The armature trigger position of multi-stage electromagnetic coil gun has great influence on the exit velocity of projectile. The energy conversion efficiency of the coil gun can be improved effectively if the armature is triggered in the optimum position. So it is important to detect the projectile position in time. Several typical electrical and optical methods for position detection are summarized in this paper. The advantages and disadvantages of each method are analyzed and evaluated. And a new laser scattering measurement method is proposed. Results show that optical detection method is simple and easy to implement, but it is susceptible to environmental impacts.
