Dynamic analysis and driving performance verification of multi-functional electric tracked vehicles for greenhouses in hilly and mountainous areas

Hilly and mountainous areas account for approximately one-third of China's total cultivated land, where crops such as tobacco, tea, fruit trees, and tall-stalk varieties such as sorghum are extensively cultivated. However, the level of mechanization in crop production remains relatively low, primarily because of the poor adaptability of existing agricultural machinery to rugged terrain. Conventional crawler chassis struggle to simultaneously meet the requirements of high ground clearance and operational stability, and their limited functionality further restricts efficient agricultural production in these regions. To address these challenges, this paper presents a novel high-clearance electric crawler chassis designed for greenhouse hilly and mountainous areas. The chassis employs a gantry frame with a ground clearance of 1550 mm, facilitating operation over tall row crops. It adopts a dual-motor independent drive scheme, ensuring the continuity of power and achieving in-place steering. A longitudinal center-of-gravity adjustment device driven by dual electric actuators allows the frame to shift ±350 mm relative to the crawler traveling system. Multibody dynamics simulations conducted in RecurDyn 2023 demonstrated that the chassis can achieve a maximum climbing angle of 38°, crossing for trenches up to 800 mm wide and can surmount vertical obstacles up to 300 mm high. Field tests carried out on slopes in accordance with Chinese National Standard GB/T 3871-2004 revealed that the longitudinal center-of-gravity adjustment device significantly enhanced the driving performance of the high-clearance crawler chassis. When activated, the maximum safe climbing angle increased from 30° to 35°, the maximum obstacle surmounting height at 3.6 km/h increased from 250 mm to 300 mm, and the maximum trench-crossing width increased from 600 mm to 700 mm. At 5.4 km/h, the trench-crossing width increased from 700 mm to 750 mm. The field test results were consistent with the simulation outcomes. The development of this high-clearance crawler chassis effectively reconciles the competing demands of high ground clearance and stability while improving overall versatility. It provides valuable technical insights for the design of safe and efficient agricultural machinery suited to complex terrains in hilly and mountainous regions, contributing significantly to the advancement of agricultural mechanization and modernization in these areas.