Research On Hydraulic Actuator Of Fast Active Reflector System

With the development of radio astronomy, the construction of the Five-hundred-meter Aperture Spherical radio Telescope(FAST) has a great scientific significance and creates a new model of building giant radio telescope. Five-hundred-meter aperture spherical active reflector systerm is one of the most important innovation points of FAST. The actuator is the core part of the active reflector system, and actuator has no off the-shelf product, needs own design manufacture. Currently, the design on the actuator is still inadequate, so this paper about design a new scheme for actuator has a great significance.This paper based on requirements of the actuator and the disadvantages of the existing scheme, designed a new scheme.Firstly, for a better knowledge of the hydraulic actuator’s working conditions, conducting research into the active reflector system. The general structure plan of the cable-net and steel sub-structures and reflector and the actuator is discussed. The locations of control cables as well as the position-transformation-strategy of active reflector are investigated respectively to find out the best set of some key parameters.Secondly, the article designs a new scheme of The Direct Drive Volume Control System, then calculates and selects the key components, as well as designs the relevant mechanical structure, including the stroke sensing cylinder、integrated valve block、Sealed oil tank and the connected components of actuator. In addition, this paper studies and introduces the reliability test scheme of the hydraulic actuator.Thirdly, the two mathematical models of the AC moto and the hydraulic part of actuator were established under the mode of Vector Control, and did simulation by matlab/simulink software. The analysis proves the feasibility of the new scheme.Finally, in order to ensure the hydraulic actuator can work with high accuracy under the complexly interference, this paper introduees SMRAC control strategy to the system and designs SMRAC controller. Then a Simulink model was built in the paper and was run to prove the system‘s well performance. And the paper verifies the correctness of the scheme about SMRAC control.