Field performance of an electric-hydraulic control system for vibrating subsoiler with flexible tines

摘要

Vibrating subsoilers with flexible fines exhibit effective obstacle avoidance and soil loosening. However, undesired depths, much less than target value, are observed for subsoilers using springs as excitation elements. Therefore, we studied electric-hydraulic control technology to improve the adaptability of the vibrating subsoiler to various soil conditions by adjusting the working pressure of the excitation element. Based on a previous study of the electric-hydraulic control system that was designed for single flexible fine (Wang a al., 2018), we improved it to allow it to be applied to various rows of subsoilers in this study. Additionally, the effect of the improved electric-hydraulic control system on the subsoil quality (tillage depth, inter-row and in-row variations of tillage depth, soil bulk density, and cone index) and tool operation (draft force and power consumption) in field conditions was investigated and compared with the classical spring system. Field tests showed that the improved electric-hydraulic control system exhibited more qualified operation results compared with the classical spring system. The excitation element for each flexible fine were adjusted independently, thereby reducing the variation of the inter-row and in-row tillage depth. The variation coefficients of the electric-hydraulic system decreased by 17.59% and 34.1% when the operating speed increased from 4.2 km/h to 5.3 and 6.2 km/h, respectively, relative to spring system. Moreover, the electric-hydraulic control system yielded better soil loosening. The soil bulk density decreased by 4.55%, 3.87%, 4.59, and 4.81% at depths of 25, 30, 35, and 40 cm, respectively. However, due to the power requirement of the tractor due to the hydraulic output, the total power of the electric-hydraulic control system slightly increased by within 6.5% compared with the rigid system. Therefore, further research is needed to achieve power saving through hydraulic system optimization.