Robustness analysis of rolling bearing friction torque data

Robustness analysis: rolling bearing friction torque data of 10 sets of rolling bearing friction torque measurement, B 2048 friction torque data obtained, namely the m to 10, 2048 N. Reflect the B rolling bearing friction torque's relationship with time. It can be seen that B rolling bearing friction torque value at zero. 1 to 0. 9 mu N: m range, each bearing friction torque range is different, among them 1, 2, 3 sets of bearing friction torque value range is larger, more than 0. 5μN~- m; The rest of the bearing friction torque value range is smaller, less than 0. 3μN:m; 6 and 7 sets of bearing friction torque value range and values are relatively small, 0. 05 ~ 0. 联合国:3米; In addition, you can see the change trend of rolling bearing friction torque B each are not identical. This shows that B rolling bearing friction torque has diversity and complexity. Due to the experimental data of rolling bearing friction torque for 2048 B, according to statistics, can think of is normal distribution. According to table 3 - 1 each rolling bearing friction torque data can be divided into 28 group, make each histogram as shown in figure 3 - bearing friction torque 5. According to figure 3 - 5 you can see, B rolling bearing friction torque data histogram in May form, such as 1, 3 sets of frequency distribution of bearing; Some shows bimodal shape, such as 5, 6, 7, 8 sets of frequency distribution of bearing; From the multiple peak shape, such as 2, 4, 9, 10 sets of frequency distribution of bearing. Visible B rolling bearing friction torque no consistent distribution, presents the complexity and diversity. Considering that normal distribution density function is unimodal, on both sides of the symmetrical distribution curve, after rolling bearing friction torque histogram and normal distribution density function, it can be seen that B rolling bearing friction torque of histogram does not agree with that of normal distribution density function, namely B rolling bearing friction torque data does not obey the normal distribution. Due to the number of 2048 experimental data, can be thought of as the normal distribution or asymptotic normal distribution, but the histogram with the normal distribution density function, existing in the rolling bearing friction torque data discrete data, is not healthy. After the B rolling bearing friction torque data to normality test, the scope of the discrete data are analysed. Line and curve line for normal distribution probability of rolling bearing friction torque B cumulative frequency curve. If accord with normal distribution, cumulative frequency curve and linear superposition; Otherwise, do not overlap with straight line. According to figure 3 - 6 it can be seen that B rolling bearing friction torque cumulative frequency curve is not coincide with the normal distribution line, show B rolling bearing friction torque data is not completely obey the normal distribution. Rolling bearing friction torque, the middle layer of the cumulative frequency curve and linear superposition, illustrate intermediate data obey the normal distribution; On both ends of the rolling bearing friction torque cumulative frequency curve and linear superposition, part of the data does not obey normal distribution on both ends of the instructions, the part at the ends of the data are discrete data. Specific to each bearing, the situation and difference. Some rolling bearing friction torque data gravely deviates from the normal distribution line cumulative frequency curve, such as 1, 3, 4, 7, 8 sets of bearings; And the rest of the rolling bearing friction torque cumulative frequency curve deviates from the normal distribution is not serious; Some rolling bearing friction torque data minimum and maximum deviation from normal distribution was widespread, such as 1, 3, 4, 5, 7, 8 sets of bearings; Some of the minimum and maximum deviation from normal distribution range is small, such as 2, 6, 9, 10 sets of bearings. It can be seen that B rolling bearing friction torque of normality test show the diversity and complexity, the probability distribution of friction torque is not completely accord with normal distribution, data exists in the discrete data. Therefore, unsound, B rolling bearing friction torque experimental data needs to be treated. According to the above A and B rolling bearing friction torque data robustness analysis result, can draw rolling bearing friction torque data does not obey normal distribution, the maximum and the minimum section data clearly deviates from the normal distribution. This suggests that the rolling bearing friction torque data exist in the discrete data, discrete data appeared in the rolling bearing friction torque order statistic at both ends.