1 / 27

Outline

DVAC PROGRESS OFFSET GREGORIAN DISH ( DVAC-1) 郑元鹏 (Yuanpeng Zheng ) Joint Lab. for Radio Astronomy and Technology MAY 29, 2012. Outline. DVAC-1 Concept Design DVAC-1 Main Specification Budget. DVAC-2. DVAC-1. 1. DVAC-1 Concept Design. Main Specifications for DVAC-1.

mayrak
Download Presentation

Outline

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. DVAC PROGRESSOFFSET GREGORIAN DISH (DVAC-1)郑元鹏 (Yuanpeng Zheng )Joint Lab. for Radio Astronomy and TechnologyMAY 29, 2012

  2. Outline • DVAC-1 Concept Design • DVAC-1 Main Specification Budget DVAC-2 DVAC-1

  3. 1. DVAC-1 Concept Design Main Specifications for DVAC-1

  4. 1. DVAC-1 Concept Design Main Specifications for DVAC-1

  5. 1. DVAC-1 Concept Design Concept design progress 2012 2011 2010

  6. 1. DVAC-1 Concept Design (1) Microwave Optical Design (2) Structure Design (3) Servo Control Design

  7. 1. Concept Design (1) Microwave Optical Design • Feed Design Operating frequency: 0.3GHz~10GHz (33 octaves) two wide-band feeds (WBF) WBF advantages: • Bandwidth of several octaves; • Dual linear or circular polarization • Constant phase centre • Equal E- and H-plane beamwidth

  8. 1. Concept Design (1) Microwave Optical Design • Feed Design Feed 1(0.3GHz ~ 1.5GHz ) and Feed 2(1.5GHz ~ 10GHz ) Eleven Feed Simulation Model

  9. 1. Concept Design (1) Microwave Optical Design • Main and Sub Reflector Curve Design 55°Opening Angle -13dB Feed Edge Taper Optimum Design

  10. 1. Concept Design (2) Structure Design • Reflector Design • Mount Design • Structural Mechanics Analysis

  11. 1. Concept Design (2) Structure Design • Reflector Design • Main reflector • Back structure • Subreflector • Feed switch mechanism

  12. 1. Concept Design (2) Structure Design • Reflector Design — Main reflector • One-piece composite foam sandwich structure with metalizing surface • Carbon fibre skins and sandwichpolyurethane foam • Back ribs • Surface accuracyσ≤0.5mm rms

  13. 1. Concept Design (2) Structure Design • Reflector Design — Back structure

  14. 1. Concept Design (2) Structure Design • Reflector Design — Subreflector One-piece composite foam sandwich structure with metalizing surface . Surface accuracy σ≤0.2mm rms Accuracyσ≤0.3mm

  15. 1. Concept Design (2) Structure Design • Mount Design Elevation Part Azimuth Part Pedestal

  16. 1. Concept Design (2) Structure Design • Mount Design — Azimuth part • Dual-motor anti-backlash drive • External gear bearing, easy to maintain • Seal cover is used to exclude dust and sand

  17. 1. Concept Design (2) Structure Design • Mount Design — Elevation part A planetary reducer with a ball screw drive is used for the elevation part.

  18. 1. Concept Design (2) Structure Design • Mount Design • A flexible-axis drive technique is adopted for Az and EI encoder mechanism. • A double-layer ring structure is used for AZ cable wrap. • A modular design for all rotating parts. • A Line-Replaceable Unit (LRU) design is applied to reducer, motor, encoder and limit device, azimuth cable wrap, and elevation lock device. Not only for ease of replacement and maintenance, but also suitable for batch production.

  19. 1. Concept Design (2) Structure Design • Structural Mechanics Analysis • Finite Element Model

  20. 1. Concept Design (2) Structure Design • Structural Mechanics Analysis • Reflector Surface Deformation by Gravity EL=15° EL=45° EL=90° Best Fit Surface Error by Gravity

  21. 1. Concept Design (2) Structure Design • Structural Mechanics Analysis • Reflector Surface Deformation by Gravity,Wind, and Temperature Total Surface Accuracy: Less than 0.62 mm from 15 to 90 degree

  22. 1. Concept Design (3) Servo Control Design • Antenna control unit (ACU) • Feed Control • Antenna drivers • Motors • Power distribution devices • Encoders • Local control pendant • Limit and safety protection device

  23. 1. Concept Design (3) Servo Control Design Main features of control system • Mature Product • State-of-the-art components • Fully digital control system • Very high reliability • Modular design, easy for maintenance • Brushless motors, no maintenance • Spare part available

  24. 1. Concept Design (3) Servo Control Design • STANDBY • Power-on default operation mode or return-on-fault mode • PRESET • Moving to predefined position • RATE • Moving at user-defined constant velocity • PROGRAM TRACK • Tracking of an object along a pre-defined path • STOW • Automatically rotating to preset stow position and locking stow pin

  25. 2.Main Specification Budget (1) Antenna Aperture Efficiency

  26. 2.Main Specification Budget (2) Pointing accuracy

  27. Thank You END

More Related