Application of the Transfer Matrix Method for Multibody Systems in Dynamics of the Self-Propelled Artillery

Author(s):  
Qicheng Zha ◽  
Xiaoting Rui ◽  
Feifei Liu ◽  
Hailong Yu ◽  
Jianshu Zhang

Transfer Matrix Method for Multibody Systems (MSTMM) has the advantages of no need to establish the global system dynamics equations, low order of the system matrix, high programming, and fast calculation speed compared to the ordinary dynamics methods. In this paper, the topological graph of the dynamics model, transfer equations, transfer matrix of overall system and the simulation program of dynamics of the self-propelled artillery system are established by using the new version of the transfer matrix method for multibody systems and the automatic deduction theorem of overall transfer equation of systems. Realize the rapid calculation of the deviation of the pitch angle and the revolution angles of the turret versus time in the self-propelled artillery. It provides a theoretical basis and simulation means for the dynamics analysis of the self-propelled artillery.

2019 ◽  
Vol 86 (6) ◽  
Author(s):  
Jianshu Zhang ◽  
Xiaoting Rui ◽  
Junjie Gu

The transfer matrix method for linear multibody systems is capable of providing precise solutions for the dynamics of various mechanical systems, but it may also suffer from numerical instability in some cases, where serial chains with a large number of mechanical elements are involved or high-frequency harmonic responses are computed. Combining such a transfer strategy with the Riccati transformation yields the Riccati transfer matrix method (RTMM), which can help improve the numerical stability. According to the existing method, the conventional transfer matrices of all the mechanical elements should be obtained first; in other words, the existence of conventional transfer matrices is a prerequisite for the application of the RTMM. Thus, it seems that the RTMM is incapable of performing the dynamics analysis of linear multibody systems with indeterminate in-span conditions due to the nonexistence of the corresponding conventional transfer matrices. Observe that, for any state variables with indeterminate input–output relationships, the complementary state variables (the complementary state variable of a displacement is the corresponding internal force and vice versa) are identically equal to zero, and that the dimension of the Riccati transfer equation is only half of that of the conventional transfer equation. It reveals that the Riccati transfer equations for the connection points associated with indeterminate in-span conditions can be formulated directly, and that there is no need to rely on the conventional transfer equation. Two numerical examples are simulated and the computational results are compared with those obtained by the finite element method, which verifies the proposed method.


Author(s):  
Qinbo Zhou ◽  
Xiaoting Rui

The obtaining of the overall transfer equation of a linear controlled multibody system is one of the key problems when the transfer matrix method for multibody systems (MSTMM) is applied to study controlled multibody dynamics. This paper applies the theory of matrix signal flow graphs (MSFG) to MSTMM. The transfer matrix signal flow graphs (TMSFG) of a mechanical element and a control subsystem can be drawn according to their transfer equations. By merging the nodes corresponding to the same state vector, the TMSFG of the entire system can be obtained. Eventually, the overall transfer equation of the linear controlled system can be systematically obtained according to the reduction rules of MSFG. An example is taken to sketch the idea and the simulation results are compared with other ordinary dynamics methods to validate the proposed method. This paper lays a foundation for automatic deduction of overall transfer equations of linear controlled multibody systems.


2016 ◽  
Vol 84 (1) ◽  
Author(s):  
Junjie Gu ◽  
Xiaoting Rui ◽  
Jianshu Zhang ◽  
Gangli Chen ◽  
Qinbo Zhou

The Riccati transfer matrix method (RTMM) improves the numerical stability of analyzing chain multibody systems with the transfer matrix method for multibody systems (MSTMM). However, for linear tree multibody systems, the recursive relations of the Riccati transfer matrices, especially those for elements with multiple input ends, have not been established yet. Thus, an RTMM formulism for general linear tree multibody systems is formulated based on the transformation of transfer equations and geometrical equations of such elements. The steady-state response under harmonic excitation of a linear tree multibody system is taken as an example and obtained by the proposed method. Comparison with the finite-element method (FEM) validates the proposed method and a numerical example demonstrates that the proposed method has a better numerical stability than the normal MSTMM.


2014 ◽  
Vol 530-531 ◽  
pp. 1043-1048 ◽  
Author(s):  
Hossam Hendy ◽  
Xiao Ting Rui ◽  
Qin Bo Zhou ◽  
Fu Feng Yang ◽  
Mostafa Khalil

Many real systems such as inertial measurement unit (IMU) in vibration environment, avionic systems in flight tests, half car dynamic model in rid comfortable test and suspension design…etc. can be expressed as Two-inputs-two-outputs (TITO) system for more realistic analysis than single-input-single-output system (SISO); but with more additional complexities. Comparing Transfer Matrix Method for multibody systems (MSTMM) with classical dynamic methods has preferences of modeling flexibility, low order of system matrix, and high computational efficiency, without necessity of deriving the system’s global dynamic equations. The need of combining control strategies with MSTMM becomes an issue of paramount importance due to that a lot of systems are considered as multibody systems, some need control to obtain higher accuracies requirement, vibration isolation treatment, …etc. As a rule of thumb the concept of designing vibration isolator in one field can be applied in many other fields. In this article a generalized TITO model is analyzed using MSTMM to deal with the vibration problem via an active isolator for both vertical translation and pitch responses. Active isolation is applied via Proportional-Integral- Derivative (PID) controller to prove the capability of formulating a relationship between MSTMM and well-known control methodologies to mitigate vibration effects. For verification purpose the analyzed model is verified using data for half car model and standard formulae for road models input excitation test. The achieved results declared that MSTMM can be combined with control techniques without need of special treatments or preconditions for different models with the advantages of MSTMM. This article allows wider developed control applications to use MSTMM simple application for more complex systems models. Dilatation in studying controlled systems using MSTMM provides a possibility for incoming control applications because of the good dealing of MSTMM with the increased complexities of multi-rigid-flexible-body problems.


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