the maximum and 2xa stands for the two times of actuator spacing from fig6 we can determine that baselining threshold for the actuator equal to u03b4 u 12 54 during the baselining process also optionally we can add the baselining threshold for the measurement u03b4 y 0 151 which can be measured in the same fashion for picketing detection during baselining actuator picketing was barely observed by visual inspection in this test the baselining scan number was set at 50 for the online detection algorithm the thresholds u03b4 u and u03b4 y were used to monitor the alignment in closed loop this test was conducted when the paper machine experienced a half zone width sheet wander fig7 a and 7b show the spread of high frequency accumulated powers for both the measurement profiles and actuator setpoint profiles during monitoring respectively it can be seen that at scan 21 both the measurement high frequency spread and the actuator high frequency spread were higher than the thresholds at this juncture picketing was detected which automatically triggered the closed loop alignment identification in order to test the reliability and efficiency of the detection algorithm the automatic closed loop identification was temporarily disabled this allowed the profile to develop fully as there was no alignment update at scan 113 see the data cursor on the plot of autoflow high frequency accumulated power in fig7 b picketing is apparent by.