Intelligent and unmanned agricultural machinery can be very necessary to develop in modern agriculture, due to the shortage of labor force against the urbanization in recent years. It is also in high demand to enhance the utilization of land and the efficiency of the machinery. Among them, autonomous driving can be expected to serve as the key technology for unmanned agricultural machinery. In this study, a set of additional auto-driving systems was established to fully meet the requirement of intelligent improvement on traditional harvesters in the full-field blocks. Firstly, a hand-compatible electric control device was designed for the simple switch between manned and unmanned operations in current agricultural production, according to the control and power system of the traditional harvesters. Secondly, a series of experiments were conducted to test the measurement and control system, as well as the steering characteristics of the single-sided brake steering harvester. The operation performance of the controller was verified using the response of the actuator, together with the relationship between steering valve opening, HST speed, and steering curvature. PD-fuzzy-BangBang joint control was then proposed to improve the accuracy of the real embedded control system, according to the pedrail steering, measurement, and control system. Finally, a prototype was developed for the automatic driving and operation on the cement surface in the rice field. The full-block automatic driving performance was achieved in the joint control system of the prototype. The cement surface online experiment showed that the over-adjustment oscillation of the system was effectively reduced for the steady-state accuracy on the line. Specifically, the online distance of the combined algorithm was shortened by 57.3%, and the steady state standard deviation was reduced by 81.3%, compared with the single PD. The cement ground experiment showed that the prototype better performed the full-block automatic driving under ideal conditions on straight paths, with a maximum deviation of 6.00 cm and a standard deviation of 2.42 cm. The accuracy of the prototype fully met the requirements during actual operation in the rice field, particularly with the over 80% cutting width and the speed of 0.7 m/s. Therefore, full-field unmanned harvesting was realized with the addition of the self-adaptive operation function. The finding can provide technical support and equipment solutions for the construction of unmanned farms.

Open channel water conservancy control components, especially gates and weirs, are widely used in most Chinese irrigation areas. They are important tools for water distribution and flow regulation, and play a crucial multifaceted role in improving the efficiency and effectiveness of agricultural irrigation systems and optimizing water resource management. In response to the inaccurate flow regulation of downstream flow in open channel irrigation in the arid areas of the northwest, resulting in low water resource utilization and crop yield loss, this paper proposes to control downstream flow through joint regulation of gates and weirs. First, through theoretical analysis of the hydraulic characteristics and flow formulas of gates and weirs in open channels, combined with FLUENT fluid simulation and single-factor experiments, it is found that the key parameters affecting the flow rate of open channels under joint gate - weir regulation are water level before gates, flow velocity before gates, and water level before weirs. The water level before gates, flow velocity before gates and gate opening are positively correlated with downstream flow, while the water level before weirs is negatively correlated with downstream flow. In terms of simulation model construction, a three-dimensional model of open channels, gates and weirs was established using SolidWorks. In FLUENT fluid simulation software, the simulation model is established using the SST k-ω turbulence model and the VOF multiphase flow model. In order to explore the interaction between factors and build a precise flow regulation model, the water level before gate, velocity before gate, water level before gate, and the water level before weir were selected as the test factors, and the flow rate in the downstream is used as the evaluation indicators, and the box-behnken design (BBD) response surface test of the four factors and three levels was carried out. After 29 simulations under different parameters, the simulation test results show that the increase of gate opening and water level before gate under the control of gate weirs, the decrease of the flow velocity before gate and water level before weir makes the downstream flow velocity and liquid level more stable and the flow rate is more stable. The results of the variance analysis show that the water level before gate, velocity before gate, gate opening, water level before weir have a significant impact on flow rate; the determination coefficient R²=0.9905 established open channel flow regulation model has good prediction accuracy. The response surface analysis shows that the water level before gate, flow velocity before gate, and water level before weir have a significant impact on the flow rate. Specifically, the interaction terms between the water level before gate and the gate opening, as well as the water level before weir and gate opening, will also have a significant impact on the flow rate. Finally, through the automated transformation of the existing manual gates, a field test platform for open channel flow regulation was built to realize automatic gate control, reducing the experimental error of manual operations. The field test results show that under the joint adjustment of the gate and weir, the relative error between the model predicted flow and the actual flow is less than 12%. The finding can provide ideas for the regulation of open canal flow in irrigation areas.