Research On Nonlinear Optimal Control Of A Tethered-Payload System And Its Experiment Validation

Cables have been widely used in engineering systems, for example, tethered crane system et al. The tethered payload system is a typical nonlinear dynamical system. Positioning control of the tethered-payload system is a open problem.A set of non-linear differential equation of the tethered crane system model is formulated based on Lagrange's Equation. The tension of the cable, the control force of translation and the control torque of rotation of the tower crane system are obtained by Newton's Laws. Nonlinear optimal control of the tethered crane system with transport time unconstrained is studied, and the quasilinearization and the truncated Chebyshev series is used to approximate the state variables of the system such that the original problem of constrained nonlinear optimal control is simplified into a set of linear quadratic programming problems which can be easily solved.The effectiveness of the proposed method has been confirmed by experiment. The experiment results show good performance and robustness.