Multi-parameter fitting method for internal trajectory based on improved particle swarm optimization algorithm

In this paper the numerical computation theory of internal trajectory was researched. Based on this, a multi-parameter fitting calculation model was established in order to get higher precise computation results. Through analysing the model, this paper selected the burning rate exponent n and the specific heat ratio gamma as the sensitive internal trajectory parameters, meanwhile selected the in-bore maximum pressure p(m) and the muzzle velocity v(g) correspondingly as the fitting parameters to improve the fitting efficiency. To do the fitting work, an improved particle swarm optimisation (PSO) algorithm was presented in this paper. The calculation results indicated that the fitting process using improved PSO was obviously better than those using standard PSO and genetic algorithm (GA) in global searching ability, convergence rate and fitting precision. In this case, the method in this paper is more suitable to the multi-parameter fitting calculation of internal trajectory considering requirements of reliable design and on site testing.