Solar Concentrator Inflation Control System
Abstract
An important component of any space-rated inflatable structure is the inflation system. Precise control of the inflation pressure during deployment and operation prevents unwanted dynamic responses in the structure. This paper describes the development and operation of an inflation control system used during low pressure (5E-5 torr) testing of an inflatable solar concentrator. An advanced rapid prototyping method was used to go from concept to vacuum chamber deployment in 6 weeks. A block diagram of the dynamic system was graphically constructed and the closed-loop controller was designed and simulated. This model was then automatically converted to optimized C code. This code was compiled. linked. downloaded. and run in real time on a special Pentium-based PC. Connections between the real hardware and the simulation program were formed and edited graphically. A user-built interactive animation interface on the host PC enabled the user to monitor all outputs and change controller parameters 'on the fly' with graphical sliders, buttons, and switches. The inflation control system uses special logic to send out very small pulses of gas during inflation. This slow inflation dramatically reduced the violent effects of gas expansion under vacuum conditions. The controller proved successful in controlling both torus and concentrator pressures to pre-set values during a 6 hour thermal vacuum test in a large NASA vacuum chamber.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 31, 2000
- Accession Number
- ADA397989
Entities
People
- B. D. Hancey
- D. M. Lester
- P. L. Siefkas
- S. R. Wassom