In this paper, we propose a distributed cooperative voltage equalization strategy in order to balance the voltages of the series-connected super-capacitors, which is the power supply of energy storage light rail vehic...
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ISBN:
(纸本)9781479917730
In this paper, we propose a distributed cooperative voltage equalization strategy in order to balance the voltages of the series-connected super-capacitors, which is the power supply of energy storage light rail vehicles. Taking each super-capacitor cell as an agent in multi-agent systems, the voltage equalization problem can be formulated as a cooperative tracking problem. The sparse communication network among the super-capacitors in the cyber layer can be modeled by a digraph. As the voltage changes within a limited range, a general saturation function is put forward to guarantee the boundedness of the control input. Based on the nearest neighborhood rule, a bounded voltage equalization controller with tunable control gains is designed accordingly. The proposed voltage equalization methodology is distributed and not using a central controller. Each super-capacitor cell only need its voltage information and its neighbors, the desired control objective can be accomplished by local interaction in a cooperative way. Under the assumption that the digraph has a spanning tree, the asymptotically stability of the overall close-loop system is rigorously proved with the aid of a novel Lyapunov function integrating Lasalle invariant principle. The voltage equalization has been achieved by the proposed cooperative control approach, which is verified by the simulations. under different initial conditions, cooperative objectives and different network sizes.
This paper presents a novel measurement method for a large stroke X Y nano-positioner(mm-stoke and nanometric accuracy). Based on recently proposed flexure-based large stroke X Y nanopositioner, a low cost and simple ...
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ISBN:
(纸本)9781467374439
This paper presents a novel measurement method for a large stroke X Y nano-positioner(mm-stoke and nanometric accuracy). Based on recently proposed flexure-based large stroke X Y nanopositioner, a low cost and simple method is proposed to measure large stroke two-dimensional motion stage. The important feature lies in only two optical gratings are adopted to achieve the measurement for a planner motion, where each optical grating is mounted on a T-shaped flexure beam rather than the ending stage. Moreover the resulting major measurement error is effectively compensated by the designed linear relationship between the stroke and parasitic motion. The experimental results of a 1.0 millimeter circular trajectory tracking is achieved by the proposed method.
This paper presents an integrated control strategy for high precision contour tracking of a newly developed parallel bi-axis servo gantry system. In specific, this integrated control method includes a time-varying int...
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This paper presents an integrated control strategy for high precision contour tracking of a newly developed parallel bi-axis servo gantry system. In specific, this integrated control method includes a time-varying internal-model-based controller designed to achieve frequency-varying trajectory tracking for each axis, a disturbance observer intended to compensate friction caused by linear guideways, and a modified variable-gain cross-coupling controller for improvement of contour *** simulation comparative results validate the ability of this integrated control strategy to achieve high precision contour performance.
Finding correspondences between pair of images of the same scene is a key problem in computer *** matching images undergo viewpoint change,partial occlusion,clutters and illumination change,there will be a lot of mism...
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ISBN:
(纸本)9781479970186
Finding correspondences between pair of images of the same scene is a key problem in computer *** matching images undergo viewpoint change,partial occlusion,clutters and illumination change,there will be a lot of mismatches due to the limited repeatability and discriminative power of *** this paper,we propose a robust matching algorithm that can remove false matches and propagate the correct ones to obtain more matches,thus improve the matching ***,extract SURF(Speeded Up Robust Features) descriptors from the input two images,which can be used to build the proximity *** perform SVD(Singular Value Decomposition) on the proximity matrix to obtain the initial ***,refine the initial matches by the unique property of Delaunay triangulation that can produce the maximum clique of the two Delaunay ***,recover the lost matches with the constraint of dual graph of *** results on Oxford datasets indicate that our algorithm can improve the match performance compared to the RANSAC-based method.
In order to construct integration model of combination pump hydraulic model with motor electromagnetic model, this paper use BP neural network structure pump hydraulic fitting model. Train BP neural network on pump pe...
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ISBN:
(纸本)9781479984671
In order to construct integration model of combination pump hydraulic model with motor electromagnetic model, this paper use BP neural network structure pump hydraulic fitting model. Train BP neural network on pump performance according to the experimental test data, to make neural network accordance with the characteristics of pump input and output. Then combine with motor electromagnetic calculation model into integration model which could be used to analysis the performance of water pump.
Weather modeling and prediction has been quite a challenge over the years. Predictions based on climatic models whose dynamical behavior is nonlinear, nonstationary, and based on high order difference equations is a t...
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ISBN:
(纸本)9781467374293
Weather modeling and prediction has been quite a challenge over the years. Predictions based on climatic models whose dynamical behavior is nonlinear, nonstationary, and based on high order difference equations is a tough task and usually requires a demanding and non-intuitive tuning expertise. This paper suggests an ensemble of evolving fuzzy models for multivariate time series prediction. The proposed ensemble approach is able to model the weather dynamics from data streams concerning variables such as wet bulb temperature, atmospheric pressure, maximum temperature, and relative humidity of the air. The purpose is to predict rainfalls 5 days ahead while providing a linguistic description of the reasoning used to give the predictions. Empirical results show that the ensemble-based fuzzy evolving modeling approach outperforms other evolving approaches in terms of accurate predictions.
In this study, we propose a variant of Particle Swarm Optimization (PSO) algorithm for chaotic synchronization based on PID control. The new method, called Improved Particle Swarm Optimization (IPSO) algorithm employs...
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In this paper, we present the design and simulation of an unconventional unmanned autonomous blimp. The dynamic model of the tri-ellipsoid blimp is built with mechanism analysis method. Based on dynamic modeling of th...
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An investigation on the performance of enhanced Nonlinear Proportional Integral Derivative (ENPID) controller is presented in this paper. The study is focused on the potential of the controller to perform well in trac...
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An investigation on the performance of enhanced Nonlinear Proportional Integral Derivative (ENPID) controller is presented in this paper. The study is focused on the potential of the controller to perform well in tracking set point of pneumatic actuator system. Two control strategies of the ENPID are considered in this paper, namely Multi-rate NPID (MN-PID) and Self-regulation NPID (SN-PID). These control strategies are tested against NPID and conventional PID controller. Also, the dead-zone compensation (DZC) is applied to the system to overcome the dead-band of the valve. Feed forward path is also included to improve the tracking performance. Two different input signals i.e. sinusoidal and S-curve waveforms are used to evaluate the performance of the techniques. To further examine the controller performance, the frequency and amplitude of the sinusoidal test signal are varied. The effectiveness of the proposed controllers is verified through simulation and experimental studies.
A discrete-time current controller is presented for the current loop of the permanent magnet synchronous motor drives. Firstly, the difference equations of current errors are obtained for constant reference values. Th...
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A discrete-time current controller is presented for the current loop of the permanent magnet synchronous motor drives. Firstly, the difference equations of current errors are obtained for constant reference values. Then, a dead-beat controller is designed to drive the dq-axes currents to the desired values. Discrete-time integral action with an anti-windup scheme is added to the dead-beat structure to achieve a better steady-state behaviour. In order to improve the transient properties of the controller, a current prediction scheme based on dead-beat structure is also introduced to the controller. Finally, the proposed controller is implemented through numerical simulations to illustrate the effectiveness for both transient and steady-state responses.
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