Title page for ETD etd-10132010-020121

Type of Document

Master's Thesis

Author

Ide, Eric Nelson

URN

etd-10132010-020121

Title

Evaluation of linear DC motor actuators for control of large space structures

Degree

Master of Science

Department

Electrical Engineering

Advisory Committee

Advisor Name	Title
Beex, A. A. Louis	Committee Member
Bingular, Stanoje P.	Committee Member
Lindner, Douglas K.	Committee Member

Keywords

Signal processing

Date of Defense

1988-05-05

Availability

restricted

Abstract

This thesis examines the use of a linear DC motor as a proof mass actuator for the control of large space structures. A model for the actuator, including the current and force compensation used, is derived. Because of the force compensation, the actuator is unstable when placed on a structure. Relative position feedback is used for actuator stabilization. This method of compensation couples the actuator to the mast in a feedback configuration. Three compensator designs are proposed. The physical limits of the LDCM place limits on the bandwidth of the closed loop actuator.
A ten mode finite element model of a flexible space structure was used in simulations to examine all aspects of the actuator's performance. The performance of the actuator is compared for the three compensator designs. The actuator bandwidth is seen to be important in the actuator's effectiveness. Increasing actuator bandwidth resulted in a saturation nonlinearity in the actuator. The excitation capability of the actuator was examined to determine the authority of the actuator. The damping of the mast modes was examined to determine the effect of the feedback configuration of the actuator/mast system. Root locus techniques were used to explain changes in the vibrational modes of the structure due to the actuator compensation. Disturbance analysis was performed to quantify the effect of corrupted measurements on the purity of force generated by the actuator.

Files

Filename		Size	Approximate Download Time (Hours:Minutes:Seconds)
Filename		Size	28.8 Modem	56K Modem	ISDN (64 Kb)	ISDN (128 Kb)	Higher-speed Access
	LD5655.V855_1988.I33.pdf	3.96 Mb	00:18:20	00:09:25	00:08:15	00:04:07	00:00:21

next to an author's name indicates that all files or directories associated with their ETD are accessible from the Virginia Tech campus network only.