The invention discloses a blade
tip clearance and
arrival time synchronous measurement method and device based on symmetric inverse function fitting, and the method comprises the steps: S1, a self-adaptive
signal interception stage: carrying out the preprocessing of an original
voltage signal collected by a capacitive sensor, including baseline correction,
signal normalization and symmetric linear segment interception; s2, a symmetric inverse function fitting stage: constructing an inverse function
data set and performing symmetric
linear fitting; the symmetric
linear fitting is that joint symmetric
linear fitting is carried out on two inverse function data sets, and a peak moment, namely
arrival time, and scale parameters are calculated through an objective function of a
minimum time residual error; s3, at a least square linear fitting stage, the baseline offset, the peak moment and the scale parameter are substituted into a direct
Gaussian fitting equation, a nonlinear fitting problem is converted into a linear fitting problem, the linear fitting problem is solved by adopting a least square method, and a closed-
form solution of the signal amplitude is obtained; and inverting a blade
tip clearance value based on a pre-calibrated relation curve between the signal amplitude and the blade
tip clearance.