In order to minimise astronauts’ EVA, these tasks can be performed by robotic systems such EUROBOT, the three-arms ESA system currently under study.
Purpose of the CONTEXT (Space A&R Controller Capabilities Extension) ESA Project has been to develop the controller for the ESTEC EUROBOT ground testbed.
The development activities exploited the results reached during the previous ESA projects SPARCO, CESAR and CIRCUS.
CONTEXT is able to control both in position and in force and to tele-manipulate three 7 degrees of freedom arms at the same time, in free motion, in free coordinated motion and by applying the SPARCO impedance control.
The activity has been carried out by Galileo Avionica (IT) as Prime Contractor and Trasys, Krypton (B) under ESA TRP contract.
The CONTEXT hardware consists of one Robot Control Unit (RCU) based on a PC 104 plus architecture.
The RCU is interfaced via the SERCOS Bus to three Arm Control Electronics (ACEs) each dedicated to a single arm.
Each ACE consists of seven Servo Control Unit (SCU) based on a Texas Instruments DSP and is supplied by a dedicated internal Power Supply Unit (PSU). Each SCU is devoted to the control of a single arm joint.
The overall electronics and arms are powered by an Auxiliary Power Supply Unit (APSU) in charge of providing the 28V and 100V power supply lines, to manage the auxiliary I/Os as well as the safety circuitry and other external safety devices.
The RCU has been designed to be located inside the mounting triangle of the EUROBOT tesbed central body; the ACEs instead are accomodated in the free space between the external cater and the central mounting triangle.
The robot control Software, already developed in the frame of the CESAR SW, has been extended to support the following new functionalities:
Last update: 28 September 2006