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Ottawa, Canada

The Canadian Space Agency ) was established by the Canadian Space Agency Act which received Royal Assent on May 10, 1990. The president of the agency is Walter Natynczyk who reports to the Minister of Industry. He was appointed as president on August 6, 2013.The headquarters of the CSA is located at the John H. Chapman Space Centre in Saint-Hubert, Quebec. The agency also has offices in Ottawa, Ontario, at the David Florida Laboratory , and small liaison offices in Washington, D.C.; Paris; Cape Canaveral, Florida; and Houston, Texas. Wikipedia.

Visually guided robotic capturing of a moving object often requires long-term prediction of the object motion not only for a smooth capture but because visual feedback may not be continually available, e.g., due to vision obstruction by the robotic arm, as well. This paper presents a combined prediction and motion-planning scheme for robotic capturing of a drifting and tumbling object with unknown dynamics using visual feedback. A Kalman filter estimates the states and a set of dynamics parameters of the object needed for long-term prediction of the motion from noisy measurements of a vision system. Subsequently, the estimated states, parameters, and predicted motion trajectories are used to plan the trajectory of the robots end-effector to intercept a grapple fixture on the object with zero relative velocity (to avoid impact) in an optimal way. The optimal trajectory minimizes a cost function, which is a weighted linear sum of travel time, distance, cosine of a line-of-sight angle (object alignment for robotic grasping), and a penalty function acting as a constraint on acceleration magnitude. Experiments are presented to demonstrate the robot-motion planning scheme for autonomous grasping of a tumbling satellite. Two robotics manipulators are employed: One arm drifts and tumbles the mockup of a satellite, and the other arm that is equipped with a robotic hand tries to capture a grapple fixture on the satellite using the visual guidance system. © 2012 IEEE. Source

Aghili F.,Canadian Space Agency
IEEE/ASME Transactions on Mechatronics | Year: 2013

The problem of self-tuning control of cooperative manipulators forming closed kinematic chain in the presence of inaccurate kinematics model is addressed in this paper. The kinematic parameters pertaining to the relative position/orientation uncertainties of the interconnected manipulators are updated online by two cascaded estimators in order to tune a cooperative controller for achieving accurate motion tracking with minimum-norm actuation force. This technique permits accurate calibration of the relative kinematics of the involved manipulators without needing high precision end-point sensing or force measurements, and hence, it is economically justified. Investigating the stability of the entire real-time estimator/controller system reveals that the convergence and stability of the adaptive control process can be ensured if 1) the direction of angular velocity vector does not remain constant over time, and 2) the initial kinematic parameter error is upper bounded by a scaler function of some known parameters. The adaptive controller is proved to be singularity-free even though the control law involves inverting the approximation of a matrix computed at the estimated parameters. Experimental results demonstrate the sensitivity of the tracking performance of the conventional inverse dynamic control scheme to kinematic inaccuracies, while the tracking error is significantly reduced by the self-tuning cooperative controller. © 1996-2012 IEEE. Source

Leveille R.,Canadian Space Agency
Planetary and Space Science | Year: 2010

Terrestrial analogs to the Moon and Mars have been used to advance knowledge in planetary science for over a half-century. They are useful in studies of comparative geology of the terrestrial planets and rocky moons, in astronaut training and testing of exploration technologies, and in developing hypotheses and exploration strategies in astrobiology. In fact, the use of terrestrial analogs can be traced back to the origins of comparative geology and astrobiology, and to the early phases of the Apollo astronaut program. Terrestrial analog studies feature prominently throughout the history of both NASA and the USGS' Astrogeology Research Program. In light of current international plans for a return missions to the Moon, and eventually to send sample return and manned missions to Mars, as well as the recent creation of various analog research and development programs, this historical perspective is timely. © 2009 Elsevier Ltd. All rights reserved. Source

Megner L.,Canadian Space Agency
Journal of Atmospheric and Solar-Terrestrial Physics | Year: 2011

Noctilucent clouds and polar mesospheric summer echoes are both manifestations of ice particles near the summer polar mesopause. These ice particles are believed to form mainly on pre-existing ice condensation nuclei. The characteristics and especially the concentrations of such nuclei have been considered important factors in determining ice properties. More ice condensation nuclei would, given the limited amount of water vapor, yield more but smaller ice particles, and thus a dimmer noctilucent cloud. However, here it is shown that the sensitivity of observable ice properties to condensation nuclei concentration is much less than one would expect from the simple situation described above. In particular, both ice mass and cloud brightness is close to independent of condensation nuclei concentration. The reason for this lack of sensitivity is further examined. © 2010. Source

In order to determine positional information, about a mobile robot, Real Time Kinematic (RTK) Global Satellite Navigation System (GNSS) measurement data are obtained by at least two GNSS receivers mounted on the mobile robot. Estimates of the covariance matrices of the measurement data are computed. The RTK GNSS measurement data are combined according to the covariance matrices to obtain enhanced positional information. The results may be fused with data from an IMU to obtain driftless attitude and/or localization information.

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