi-user access. This paper briefly introduces the meaning and development of WiFi technology and predicts its future development trend. The communication modulation technology QPSK, 16QAM in WiFi is described in detail, and its characteristics are compared by systemview and MATLAB software. Finally, we summarize the common techniques in WiFi.

In the process of site selection for the deployment of distributed systems, in order to solve the problem of inaccurate spatial isolation simulation results caused by the large influence of complex geographic information such as terrain and weather on the propagation of radio waves, and to solve the problem of inefficient and inefficient spatial isolation testing. This paper proposes to select suitable propagation models for different geographical information in different regions, clarifies the simulation calculation method, and proposes a test method to accurately determine the direction of the transceiver antenna for the minimum spatial isolation. By comparing and analyzing the simulation calculation results and test verification results, correction parameters such as simulation system error, atmospheric absorption loss, and geological absorption loss are proposed. This article analyzes and studies the correction value of radio wave transmission loss of S-band electromagnetic signal under different geographic information conditions such as snowfall and iron ore through an example. It can provide reference values for some of the influencing factors of electromagnetic signal propagation loss under geographic information conditions, and it can improve the accuracy of the simulation calculation results of the spatial isolation under the conditions of geographic information.

This paper discusses the setting of transceiver based on functional programming, and decouples the differences between communication protocol and network transmission protocol from the specific business implementation. In the actual application, the service implementation is set up. When the communication protocol changes, the function can be realized only by modifying the communication protocol, which improves the readability of the program and reduces its maintenance overhead

When the rocket uses low-orbit satellite space-based measurement and control, due to the relatively large Doppler shift in relative motion, a spread spectrum system is needed to improve anti-interference; the spread spectrum signal under high dynamic conditions often uses partial matched filtering based on FFT (PMF-FFT) algorithm, but due to the introduction of FFT, this algorithm has serious scallop loss, which affects the system's capture performance. Through the improved method of adding a Hamming window to the system, theoretical analysis and simulation show that it effectively suppresses scallops. Loss has a certain meaning for the acquisition of spread spectrum signals.

An adaptive optics system can measure and compensate the wavefront distortion caused by dynamic disturbance in real time. It is usually used for astronomical observation and other occasions. According to the current technology, it is only suitable for small field of view optical system or point target, but not for ground extended target detection. In order to solve this problem, a correction method is proposed: firstly, the sub aperture image of wavefront sensor is divided into several sub regions, each sub region corresponds to a certain light direction or field angle range; secondly, calculate the offset of the image feature points in each sub region, and an image with good correction effect in a field of view in this direction is obtained; the last step is to measure each sub region one by one and combine these images into a full frame image. Through comparison, it is found that the method proposed in this paper is essentially to divide the extended target into multiple point light sources for correction.

Considering the end effect, the three-dimensional finite element calculation model of the magnetic coupling is established. The three-dimensional distribution nephogram of the induced current and eddy current loss on the isolation cover is obtained, and the distribution trends of the two are consistent. The influence of size, material, and operating condition of magnetic coupling on eddy current loss is studied. The results show that the selection of isolation material with high resistivity and the reduction of isolation thickness are helpful to reduce the eddy current loss. The higher the rotating speed of the magnetic coupling, the greater the eddy current loss. At the same speed, the greater the load, the greater the magnetic declination, the smaller the eddy current loss. The research results can provide a reference for reducing energy loss and cooling structure design of magnetic coupling.

In order to improve distribution equipment reliability and emergency repair response speed, a distribution equipment monitoring system based on Internet of things and multi-agent is designed by building a hierarchical model. The system is based on the power Internet of things, which is divided into sensing layer, device layer and data center layer. The sensing layer realizes multi-source data acquisition through sensors and acquisition devices; the device layer deploys edge computing agents to realize device-level monitoring; and the data center layer deploys coordinating agents to realize system-level analysis. The dual-way communication is used to realize data transmission between up layer and down layer. The system has the characteristics of distribution, autonomy and multi-objective interaction, which can meet and adapt to the demand and development trend of intelligent operation and maintenance of distribution equipment.

In this study, based on Galerkin discretization and frequency splitting, the forced vibration response of a large span cable with time periodic tension is approached as a closed-form solution, i.e. a special trigonometric series with mode functions. According to the principle of modulation feedback, the forced vibration response solution can be expressed as a series of linear combination of external excitation frequency and parametric excitation frequency with modes. Using orthogonality relation, the formula of forced vibration response approach is obtained. Investigations show that the presented approach computes the forced vibration response with higher accuracy. Therefore, this study is available to analyze the vibration of a large span cable with time periodic tension, and the characteristics of vibration response could be used as an important information source for the failure diagnosis and the health monitoring of cable structure.

This paper presents a multi-point strain monitoring method based on distributed sensors, which can monitor the multi-point stress of prestressed tendons in concrete. Firstly, the special sensor protection device is installed in the designated position of the component. Then, the sensor is placed in the device and attached to the monitored prestressing tendon. After concrete pouring, the device can form a closed space around the sensor to ensure that the sensor can freely expand and move in a small range when the prestressed tendon is tensioned. The proposed method is applied to the monitoring of the construction period and initial operation period of a large-span spatial structure, and the research results show that the method proposed in this paper can well realize the multi-point monitoring of the prestressed tendon strain in the concrete, and effectively solve the engineering problems; through the analysis of the long-term monitoring data, we can accurately grasp the influence of each construction condition on the structure stress, and clarify the actual stress state and long-term change trend of the structure. The obtained monitoring data play a positive role in guiding the construction of prestressed structure, and the construction safety can be objectively evaluated by analyzing the monitoring data.