The paper proposes an initial rotor position detection strategy for permanent magnet synchronous motors (PMSMs) based on high-frequency elliptical voltage injection. By analyzing the response current model of PMSM, th...
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ISBN:
(纸本)9798350363272;9798350363265
The paper proposes an initial rotor position detection strategy for permanent magnet synchronous motors (PMSMs) based on high-frequency elliptical voltage injection. By analyzing the response current model of PMSM, the strategy utilizes the improved gradient descent algorithm to update and optimize the skew angle of the elliptical voltage, thereby analyzing the variation characteristics of the response current and obtaining the initial position of the rotor from it. Compared with traditional methods of initial rotor position detection, this strategy has a simpler structure, does not require specific motor parameters, and no longer relies on the cooperation of multiple filters to obtain positional information from the response current. It avoids the impact of filters on the current amplitude and reduces phase shifts caused by signal processing. The proposed initial rotor position detection strategy has been validated through simulation.
In this paper,the parameter estimation for Hammerstein-Wiener nonlinear systems with unknown delay is *** on the hierarchical identification principle and two-step identification,the maximum likelihood recursive algor...
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ISBN:
(数字)9789887581536
ISBN:
(纸本)9781665482561
In this paper,the parameter estimation for Hammerstein-Wiener nonlinear systems with unknown delay is *** on the hierarchical identification principle and two-step identification,the maximum likelihood recursive algorithm is used to identify the parameters of the system,and the gradientdescent method is used to identify the time ***,the algorithm is verified by a numerical example,and the simulation results show that the algorithm has the characteristics of fast convergence speed and high identification accuracy.
The gradient descent algorithm is applied to the model parameter correction algorithm in view of the shortcoming that T-S fuzzy model cannot be used for real-time adaptive parameter correction. In this paper, an onlin...
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ISBN:
(纸本)9781665440899
The gradient descent algorithm is applied to the model parameter correction algorithm in view of the shortcoming that T-S fuzzy model cannot be used for real-time adaptive parameter correction. In this paper, an online model correction method combining T-S fuzzy model with gradient descent algorithm is proposed, and the operation data of a subway air-conditioning system in Wuhan is used for verification. The experimental results show that the T-S fuzzy model modified by gradient descent algorithm has better accuracy and higher operational efficiency.
To reduce the backflow power of dual-active-bridge (DAB) DC-DC converter and improve the operating efficiency, this paper proposes a gradient descent algorithm (GD-EPS) based extended-phase-shift (EPS) control. Firstl...
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ISBN:
(纸本)9781728116754
To reduce the backflow power of dual-active-bridge (DAB) DC-DC converter and improve the operating efficiency, this paper proposes a gradient descent algorithm (GD-EPS) based extended-phase-shift (EPS) control. Firstly, the transmission and backflow power models of DAB converter with EPS and single-phase-shift (SPS) control are established, and the influencing factors of backflow power are analyzed. Secondly, according to the backflow power model, the gradient descent algorithm for solving the optimal solution of backflow power is obtained. On this basis, the output voltage closed-loop control is added to derive the DAB overall optimal control scheme. At last, the simulation models of DAB converter with GD-EPS and SPS control are built and compared, it is verified that the GD-EPS control can optimize the backflow power better than the SPS control when the load and input voltage change.
This paper presents a new optimal controller using the Binary gradientdescent (BGD) algorithm to manage distributed generations effectively in a grid network. The algorithm aims to minimize power consumption from the...
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This paper proposes a loss minimization control method based on improved gradient descent algorithm (GDA) for interior permanent magnet synchronous machine (IPMSM). Since the power of PMSM is derived from the measured...
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This paper proposes a loss minimization control method based on improved gradient descent algorithm (GDA) for interior permanent magnet synchronous machine (IPMSM). Since the power of PMSM is derived from the measured phase voltage and current, this method is independent from the iron loss model containing motor parameters. Meanwhile, it can guarantee the stability of PMSM system when entering the searching period. Both maximum torque per ampere (MTPA) and i(d) = 0 control are carried out to validate the effectiveness of the proposed method. The experimental results are demonstrated to verify the proposed approach.
In this paper, we propose a new online portfolio selection strategy based on a weighted learning technique and an online gradient descent algorithm. Our strategy, named combination weights based on online gradient des...
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In this paper, we propose a new online portfolio selection strategy based on a weighted learning technique and an online gradient descent algorithm. Our strategy, named combination weights based on online gradientdescent (CW-OGD), achieves improved robustness by integrating different expert strategies and overcomes the difficult problem of complex computational time. First, an expert system including many basic expert strategies, in which we choose the strategy that invests in a single stock as the basic expert strategy, is established. Second, we exploit the loss function to evaluate the performance of different basic expert strategies and use the OGD algorithm to update the weight vector for the experts based on their losses. In addition, we theoretically prove that the proposed strategy has a regret bound. Finally, extensive experiments conducted on four stock combinations and seven benchmark datasets show that our strategy can outperform some state-of-the-art strategies in terms of the return, risk and computational time metrics. Furthermore, our strategy can achieve higher returns even at certain transaction cost rates, which illustrates its effectiveness in the actual stock market. (C) 2021 Elsevier B.V. All rights reserved.
Recently, the Rao-Blackwellized particle filter (RBPF) has been used to solve the problem of simultaneous localization and mapping (SLAM). Using the odometer information of robot to calculate the proposed distribution...
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Recently, the Rao-Blackwellized particle filter (RBPF) has been used to solve the problem of simultaneous localization and mapping (SLAM). Using the odometer information of robot to calculate the proposed distribution requires a number of sampled particles, which increases the calculation complexity in the RBPF operation. In this paper, we integrate the odometer measurement and sensor observation into the proposed distribution, effectively reducing the particle sample scale. To reduce the inconsistency in the map model caused by the cumulative error of the odometer information of robot, we applied a gradient descent algorithm to fuse the sensor data to obtain the real-time attitude angle. This combination method, based on the robot operation system (ROS), runs on a platform of self-built mobile robot equipped with a laser rangefinder. The experimental results show that this method can realize the online real-time high-precision grid map which provides a new approach for robot navigation and SLAM.
A typical grey prediction control system is composed of a proportional-integral-derivative controller and a grey predictor. Rather than using differential evolution algorithms to optimize the grey prediction control s...
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A typical grey prediction control system is composed of a proportional-integral-derivative controller and a grey predictor. Rather than using differential evolution algorithms to optimize the grey prediction control system as in our previous work, this study attempts to apply the gradient descent algorithm to derive the self-tuning rules for both the coefficients of proportional-integral-derivative controller and the parameters of grey model. This study also attempts to replace the original GM(1,1) with a simple equivalent GM(1,1) in order to reduce computational complexity. Analogously, an objective function in terms of the maximal overshoot, rising time, steady-state error, and settling time is used to evaluate the performance of the comparison control systems. While using the self-tuning rule, simulation results on two single-variable plants demonstrate that the grey prediction control system with equivalent GM(1,1) could perform better than the original grey prediction control system.
Information theoretic learning is a learning paradigm that uses concepts of entropies and divergences from information theory. A variety of signal processing and machine learning methods fall into this framework. Mini...
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Information theoretic learning is a learning paradigm that uses concepts of entropies and divergences from information theory. A variety of signal processing and machine learning methods fall into this framework. Minimum error entropy principle is a typical one amongst them. In this paper, we study a kernel version of minimum error entropy methods that can be used to find nonlinear structures in the data. We show that the kernel minimum error entropy can be implemented by kernel based gradient descent algorithms with or without regularization. Convergence rates for both algorithms are deduced. Published by Elsevier Inc.
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