Autonomous Serendipitous Science Acquisition for Planets (ASSAP)
This paper discusses work in progress to develop and demonstrate a set of autonomy technologies that provide teh onboard capability to redirect science observations.
redirect↗
Engineering topics
Eldred, D.
Publications and source records attributed to Eldred, D..
Precision Segmented Reflector figure control system architecture
A control system architecture for an actively controlled segmented reflector is described along with a design realization for achieving precision alignment of reflector panels. Performance requirements are derived in part from the Large Deployable Reflector, which is a representative mission, and error allocations are made which consider mirror panel surface errors, position measurement and figure estimation, and position control of both quasi-static and dynamic disturbances. The design uses multiple wavelength interferometric edge sensors and voice coil actuators in conjunction with a hybrid control strategy to correct panel position errors. A unit cell shown to be central to the concept is analyzed. The cell integrates the sensing, actuation, and mechanical functions of a control module together with a reflector panel to form a unitized assembly.
Mettler, E.↗
Experimental demonstration of static shape control
Previously cited in issue 03, p. 344, Accession no. A82-13998
Eldred, D.↗
Experimental demonstration of static shape control
Results of a microprocessor-controlled implementation of static shape control using a specially constructed flexible beam facility are presented. The discussion covers the development of shape control algorithms, adaptation of the algorithms for use with finite element models, construction of a flexible beam, characterization and calibration of the facility, development of a finite element model for the beam, and the development of computer hardware and software. It is shown that feedback control yields better results than open-loop control, and that the use of more than two sensors in the control loop has little effect on the system performance.
Eldred, D.↗