Parameter estimation for towed cable systems using moving horizon estimation

This paper presents a strategy for optimal estimation of parameters for towed cable systems using moving horizon estimation (MHE). The main contributions of the work include a novel formulation of MHE using a dead-band that explicitly rejects measurement noise, real-time implementation results, and the investigation of time-varying stochastic disturbances as well as unknown yet constant disturbances. Further analysis is conducted on the observability and sensitivity of key parameters to determine which parameters can be estimated by the proposed approach using real-time streaming data from experiments. In addition to the real-time results, an offline multiobjective optimization is conducted to reveal the tradeoff between the computational burden and estimation variation. A Pareto frontier is used to demonstrate a series of optimal experimental configurations obtained by adjusting the model complexity (number of cable links and horizon steps). Finally, a multivariate parameter estimation is performed to explore the applicability of the proposed approach in simultaneously estimating multiple parameters.