A paper describes a modular design for new controllers for infrared heating during cruise stage solar thermal vacuum test of the Mars Science Laboratory. The controllers had to be easy to use and maintain, used with a wide variety of different control schemes, and made using commercial off-the-shelf (COTS) components wherever possible.
A new controller was designed and built using COTS components that could be operated manually, or automatically in a temperature control mode through the use of programmable PID (proportional–integral–derivative) controllers. Another option is through computer control to implement control schemes involving average over a number of sensors, with no sensor above or below the temperature set point or use of non-thermocouple sensors such as PRTs (platinum resistance thermometer), calorimeters, etc. The system incorporates a thermal failsafe to guard against high-temperature overruns of the test item, ground fault circuit interrupters for personal protection, and has provision for an external shutdown signal for other conditions such as a vacuum system entering the corona region with the addition of a proper alarm system.
This controller was designed and built as a versatile general-purpose controller. Its modular design will make upgrades or modifications simple to implement. Previous controllers used at JPL were purpose-built for the project that required them, and difficult to upgrade or modify.
This work was done by Michael R. McKee, Isaac M. Brown, Seth L. Chazanoff, and Bruce Woodward of Caltech for NASA’s Jet Propulsion Laboratory. NPO-47402
This Brief includes a Technical Support Package (TSP).
Versatile Controller for Infrared Lamp and Heater Arrays
(reference NPO-47402) is currently available for download from the TSP library.
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Overview
The document is a Technical Support Package for the Versatile Controller for Infrared Lamp and Heater Arrays, associated with NASA's aerospace testing initiatives. It was presented at the 25th Aerospace Testing Seminar in October 2009 and outlines the design requirements, functional specifications, and operational goals for the controller system.
Key design requirements emphasize maximizing the use of Commercial Off-The-Shelf (COTS) equipment in the controllers and reusing existing lamp fixtures whenever possible. The controllers are designed to be flexible, allowing for manual control as well as automated control based on temperature, Proportional-Integral-Derivative (PID) strategies, or other unspecified methods. Safety is a paramount concern, with explicit goals to avoid damaging the hardware under test and ensuring the safety of personnel during operations.
The functional requirements highlight the need for significant heat generation, particularly for applications involving solar panels and aero-shell warm-up after testing. The document notes that the exact amount of heat required is still to be determined, indicating an iterative design process that adapts to specific testing needs.
Visual aids, such as pictures of upper and lower lamp arrays and controller front panels, are included to provide a clearer understanding of the system's components and layout. These images support the technical descriptions and illustrate the practical aspects of the controller's design.
The document also serves as a part of NASA's Commercial Technology Program, aimed at disseminating aerospace-related developments with broader technological, scientific, or commercial applications. It encourages collaboration and further inquiries through contact information for the Innovative Technology Assets Management at JPL.
Overall, this Technical Support Package encapsulates NASA's commitment to advancing aerospace testing technologies, focusing on the development of versatile and safe infrared lamp and heater array controllers. It reflects a blend of innovation, safety, and practicality, ensuring that the systems developed can meet the rigorous demands of aerospace testing while also being adaptable for various applications.
