Precision Analysis of Armature Velocity Measurement by Principal Component Analysis Method

B-dot probes are one of the most commonly used devices for measuring armature velocity in electromagnetic rail launch systems. In this study, we present a mathematical model of the induced voltage of the b-dot probe, including factors such as the armature average velocity, the current rate of change, the current skin depth, the b-dot probe’s position error, and data acquisition to estimate the precision of the b-dot probe. Leveraging the method of principal component analysis (PCA), the key factors affecting the velocity measurement accuracy of the b-dot probe were obtained. The results reveal that the theoretical measurement accuracy of the b-dot probes reaches 0.4563%, with data acquisition emerging as the principal contributor affecting measurement precision. Furthermore, the results of the theoretical analysis are verified by actual experiments. This method provides a theoretical basis for the accurate measurement of armature velocity.