Comparison of Filtering Methods for Vibration Reduction
Digital notch filtering, lowpass filtering, and input shaping are three well-known methods for shaping reference commands to reduce vibration in flexible systems. Both filters and input shapers are used to modify signal commands in such a way as to minimize vibration. In unshaped signal generation of tower cranes, the load on the crane will always have residual oscillation or swaying due to the crane’s motion. Filters and input shapers minimize this motion by shaping the original command through a series of impulses designed to be out of phase with the unshaped oscillation thus canceling the vibration. Since the introduction of robust input shaping (Singer, 1990) substantial evidence has led to the assessment that input shaping is superior to both notch and lowpass filtering for suppressing vibration in mechanical systems (Singer 1999). This project examines the validation of theoretical developments in the comparison between notch filtering, lowpass filtering, and input shaping utilizing portable bridge and tower cranes. Also, work was previously done with the WinCC software, provided by Siemens, in order to create a user interface in which the position of the tower crane trolley and payload are displayed on the WinCC along with the available workspace and a set of controls for actuating the crane. This project further develops the user interface of the WinCC software by providing a predictor which predicts the trolley motion of the tower crane.
- The Tower