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Method for positioning loosening element based on multiobjective optimization

A multi-objective optimization and positioning method technology, applied in the field of fault diagnosis of nuclear power plants, can solve problems such as large errors and low positioning accuracy

Inactive Publication Date: 2012-05-30
ZHEJIANG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0015] In order to overcome the shortcomings of large errors and low positioning accuracy in the prior art, the present invention provides a positioning method for loose parts based on multi-objective optimization that avoids positioning errors caused by inconsistent wave velocities and has high positioning accuracy

Method used

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  • Method for positioning loosening element based on multiobjective optimization
  • Method for positioning loosening element based on multiobjective optimization
  • Method for positioning loosening element based on multiobjective optimization

Examples

Experimental program
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Embodiment 1

[0054] refer to Figure 1-4 , to further illustrate the present invention:

[0055] Loose parts location method based on multi-objective optimization, including the following steps:

[0056] 1. Install M acceleration sensors in the primary circuit of the nuclear reactor to obtain the shock signal generated when the loose parts fall, where M≥4;

[0057] 2. Synchronously collect the impact signals received by each sensor, and obtain the time when each sensor receives the impact signal;

[0058] 3. Set the constraint range of horizontal coordinate z and vertical coordinate s according to the diameter and height of the cylindrical shell, establish a particle swarm within the constraint range, use a point coordinate within the constraint range as a particle of the particle swarm, the number of particles and The number of iterations is set according to experience; the particle swarm is initialized, the inertia weight, the coordinates of the current particle, the cognitive coeffici...

Embodiment 2

[0114] combine Figure 5a , 5b And simulation experiment, further illustrate the present invention:

[0115] 1. Simulation conditions

[0116] Experiments are carried out on the reactor simulation device, which is composed of a cylindrical shell and a hemispherical shell connected, and its shape is as follows Figure 5a As shown, expand it to a plane, the position of the sensor and the tapping point is as follows Figure 5b shown. The thickness of the simulation device is 16mm, the height is 2m, and the diameter is 1.2m. The masses of the steel balls knocked are 55g and 720g respectively. Four acceleration sensors are adopted, and the sampling frequency of each sensor is 60kHz.

[0117] 2. Simulation results

[0118] After expanding the cylinder, it is established as Figure 5b See Table 1 and Table 2 for the Cartesian coordinate system shown, the actual coordinates of each tapping point, and the positioning estimation results.

[0119] Table 1 Estimation results of lo...

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Abstract

The invention relates to a method for positioning a loosening element based on multiobjective optimization, which comprises the following steps of: installing M acceleration sensors in a loop of a nuclear reactor to obtain an impact signal generated when a loosening element falls; synchronously collecting the impact signal to obtain time for receiving the impact signal; establishing particle swarms and initializing the particle swarms; obtaining all particles to be iteratively operated and calculating each particle to obtain a variance of axial speed and a variance of circumferential speed ofthe point; searching the current optimal particle; constructing a Pareto optimal solution pool, updating the Pareto optimal solution pool and updating a global optimal value and local optimal values of all the particles; updating the speeds and positions of all the particles; judging whether the preset iterative frequency is achieved or not; and selecting a particle from the Pareto optimal solution pool as a final solution, wherein coordinates of the particle are the falling position of the loosening element. The invention has the advantages of high positioning precision and high searching speed.

Description

technical field [0001] The invention belongs to the field of fault diagnosis of nuclear power plants (Nuclear Power Plants, NPPs), is a part of a loose parts monitoring system (Loose Parts Monitoring System, LPMS), and is applied to the estimation of the falling position of loose parts. Background technique [0002] Metal parts in nuclear power plants that are loose or even dropped due to corrosion, depreciation, and friction, as well as metal fragments that enter the system from the outside during system testing, refueling, and overhaul stages, will reduce the stability and reliability of system operation. As an important part of the loose parts detection system, the location of loose parts can accurately detect the position where the loose parts fall, and then take them out, which is of great help to the stability and safety of the nuclear power plant. Existing documents related to loose parts location include: [0003] [1]Dowon Lee, Jacek Jarzynski, H.Berthelot, A study ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G06F19/00G01B17/00
Inventor 曹衍龙郑华文杨将新何元峰程实
Owner ZHEJIANG UNIV