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To protect the structural feature and polarimetrie property in the speckle reduction of polarimetrie synthetic aperture radar (PolSAR) images, an improved speckle filter is developed based on a novel structural judgment and an improved four-components polarimetric decomposition (IFCPD) proposed from the Pauli decomposition and the Yamaguchi decomposition. The novel structural judgment based on the...
Grid-connected converters have been widely used in distributed generations. However, the resonance brought by converters in weak grid has been a great threat to system stability. Impedance-based method provides a powerful tool for stability analysis. Active damping is also widely applied to improve system stability. This paper derives the impedance model of grid-connected converter system and analyzes...
Accurate fault diagnosis, with immediate fault identification and isolation, is of paramount importance for power converters of switched reluctance motor drives, as it allows early adoption of fault tolerant procedures that eliminate the adverse effects of faults on machine operation. This paper presents an online fault diagnostic algorithm for power converter faults in SRM drives based on high frequency...
The paper deals with various sensorless techniques for SRM. The theory of most these techniques is described and their advantages and disadvantages are discussed. Simulation of a SRM traction drive for an electric vehicle was created and experimentally verified. A selected method is simulated on the base of a real SRM for various operating range and conditions. The method is analyzed from the point...
Light field can generate a set of refocused images by integrating rays into any image plane. It is useful to segment focus region from the refocused image because the focus region contains depth clues. However, to the best of our knowledge, focus-region segmentation for light field images has not been reported. We firstly transform the refocused image into the space of neuron ignition sequence with...
This paper describes the soft start and grid connection control strategies for high power synchronous compensator fed by low-voltage load-commutated inverters (LCI). In the start-up stage, field weakening method is used to make the motor start stably, and the back electromotive force (EMF) basically remain stable within the LCI withstand voltage at the same time. When the motor speed up to above the...
This paper proposes a strategy for identification of inertia for synchronous motors fed by load commutated inverters (LCI). As an important parameter of the synchronous motor's mathematical model, inertia makes an important impact in optimizing controlling capability. In this paper, the identification of inertia is based on recursive least-squares method (RLS). The viability of this method is proved...
The switching frequency of power inverters among the traditional motor drive systems are almost between 4kHz to 20kHz. The appearance of SiC or GaN devices make it is possible to increase the switching frequency for improving the performance of power inverter. In this paper, a high switching frequency control scheme based on DSP and FPGA is proposed to drive a SiC power inverter. Multiphase motor...
The presence of periodical impulses in vibration signals usually indicates the occurrence of faults in mechanical systems. Unfortunately, in the working condition, detecting the faults in mechanical systems is a difficult job because they are rather weak and often interfered by heavy noise. Therefore, noise suppression is one of the most important tasks in the fault diagnosis for mechanical systems...
The rapid development of big data puts forward higher requirements on computational efficiency and storage capacity. But the traditional mining algorithms based on classical computing were unable to satisfy the demand of data analysis and computing. Because of quantum systems unique ability of hyper parallel computation and hyper acceleration, the large-scale computing and data storage can be solve...
Traditional intelligent substation communication network has the problem in large transmission delay and delay jitter. This paper studied service isolation and low delay technology as the key technologies of EPON communication network for new intelligent substation. We built the experimental network and tested the performances of various services under different load conditions, the results verified...
With the development of modern intelligent, automation and integration of the increasingly complex industrial process control system, the traditional prediction methods of faults perform not well, so it has faced a huge challenge. In this paper, a new improved kernel principal component analysis method is presented which uses the concept of indiscernibility and eigenvector applied to distillation...
The paper applies a scaled multi-gradient edge detection algorithm to infrared criminal investigation images to extract the edge of the targets. It uses eight orientation detection templates to process the original image, which can reduce the lack of the edge details and improve the accuracy of edge extraction. Then using Otsu to scale the gradient information extracted from the former step, which...
Considering that the actual assembly work demands high precision and flexibility for the dual-arm robot at high speed. This paper introduces the design of the dual-arm robot architecture from two aspects of hardware and communication. The work space and constraint relationship of the dual-arm robot during the assembly process are analysed, and the force feedback loop control based on neural networks...
In order to reduce speckle noise and maintain targets' characteristics in SAR image with low signal to noise(SNR), an adaptive speckle reduction algorithm based on the wavelet threshold de-noising and the Forward and Back(FAB) diffusion equation for marine scenes is proposed. First, a new wavelet thresholding de-noising function which can avoid shortcomings of other wavelet de-noising function such...
In view of nonlinear, external disturbances and strong coupling features of the quadrotor UAV. A combination of internal model control and tracking differentiator (TD — IMC) is proposed to design a controller for Quadrotor. The function matrix of the quadrotor can be obtained by the LPV method linearizing the nonlinear model. Tracking differentiator (TD) is introduced to arrange the transition process,...
The Cooperative Multi-Area Coverage (CMAC) refers to a class of complex tasks in which multiple robots are required to jointly cover multiple areas by performing specific operations while moving across them. Practical operations may be garbage clearance, demining, area scanning for information acquisition, and so on. This paper proposes a distributed motion planning method for multiple robots to cooperatively...
This paper analyzes the requirements of the offshore oil platform of the distributed control system and aims at the lack of performance testing of the distributed control system in the process of offshore oil platform oil and gas separation. Based on two different PLC, a performance detection system of oil and gas separation control system was built. The system is consisted of software program client,...
A novel approach to estimate rotor position of a dual three-phase permanent magnet synchronous motor (PMSM) at low speed is investigated in this paper. A position estimation algorithm is developed in two dimensional nature static frame. Proposed algorithm exploits the transient response of line currents, which are integrated within fundamental PWM cycle to estimate rotor position and speed. For successful...
Selection of electricity fee payment site (EFPS) is a complex multi-objective optimization problem. Proper site selection of EFPS can not only facilitate the users to pay the electricity payments, but also save costs in running processes of the power enterprises (PEs). Firstly, two-dimensional genetic code is improved and the multi-object optimization model of EFPS is established. Secondly, considering...
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