A new method for evaluating the firing precision of multiple launch rocket system based on Bayesian theory

How to effectively evaluate the firing precision of weapon equipment at low cost is one of the core contents of improving the test level of weapon system.A new method to evaluate the firing precision of the MLRS considering the credibility of simulation system based on Bayesian theory is proposed in this paper.First of all,a comprehensive index system for the credibility of the simulation system of the firing precision of the MLRS is constructed combined with the group analytic hierarchy process.A modified method for determining the comprehensive weight of the index is established to improve the rationality of the index weight coefficients.The Bayesian posterior estimation formula of firing precision considering prior information is derived in the form of mixed prior distribution,and the rationality of prior information used in estimation model is discussed quantitatively.With the simulation tests,the different evaluation methods are compared to validate the effectiveness of the proposed method.Finally,the experimental results show that the effectiveness of estimation method for firing precision is improved by more than 25%.

A novel launch dynamics measurement system for multiple launch rocket system and comparative analysis with numerical simulations

In this paper,a novel launch dynamics measurement system based on the photoelectric sensor pair is built.The actual muzzle time(i.e.a time duration that originates from the initial movement to the rocket’s departure from the muzzle)and the muzzle velocity are measured.Compared with the classical methods,the actual muzzle time is obtained by eliminating the ignition delay.The comparative analysis method is proposed with numerical simulations established by the transfer matrix method for multibody systems.The experiment results indicate that the proposed measurement system can effectively measure the actual muzzle time and reduce the error of classical methods,which match well with the simulation results showing the launch dynamics model is reliable and helpful for further analysis and design of the MLRS.

Novel sensitivity analysis method and dynamics optimization for multiple launch rocket systems

This study establishes the launch dynamics method,sensitivity analysis method,and multiobjective dynamic optimization method for the dynamic simulation analysis of the multiple launch rocket system(MLRS)based on the Riccati transfer matrix method for multibody systems(RMSTMM),direct differentiation method(DDM),and genetic algorithm(GA),respectively.Results show that simulation results of the dynamic response agree well with test results.The sensitivity analysis method is highly programming,the matrix order is low,and the calculation time is much shorter than that of the Lagrange method.With the increase of system complexity,the advantage of a high computing speed becomes more evident.Structural parameters that have the greatest influence on the dynamic response include the connection stiffness between the pitching body and the rotating body,the connection stiffness between the rotating body and the vehicle body,and the connection stiffnesses among 14^(#),16^(#),and 17^(#)wheels and the ground,which are the optimization design variables.After optimization,angular velocity variances of the pitching body in the revolving and pitching directions are reduced by 97.84%and 95.22%,respectively.

Study on Feasibility of Reusable Rocket Launching Technology by Use of Scramjet and Maglev Technologies

The scramjet and maglev engineering technology development and trends at home and abroad are firstly presented in this paper. A new launch mode of space transportation system is proposed based on scramjet and magnetic suspension technologies, and its key technologies required are given. This paper also makes analysis on using scramjet and magnetic suspension technologies to launch a reusable rocket, and the results show that a normal temperature conductor maglev launch system is feasible.

An efficient and modular modeling for launch dynamics of tubed rockets on a moving launcher

This paper develops a modular modeling and efficient formulation of launch dynamics with marching fire(LDMF)using a mixed formulation of the transfer matrix method for multibody systems(MSTMM)and Newton-Euler formulation.Taking a ground-borne multiple launch rocket systems(MLRS),the focus is on the launching subsystem comprising the rocket,flexible tube,and tube tail.The launching subsystem is treated as a coupled rigid-flexible multibody system,where the rocket and tube tail are treated as rigid bodies while the flexible tube as a beam with large motion.Firstly,the tube and tube tail can be elegantly handled by the MSTMM,a computationally efficient order-N formulation.Then,the equation of motion of the in-bore rocket with relative kinematics w.r.t.the tube using the Newton-Euler method is derived.Finally,the rocket,tube,and tube tail dynamics are coupled,yielding the equation of motion of the launching subsystem that can be regarded as a building block and further integrated with other subsystems.The deduced dynamics equation of the launching subsystem is not limited to ground-borne MLRS but also fits for tanks,self-propelled artilleries,and other air-borne and naval-borne weapons undergoing large motion.Numerical simulation results of LDMF are given and partially verified by the experiment.

A novel non-separation opening scheme of front cover for rocket launch canister

In view of that existing opening technologies of front cover for rocket launch canister have disadvantages such as causing damage on the ground equipment,not being reused and easily broken.A novel reusable non-separation spring-driven opening scheme is proposed to achieve rapid and reliable opening of the front cover.The mathematical model of the opening process of the front cover is established by the rigid body dynamics theory.To establish a response surface model to optimize the opening scheme,three main influencing factors of the opening process are obtained through the designed experiments,including the pre-compression,the stiffness of the thrust spring,and the thrust spring force arm length.In addition,the prescribed kinematic law was taken as constraint,and the smaller thrust spring preliminary pressure and angular velocity was taken as optimization expectations.The results show that the opening scheme meets the design requirements on opening process well.It also shows that the optimized scheme can reduce the kinetic energy of the front cover,and the impact on the canister effectively,achieving a reliable and rapid opening of the front cover.

LM-4B Rocket Launches the ZY-3 Satellite

At 11:17 on January 9,a LM-4B carrier rocket lifted off from the Taiyuan Satellite Launch Center,sending the first high-precision civilian stereo mapping satellite of China,Ziyuan 3 (ZY-3),into its preset orbit,marking the first launch mission of 2012 a success.A small satellite of Luxembourg,VesselSat-2,was launched aboard the LM-4B as well.The ZY-3 satellite weighs 2650kg with a design lifetime of 5 years.The satellite was built to acquire rapidly

Solid Rocket Motors for Launch Escape Tower Provide Safety to Astronauts

Compared with other ordinary launch vehicles, the LM-2F launch vehicle has two special systems, the fault detection processing system and launch escape system, because it is used for manned spaceflight missions. During the 10 flight missions carried out by LM-2F, only the

Digital Assembly Technology Applied for Large Rocket Sections Assembly and Mating

Tianjin Aerospace Long March Rocket Manufacturing Co.,Ltd.under CASC successfully completed the digital assembly of the first-stage hydrogen tank and oxygen tank and the inter-tank section of the LM-5 launch vehicle for its maiden flight.It is the first time that indigenous developed equipment,for digital assembly,was used formally in product assembly,

The First Launch of Europe-made Satellite by China's Rocket Achieved Great Success

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LM-3B Launches Tiantong 1 Satellite

China Launched its first satellite for mobile communications on a LM-3B launch vehicle from the Xichang Satellite Launch Center at 0：22 on August 6,2016.The Tiantong 1 satellite was developed by the China Academy of Space Technology under CASC to provide all-weather,all-time stable and reliable mobile communications services to China and surrounding regions as well as to the Middle East,Africa,

A LM-4C Launches the GF-3 Satellite

The GF-3 satellite was successfully launched at 06：55 Beijing time on August10 using a LM-4C launch vehicle from the Taiyuan Satellite Launch Center.The launch was the 233rd flight of a LM family launch vehicle and the carrier rocket LM-4C was developed by the Shanghai Academy of Spaceflight Technology.

China's First Space Laboratory Tiangong 2 Was Launched into Space Successfully

A LM-2F launch vehicle lifted off from the Jiuquan Satellite Launch Center at22：04 Beijing time on September 15,putting China’s first space laboratory Tiangong 2 into space.575 seconds after the liftoff,Tiangong 2 separated from the carrier rocket and entered its preset orbit.The launch achieved complete success.

LM-2F Carries out Shenzhou 11 Mission Successfully

At 7：30 Beijing time on Ocotber17,2016,a LM-2F launch vehicle soared up from the Jiuquan Satellite Launch Center,successfully putting the Shenzhou 11 spaceship and its crew into space.Two astronauts,JING Haipeng and CHEN Dong will carry out the 6th manned spaceflight mission of the country.