Multi-sensor tracing principle for crankshaft roundness measurement during noncircular grinding procesS

During noncircular grinding process (NGP), the crankshaft eccentrically rotates around the crankpin center, instead of itself center. This paper presents an expatiation on the three-sensor tracing principle of crankshaft roundness error measurement. The weighted signals are transformed from time domain to frequency domain using FFT for analysis conveniently. It is discussed for the relationship of the weight function and the various harmonic components of sampled signals. Based on above work, the two-sensor tracing principle is presented for roundness error in-situ measurement of crankshaft. The measurement precision and the measurement error of two-sensor tracing principle are also analysed in this paper. Finally, some experiments are carried using the two-sensor tracing principle, and the conclusion is given contrasted with the compute result using three-sensor principle and off-line measurement, which proves the validity of multi-sensor tracing principle for crankshaft roundness error measurement during NGP.