According to Gramer theorem,the non-stationary wind speed may be decomposed into a deterministic time-varying mean wind speed component plus a stationary fluctuating wind speed component with zero mean value.

Based on Andrew,we put forward a nonstationary robust and general long memory testing approach.

To realize the auto-leveling control of draw frame during its start and stop process, a premise to solve this problem is to keep a steady speed change during the accelerating and decelerating process.