TY  - JOUR
AU  - Li, Mingsheng
AU  - Wang, Zihan
AU  - Li, Xiang
AU  - Pu, Yingjun
AU  - Huang, Jintao
AU  - Xie, Shouyong
AU  - Yan, Yulin
PY  - 2026
TI  - Design and experiment of a micro articulated chassis based on multi-objective optimization
JO  - Transactions of the Chinese Society of Agricultural Engineering
SN  - 1002-6819
SP  - 99
EP  - 110
VL  - 42
IS  - 13
AB  - Hilly and mountainous areas are characterized by complex, rugged terrain, steep slopes, narrow and winding operation spaces, and scattered natural or man-made obstacles such as field ridges and stone steps. These geographical features have posed substantial challenges to maneuverability, slope stability, and obstacle passing of conventional agricultural power chassis. It is an urgent demand for adaptable and efficient powered platforms in such regions. In this study, a micro articulated power chassis was specially designed to clarify the structural configuration and mechanism. The compact dimensions of 1650 mm × 1000 mm × 1100 mm were specifically improved for sufficient load bearing on narrow mountain roads, dense crop rows, and narrow field ridges. Mechanical articulated steering was adopted for the flexible folding and relative rotation between the front and rear frames. Turning radius was significantly reduced to fully meet the requirements of hilly areas, in terms of maneuverability, stability, and terrain trafficability. A multi-objective optimization model was constructed with three critical indicators as objective functions: the minimum turning radius (to enhance maneuverability in confined spaces), the maximum uphill stability angle (to prevent forward tilting during ascending), and the maximum downhill stability angle (to avoid backward tilting when traveling down slopes). These variables included the hinge position of the articulated structure and wheelbase parameters. Non-dominated sorting genetic algorithm (NSGA-II) was applied to optimize the Pareto best solution set. A wide range of schemes were used to balance these mutually conflicting goals. Systematic theoretical calculations and dynamic simulations were conducted on power transmission paths, articulated steering kinematics, and load distribution on sloped terrain. Three performance indicators were evaluated, including steering performance (evaluated by minimum turning radius and steering angle range), slope stability (quantified by longitudinal and lateral stability angles), and obstacle crossing (assessed by chassis posture during obstacle crossing). The simulation results demonstrate that the chassis was achieved the maximum articulation angle of 30.19°, indicating excellent maneuverability in narrow spaces; The maximum longitudinal and lateral stability angles reached 33.8° and 30.8°, respectively, indicating strong resistance to tilting on sloped terrain; when crossing obstacles with an average height of 165 mm, the chassis maintained continuous wheel grounding without any posture deviation, indicating excellent terrain adaptability. Field tests were conducted in a typically hilly agricultural area. The test data verified the reliability of the simulation. Once the rear frame was in an unconstrained state (consistent with actual operational conditions), both frames generated slight deflection due to uneven terrain loads and steering forces, directly leading to an increase in actual turning radius, compared with theoretical calculations. Geometric correction of the minimum turning radius was performed using measured frame deflection angles, where the average minimum turning radius was corrected to 2 145.55 mm. Additionally, the average articulation angle was 29.95° after measurement in field tests. It was highly consistent with the simulation (30.19°), thus verifying the accuracy of the first design. The chassis exhibited no overturning or sideslip under both unloaded and loaded conditions when traveling up and down a 24° slope or moving on a 15° lateral slope. Obstacle-crossing tests showed that the chassis successfully passed over 210 mm high field ridges and 150 mm high stone steps. Finally, a comparison was conducted on existing similar agricultural power chassis, in terms of maneuverability (minimum turning radius), slope stability (longitudinal and lateral stability angles), and terrain trafficability (maximum obstacle-crossing height). The micro articulated power chassis performed best to verify the practicability of the scheme, fully meeting the large-scale requirements in hilly and mountainous areas.
UR  - https://doi.org/10.11975/j.issn.1002-6819.202510161
DO  - 10.11975/j.issn.1002-6819.202510161