Summary
On one hand, the new version of transfer matrix method for multibody systems (NV‐MSTMM), has been proposed by formulating transfer equations of elements in acceleration level instead of position level as in the original discrete time transfer matrix method of multibody systems to study multibody system dynamics. This new formulation avoids local linearization and allows using any integration algorithms. On the other hand, sensitivity analysis is an important way to improve the optimization efficiency of multibody system dynamics. In this paper, a totally novel direct differentiation method based on NV‐MSTMM for sensitivity analysis of multibody systems is developed. Based on direct differentiation method, sensitivity analysis matrix for each kind of element is established. By assembling transfer matrices and sensitivity analysis matrices based on differentiation law of multiplication, the sensitivity analysis equation of overall transfer equation is deduced. The computing procedure of the proposed method is also presented. All these improvements as well as three numerical examples show that the direct differentiation method based on NV‐MSTMM is suitable for optimizing the dynamic sensitivity in multi–rigid‐body systems.
Vibration control in launching process is an effective way to improve the dispersion characteristics of Multiple Launch Rocket System (MLRS). In this paper, a novel methodology for MLRS vibration controller design with the application of pulse thrusters and its parameters optimization is introduced. Based on the Transfer Matrix Method for Multibody Systems (MSTMM), the dynamic model of the controlled MLRS with pulse thrusters is established and the launch dynamic simulation system of controlled MLRS is developed. To suppress vibrations of the elevation part using the annularly arranged pulse thrusters, a management scheme based on impulse equivalence approach is presented to adapt the continuous force generated by the PID control law to impulse force. Controller optimization is achieved coupling Particle Swarm Optimization-Genetic Algorithm (PSO-GA) with the established simulation system of controlled MLRS. Finally, the simulation results verify the effectiveness of the proposed controller and demonstrate the engineering practicability value of this methodology.
Natural vibration characteristics and dynamics response of multiple launch rocket system (MLRS) are of fundamental importance from the viewpoint of vibration levels, firing dispersion, and stability. In this study, a new launch vehicle-supports-rockets coupling dynamic model for a practical MLRS is established. Rui method, namely the transfer matrix method for multibody systems (MSTMM) is a new and efficient method for multibody system dynamics (MSD) and is used to obtain the vibration characteristics and dynamics response. The dynamics model, the topology figure of dynamics model, the transfer equations of elements, the overall transfer equation, the eigenfrequency equation, the body dynamics equations, the generalized coordinate equations, and the dynamics simulation system for the MLRS are established. Based on the advantages of MSTMM in studying MSD, the vibration characteristics and dynamics response of complex MLRS are computed rapidly. Finally, the new model is validated in three ways: (1) modal experiment of MLRS, (2) launch dynamics experiment of non-full loading rockets, and (3) launch dynamics experiment of full loading rockets. The results show that the proposed model can not only simulate the natural vibration characteristics of the MLRS but also effectively perform dynamic simulations of the MLRS during launching process.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.