Automatic height-adjustment for a cutter disk on a sugarcane harvester using cutting pressure

A sugarcane harvester is commonly used for mechanized harvesting in the hilly and mountainous areas. However, the cutter disk of the sugarcane harvester cannot automatically adjust with the fluctuation of ridge height, leading mainly to the sugarcane ratoon damage and wastes during the harvesting process. In this study, a data acquisition device was proposed for the cutting pressure of a hydraulic motor in a cutter disk, and then a simulation device was developed for adjusting the cutting height of the cutter disk with the ridge height. The data collection device for the cutting hydraulic motor was installed on the 4GZQ-260 sugarcane harvester. The hydraulic pressure of a cutter disk motor was collected, when the sugarcane was harvested at the planting site in Mingjiang Town, Ningming County, Guangxi, China. The results showed that the hydraulic pressure for the cutter disk of the harvester greatly varied, when cutting sugarcane into the soil and not into the soil, where the planting density and physical characteristics of sugarcane were fixed. A set of automatic control and adjustment device was designed for the height of the cutter disk, with the aid of hydraulic pressure in the cutting system. The device was mainly composed of a cutter disk lifting system, a cutter disk and a hydraulic motor, a data acquisition system of hydraulic pressure and speed. The hydraulic pressure sensor was used to detect the pressure of the hydraulic motor during cutting the sugarcane. The cutter disk lifting system was used to realize the lifting and lowering of the cutter disk according to the pressure value. The pressure of the hydraulic motor was measured, when the cutter disk was no-load, no soil cutting, and cutting into the soil depth of 3 and 5 cm. The pressure varied greatly when cutting in different depths. The critical pressures were obtained under three conditions, thereby formulating the lifting rules of the cutter disk. A field test was carried out to verify the automatic regulation and control the cutting depth of the cutter disk into the soil, where the benchmark cutting depth was set to be 3 cm, particularly when the height of the sugarcane ridge changed. The test results showed that when the cutter disk advanced at a speed of 0.25 m/s, the maximum error between the cutter disk entering the soil and the preset depth was 0.7 cm. When the cutter disk advanced at a speed of 0.4 m/s, the maximum error between the cutting depth of cutter disk and the preset depth was 0.8 cm, indicating the automatic adjustment of cutting depth according to the ridge height change of sugarcane. The provisions of sugarcane stubble can be less than 3 cm to meet the design requirements. This finding can provide a technical foundation for the automatic adjustment of cutting height for the cutter disk on the sugarcane harvester in the hilly and mountainous areas of China.