Design of Electromagnetic Lock System for Space Applications

The latest developments in the field of space robotics and miniature satellites are demanding non-pyrotechnic based locks for arresting parts or subassembly to the main structure of the launch vehicle or spacecraft. An electromagnetic lock using Iron-Cobalt alloy as the core material is presented in this paper as a simple, resettable, no-impact method for holding down and releasing. The drive scheme for the electromagnetic lock with a demagnetization circuit ensures smooth release after the de-energization of the lock. The gap sense algorithm included in the drive scheme can be useful to ensure the desired air gap in the magnetic flux path for adequate force generation. Molybdenum disulfide (MoS
2
) coating is provided on the lock interfaces to avoid the occurrence of a cold weld. Details of the hardware realized and its test results are also presented in this paper.