Elastic Dynamic Model Research Articles

Study on the Controllability of Complex Flexible Hydraulic Vehicle Robot System and its Dynamic Simulation

Based on elastic dynamic model, an elastic dynamic controllable model of the vehicle flexible robot system was established. Regarding the low-order modes as the control modes, setting the boundary coordinates in the locations of the hydraulic actuator, the controllable state-space equations of the system was formed. A precondition for realizing system’s precise control is that the system is controllable. According to system’s controllability discriminant qualification, the influence of physical parameters on the controllability of system got broad discussed, and some reference data was obtained, which would be helpful for the next step to control the vibration. Aiming at the interference of the state-space equations, disturb distributing matrix was merged with input matrix, disturb vectors was merged with input vectors, a new state-space equation was established. By dynamic simulation, vibration response of the vehicle flexible robot system was achieved, and the experimental results showed that the treatment about disturb distributing matrix is feasible.

Dynamic modeling and wind vibration control of the feed support system in FAST

The Feed Support System (FSS) addressed here is the receiver carrier of the Five-hundred-meter Aperture Spherical radio Telescope (FAST) in China. The FSS is a complex hybrid manipulator, which consists of a cable-driven Stewart manipulator, an A–B rotator and a rigid Stewart manipulator. The cable-driven Stewart manipulator, which is a long-span flexible cable structure, is sensitive to the wind disturbance and induces the FSS vibration. The rigid Stewart manipulator is designed to suppress the vibration and improve the terminal accuracy of the FSS. In the paper, the elastic dynamic model of the cable-driven Stewart manipulator is deduced by simplifying the flexible cable as the spring damping model, while the rigid-body dynamic model of the A–B rotator and the rigid Stewart manipulator is obtained in detail, using the Newton–Euler method. The internal coupling forces of the FSS are figured out. The wind disturbance model is established according to the Davenport spectrum. By adopting the kinematic and dynamic parameters of the FAST prototype, the simulation model of the FSS is completed. Kinematic and dynamic vibration control strategies are evaluated with simulations. Results show that the dynamic vibration suppression strategy well satisfies the FSS terminal accuracy requirement, keeps the rigid Stewart manipulator working with reasonable driving forces, and should be adopted in the control system of the FAST prototype.

Elastic Dynamics Analysis and Simulation of New Tire Building Drum

A new type of variable topology parallel tire building drum mechanism was presented in this paper and the solid model of the mechanism was established. The elastic dynamics model has been established by the condition of displacement and power which the rigid connected with elastic body. The model of variable topology parallel mechanism was imported into the ADAMS and analyzed the elastic dynamic simulation of the mechanism.

Tooth wear modeling and prognostication parameters of engagement of spur gear power transmissions

In this paper, the wear model of tooth surface contact has been developed. This model takes into consideration the conditions of machine operation, corresponding tribological theories, the eccentricity of pitch circle and the instant temperature in the contact. The prognostication model of gear teeth characteristics takes into account the continuous influence of profile form on the contact parameters and the influence of parameters of contact on the profile form. The full model is done in the form of a package of computer programs. This model includes the kinematic model of tooth engagement with any form of profiles, the elastic dynamic model with four degrees of freedom, the tooth wear model for the boundary lubrication regime of friction and the model of synthesis of tooth wear profile.