Laboratory of the Dynamics of Space Manipulators

Test-bed for the investigations of the dynamics of planar manipulators working in the simulated microgravity conditions is located in the Laboratory of the Dynamics of Space Manipulators. In microgravity conditions motions of the manipulator can induce changes of orientation and motion of the satellite, on which this manipulator is mounted. Control of the satellite-manipulator system and trajectory planning of the manipulator’s end-effector is extremely complex due to disturbances caused by the motions of the manipulator. Test-bed located in the Laboratory of the Dynamics of Space Manipulators gives the unique possibility to perform experimental investigations of some aspects of the dynamics of such systems. Control algorithms for space manipulators could also be tested and verified on this test-bed.

Test-bed consists of the 2x3 meter granite table, flat and precisely levelled. Satellite model (test platform) with two-link manipulator is moving on the table. Free motion of the manipulator-equipped test platform is possible due to the application of planar air-bearings supplied with air from a cylinder located on the platform. The are no external forces acting on the system – friction coefficient between air-bearings and surface of the table is around 10-5, hence motion of the system can be classified as almost frictionless. Microcontroller located on the platform is responsible for controlling the motions of the manipulator during tests. PC computer with Bluetooth modem is used for wireless communication with this microcontroller (presence of cablesconnected to the platform would disturb the free motion of the system). Total mass (together with the cylinder and electronics) of currently used platform is 12.9 kg, while two-link manipulator has a mass of 6 kg and total length of 120 cm.