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Firing accuracy is a critical quantity of interest in the performance analysis of electromagnetic railgun (EMRG) exterior ballistics. Since the simulation technique is always used to simulate the complex physical system at a low cost, it is employed to evaluate the firing accuracy of railgun projectile with uncertainty in this paper. An exterior ballistics simulation model of the railgun, including 3-DOF flight mechanical model, relative kinematic model, and guidance law model, is developed to simulate the ballistics behavior in the missile target intercept mission. The firing accuracy is studied in this paper to compare the capability of EMRG with different ranges and muzzle velocities. In order to explore the firing accuracy of the guided projectile, the guidance precision analysis and ballistics uncertainty quantification are studied. In the guidance precision analysis, the shot range and efficiency are used to make a comparison. In addition, the sensitivity analysis and firing accuracy analysis are also performed in terms of uncertainty quantification. The simulation results illustrate that the simulation of the guided projectile can give some practical guide to the projectile design of EMRG. [ABSTRACT FROM AUTHOR]

Energy efficiency is a critical quantity of interest in the performance of electromagnetic railgun (EMRG). To improve the energy efficiency of EMRG with the presence of uncertainty, a hybrid robust optimization method is proposed. EMRG simulation model is developed to simulate the behavior of exterior ballistics and the corresponding robust optimization issue is formulated. With the help of the impact factor analysis, several significant factors of energy efficiency are selected as the design variables while the insignificant ones are not taken into account. In the robust optimization, the polynomial chaos expansion approach coupled with Latin hypercube design is proposed to propagate the uncertainty for alleviating the computational burden of fitness function (energy efficiency) evaluation. Then, the genetic algorithm is employed to solve the EMRG energy efficiency optimization problem with the constraint of mean miss distance. The optimization results illustrate that the hybrid robust optimization method is an efficient approach to improve the energy efficiency, which can be applied in the practical application of EMRG projectile design. [ABSTRACT FROM AUTHOR]

Electromagnetic railgun (EMRG) is a promising candidate weapon system for the future surface-fire support mission characterized by quick response, hypersonic velocity, and high damage efficiency. Since the huge power consumption during launching, priority should be given to the precise strike. Firing accuracy of EMRG, which refers to the closeness degree of the projectiles’ impact points to the target, is an important performance metric in the EMRG exterior ballistic performance assessment. To provide a systematic solution for the measure of firing accuracy, the assessment factors are formulated in detail. Then, a general framework, including trajectory simulation, data preprocessing, parameters estimation, and hit probability calculation, is proposed to evaluate EMRG firing accuracy. Considering the trajectory simulation experiments may be time consuming, a new multicriteria optimal Latin hypercube design method is presented to maintain the balance between experiment time and sampling performance. Finally, firing accuracy assessment of 16-kg projectiles is performed using the designed framework and proposed experimental design method. The result reveals that the circular error probability is about 5 km under current defined scenarios, which means the initial disturbances may have great impact on the firing accuracy of projectiles without guidance and control units. [ABSTRACT FROM PUBLISHER]