As NASA solves a problem of modeling of refueling of spacecrafts using robots and Solid Edge

The Robotic Refueling Mission (RRM) program developed since 2011 by the NASA agency can become a turning point in the history of space exploration. Its purpose - to perform carrying out refueling of satellites fuel from the automatic ship. Gas station is carried out without any intervention of the person. However the space robot of NASA needs the help and here, on Earth.

The NASA Robotic Refueling Mission (RRM) program can become a turning point in the history of space exploration

Modeling of refueling in NASA

Mike Fortier and his employees in Mikrolar company are engaged in development of robots from 1980th years. During this time Fortier developed many new technologies, but creation of the high-precision "hexapod" robots who became this break became its main achievement.

The Hexapod robot created in Mikrolar is the table set on a number of parallel double drives. And a table, and everything that on it is fixed, six degrees of freedom have.

Hexapod (which is also called by "Stewart's platform") finds a set of different applications, but most often forms a basis for creation of flight simulators, imitating movements of a cabin.

Considering rich experience of Mikrolar company on design of hexapods, it is no wonder that NASA addressed Fortye with a task for development of the test stand for the space robot refueler.

When the satellite comes to an end of the service life, it is reduced from an orbit and replaced new — Fortye tells. - This very expensive case

For life extension of spacecrafts engineers of NASA develop the special robotic device for refueling. It will be started from a board of the International Space Station (ISS) and to carry out automatic filling of the satellite which developed the resource.

One of problems which NASA in work flow on the RRM program faced — lack of an opportunity to test the equipment in the conditions of zero gravity.

The RRM robot should remove a heat-protective covering from the satellite, join and pump over liquid fuel aboard. At each stage of this difficult process it is easy to make a mistake. Actually even the slightest error in work of RRM can not only push away it from the filled satellite, but also break a spacecraft orbit.

One of problems which NASA in work flow on the RRM program faced — lack of an opportunity to test the equipment in the conditions of zero gravity, Hexapod allowed to solve this problem

That specialists of NASA could develop optimal construction of RRM, engineers of Mikrolar were engaged in creation of the robot who, according to Fortye, could imitate zero gravity.

For this purpose Fortye's group developed a robotic system with six degrees of freedom. In it there are six rotary platforms set on the ring made with a high accuracy. On each platform the tough rack with two hinges connecting the platform to a mobile table on which the satellite is fixed is set.

Existence of sensors of effort in a feedback loop and the corresponding combination of six racks and mobile platforms allowed engineers of Mikrolar to implement movement of the satellite on a table under the same mathematical laws, as in space.

According to Fortye, thanks to application of the Solid Edge system developed by Siemens PLM Software company design of the hexapod according to the RRM program came down to simple consolidation of parametrical models in ready construction. One more problem was to program the robot so that completely to imitate work in a space vacuum.

Thanks to application by the developed company Siemens the Solid Edge systems design of the hexapod according to the RRM program came down to simple consolidation of parametrical models in ready construction

NASA wanted that we created the robot who is docked to an object weighing 500 kg, - Fortye tells. - In case of collision we had to measure force of blow and sail from an object precisely as it occurs in zero gravity. This extremely unusual requirement at design of the robot. Simulation of zero gravity — very difficult task requiring serious study

During joint work with NASA specialists of Mikrolar company created special tool kit of tracking of coordinates of objects in real time. For this purpose it was required to develop a difficult mathematical model.

After very labor-consuming programming it was succeeded to make and debug the robot who is capable to move also easily and precisely, as in zero gravity.

In 2017 NASA works on the second stage of the RRM program. A part of the equipment is already delivered to the ISS, preparation for the first-ever automatic filling of the satellite is conducted.

Though the term of carrying out such gas station is not determined yet, it is obvious that without the deposit Fortye and other specialists of Mikrolar company the ambitious project of NASA could and not be realized.

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