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CN-122021212-A - Electromagnetic orbit emission simulation method for solving contact resistance based on improved PSO algorithm

CN122021212ACN 122021212 ACN122021212 ACN 122021212ACN-122021212-A

Abstract

The invention discloses an electromagnetic orbit emission simulation method for solving contact resistance based on an improved PSO algorithm, which firstly models the complex geometric shape of electromagnetic orbit emission equipment based on a TrueGrid platform, and then solving the contact resistance by improving a PSO inversion algorithm, and loading a dynamic evolution process curve into the model, thereby improving the accuracy of the simulation result. The method solves the problem of dynamic response misalignment caused by the mapping capability of geometric modeling to actual working conditions and the inaccurate key parameters between central rails in the transmitting process, the simulation result reflects the motion state and the time-space evolution of dynamic response of the transmitting equipment in the whole process more accurately, and an effective simulation means is provided for the design, optimization, test and evaluation of the electromagnetic track transmitting equipment.

Inventors

  • YAN RONGGE
  • Yang Zhaping
  • ZHAO WENYUE
  • JIA JUNHUI
  • XIE YUNSONG
  • SU CHENHAO

Assignees

  • 河北工业大学

Dates

Publication Date
20260512
Application Date
20251217

Claims (7)

  1. 1. The electromagnetic orbit emission simulation method for solving the contact resistance based on the improved PSO algorithm is characterized by comprising the following steps of: step 1, geometric modeling of electromagnetic orbit emission equipment based on TrueGrid According to the actual structure and the size of an armature-rail system of the electromagnetic rail emission device, utilizing TrueGrid software to establish a three-dimensional geometric model of the armature-rail system, and completing grid division to obtain a TrueGrid model of the armature-rail system; step 2, formulating description of the track and the armature in the transmitting state The electromagnetic field control equation for the electromagnetic orbit launching device is as follows: (1) In the formula (1): Is Hamiltonian, μ is the magnetic permeability of the armature, A is the vector magnetic potential, φ is the scalar potential, σ is the electrical conductivity of the armature, v is the armature movement speed, Time is; The sign "×" indicates the spin, the sign "·" indicates the divergence, and the same applies below; Deriving a system of thermal diffusion equations in a motion coordinate system under the assumption of energy balance: (2) in the formula (2), T, And Temperature, specific heat capacity and thermal conductivity, respectively; t is the gradient of temperature and Q is ohmic heat, which can be expressed as: (3) the electromagnetic thrust experienced by the armature can be expressed as: (4) in the formulas (3) and (4), B is magnetic flux density, J is current density; Is the area occupied by the armature in three dimensions, The formula (4) represents integrating the current density J and the magnetic induction intensity B over the armature volume; and (3) carrying out mechanical analysis according to Newton's second law to obtain a kinematic control equation of the armature: (5) in the formula (5), m is the mass of the armature, a is the acceleration of the armature; the friction force to which the armature is subjected is as follows: (6) In the formula (6), mu f is the sliding friction coefficient, F pre is the pretightening force and is a fixed value; Is the included angle between the direction of current entering the armature and the moving direction of the armature; step 3, inversion calculation of pivot rail contact resistance based on improved PSO algorithm The muzzle voltage U of an electromagnetic track firing apparatus may be expressed as: (7) In the formula (7), I is excitation current of a system, R c is contact resistance between pivot rails, M is mutual inductance gradient of the rails, L is rail length, x is the position of an armature, x is [0, L ], M is the speed of the armature, v is M/s, and data curves of I, x and v are measured in an electromagnetic rail emission experiment; R a is the armature resistance, which can be expressed as: (8) in the formula (8), h is the track height, b is the horizontal distance between two tracks contacted with two sides of the armature, ρ a is the resistivity of the armature, and μ is the magnetic permeability of the armature material; Time is; the solution space for establishing an objective function and corresponding parameters from equation (7) is as follows: (9) In the formula (9), U m is the voltage of the bore hole measured in the experiment; for the t time instant As an objective function of improving PSO algorithm, contact resistance is aimed at minimizing the objective function And mutual inductance gradient As parameters to be optimized, setting the population size n of an improved PSO algorithm, generating a chaotic sequence by using Logistic chaotic mapping, and initializing the position of each particle; First, a chaotic sequence is generated: (10) in the formula (10), r is a control parameter, the value is 4, P=1, 2,3, n; z 0 is a random number between 0 and 1 and z 0 noteq 0, 0.25, 0.5, 0.75, 1, initializing the initial position of the ith particle by using a chaotic sequence: (11) In the formula (11), j is 1,2, a j is the lower limit of the j-th dimensional solution space, b j is the upper limit of the j-th dimensional solution space, and z i is the value corresponding to the i-th particle in the chaotic sequence; the velocity and location update formula for improving PSO algorithm particles is: (12) in the formula (12), the amino acid sequence of the compound, 、 Respectively the ith particle in the d-th iteration the speed and position when the iteration of the round is completed; 、 the individual optimal solution searched by the particle i after the d-th round of iteration and the global optimal solution of the whole particle swarm are respectively obtained; C 1 、c 2 is an individual learning factor and a social learning factor respectively, and r 1 、r 2 is a random number between 0 and 1; The inertia weight in the formula (12) adopts dynamically adjusted inertia weight, and the inertia weight w i d of the d-th wheel particle i meets the following conditions: (13) In the formula (13), the amino acid sequence of the compound, N is the size of the population scale, Is the objective function value of particle i at iteration round d-1, Is the minimum value of the objective function values of all particles in the d-1 iteration; 、 respectively setting a given minimum inertia weight and a maximum inertia weight value; When each iteration round is completed, a global optimal solution of the whole particle swarm is obtained, when the objective function value of the global optimal solution is not more than a set threshold value, iteration is terminated, and the optimal at the t moment is obtained according to the global optimal solution And Each time according to the optimal value of the t time And Obtaining the corresponding optimal values of R c and M, and finally obtaining an R c data curve of the target duration; Step 4, importing the TrueGrid model established in the step 1, the formulated description of the track and the armature in the transmitting state obtained in the step 2 and the contact resistance R c data curve obtained in the step 3 into LS-PrePost software, and preprocessing the TrueGrid model by setting corresponding keywords to obtain a k file, wherein the preprocessing comprises the following specific steps: (1) Setting material parameters, namely setting material properties, namely setting corresponding material properties for the track and the armature according to actual material parameters, wherein the material properties comprise conductivity, density, elastic modulus and poisson ratio; (2) The electromagnetic calculation module is initialized, an explicit electromagnetic-structure coupling solver is started, the EM solver is activated in the EM_CONTROL, the time step of the EM module is set, the loop and the material conductivity are defined, the electromagnetic field update period is set, and the electromagnetic field update period is set through the EM_CONTROL_ TIMESTEP; (3) The motion constraint system is defined as that full constraint is implemented on the track, motion of any degree of freedom of the track is not allowed, and unidirectional slip constraint is arranged on a pivot track contact interface, namely motion along the track direction is allowed, but motion perpendicular to the track direction is not allowed; (4) Transient load loading, namely leading in a real excitation CURRENT waveform through a DEFINE_CURVE function, and realizing CURRENT loading of an armature through an EM_current_BEAM unit; (5) The contact resistance data CURVE is loaded, namely the contact resistance data CURVE obtained in the step 3 is imported by adopting a DEfine_CURVE function, and the contact resistance data CURVE is loaded on the equivalent contact resistance of the TrueGrid model through EM_EOS_ TABULATED 2; (6) Setting a maximum time step and a termination condition; (7) Defining an output of the binary state file D3 PLOT; (8) The model file obtained after being processed by LS-PrePost software is stored as a k file; Step 5. Solving the. K file generated by step 4 in LS-Run software Starting LS-Run software and selecting a k file to be solved, setting parameters of a solver in the LS-Run software, clicking an operation button to start a solving process, obtaining a solving result file after the solving is finished, inputting the solving result file into the LS-PrePost software, selecting different time steps to carry out visual display, and obtaining change curves of different physical quantities along the track along the time in the accelerating motion process of the armature under the action of electromagnetic force.
  2. 2. The electromagnetic orbit emission simulation method for solving for contact resistance based on the improved PSO algorithm according to claim 1, wherein in step 3, a given minimum inertial weight is given And maximum inertial weight value Taking 0.4 and 0.9 respectively.
  3. 3. The electromagnetic orbit emission simulation method for solving contact resistance based on the modified PSO algorithm according to claim 1, wherein in step 4, the time step of the EM module is set to 5 μs.
  4. 4. The electromagnetic orbit emission simulation method for solving the contact resistance based on the improved PSO algorithm according to claim 1, wherein in the step 1, the TrueGrid model comprises 9 parts, namely four red copper orbits, two convex guide rails, an armature and two transverse guide rails, wherein the armature is made of an aluminum alloy material, and the two transverse guide rails only play a role in electric conduction and do not belong to orbit parts; The main body part comprises two convex guide rails and four rectangular red copper rails, wherein the axial directions of the two convex guide rails are equal in length and equal in height, the size of a convex part on each convex guide rail is matched with the size of an inward concave part on two sides of an armature, the two convex guide rails are in dynamic contact with the armature through a concave-convex jogged design, the convex parts of the two convex guide rails are horizontally and oppositely arranged on two sides of the armature, the convex parts of the two convex guide rails are opposite to each other and jogged with the inward concave parts on two sides of the armature in a sliding manner, and are respectively named as a first convex guide rail and a second convex guide rail; The first convex guide rail, the first red copper rail and the third red copper rail are positioned on one side of the armature, the second convex guide rail, the second red copper rail and the fourth red copper rail are positioned on the other side of the armature, the current flows in from the third red copper rail to the fourth red copper rail through the first transverse guide rail, then is conducted to the first red copper rail and the first convex guide rail through the second transverse guide rail, flows out from the second red copper rail after flowing through the armature, and the parts of the two sides of the armature, which are horizontally arranged from the inner concave surfaces of the parts to the center of the armature, are respectively two equivalent contact resistances of the armature.
  5. 5. The electromagnetic orbit emission simulation method for solving the contact resistance based on the improved PSO algorithm according to claim 1, wherein the electromagnetic orbit emission simulation method for solving the contact resistance based on the improved PSO algorithm according to claim 4 is characterized in that the orbit length is 2.18m, the orbit height is 30mm, and the horizontal distance between two orbits contacting both sides of the armature is 13.88mm.
  6. 6. The electromagnetic track emission simulation method for solving the contact resistance based on the improved PSO algorithm according to claim 4, wherein the convex track is a part in direct contact with the armature, the length is 2180mm, the height is 30mm, the edge width is 2mm, the electromagnetic track emission simulation method is made of wear-resistant steel materials, the center of the left side surface is a curved surface protruding portion with the same length as the convex track, the section of the curved surface protruding portion is a plane surrounded by an arc corresponding to a chord with the chord length of 10mm of a circle with the radius of 8.5mm and the chord.
  7. 7. The electromagnetic orbit emission simulation method for solving contact resistance based on the improved PSO algorithm according to claim 1, wherein in step 4, the maximum time step size 5e -6 s is limited, and the calculation end time is 1.5ms.

Description

Electromagnetic orbit emission simulation method for solving contact resistance based on improved PSO algorithm Technical Field The invention belongs to the technical field of numerical simulation of high-energy electromagnetic emission systems, and particularly relates to an electromagnetic orbit emission simulation method for solving contact resistance based on an improved PSO algorithm. Background Electromagnetic energy propulsion devices are a new type of launching device that works by converting electromagnetic energy into kinetic energy on a propelled load by injecting a large current into the propulsion device, accelerating the load to extremely high speeds in a few milliseconds by the electromagnetic thrust produced. The electromagnetic track emission device is a technical branch of an electromagnetic energy propulsion device, and the emission efficiency of the electromagnetic track emission device is far higher than that of the traditional chemical emission and can reach up to 50 percent. The traditional chemical emission can generate chemical combustion in the emission process to generate chemical gas, is not friendly to the environment, and the electromagnetic orbit emission equipment can not generate chemical gas. Compared with the traditional chemical emission, the controllability of the electromagnetic track emission device is better, and the projectile can obtain different speeds by changing the injection current, so that different military purposes are achieved. The whole transmission process of the electromagnetic track transmission equipment is extremely complex, the dynamic transmission process is the result of interaction of a plurality of physical fields, the process mainly involves electromagnetic fields, structural fields and temperature fields, and in addition, due to the compact mechanical structure of the electromagnetic track transmission equipment, some data cannot be measured from experiments, so that in conclusion, the research on the dynamic transmission process of the electromagnetic track transmission equipment through numerical simulation calculation is a feasible method. In order to make the numerical simulation calculation result more in line with engineering practice, it is required that the finite element model to be built is more close to the practical situation when modeling is performed. However, the existing method still has the defect that the actual geometric dimension is excessively simplified when the model is geometrically constructed, which can lead to the fact that the model deviates from the actual result too much, and the accuracy is difficult to ensure. The existing pivot rail contact resistance solving algorithm mostly uses dynamic parameter analysis, the pivot rail contact resistance solved by the method deviates from an actual result greatly, a learner uses an improved simulated annealing algorithm to invert and solve the pivot rail contact resistance, but the algorithm has the defects of low convergence speed, sensitive and complex parameter adjustment, lack of information sharing in single solution searching and easiness in finally falling into a local optimal solution, and in addition, the existing research method mostly is based on static parameters, and is difficult to accurately describe the influence of the dynamic parameters on a model. Disclosure of Invention The invention provides an electromagnetic orbit emission simulation method for solving contact resistance based on an improved PSO (PARTICLE SWARM Optimization ) algorithm, aiming at solving the problem that the dynamic response misalignment caused by key parameters among central orbits in the dynamic emission process is not considered in the existing electromagnetic orbit emission equipment simulation technology. The method establishes an electromagnetic orbit emission equipment simulation model considering the electromagnetic-thermal-force multi-physical field coupling of the pivot orbit contact resistance based on LS-DYNA, and realizes high-precision dynamics simulation of the electromagnetic orbit emission equipment under extreme conditions. The technical scheme for solving the technical problems is that an electromagnetic orbit emission simulation method for solving contact resistance based on an improved PSO algorithm is designed, and the method is characterized by comprising the following steps: step 1, geometric modeling of electromagnetic orbit emission equipment based on TrueGrid According to the actual structure and the size of an armature-rail system of the electromagnetic rail emission device, utilizing TrueGrid software to establish a three-dimensional geometric model of the armature-rail system, and completing grid division to obtain a TrueGrid model of the armature-rail system; step 2, formulating description of the track and the armature in the transmitting state The electromagnetic field control equation for the electromagnetic orbit launching device is as follows: (1) In