The principal objectives of the SPEAR (Servo & Power Electronics for Automation and Robotics) activity were:
The development of SPEAR was performed by an industrial team composed by Tecnospazio (I), as prime
contractor, DASA (D), Phase Motion Control (I) and Hymec (NL). The activity was funded by ESA with a GSTP contract.
to develop a low cost power pack specifically designed for a space robot controller, implementing the
function of servoamplifier for a space manipulator arm;
to ensure SPEAR compatibility for use with the SPIDER arm - developed by an italian industrial team
under a contract of the Italian Space Agency - in an extravehicular flight experiment
to achieve a very high level of unit's compactness (i.e. low volume and mass)
SPEAR main features
the main features of the developed unit are:
The unit was subject to functional, vibration and thermal vacuum tests. A preliminary integration with the
SPIDER arm was also successfully performed.
capability to drive simultaneously up to 8 DC brushless motors (3A nom. current, 5A peak), either biphase or three-phase;
operation in nominal mode, with SPEAR unit "driven" by the Robotic Controller;
operation in non-nominal mode through external commands generated by an operator, which
guarantees the basic functionalities (i.e. driving one motor at a time). This mode of operation is
intended to recover the arm in case of robotic controller non-availability;
autonomous thermal control (only heating, 10 heaters controlled by 4 redundant thermostats);
operation in a space extravehicular environment with temperature ranging from -20°C to +60°C; non
operative temperature between -55°C to 80°C;
dimensions: 314mm x 256 mm x 132.7 mm;
mass: 7980 g.
Last update: 11 October 2006