Early Fault Diagnosis of Rolling Bearing Based on Lyapunov Exponent

Lyapunov exponent is an important quantitative index to measure the dynamic characteristics of the system. It represents the average exponential rate of convergence or divergence between adjacent orbits in phase space. Whether there is dynamic chaos in the system can be judged intuitively from whether the maximum Lyapunov exponent is greater than zero. The Lyapunov exponent obtained by the small data method has the characteristics of simple calculation process and accurate calculation results, and it is applied to the fault diagnosis of rolling bearings. By calculating the Lyapunov exponents of bearing rollers, bearing outer rings, bearing inner rings and normal state bearings, and comparing the calculation results under different working conditions, it is concluded that Lyapunov exponents are of great significance in judging the early failure of rolling bearings.