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gradient descent algorithm Inspired Adaptive Time Synchronization in Wireless Sensor Networks

IEEE SENSORS JOURNAL 2016年第13期16卷 5463-5470页

作者： Yildirim, Kasim Sinan Delft Univ Technol Embedded Software Grp NL-2628 CD Delft Netherlands Ege Univ Dept Comp Engn TR-35100 Izmir Turkey

This paper proposes another direction to implement a lightweight synchronization service for wireless sensor nodes. To this end, we present gradient descent synchronization (GraDeS), a novel multi-hop time synchronization protocol based upon gradient descent algorithm. We give details about our implementation of GraDeS and present its experimental evaluation in our testbed of MICAz sensor nodes. Our observations indicate that GraDeS is scalable, and it has identical memory and processing overhead, better convergence time, and comparable synchronization performance as compared with the existing lightweight solutions.

关键词： Wireless sensor networks time synchronization least-squares gradient descent algorithm

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gradient descent algorithm-Based Adaptive NN Control Design for an Induction Motor

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IEEE TRANSACTIONS ON SYSTEMS MAN CYBERNETICS-SYSTEMS 2021年第2期51卷 1027-1034页

作者： Yang, Xuebo Zheng, Xiaolong Harbin Inst Technol Res Inst Intelligent Control & Syst Sch Astronaut Harbin 150001 Peoples R China

This paper investigates the position tracking control problem for an induction motor with completely unknown nonlinearities. A novel control scheme is presented by using the gradient descent algorithm, adaptive backstepping technique, neural networks (NNs), and extended differentiators. Differing from some existing results which only designed the adaption of weights of NNs, our proposed control strategy provides training for all the parameters of NNs, including the basis functions' widths and centers. With the help of the gradient descent algorithm and Lyapunov stability criterion, the convergence of both the NN approximation error and the system tracking error can be guaranteed. Finally, a simulation example shows the advantages of our proposed method compared with direct adaptive NN control strategy.

关键词： Backstepping gradient descent algorithm induction motor neural networks (NNs)

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gradient descent algorithm for Small UAV Parameter Estimation System

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Transactions of Nanjing University of Aeronautics and Astronautics 2017年第6期34卷 680-687页

作者： Guo Jiandong Liu Qingwen Wang Kang Key Laboratory of Unmanned Aerial Vehicle Technology of the Ministry of Industry and Information Technology Nanjing University of Aeronautics and AstronauticsNanjing 210016P.R.China College of Automation Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016P.R.China

A gradient descent algorithm with adjustable parameter for attitude estimation is developed,aiming at the attitude measurement for small unmanned aerial vehicle(UAV)in real-time flight *** accelerometer and magnetometer are introduced to construct an error equation with the gyros,thus the drifting characteristics of gyroscope can be compensated by solving the error equation utilized by the gradient descent *** of the presented algorithm is evaluated using a self-proposed micro-electro-mechanical system(MEMS)based attitude heading reference system which is mounted on a tri-axis *** on-ground,turntable and flight experiments indicate that the estimation attitude has a good ***,the presented system is compared with an open-source flight control system which runs extended Kalman filter(EKF),and the results show that the attitude control system using the gradient descent method can estimate the attitudes for UAV effectively.

关键词： gradient descent algorithm attitude estimation quaternions small unmanned aerial vehicle(UAV)

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Maximum Torque Per Ampere Control for IPMSM Using gradient descent algorithm Based on Measured Speed Harmonics

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IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS 2018年第4期14卷 1424-1435页

作者： Lai, Chunyan Feng, Guodong Mukherjee, Kaushik Tjong, Jimi Kar, Narayan C. Univ Windsor Dept Elect & Comp Engn Windsor ON N9B 3P4 Canada Indian Inst Engn Sci & Technol Sibpur 711103 Howrah India

This paper proposes a novel gradient descent based maximum torque per ampere (MTPA) control algorithm for interior permanent magnet synchronous machines (IPMSMs) by using the measured speed harmonics. The proposed approach does not require machine parameters and thus is not influenced by the machine and drive nonlinearities. Hence, the proposed approach can ensure a robust MTPA control under different loading conditions. Specifically, in the proposed approach, a small q-axis harmonic voltage is injected into the machine to induce a small harmonic component in the machine speed. Based on the PMSM torque equation, the mathematical relation between the induced speed harmonic and the output torque is derived, which shows that the magnitude of the induced speed harmonic is proportional to the output torque of an IPMSM. Therefore, the speed harmonic is explored to seek the MTPA angle, in which the MTPA angle is found when the speed harmonic magnitude is maximized. In particular, the gradient descent algorithm is employed to detect the MTPA angle, which is computationally efficient and converges quickly. The proposed approach is evaluated with both simulations and experiments based on a laboratory IPMSM drive system.

关键词： gradient descent algorithm interior permanent magnet synchronous machine (IPMSM) maximum torque per ampere (MTPA) control speed harmonic

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Improved specular point prediction precision using gradient descent algorithm

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ADVANCES IN SPACE RESEARCH 2020年第6期65卷 1568-1579页

作者： Tian, Yusen Xia, Junming Sun, Yueqiang Wang, Xianyi Du, Qifei Bai, Weihua Wang, Dongwei Cai, Yuerong Wu, Chunjun Li, Fu Qiao, Hao Chinese Acad Sci Natl Space Sci Ctr 1 Nanertiao Beijing 100190 Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China Beijing Key Lab Space Environm Explorat Beijing 100190 Peoples R China Chinese Acad Sci Key Lab Sci & Technol Space Environm Situat Aware Beijing 100190 Peoples R China

Global Navigation Satellite Systems Reflectometry (GNSS-R) utilizes GNSS signals reflected off the Earth surface for remote sensing applications. Due to weak power of reflected signals, GNSS-R receiver needs to track reflected signals by open loop. The first step is to calculate the position of specular point. The specular point position error of the existing algorithm-Quasi-Spherical Earth (QSE) Approach-is about 3 km which may cause troubles in data post-processing. In this paper, gradient descent algorithm is applied to calculate position of specular point and the calculation is based on World Geodetic System 1984 (WGS 84) ellipsoid in geodetic coordinate. The benefit of this coordinate is that it is easy to investigate the effect of real surface's altitude. Learning rate-the key parameter of the algorithm-is adaptively adjusted according to initial error, latitude and gradient descent rate. With self-adaptive learning rate strategy, the algorithm converges fast. Through simulation and test on Global Navigation Satellite System Occultation Sounder II (GNOS II), the performances of the algorithm are validated. The specular point position error of the proposed algorithm is about 10 m. The speed of the proposed algorithm is competitive compared with the existing algorithm. The test on GNOS II shows that the proposed algorithm has good real-time performance. (C) 2019 Published by Elsevier Ltd on behalf of COSPAR.

关键词： GNSS-R Specular point gradient descent algorithm Self-adaptive learning rate

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Distributed kernel gradient descent algorithm for minimum error entropy principle

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APPLIED AND COMPUTATIONAL HARMONIC ANALYSIS 2020年第1期49卷 229-256页

作者： Hu, Ting Wu, Qiang Zhou, Ding-Xuan Wuhan Univ Sch Math & Stat Wuhan 430072 Peoples R China Middle Tennessee State Univ Dept Math Sci Murfreesboro TN 37132 USA City Univ Hong Kong Sch Data Sci Kowloon Hong Kong Peoples R China City Univ Hong Kong Dept Math Kowloon Hong Kong Peoples R China

Distributed learning based on the divide and conquer approach is a powerful tool for big data processing. We introduce a distributed kernel gradient descent algorithm for the minimum error entropy principle and analyze its convergence. We show that the L-2 error decays at a minimax optimal rate under some mild conditions. As a tool we establish some concentration inequalities for U-statistics which play pivotal roles in our error analysis. Published by Elsevier Inc.

关键词： Distributed learning Minimum error entropy gradient descent algorithm Kernel method

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Exponentially convergence for the regressor-free adaptive fuzzy impedance control of robots by gradient descent algorithm

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INTERNATIONAL JOURNAL OF SYSTEMS SCIENCE 2020年第11期51卷 1883-1904页

作者： Nazmara, Gholamreza Fateh, Mohammad Mehdi Ahmadi, Seyed Mohammad Shahrood Univ Technol Dept Elect & Robot Engn Shahrood *** Iran

Having the capability to estimate parametric and non-parametric uncertainties, this paper investigates a regressor-free adaptive model-reference scheme for impedance control of robotic systems interacting with an environment. Using the gradient descent algorithm for designing a fuzzy estimator makes the tune of controller's parameters possible in different physical situations and uncertainties. Thanks to the voltage control strategy and fuzzy systems, there is no need for designers to have the knowledge of robots and actuators' dynamics. In addition, the force feedback is not employed in the structure of control law. Using the Lyapunov-like stability analysis, not only the exponential convergence of error signal and its time derivative to zero are guaranteed in the decentralised form but also the boundedness of all signals is ensured. To confirm the efficiency of proposed control algorithm, several simulations as well as a comparison with a positioned-based impedance controller and a regressor-based adaptive impedance controller are conducted on a two-link planar robot manipulator considering a tunable desired trajectory and different stiffness of environment. Additionally, the proposed adaptive impedance controller is applied to a six degree of freedom revolute-joint manipulator to provide better evaluation.

关键词： Exponential convergence impedance control gradient descent algorithm fuzzy estimator robot manipulators

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Parametric Tracking of Electrical Current Components Using gradient descent algorithm

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PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE 2022年第16期236卷 8834-8841页

作者： Frini, Marouane Choqueuse, Vincent Auger, Francois Univ Nantes IREENA 37 Blvd Univ F-44600 St Nazaire France Univ Bretagne Occidentale LAB STICC Brest France

In the last few years, Motor Current Signature Analysis (MCSA) has proven to be an effective method for electrical machines condition monitoring. Indeed, compared to vibration and temperature analysis, current measurement proves to be a convenient and non-invasive alternative. Moreover, it has proven to be a reliable method since many mechanical and electrical faults manifest as side-band spectral components generated around the fundamental frequency component of the motor's current. These components are called interharmonics and they are a major focus of fault detection using MCSA. However, the main drawback of this approach is that the interference of other more prevalent components such as the fundamental and noise components can obstruct the effect of interharmonics in the spectrum and may therefore affect fault detection accuracy. Thus, we propose in this paper an alternative approach that aims to decompose the different current components using a model based on a Vandermonde matrix, in order to monitor each component independently. Then, the tracking of each distinct component in time and spectral domains is implemented. This is achieved by estimating their respective relevant parameters using the gradient descent algorithm. This method has been favorably compared to an existing estimation algorithm (MUSIC) and its efficiency has been validated. The results of this work prove to be promising and establish the parametric tracking of the electrical current components using the gradient descent algorithm as a reliable monitoring approach.

关键词： motor current signal analysis current components decomposition parametric model estimation gradient descent algorithm

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Maximum Efficiency Control of PMSM Drives Considering System Losses Using gradient descent algorithm Based on DC Power Measurement

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IEEE TRANSACTIONS ON ENERGY CONVERSION 2018年第4期33卷 2240-2249页

作者： Balamurali, Aiswarya Feng, Guodong Lai, Chunyan Tjong, Jimi Kar, Narayan C. Univ Windsor Dept Elect & Comp Engn Windsor ON N9B 3P4 Canada

This paper proposes a novel method of efficiency improvement in a vector controlled permanent magnet synchronous motors (PMSM) through system level maximum efficiency point determination using current angle as a control variable. Loss models for the inverter and the motor fundamental and harmonic losses, which are capable of being solved online using available terminal measurements in the system are initially developed. The loss models and dc-link power measurement are then used to seek the maximum efficiency angle for different operating conditions using a gradient descent optimization algorithm. The developed method is robust against changes in inductances due to saturation and cross saturation with loading conditions as well as temperature effects. The effectiveness of the developed method in improving the system efficiency is verified and compared with conventional maximum torque per ampere method. The proposed strategy has been validated on a laboratory interior PMSM, and the efficiency has been calculated for different speed and torque conditions. The experimental validations confirm the effectiveness of the proposed solution in improving the motor drive system energy efficiency.

关键词： Current angle DCpower losses gradient descent algorithm maximum efficiency permanent magnet motor

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Finding the chaotic synchronizing state with gradient descent algorithm

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PHYSICS LETTERS A 1999年第4-6期263卷 315-322页

作者： Chen, JY Wong, KW Shuai, JW City Univ Hong Kong Dept Elect Engn Kowloon Peoples R China Xiamen Univ Dept Phys Xiamen Peoples R China Case Western Reserve Univ Dept Biomed Engn Cleveland OH 44106 USA

In this Letter, the gradient descent algorithm is proposed to search for the optimal synchronization between a drive and a response hyperchaotic systems that are coupled with a scalar signal. The energy corresponds to the largest Lyapunov exponent of the response system is defined. Its convergence indicates that the corresponding Lyapunov exponent is always negative. (C) 1999 Elsevier Science B.V. All rights reserved.

关键词： nonlinear dynamics chaotic synchronization Lyapunov exponents gradient descent algorithm

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