Analysis of a Measurement Method for the Railgun Current and the Armature's Speed and Initial Position

This paper introduces a measurement method for the railgun current and the armature's speed and initial position for electromagnetic launch systems. The measurement device consists of several parts: a current B-dot probe, several speed B-dot probes, the data acquisition system, and a computer. A calibration experiment was done by comparing with another commercial Rogowski coil. The measured instantaneous continuous speed curve of the armature has a characteristic of extrapolation and shows clear physical meaning. At the same time, the method can also give us the main transient railgun current and the armature's initial position data. The results show that the method can get the railgun transient main current waveform, the armature's instantaneous continuous speed waveform, and the initial position data simultaneously. It would benefit the electromagnetic launch system design.