| Summary: | 碩士 === 國立成功大學 === 機械工程學系碩博士班 === 97 === Cranes play an important role in many factories for transferring a payload from one place to another. These systems usually require a fast maneuver with small motion-induced vibration amplitudes. However, the motion induced swings during crane movements make it difficult to transfer the payload rapidly with high positioning accuracy. Furthermore, for hazardous or fragile payloads, such a generated swing could possibly cause significant safety concerns. In order to increase the work efficiency, residual vibration resulting from structure motion must be analyzed and suppressed. Input shaping provides a cheap and effective method of suppressing the payload swings and residual vibrations during a rapid maneuver. However, the traditional designs of the shaper have all been based on rigid pendulum model in one-dimensional motion, which may not be realistic for many applications. Besides, it is very difficult to obtain the equations of motion by analytical approach for complicated systems. In this dissertation, the author integrates finite element dynamic analysis with the shaper design to suppress swing and vibrations for crane-based transportation. A rigid pendulum and a flexible pendulum are designed as the equivalent models for cranes, respectively. These pendulums are mounted on a two-axis liner servomotor for serving as a platform to simulate the motion of a payload under a crane. ZV, ZVD, ZV-ZV, and ZVD-ZVD shapers are applied to evaluate the capability of suppressing motion induced payload swings and residual vibrations. The results demonstrate that the input shaping methods allow the test systems to maneuver smoothly and rapidly to the final destination with only a small swing angle and almost no residual vibrations. The robustness of these shapers is investigated through both simulations and experiments and the results shows that the ZVD and the ZVD-ZVD shapers are more robust to resist dynamic parameter variations than the other methods. Meanwhile, essential finite element simulations are also conducted and verified using the experimental data. The simulation results indicate that the finite element simulation can potentially be a powerful tool for analyzing the dynamic behavior and for designing input shapers of more realistic and complicated mechanical systems.
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