A Preliminary Study of Seeding Absence Detection Method for Drills on the Soil Surface of Cropland Based on Ultrasonic Wave without Soil Disturbance

Table 3

The result of measurements using the ultrasonic instrument (mm).

40	35	25	14.0875	60.35	4.7	38.5	66.2	100	33.1	69.25	35	70	−1.9	−0.75
60	35	25	14.0875	60.35	4.9	60	60	120	30	90	35	90	−5	0
70	35	25	14.0875	60.35	4.8	64.2	70.2	129	32.1	99.6	35	100	−2.9	−0.4
80	35	25	14.0875	60.35	4.8	65.3	81.4	138.3	32.65	109.85	35	110	−2.35	−0.15
40	35	30	14.0875	71.96	4	40	78.1	109.5	39.05	74.75	40	75	−0.95	−0.25
60	35	30	14.0875	71.96	4	60	72	135.2	36	97.6	40	95	−4	2.6
70	35	30	14.0875	71.96	4	70	70	142.3	35	106.15	40	105	−5	1.15
80	35	30	14.0875	71.96	4	77	77.2	152.3	38.5	114.75	40	115	−1.5	−0.25

The average values of measured information for three times are presented in Table 3. and represents the actual left and right boundary lines of seeding absence, respectively. and are the average measured results of the proposed method, and and are the average errors. The results show that, in the measured environment and condition, the errors and are less 5 mm, in line with the accuracy range of ±5 mm.