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Bit-Level Composite Signal Design for Simultaneous Ranging and Communication

China Communications 2021年第6期18卷 214-227页

作者： Weigang Chen Yalong He Changcai Han Jinsheng Yang Zhan Xu School of Microelectronics Tianjin UniversityTianjin 300072China Key Laboratory of Modern Measurement and Control Technology Beijing 100192China School of Information and Communication Engineering Beijing Information Science and Technology UniversityBeijing 100192China

As the complexity of space exploration missions augments,how to enhance the overall performance of communication,ranging or other functions has become a challengeable *** the integration of communication and ranging,we present a bit-level composite signal for simultaneous ranging and *** this composite method,through a specially designed mapping scheme using low-weight codewords,the information sequence is converted to a sparse sequence which is then superimposed on the ranging *** ranging,the correlation characteristics of the ranging code component can be maintained to calculate the transmitter-receiver *** communications,the sparse sequence can be extracted without interference by eliminating the ranging code *** results show that the proposed composite signal can support communication and ranging simultaneously with limited sacrifice of ranging performance,and the performance loss of ranging can be controlled and minimized by lowering the density of information sequences using different sparsification encoding methods.

关键词： composite signal spectrum sharing lowweight codeword regenerative PN ranging code

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Design and Fabrication of Highly Thermally Conductive 1-1-3 Piezoelectric Composites

SSRN

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SSRN 2024年

作者： Liu, Zhiyang Zhang, Zhiwei Qin, Lei Beijing Key Laboratory for Sensors Beijing Information Science & Technology University Beijing100192 China Key Laboratory of Modern Measurement and Control Technology Ministry of Education Beijing Information Science & Technology University Beijing100192 China

1-3 piezoelectric composites have been widely used in transmitting transducers, medical devices, navigation, and aerospace. Due to poor thermal conductions inside piezoelectric composite, performance degradation and service life shortening are easily caused while transmitting transducer are working under high-power or continuously operated environments. A solution to this problem is provided by designing and creating highly efficient thermally conductive paths in 1-1-3 piezoelectric composite. This novel design resulted in two-fold increase in heat dissipation rate of 1-1-3 piezoelectric composite, at the meanwhile the electromechanical coupling factor remains higher than 0.61. © 2024, The Authors. All rights reserved.

关键词： Finite element method

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MARS ENTRY TRAJECTORY TRACKING COMPOUD control BASED ON NONSINGULAR FAST TERMINAL SLIDING MODE AND RBF NEURAL NETWORK 9

MARS ENTRY TRAJECTORY TRACKING COMPOUD CONTROL BASED ON NONS...

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9th International Symposium on Test Automation and Instrumentation, ISTAI 2022

作者： Dai, Juan Zhu, Shengtao Fan, Cunli Li, Jianfeng University of Beijing Information Science & Technology Beijing Key Laboratory of High Dynamic Navigation Technology Beijing100192 China Key Laboratory of Modern Measurement & Control Technology Ministry of Education Beijing100192 China School of Automation Beijing Information Science & Technology University Beijing100192 China

ISBN: (纸本)9781839538391

To realize the exact location of the Mars probe's entry trajectory, a glide mode control method based on the radial base function (RBF) neural network and non-lingual high-speed terminal is proposed. A model of the Mars probe's atmospheric entry section has been created, and the high-speed non-digital final slip controller is designed to approach track tracking error in a limited time and accelerate the approach speed. Neural networks are used to estimate and correct for complete system interruptions, and the stability of the system has been proven according to Lyapunov's theory of stability. The results of the Mars landing simulation show that the proposed control method can quickly approach unknown uncertain alarms, effectively monitor the landing trajectory of the probe to reach the parachute opening point with high precision, and improve the landing stability of the catheter. © 2022 IET Conference Proceedings. All rights reserved.

关键词： Probes

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Dynamic Compensation Method for CNC Crankshaft Grinding Machine 1

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TEPEN International Workshop on Fault Diagnostics and Prognostics, TEPEN-IWFDP 2024

作者： Zhang, Peishuo Wang, Hongjun Ge, Henglin China Academy of Machinery Science and Technology Group Co. Ltd. Beijing100044 China School of Mechanical and Electrical Engineering Beijing Information Science and Technology University Beijing100192 China Key Laboratory of Modern Measurement and Control Technology Ministry of Education BISTU Beijing100192 China Beijing International Science Cooperation Base of High-End Equipment Intelligent Perception and Control BISTU Beijing100192 China

ISBN: (数字)9783031694837

ISBN: (纸本)9783031694820

Crankshaft journal size errors are unavoidable during the machining process, and limiting them within a certain range is crucial to ensuring the overall precision of the engine. When comparing domestically produced crankshaft grinding machines with those from abroad, it is evident that while the processing accuracy is similar, there is a significant gap in terms of processing stability. By analyzing the characteristics of the online measurement instrument and grinding process matching in crankshaft grinding, a simple online monitoring method for journal size errors is proposed. A dynamic error compensation method is proposed for such size errors, allowing the machine tool to automatically adjust the compensation amount to achieve self-adaptation and self-matching for the online measurement instrument and dimensional tolerances. Experimental verification shows that this method can significantly improve the dimensional error accuracy of the machine tool, meeting the needs of most customers in the market. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.

关键词： Grinding machines

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Traffic Sign Recognition Method Based on Dual-Channel CNN 15

Traffic Sign Recognition Method Based on Dual-Channel CNN

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15th IEEE International Conference on Electronic measurement and Instruments, ICEMI 2021

作者： Zhao, Zeyi Zhou, Fuqiang Wang, Shaohong Xu, Xiaoli Chao, Fenjin Lin, Zhoupeng Beijing Information ScienceTechnology University Ministry of Education Key Laboratory of Modern Measurement Control Technology Beijing China

ISBN: (纸本)9781665444910

Aiming at traffic sign problem, the traditional LeNet-5 network structure has low accuracy of traffic sign recognition, slow identification speed and ignores natural factors such as weather. A convolutional network structure model with two-channel and multi-scale based on LeNet-5 improvement is proposed by convolutional neural network technology. In the dual-channel structure, each channel contains two branching structure, and the number of convolution and image scale of each channel is different, making the feature extraction of different image scales richer. Secondly, the improved network structure greatly increases the number of convolutional kernels compared to the traditional LeNet-5 network structure. Finally, by changing the Sigmoid activation function to the ReLu activation function, changing the stochastic gradient descent algorithm to the Adam algorithm, and adding Dropout layers to prevent overfitting and setting the learning rate, thus increasing the traffic sign recognition rate. The recognition rate of the improved network is 98.6%, floating by 0.5%, relative to the traditional LeNet-5 network structure, the recognition rate increases by more than 15%, verifying that the improved network structure has a certain robustness. © 2021 IEEE.

关键词： Convolution

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Study of the sensitivity mechanism of a flexible temperature sensor

Study of the sensitivity mechanism of a flexible temperature...

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10th International Symposium on Test Automation & Instrumentation (ISTAI 2024)

作者： Jiahao Sun Linhua Piao Yonghao Zhang Beijing Key Laboratory of Sensors Beijing People's Republic of China Modern Measurement and Control Technology Ministry of Education Beijing People's Republic of China

ISBN: (数字)9781837241910

In this paper, a structure of a flexible temperature sensor is proposed. And its sensitivity mechanism is investigated. A physical model is established based on the proposed structure. A mathematical model is established based on the actual situation. A 3D model of the structure is created by COMSOL software. In which the mathematical model is studied for this sensor. The temperature field within this sensitive structure was calculated using the finite element method. The corresponding material properties in the sensor structure were set. Setting up the physical fields required for operation. Mesh this 3D structure. Setting the external ambient temperature. Setup of the type of study according to the actual situation. The sensor detects the ambient temperature. Calculations are made based on the results of the finite element method, combined with the corresponding theoretical formulas. It is calculated that the temperature coefficient of resistance is 0.0316/° C in the temperature range of -18~80 ° C, and the nonlinearity is 1.36%. There results conclude that the relationship between temperature and resistance is proportional. This lays a theoretical foundation for the optimisation of subsequent structural studies of flexible temperature sensors. It facilitates further performance enhancement in subsequent research. This promotes the research progress in related fields.

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Precipitation Retrieval of FY-3D MWHTS and MWRI Data Based on Light Gradient Boosting Model

Precipitation Retrieval of FY-3D MWHTS and MWRI Data Based o...

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Progress in Electromagnetic Research Symposium (PIERS)

作者： Yanfang Lv Lanjie Zhang Yifan Zhang Biao Zhang Key Laboratory of Information and Communication Systems Ministry of Information Industry Beijing Information Science and Technology University Beijing China Key Laboratory of Modern Measurement and Control Technology Ministry of Education Beijing Information Science and Technology University Beijing China

ISBN: (数字)9798350375909

ISBN: (纸本)9798350375916

As an essential component of the earth system, precipitation plays a crucial role in the regional and global water cycle. This paper uses observations from the Fengyun-3D microwave humidity and temperature sounder and microwave radiation imager, as well as Integrated Multi-satellite Retrievals for GPM (IMERG), to establish a precipitation retrieval model based on the light gradient boosting model (LGBM). Using IMERG as the comparison data, the performance of precipitation identification with the LGBM-based precipitation retrieval model is as follows: accuracy is 0.9302, probability of detection is 0.7683, false alarm rate is 0.3529, and critical success index is 0.5414. The performance of precipitation estimation is also evaluated, with a correlation coefficient of 0.7536, a mean absolute error of 0.9119, and a mean squared error of 3.9506. In summary, this study achieves good performance in precipitation identification and estimation by the LGBM model.

关键词： Earth Correlation coefficient Precipitation Estimation Humidity Boosting Data models

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Typhoon Wind Speed Retrieval from HY-2C Microwave Radiometer Based on LightGBM

Typhoon Wind Speed Retrieval from HY-2C Microwave Radiometer...

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Progress in Electromagnetic Research Symposium (PIERS)

作者： Xuchen Dai Biao Zhang Yifan Zhang Lanjie Zhang Key Laboratory of Information and Communication Systems Ministry of Information Industry Beijing Information Science and Technology University Beijing China Key Laboratory of Modern Measurement and Control Technology Ministry of Education Beijing Information Science and Technology University Beijing China

ISBN: (数字)9798350375909

ISBN: (纸本)9798350375916

In this paper, the sea surface wind speed (SSWS) retrieval accuracy for HaiYang-2C (HY-2C) passive microwave radiometer under the severe weather such as typhoon is evaluated. Based on the observation data of HY-2C, this study explores the influence of brightness temperature (TB) observed by microwave radiometer on sea surface wind speed retrieval under typhoon conditions. In the case of typhoon precipitation, the attenuation of the atmosphere to the high frequency channel is stronger, which makes the sea surface information observed by the microwave radiometer very weak. Therefore, we mainly select the TB of horizontal polarization and vertical polarization observation of 6.9GHz and 10.7GHz channels to carry out the study of typhoon wind speed retrieval. This paper constructs a matching data set based on the TB observed by HY-2C passive microwave radiometer, HY-2C L2B wind product and H*wind reanalysis wind field data in October and November 2020. The maximum differences of spatial and temporal were set as 25km and 30minutes, respectively. Then, the typhoon wind speed retrieval model based on LightGBM is established. We use the data of October 2020 to train the model and the data of November 2020 to test model performance. Comparing with the H*wind reanalysis wind field data, the bias and root-mean-square error of retrieved wind speed are 0.15m/s and 1.26m/s, respectively. In addition, the correlation coefficient is 0.90, indicating that the retrieved wind speed has a good consistency with H*wind data.

关键词： Microwave measurement Sea surface Tropical cyclones Wind speed Microwave theory and techniques Data models Brightness temperature

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A Handover Self-optimization Mobility Load Balancing for Ultra-dense Networks 23

A Handover Self-optimization Mobility Load Balancing for Ult...

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23rd IEEE International Conference on High Performance Computing and Communications, 7th IEEE International Conference on Data Science and Systems, 19th IEEE International Conference on Smart City and 7th IEEE International Conference on Dependability in Sensor, Cloud and Big Data Systems and Applications, HPCC-DSS-SmartCity-DependSys 2021

作者： Li, Yujie Tang, Zhoujin Sun, Jian Yang, Xiaolong Chen, Shou Beijing Information Science and Technology University Beijing China Beijing Information Science and Technology University Key Laboratory of Modern Measurement & Control Technology Ministry of Education Beijing100101 China China Academy of Information and Communications Technology Beijing100191 China

ISBN: (纸本)9781665494571

The rapid increase in wireless data applications has caused the traffic congestion problem in local networks. Mobility Load Balancing (MLB) is an approach that timely and effectively deals with the load imbalance caused by traffic congestion. In this paper, we propose a handover (HO) self-optimization MLB algorithm, via cooperative user equipment (UE) selection, target cell selection and HO parameter adjustment to improve cell load balancing. Switching the least number of UEs to achieve the balance and guaranteeing the UE QoS after handover are both obtained with the proposed method. Simulation results show that the proposed algorithm can improve the cell coverage performance and communication capacity and also enhance resource block (RB) utilization under the load balancing framework in Ultra-dense Networks. © 2021 IEEE.

关键词： Wireless communication Simulation Switches Quality of service Handover Load management Big Data applications

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Tool Wear Prediction Based on Ball-End Milling Tool Milling Area 1

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TEPEN International Workshop on Fault Diagnostics and Prognostics, TEPEN-IWFDP 2024

作者： Liu, Jiacheng Wang, Hongjun Yang, Wenxian Wang, Zheng Cui, Yanyan Fu, Mingzhu School of Mechanical and Electrical Engineering Beijing Information Science and Technology University Beijing100192 China High-End Equipment Intelligent Perception and Control Beijing International Science and Technology Cooperation Base Beijing Information Science and Technology University Beijing100192 China MOE Key Laboratory of Modern Measurement and Control Technology Beijing Information Science and Technology University Beijing100192 China Centre for Efficiency and Performance Engineering University of Huddersfield HuddersfieldHD1 3DH United Kingdom

ISBN: (数字)9783031694837

ISBN: (纸本)9783031694820

The special geometry of ball-end milling tool is widely used in the precision machining and ultra-precision machining of complex surfaces. However, when enterprises are finishing, in order to ensure the processing quality, they often change the tool before the milling tool reaches the dull standard, increasing the production cost of the enterprise. In addition, different processing types also have different requirements for tool flank wear. Therefore, it is necessary to determine the flank wear of the ball-end milling tool during the machining process. In order to solve this problem, the cutting area in milling process is determined according to the cutting parameters and the geometric parameters of the ball-end milling tool, and the cutting force model based on the cutting area is constructed. At the same time, according to the material and geometric parameters of the tool, the wear model of the tool is constructed. The value of flank wear is determined by the calculated cutting force. Finally, using the high speed milling tool wear data set published in the PHM Society data Competition in 2010, the correctness of the wear model is verified by experiments and analysis. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.

关键词： Ball milling

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