Spar Aerospace

About: Spar Aerospace is a based out in . It is known for research contribution in the topics: Antenna (radio) & Communications satellite. The organization has 272 authors who have published 252 publications receiving 3186 citations. The organization is also known as: Special Products/Applied Research.

Human-in-the-loop machine control loop

Abstract: In a human-in-the-loop robotic control loop, the constrained forces and moments at the gripper (also called hand or end effector) of the manipulator are measured by a force-mement sensor. The resulting force and moment signals are scaled and fed as input voltages to motors in a hand controller to provide torques which oppose deflection of the hand controller. Thus, the operator feels the opposing torques which are proportional to the magnitude of the constrained forces and moments. The force feedback loop may be opened to selectively provide a passive control loop. In either the active or passive mode, the hand controller position signals may be selectively mapped to either gripper position signals or gripper velocity signals in order to control movement of the gripper in the desired manner.

Dynamic ship positioning using a self-tuning Kalman filter

Abstract: A novel adaptive filtering technique is described for a class of systems with unknown disturbances. The estimator includes both a self-tuning filter and a Kalman filter. The state estimates are employed in a closed-loop feedback control scheme which is designed via the usual linear quadratic approach. The approach was developed for application to the dynamic ship positioning control problem and has the advantage that existing nonadaptive Kalman filtering systems may be easily modified to include the self-tuning feature.

Data communication satellite system and method of carrying multi-media traffic

Abstract: A satellite data communication system and method of operating the same is disclosed. The satellite data communication system provides switched transport services for multi-media networks, wherein access schemes, protocols and switching techniques are combined to offer optimized dynamic bandwidth-on-demand on a cell-by-cell basis.

Probing signals for model reference identification

Abstract: This paper examines certain properties of probing signals employed in a model reference identification procedure which guarantee identification of the parameters of a linear multivariable system. The property of persistent excitation is examined with respect to a new class of (persistently spanning) signals. In particular, this class of signals includes many (periodic or almost periodic) signals which have previously been considered as effective probing signals, The results yield concrete guidelines useful in the practical design of probing signals.

RADARSAT (SAR imaging)

Abstract: RADARSAT, the first Canadian remote-sensing spacecraft, is designed to provide Earth observation information for five years. The satellite is scheduled for launch in 1994. The only payload instrument is a 5.6-cm-wavelength (C-band) synthetic aperture imaging radar (SAR). RADARSAT will gather data on command for up to 28 min during each cycle of its 800-km (nominal) near-polar orbit. Image resolutions from 10 to 100 m at swath widths of 45 to 500 km will be available. The RADARSAT mission is reviewed, and the design, characteristics, and implementation of the radar are introduced. Technical problems addressed include calibration, rapid data processing, the phased array antenna that provides controlled beam steering, and the first satellite implementation of a special radar technique known as ScanSAR. >