中文摘要：

目前电磁轨道发射装置中膛内电枢位置测量多采用B—dot磁探针。但在连续发射的模式下，电枢电流不连续，B-dot磁探针失效，需要新的测量方法检测电枢经过关键位置的时刻及运动速度。为此，根据轨道发射装置的结构特点，提出采用直接接触式测量方法。即在电枢配重中安装金属纤维，同时在绝缘隔板中沿电枢运动方向分布金属触头，金属触头与外接电源相连接；电枢运动时，其配重中的金属纤维与金属触头接触时，回路闭合，在取样电阻上获取高电平信号，该信号上升沿即为电枢位置信号。同时根据相邻电平上升沿的时间差以及所对应金属触头的间距，可以获得电枢在膛内的速度。在实际发射实验中，利用该方法准确测得发射过程中电枢的位置，及对应发射速度，且该测量有效地避免了发射过程中烟雾及弧光的影响。

英文摘要：

Presently, in railgun systems, B-dot probe is the common method for detecting armature＇s in-bore position and velocity. However, for rapid fire railguns, B-dot probe system is not effective since the driving current is discontinuous, and it is necessary to find a new way to detect the in-bore position and velocity of armatures. According to the structural features of railgun, we proposed a direct measurement method. We installed some metal contacts in the insulators along the armature＇s moving direction, and installed a metal fiber in the payload of armature as a switch that connected or dis- connected metal contacts. With the contacts and the fiber, pulsed signals can be obtained on a sampled resistance, and the rising times of these signals are the time of the armature arriving at the measuring positions. Then the armature＇s velocity be calculated using the positions and time information. In practical launch experiments, we successfully obtained the in-bore movement information of armatures, which can effectively prevent influences from arc and smoke in the launches.