Department of Public Affairs
University of Toronto
Professor Christopher Damaren
U of T Institute for Aerospace Studies
ph: (416) 667-7704; email:
U of T Public Affairs
ph: (416) 978-6974; email:

Entering corrected equation rather than actual data into control system produces quicker task time

By Janet Wong
A well-calculated fib is proving highly useful when it comes to robots in space and could reduce the amount of time and effort needed to complete tasks during space missions, a U of T engineer has discovered.
Professor Christopher Damaren of the Institute for Aerospace Studies has devised a method to control vibrations and reduce deformations of robots assembling or repairing objects in outer space. By changing the
mathematical calculations for robotic movement — or "lying" to the control system — he can decrease vibrations as robots move an object from one place to another.
These robots, he notes, are modelled after the human arm and are often required to manipulate objects much larger than the robot itself. This can put stress on the arm, leading to vibrations or deformations difficult for scientists and astronauts to control. "The result is it takes more time to complete a task because it takes more time to regain control of the arm."
Damaren’s method involves entering a "corrected" equation into the system, rather than actual data. The work can then be accomplished more quickly, with fewer shuttle missions needed for repairs.
This research can be applied to the deployment and retrieval of objects from a space shuttle’s cargo bay or capturing and de-spinning of satellites, notes Damaren, who co-authored the paper with Eftychios Christoforou of the University of Canterbury in New Zealand. The Natural Sciences and Engineering Research Council of Canada and the University of Canterbury funded the study.
[Janet Wong is a news services officer with the Department of Public Affairs.]