Fall / Automne 2017 19 institutions for learning: Technion in Israel for 1st and 2nd degree and University of Toronto for the 3rd degree. It worked very well for me because I spotted the right trends. As an undergraduate, I was a so- and-so student until the 3rd year when I met a better scholar than me from the Faculty of Architecture of the same school (Technion) — my wife of over 47 years. By the 2nd half of the 3rd year I became a studious person, hungry for profes- sional and general knowledge and looking forward to challenges; this continues unabated to date. All and all, I have had great undergraduate studies, exception- al graduate studies supervision and great inspiration from select- ed models — professionals who were unaware that I was studying them, leading to extremely good preparation professionally, men- tally and strong habits of working intensively and passionately. INDUSTRY STAGE When I finished my PhD at Toronto in 1975 I tried to land a post- doctoral position in Canada; there were not many opportunities avail- able back then that were suitable for me. However, I was extremely lucky to be hired in July 1975 by SPAR Aerospace Ltd. of Toronto to work on what was then called Space Shuttle Remote Manipu- lator System — SSRMS and later renamed Canadarm. I started working on the control system of the SSRMS joint. Later I worked on the whole of SSRMS kinemat- ics, dynamics and its 99-DOF simulation model, as well as on other space robotics and various satellite projects. The SSRMS project completely shaped my professional future: it was unique, ahead of the times, very challenging and outrageous- ly interesting.A totally captivating endeavour. It was the period of growing up and maturing profes- sionally (and personally with a pair of identical twin daughters) to eventually realize that knowledge is never complete, and learning is an endless job. This applies to me today as it did then. Fall / Automne 2017 19 ...Continued on page 16 Space Robots 19 SPACE SHUTTLE REMOTE MANIPULATOR SYSTEM (SSRMS) The Space Shuttle Remote Manipulator System (SSRMS) or “Canadarm” was a joint venture between the governments of the United States and Canada to supply the NASA Space Shuttle program with a robotic arm for the deployment/ retrieval of space hardware from the payload bay of the orbiter. A schematic view of the SSRMS is shown at top. It is a robotic arm consisting of a shoulder, elbow and wrist separated by an upper and lower arm boom giving it a total of six DOFs (shoulder pitch and yaw, elbow pitch, wrist pitch, yaw and roll). At a total weight of approximately 431 kg, the SSRMS is capable of maneuvering payloads of up to 14,515 kg at a rate of 0.06 m/sec with a maximum contingency operation payload weight of 265,810 kg. Under unloaded condi- tions the SSRMS can achieve a max- imum translational rate of 0.6 m/sec. However, the SSRMS is incapable of supporting its own weight on earth. It must be supported by specialized ground handling equipment during its testing and packaging for shipment. Although the SSRMS can handle very heavy payloads, movement of the tip is very accurately controlled, allowing precise handling of delicate payloads. The length of the SSRMS is approxi- mately 15 m. A control system is used to deploy payloads in auto- matic mode to a positional accur- acy of +/- 2.0 in and +/- 1.0 degree of a pre-programmed target point and orientation at the afore-men- tioned rates and load conditions. The SSRMS may also be operated manually (remote control) by the astronauts to the same accuracy with the use of hand controllers and closed circuit televisions (CCTV) mounted on the manipulator arm. The SSRMS was designed to have a life of 10 years or 100 missions. Analytically, the major challenge in the development of the SSRMS was the structural flexibility of the mechanical system generated by the limitations of SSRMS weight. On the ground the arm had to be supported with braces. In the weightless of space, its own mass was no issue, but the light materials that made the arm structure were generat- ing unwanted bending and torsion moments that were hard to control for accurate positioning of the arm to grab satellites. The joints and the boom were very flexible; the system had 99 DOFs, making the control system design of the joint and of the arm a major challenge that has not been completely solved even to date. ADVANCED ROBOT ARMS: PLANETARY MEDIUM MANIPULATOR This robot was developed to advance the state-of-the-art of manipulators for planetary explora- tion and to perform simulated Moon and Mars missions on Earth. It is made up of eight modules: Turret, Shoulder, Upper Arm, Elbow, Lower Arm, Wrist, Automatic End Effector Exchanger (AEEE) and Controller. The turret provides azimuth motion, while the shoulder, elbow and wrist each provide pitch and roll. The system operates under remote control commands, as well as autonomously through a scripting interface. The autonomous motion is achieved using advanced meth- ods of visual servo, force, imped- ance, and adaptive control. The AEEE interface is used to autono- mously load tools and other pay- loads onto the arm. SSRMS mechanical subsystem (Spar Aerospace Ltd., Toronto, Ontario) ...Continued on page 21 Fall / Automne 2017 Planetary Medium Manipulator (PMM)