摘要 :
For a novel 3SPS+PS parallel bionic processing platform with 4-DOF (degree of freedom) simulating the complex processing path including optical processing and machining, the kinematic model based on Rodrigues parameters is establi...
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For a novel 3SPS+PS parallel bionic processing platform with 4-DOF (degree of freedom) simulating the complex processing path including optical processing and machining, the kinematic model based on Rodrigues parameters is established. The singular configurations of the processing platform are obtained from kinematic poses and geometry essence by means of Grassmann line geometry. The numerical simulations show the motion curves and surfaces of the singular configurations with lower linear variety of rank 1 to 3. Then the distribution characteristics of the singular trajectories are studied. It provides an analytical basis for workspace construction, singularity avoidance, and size optimization of the parallel bionic processing platform, as well as the other parallel manipulators.
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摘要 :
For a novel 3SPS+PS parallel bionic processing platform with 4-DOF (degree of freedom) simulating the complex processing path including optical processing and machining, the kinematic model based on Rodrigues parameters is establi...
展开
For a novel 3SPS+PS parallel bionic processing platform with 4-DOF (degree of freedom) simulating the complex processing path including optical processing and machining, the kinematic model based on Rodrigues parameters is established. The singular configurations of the processing platform are obtained from kinematic poses and geometry essence by means of Grassmann line geometry. The numerical simulations show the motion curves and surfaces of the singular configurations with lower linear variety of rank 1 to 3. Then the distribution characteristics of the singular trajectories are studied. It provides an analytical basis for workspace construction, singularity avoidance, and size optimization of the parallel bionic processing platform, as well as the other parallel manipulators.
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Pareto sort classification method is often used to compute the fitness value of evolutionary groups in multi-objective evolutionary algorithms.However this kind of computation may produce great selection pressure and result in pre...
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Pareto sort classification method is often used to compute the fitness value of evolutionary groups in multi-objective evolutionary algorithms.However this kind of computation may produce great selection pressure and result in premature convergence. To address this problem,an improved method to compute the fitness value of multi-objective evolutionary algorithms based on the relative relationship between objective function values is proposed in this paper, which improves the convergence and distribution of multi-objective evolutionary algorithms. Testing results of test functions show that the improved computation method has a higher ability of convergence and distribution than the evolutionary algorithm based on Pareto sort classification method.
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摘要 :
Pareto sort classification method is often used to compute the fitness value of evolutionary groups in multi-objective evolutionary algorithms.However this kind of computation may produce great selection pressure and result in ...
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Pareto sort classification method is often used to compute the fitness value of evolutionary groups in multi-objective evolutionary algorithms.However this kind of computation may produce great selection pressure and result in premature convergence. To address this problem,an improved method to compute the fitness value of multi-objective evolutionary algorithms based on the relative relationship between objective function values is proposed in this paper, which improves the convergence and distribution of multi-objective evolutionary algorithms. Testing results of test functions show that the improved computation method has a higher ability of convergence and distribution than the evolutionary algorithm based on Pareto sort classification method.
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This paper presents a way to calculate the invalidity and unreliability in each degree of the pneumatic plant for remotely controlling ship main diesel engine by means of history data of faults and maintenance records. It is also ...
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This paper presents a way to calculate the invalidity and unreliability in each degree of the pneumatic plant for remotely controlling ship main diesel engine by means of history data of faults and maintenance records. It is also described to search and queue the FT(Fault Tree) based on the maximum probability path to attain the aim of quantitative and optimized analysis. The application software developed has been used in vessels.
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With the scale of wind power connected to the main grid continuing to expand, reactive power and voltage problems of the wind farm are attracting more and more attention. In this paper, two electrical microscopic models are separa...
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With the scale of wind power connected to the main grid continuing to expand, reactive power and voltage problems of the wind farm are attracting more and more attention. In this paper, two electrical microscopic models are separately built which are based on two typical grid-connected wind farms combined the actual condition of Jiangsu grid in summer 2009, and the paper also carries on the simulations with the PSASP tool. The reactive power variation of wind farms is studied according to the simulation results. Meanwhile, the simulation results is compared with the statistical data of the power quality monitoring system, the two results are almost the same, which prove the models are reasonable.
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摘要 :
With the scale of wind power connected to the main grid continuing to expand, reactive power and voltage problems of the wind farm are attracting more and more attention. In this paper, two electrical microscopic models are separa...
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With the scale of wind power connected to the main grid continuing to expand, reactive power and voltage problems of the wind farm are attracting more and more attention. In this paper, two electrical microscopic models are separately built which are based on two typical grid-connected wind farms combined the actual condition of Jiangsu grid in summer 2009, and the paper also carries on the simulations with the PSASP tool. The reactive power variation of wind farms is studied according to the simulation results. Meanwhile, the simulation results is compared with the statistical data of the power quality monitoring system, the two results are almost the same, which prove the models are reasonable.
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Friction is one of the main factors decreasing tracking precision for servo system at low speed or back-forth-movement. To reduce the influence of friction on the system, a compound compensation strategy based on Stribeck model an...
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Friction is one of the main factors decreasing tracking precision for servo system at low speed or back-forth-movement. To reduce the influence of friction on the system, a compound compensation strategy based on Stribeck model and GPI observer is designed in this paper. Firstly, q-axis current and speed information are sampled. Then, genetic algorithm is used to identify the model parameters. At last, on-line friction compensation is added on the servo system based on the identified model. Due to the variation of the operating conditions, the compensation of the friction model based on the nominal working condition has a deviation. Considering friction compensation model error does not belong to the slow and constant disturbance, which is more suitable for the processing of polynomial form. Therefore, a GPI observer is designed. Simulation results are provided to demonstrate the proposed control method can effectively improve the flat top phenomenon in position tracking and dead zone phenomenon in speed tracking.
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In this paper, a sojourn-probability-dependent method is proposed to investigate robust H_r, dynamic output feedback control for discrete switched systems with input delays by using sojourn-probability-dependent method. The output...
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In this paper, a sojourn-probability-dependent method is proposed to investigate robust H_r, dynamic output feedback control for discrete switched systems with input delays by using sojourn-probability-dependent method. The output feedback controller is designed by using the probability of switched system staying in each subsystem. By using the sojourn probability information, a new type of switched system model is built. Then based on multiple Lyapunov functional method and LMI technique the sufficient conditions ofthe robust H_f mean square stability ofthe system are derived, after that the H_r norm bound Y and the output feedback H_x controller can be given. At last, some numerical examples are proposed to show the effectiveness ofthe proposed model and method.
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In this paper, a sojourn-probability-dependent method is proposed to investigate robust H dynamic output feedback control for discrete switched systems with input delays by using sojourn-probability-dependent method. The output fe...
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In this paper, a sojourn-probability-dependent method is proposed to investigate robust H dynamic output feedback control for discrete switched systems with input delays by using sojourn-probability-dependent method. The output feedback controller is designed by using the probability of switched system staying in each subsystem. By using the sojourn probability information, a new type of switched system model is built. Then based on multiple Lyapunov functional method and LM technique the sufficient conditions of the robust H mean square stability of the system are derived, after that the H norm bound / and the output feedback H controller can be given. At last, some numerical examples are proposed to show the effectiveness of the proposed model and method.
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