Abstract:

The feed cabin of the next generation large spherical radio telescope is pulled with six long cables, which are driven cooperatively with motors to track radio sources. Similar to a parallel manipulator, the cable-cabin structure can be viewed as a cable-supported parallel manipulator (CPM). Due to the inherent characteristics of nonlinearity, delay and multivariable coupling for this flexible structure, a novel control method combining sliding mode control (SMC) with fuzzy logic control is developed to realize trajectory tracking of the feed cabin, in which SMC parameters can be adjusted with fuzzy logic in real time. At the same time the exponent approximating control is added by grading. This approach not only increases the respond speed and improves the robustness of the control system, but also weakens its chattering. Simulation results show the effectiveness of the proposed method.

Key words: cable-supported parallel manipulator, sliding mode control, servo controller design, trajectory tracking