## 3 Control System for Work Vehicle  
### Control System Composition  
In recent years, the improvement in battery energy density, advancements in fast-charging technology, and the implementation of national infrastructure policies have led to the emergence of various forms of new energy including hydrogen energy, lithium iron phosphate batteries, ternary lithium batteries, lead-acid batteries, and oil-electric hybrid technology. These developments have significantly promoted the growth of new energy vehicles; electric technology has significant advantages in the field of agricultural machinery. Compared with diesel-powered vehicles, electric agricultural machinery reduces particulate emissions by 90% and can significantly reduce greenhouse gas and harmful gas emissions, meeting the environmental protection requirements. Moreover, the electric system operates  
Figure 9: Folding mechanism diagram. 1—Pin. 2—Quick-release hinge. with a noise level 15-20 decibels lower than that of traditional machinery, causing less disruption to the agricultural ecosystem. In contrast to hybrid systems, electric technology features a simpler structure and lower maintenance costs. For instance, a comparative study showed that the maintenance costs of electric vehicles could be reduced by approximately 30% compared to hybrid vehicles. Furthermore, with advancements in battery technology, the range of electric vehicles has gradually improved, and charging facilities are becoming increasingly sophisticated, better meeting the demands of agricultural production [21]. Market research shows that the market for electric agricultural machinery in China is growing rapidly, with an annual compound growth rate of approximately 15%, while the annual growth rate of traditional agricultural machinery is only about 5% [22], highlighting the recognition and huge potential of electric technology in this field. In this study, the vehicle was powered by a propulsion system consisting of six 12 V, 100 Ah lead-acid batteries connected in series. These lead-acid batteries are suitable for low-speed electric vehicles, with a cost approximately 60% that of lithium-ion batteries [23], making them more suitable for large-scale rural applications. They effectively meet the power demands for low-speed operation and are easy to maintain. However, the energy density of lead-acid batteries is lower than that of lithium-ion batteries, resulting in a relatively shorter range and heavier weight, which affects the vehicle performance. Considering the complex field environment and the characteristics of low-speed electric vehicles, lead-acid batteries remain a viable option. Under normal conditions, these batteries can undergo approximately 600 charge-discharge cycles. If used daily in agricultural operations, they are expected to provide reliable power for about 3-4 years. In terms of battery maintenance, after each use, the surface of the battery should be kept clean to prevent the accumulation of dust and debris from affecting heat dissipation. At the same time, at least one inspection should be carried out every month to check whether the battery terminals are corroded and whether the battery casing is intact to ensure that there are no cracks or leaks. The electronic control system of the work vehicle is composed of six key components, which play a central role in the field. The walking and driving circuit ensures that the vehicle moves stably on various terrains and can successfully cope with starting, climbing, and heavy-load conditions. The steering mechanism operation circuit improves the flexibility of vehicle steering through electric power assistance, facilitating operation in narrow passages and irregular terrains. The lifting mechanism circuits of the fertilization frame and spraying frame can adjust the heights of fertilization and spraying, respectively. The fertilization width adjustment control system can adjust the position of the fertilization monomer manually or automatically to achieve the optimal working width and adapt to changes in field conditions.