An automatic impulse controlled implement control system for plant rows

For automatic steering on plant rows of implements with on-off systems a continuous feedback signal is required. Because of the spacing between 2 small plants in a row no continuous feedback signal can be given when using an implement with small sensors. To solve this problem a system was developed which only uses the impulses of small sensors which are given off when detecting a plant. This system uses constant step sizes for positioning the implement after an impulse from the feeler has appeared. Such systems in their simplest form use 2 sensors, 1 on each side of the plant row; for better accuracy more sensors may be used. A system with 2 sensors was built and was investigated in a soil bin. The plants had a size of 5–8 cm (4–6 leaves state). The distribution of the plants, relative to a straight middle line, was similar to that in the field, which was analysed before. The steering error of tractors or machines on which the implements were mounted were also simulated with different wave lengths. With a 2-sensor system an accuracy was reached experimentally which is sufficient for practical application. With a spacing of 7 cm between the implements of a hoeing system plant losses of only 1% occurred. The investigation of a 4-sensor system with a computer showed that the accuracy can be increased by a factor of 4 and the danger of losing the row can be avoided. The investigated system is very simple and can be operated at low cost. Different sensor systems, e.g. pneumatic, electronic, optical or electromechanical, can be used. An investigation under real field conditions has not yet been done, but a practical application would be possible because similar sensor systems have successfully been used for singling machines for sugar beet.