Estimating the Parameters of Superposed Oscillations of Mobile Construction Machines like Diaphragm Wall Hydraulic Grabs

The operation of mobile construction machines like cranes or grabs is influenced by oscillations from their cable-suspended end-effector. For Diaphragm Wall Hydraulic Grabs focused in this article, end-effector oscillations can be inferred from pressure oscillations in the hydraulic actuators. The oscillating end-effector stimulates the hydraulic actuators that respond with pressure oscillations. These pressure oscillations are noisy and superposed by multiple single oscillations from different sources like machine vibration and hydraulic circuit oscillation. The end-effector oscillations can be inferred from single pressure oscillations that must be separated from the pressure signal to enable control in future work. Signal decomposition is numerically expensive and time-consuming and can be optimized by providing a ballpark estimation for the single oscillation parameters, introduced and validated in this article on a benchmark data set. Amplitude, frequency, phase, and decay rate are estimated from the superposed oscillation without providing prior information about the data set.