Papers by Keyword: Dynamic Modeling

Abstract: This paper investigates the influence of finite element mesh parameters on the accuracy of modeling the penetration of a steel plate by a bullet in the ExplicitDynamics ANSYS WB computational module. The best results were obtained for the 3rd type of mesh, which included 180 finite elements in the contact zone. For the plate made of impact-resistant S-7 steel, the maximum stresses for the 2nd type of mesh at the attempted penetration reached 1 572,7 MPa, but no penetration was observed. For the S-7 steel plates, penetration was observed only when using the third type of mesh, which confirms the importance of density in the contact zone for an adequate description of dynamic processes. The analysis showed that the Sweep method with density is optimal for modeling steel plate penetration due to the balance of calculation performance and accuracy of the results.

Abstract: Space solar power satellite (SSPS) as a very large flexible spacecraft structure with complex configuration, large size and number of units bring the difficulties to dynamics modeling and analysis. Considering SSPS structure characteristics, equivalent strain and kinetic energy theory is adopted to establish the equivalent beam model of SSPS truss structure. The assumed mode method is adopted to describe the flexible body. The modal truncation method implements the dynamics system order reduction. Mixed coordinates method is adopted to establish the rigid-flexible coupled dynamic model. The established dynamic model can reflect dynamic characteristics of SSPS, achieve control requirements for SSPS and decrease the workload of simulation calculation. The independent modal space control (IMSC) method is proposed to active control research view of the large displacement, nonlinearity, low and dense mode frequency, light damping of flexible structures. Simulation results on flexible solar array show the effectiveness of the control method.

Abstract: In the process of acceleration dynamic measurement, the measurement results have quite large dynamic errors, due to the resonance of acceleration sensors. Using the system identification theory and combining with the dynamic calibration experimental data of acceleration calibration system based on Hopkinson bar, the dynamic model of the sensor is deduced, the dynamic compensation filter is designed. Simulation results show that the compensation filter can broaden the work band effectively. It improves the system dynamic response speed by nine times and advances the measuring accuracy of the test system.

Abstract: In this paper, a comprehensive model is used to describe dynamic behavior of SDA and its components during stepwise motion. In this model, Hamilton’s principle and Newton's method are used to extract dynamic equations of the SDA plate and dynamic equation for the linear motion of SDA. Comparison between the modeling results and available experimental data shows that this model is very effective in predicting some design objectives such as step size and output force for this type of actuators.

Abstract: In the d-q coordinate system, UPFC mathematical model reveals a nonlinear system with features of a multi-variable, strong coupling, and more interference. In view of these system characteristics, the paper presents a nonlinear overlapping decoupled strategy with better stability and dynamic performance for UPFC control. The control strategy is analyzed and tested with the MATLAB simulative experiments. Simulation results show that the proposed control strategy can quickly and accurately respond to the needs of the power system, and realize real power and reactive power decoupling control effectively. Keywords: Dynamic Modeling, Nonlinear, Decoupling Controller, UPFC, MATLAB

Abstract: In order to study the dynamic performance with respect to a drum type washing machine, a detailed three dimensional dynamic model considering six degrees of freedom is established in the commercial software Adams. The characteristics of model are in good consistency with the simulation results on the movement of measure point in the x-z plane and eigen modes of the rigid body system. An automatic counterbalancing model of balls with different torsion damping coefficient is designed for vibration reduction. The parameters affecting the vibration are investigated by the approach of design of experiments which can reduce design cycle significantly. Its optimization results show a good performance compared to a washing machine model without balance balls attached.

Abstract: Improved 5-DOF vehicle which contains nonlinear steering and tire models was established to solve the deficiency of conventional dynamic linear models to analyze coupling characteristics. Based on GPS technology, a developed vehicle handing and steering stability detecting system comprised by Steering Force and Angle Tester, GPS, Gyroscope and high precision Data Collector was introduced. According to Matlab/Simulink platform and vehicle test, the dynamic model was verified. Then some influence factors on bus handing and steering stability such as structure parameters, suspension parameters and tire parameters were analyzed. The results show that the longitudinal position of gravity and the vertical distance of gravity and roll axis have a good effect on vehicle yaw and roll responses. Spring roll stiffness is important parameter for vehicle roll. The pneumatic trail is closely related on steering reversibility and comfort. These researches have direct reference value for bus design.

Abstract: This paper discovers the dynamic modeling process based on equilibrium condition of forces and moments, in order to improve handling stability, the side-slip angle need to be reduced to zero, special process is used in the dynamic equations simplification for demanded theoretical steering angle of each axel. At last this systems steady-resonance characteristics are researched.

Abstract: This paper presents the dynamic modeling of a new variant of helical planetary gear proposed by the authors, generated by the Vaucanson`s planetary mechanism. This model can be apply successfully helping a robotic arm in motion. It is considered that the gear made connects between a motor and a pump, whose mechanical properties are known. Using Matlab-Simulink is setting the equations of motion and dynamic response, both in premise neglect friction and the premise of considering friction.

Abstract: The off-line test method which is generally employed in modeling of generator excitation system has parameter lag and does not fully reflect dynamic characteristics. This article established an online identification and dynamic modeling for the excitation system by smart component technique combined with particle swarm optimization algorithm. It studied the principles of dynamic modeling, taking model parameters corresponding to the minimum objective function as the output result of the identification, also set up implementation steps and flowcharts of the parameter identification based on particle swarm optimization algorithm. An example case was given based on the measured data, and the identification results of the case were taken as the set value of the simulation model. The article compared simulation results to the field test data of 5% step response condition. The comparative results indicated that particle swarm optimization algorithm based on synchronization intelligent component data had the ability to adapt to online identification decently and high identification accuracy.