Active narrowband disturbance rejection on an ultra quiet platform
Edwards, Stephen G.
MetadataShow full item record
Vibration isolation on spacecraft is needed for imaging sensors, microgravity experiments, and other sensitive payloads. The preferred method thus far has been passive isolation because of its simplicity and low cost. Active vibration isolation and disturbance rejection will soon be more common as space qualified sensors, actuators and processors become more capable and affordable, and performance requirements increase. Spacecraft disturbances are typically periodic vibrations which are most effectively controlled through feedforward techniques. A popular choice of feedforward control methods for disturbance rejection is the Multiple Error Least Mean Squares (LMS) algorithm which requires a separately measured disturbance correlated signal in its implementation. A new technique called Clear Box makes extensive use of identification to bring out information that is normally hidden or not used by traditional control methods. It allows operation in an information rich environment with built in fault tolerance, the ability to control unanticipated disturbances, and the ability to select which modes to control (if saturation of the actuators is a possibility or concern), all without the need for a separately measured disturbance correlated signal. Experiments using both Multiple Error LMS and Clear Box on an Ultra Quiet Platform provide an effective demonstration of the advantages of the Clear Box Algorithm, including a new Adaptive Basis Method which allows control of rapidly varying frequencies.
Showing items related by title, author, creator and subject.
Yale, G.; Agrawal, B.N. (1994);This paper concerns the cooperative control of multiple manipulators attached to the same base as they reposition a common payload. The theory is easily applied to inertially based problems as well as space based free-floating ...
Alfawzan, Fawzan, A. (Monterey, California: Naval Postgraduate School, 2015-09);The research provides facts showing Iran’s capabilities in processing nuclear weapons at a high degree. Nuclear capabilities provided Iran with uranium enrichments abilities and nuclear weapons to enable the country to ...
Herbert, Eric W. (Monterey California. Naval Postgraduate School, 2004-09);NPSAT1 is a gravity-gradient friendly, prolate body designed to fly at 600 Å 40 km inclined to 34.5 degrees. The satellite uses a magnetic 3-axis active attitude control system (ACS) using magnetic torque rods that interact ...