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This study aimed to develop a water rocket launcher kit with a Do-It-Yourself (DIY) concept for science trainee teachers. The research design is the developmental research using the ADDIE model. The need analysis found that many trainee teachers had never handled water rocket activities. The intended kit was successfully developed with an acceptable Content Validity Index of 0.92 from three experts. The water rocket kit consisted of an easily assembled launcher of segmented PVC pipes and several essential components with an instruction manual. Qualitative feedback was obtained from a group of science trainee teachers in an accessible population of a Malaysian university. This study implies that water rocket activities can be performed by trainee teachers with simple kits that can be built on their own, thereby achieving the specific learning objectives in the planned classroom. In addition, this study can also provide early exposure to trainee teachers in the construction and operation of water rocket launchers in schools.

In the case of a multiple-launch rocket system firing in salvo, the rocket gas jet with different spacing will have different effects on the launch box. In this paper, the multi-barrel rocket launcher launch box was taken as the research object, and the development process of the double-launched and four-launched rocket gas jet impinging launch box under different spacing was numerically simulated. The results showed that under the double salvo, with the increase of the emission spacing, the speed of the gas jet increased, the degree of mutual interference decreased, and the surface pressure on the launch box gradually decreased. A smaller emission spacing would form a stronger airflow interference. The change trend of the four-shot salvo was similar to that of the double-shot salvo, and the change of the phenomenon is more obvious. This study provides a useful reference for further understanding the salvo law of rocket launcher and provides strong support for improving the performance of rocket launcher.

One of the most sophisticated causes of unguided rocket dispersion is the uncertainties in launch conditions. This arises due to the fact that a launcher, in reality, shows dynamic behavior as it is a multibody system. This paper investigates the dynamic behavior of a wheeled rocket launcher that is loaded on a vehicle. The launcher and vehicle system are modeled as a multibody system using the transfer matrix method of multibody system (TMM). TMM is chosen due to its suitability for linear systems and its ability to obtain the overall transfer matrix for the entire system by performing successive matrix multiplications of the individual body’s matrix, thereby avoiding the complexity of solving the overall dynamic equations of the system. The developed dynamic model is then validated by comparing its results with those in the open literature using the Lagrange approach. The study considers dynamic loads that result from the rocket motion on the launcher. A parametric study is conducted to address the impact of launcher structural aspects. By investigating the dynamic behavior of the wheeled rocket launcher, this study aims to enhance the understanding of its performance.

Different from traditional EM coil launcher, a new type of primary construction was brought forward in this paper. The energy storage capacitor and primary winding were integrated into one component. The relevant basic equations of mathematical physics were deduced, the finite element simulation was carried out, and the experimental principle prototype was set up for experimental verification, which proves that the new structure is expected to enable the development of more compact and more efficiency EM coil launcher.

In this paper, a disturbance-compensated robust controller was used for electrohydraulic missile launchers with the aim of improving the motion accuracy of the system. In the case of both matched and unmatched disturbances, adaptive extended state observers were employed in order to estimate unmodelled disturbances, external disturbances, and so forth. It was thus resolved to implement a feedforward compensation mechanism in order to counteract the effects of unknown disturbances, based on online estimates of the disturbances with the intention of enhancing the performance of the proposed controller. In addition, in order to address the problems of difficulty in obtaining the differential value of the virtual control law and “Curse of Dimensionality”, an improved first-order sliding-mode differentiator (IFOSMD) was employed. The theoretical analysis demonstrated the stability of the multi-observer and the closed-loop system under the proposed control scheme. The efficacy of the controller was demonstrated through the utilisation of numerical simulations.

A small launching system with autonomous regulation and recognition guidance is designed. Firstly, it ensures a solid and reliable transmission on the mechanical structure of the launcher and the small vehicle. Further, stepper motors and sensors are used to ensure precise control and effective feedback of the angle of the launcher. The small vehicle is equipped with the functions of guidance signal recognition and attitude adjustment, which have the advantages of strong real-time and high versatility. Finally, the practicality and accuracy of the designed launching system to a certain extent are verified through tests.

Traumatic brain injury(TBI) is one of the most common cause of major casualties in the battlefield. Soldiers may be endangering their brains when they operate certain shoulder-fired weapons or large-caliber artillery for long periods of time. It is necessary to pay attention to protection and prevention of brain injury in daily training. In this paper, the characteristic of shock wave propagation on the head with/without helmet protection when soldiers operated shoulder-fired rocket-propelled grenade launcher. The head-helmet surrogate was constructed in combination with pressure sensors. The pressure sensors were installed on the forehead, temples, top, and back of the head surrogate respectively and the sensors kept a plane with the surface of the head surrogate. The pressure variation of the shock wave flow field under different working conditions was analyzed in three types such as with/without combat helmet and integrated helmet. The results show that the peak overpressure of the shock wave from the back of the head can reach 80∼105kPa without combat helmet. The combat helmet can effectively reduce the shock wave overpressure. The integrated helmet has the best protection and can reduce the overpressure on the forehead, temple, top, and back of the head by 73%, 58%, 80%, and 83% respectively. Meanwhile the shock wave is prone to reflection and diffraction as it transmits inside the helmet. This significantly increase the overpressure of the shock wave on the forehead and the duration of the shock wave in the helmet, which has a negative effect on the protection provided by the shock wave.

Launcher efficiency is an important index for evaluating the performance of the electromagnetic launcher, and it reflects the ability of the launcher to convert input electrical energy into kinetic energy of the armature. In this paper, the launcher efficiency is taken as the objective function of bore parameter optimization, and particle swarm optimization is used to optimize the initial parameters of the BP neural network to improve the accuracy of the neural network in predicting launcher efficiency. The results show the following: (1) The predicted efficiency of the launcher shows the same trend as the experimental results. When the ratio of rail separation and rail height is greater than 1.75, the rate of change in the launcher efficiency curve decreases as the rail separation increases. (2) The weight of the influence of each parameter on the launcher efficiency follows the following law: convex arc height > rail separation > rail height > rail thickness. (3) The mean absolute error of the BP neural network prediction is 0.70%; after optimization by PSO, the mean absolute error is reduced to 0.28% and the mean relative accuracy is improved from 0.9774 to 0.9910, which indicates the feasibility of the PSO-BP neural network for the prediction of the launcher efficiency of an electromagnetic launcher.

Aiming at the problems of large size and weight of electric cylinder, low efficiency and large pressure fluctuation of centralized hydraulic drive system, a drive system of anti-aircraft gun and missile weapon system based on electro-hydrostatic actuator is designed. The working principle of the hydraulic system of electro-hydrostatic actuator is discussed, its components are selected and designed, the micro cartridge hydraulic control check valve is designed and the electro-hydrostatic actuator is analyzed and integrated structure is designed;The simulation model is established by AMEsim software. The simulation results show that the electro-hydrostatic actuator can move the missile driving device to the highest position within 2s, meet the working requirements, and have certain guiding significance for the research and development of missile launcher driving.

This paper puts forward the importance of artillery equipment failure prediction, introduces the basic principles of grey prediction modeling, and finds the traditional GM (grey model) (1,1)deficiency. Aiming at this deficiency, the GM(1,1) model is improved based on residual correction and adaptive learning. The fault prediction of a rocket launcher automatic leveling system is taken as an application example, and the grey prediction GM(1,1) is compared and analyzed. Basic model and improved prediction of GM(1,1) model. The analysis shows that the improved GM(1, 1) grey prediction method improves the prediction accuracy and achieves a faster convergence speed, which indicates that the model is feasible and effective, and can provide an effective technical basis for the rocket gun automatic leveling system fault prediction.