This paper proposes a novel active attitude adjustment mechanism (A3M), integrated with a passive balanced rocker suspension (BRS), to address the challenges of rollover risk and terrain adaptability for side-slope agricultural vehicles (SSAVs). The A3M provides adjustable ground clearance, unilateral height adjustment, and lateral body leveling, thereby eliminating the geometric tire-ground contact mismatch and optimizing the pressure distribution with the ground. The mechanism configuration and working principle are described. This study performs dimensional synthesis and NSGA-II-based multi-objective optimization of actuator and link lengths, producing a set of Pareto-optimal parameters. The kinematic predictions show close agreement with multibody dynamics simulations, validating model accuracy. Finite element analysis (FEA) confirmed that the optimized design achieves a more uniform pressure distribution, which helps minimize soil compaction. This work provides a validated design framework and a methodological foundation for implementing active attitude adjustment in slope-operating agricultural vehicles.
TuYWuSChenB, et al. A 30 m annual cropland dataset of China from 1986 to 2021. Earth Syst Sci Data2024; 16(5): 2297–2316.
2.
LuDWangZLiX, et al. Evaluation of the efficiency and drivers of complemented cropland in Southwest China over the past 30 years from the perspective of cropland abandonment. J Environ Manag2024; 351: 119909.
3.
FacchinettiDSantoroSGalliLE, et al. Agricultural tractor roll-over related fatalities in Italy: results from a 12 years analysis. Sustainability2021; 13(8): 4536.
InotsumeHSutohMNagaokaK, et al. Modeling, analysis, and control of an actively reconfigurable planetary rover for traversing slopes covered with loose soil. J Field Robot2013; 30(6): 875–896.
6.
MashadiBNasrolahiH. Automatic control of a modified tractor to work on steep side slopes. J Terramechanics2009; 46(6): 299–311.
7.
JiangHXuGZengW, et al. Design and lateral stability analysis of an attitude adjustment tractor for moving on side slopes. Appl Sci2024; 14(5): 2220.
8.
WangWHXuXJXuHJ, et al. Development of variable-configuration wheeled driving system for enhancing the obstacle-crossing ability of unmanned vehicles. Proc Inst Mech Eng C J Mech Eng Sci2021; 235(9): 1645–1659.
9.
PolzinMGuanQHughesJ. Robotic locomotion through active and passive morphological adaptation in extreme outdoor environments. Sci Robot2025; 10(99): eadp6419.
10.
AhmadiI. Dynamics of tractor lateral overturn on slopes under the influence of position disturbances (model development). J Terramechanics2011; 48(5): 339–346.
11.
TanHWangGZhouS. Development of a crawler chassis attitude adjustment device for a self-propelled maize harvester and experiment of fuselage leveling. Int J Agric Biol Eng2024; 17(6): 111–120.
12.
QinJWuASongZ, et al. Recovering tractor stability from an intensive rollover with a momentum flywheel and active steering: system formulation and scale-model verification. Comput Electron Agric2021; 190: 106458.
13.
WangBZhuJChaiX, et al. Research status and development trend of key technology of agricultural machinery chassis in hilly and mountainous areas. Comput Electron Agric2024; 226: 109447.
14.
JiangYWangRDingR, et al. Research review of agricultural machinery power chassis in hilly and mountainous areas. Agriculture2025; 15(11): 1158.
15.
DenisDThuilotBLenainR. Online adaptive observer for rollover avoidance of reconfigurable agricultural vehicles. Comput Electron Agric2016; 126: 32–43.
16.
WangYYangFPanG. Design and testing of a small remote-control hillside tractor. Trans ASABE2014; 57(2): 363–370.
17.
SunJMengCZhangY, et al. Design and physical model experiment of an attitude adjustment device for a crawler tractor in hilly and mountainous regions. Inf Process Agric2020; 7(3): 466–478.
18.
HuJPanJDaiB, et al. Development of an attitude adjustment crawler chassis for combine harvester and experiment of adaptive leveling system. Agronomy2022; 12(3): 717.
19.
GaoQGaoFTianL, et al. Design and development of a variable ground clearance, variable wheel track self-leveling hillside vehicle power chassis (V2-HVPC). J Terramechanics2014; 56: 77–90.
20.
JiangHXuGZengW, et al. Design and kinematic modeling of a passively-actively transformable mobile robot. Mech Mach Theory2019; 142: 103591.
21.
JiangHXuGZengW, et al. Lateral stability of a mobile robot utilizing an active adjustable suspension. Appl Sci2019; 9(20): 4410.
YangYChengSQiJ, et al. Design and test of automatic leveling system for agricultural machinery seat based on ergonomics. Trans Chin Soc Agric Mach2022; 53(6): 434–442.
24.
LuHSongZTangY, et al. Reliability assessment of the mining monorail crane drive system under heavy load and steep slope conditions. Mech Based Des Struct Mach2025; 53: 6474–6496.
25.
ZhaoJSZhouKFengZJ. A theory of degrees of freedom for mechanisms. Mech Mach Theory2004; 39(6): 621–643.
26.
GaoHLuRDengZ, et al. One necessary condition for passive all-wheel attachment of a wheeled planetary rover. Mech Mach Theory2023; 182: 105226.
27.
LuRGaoHLiuZ, et al. Design and analysis of a high-speed planetary rover with an adaptive suspension and spring damper. Acta Astronaut2023; 211: 827–843.
28.
DebKPratapAAgarwalS, et al. A fast and elitist multiobjective genetic algorithm: NSGA-II. IEEE Trans Evol Comput2002; 6(2): 182–197.
29.
GuerreiroAPFonsecaCMPaqueteL. The hypervolume indicator: computational problems and algorithms. ACM Comput Surv2022; 54(6): 1–42.
30.
DebK (ed.). Optimization for engineering design. 2nd ed. PHI Learning India, 2012, p.121.
31.
WangZJinZ. Motion optimization of a six-degree-of-freedom robotic arm based on Denavit-Hartenberg parameter method and NSGA-II. In: 2024 IEEE 2nd international conference on electrical, automation and computer engineering (ICEACE), Changchun, China, 8–10 November 2024, pp.1545–1551. IEEE.
32.
GulecMOErtugrulS. Pareto front generation for integrated drive-train and structural optimisation of a robot manipulator conceptual design via NSGA-II. Adv Mech Eng2023; 15(3): 16878132231163051.
KuslitsMBestleD. Multiobjective performance optimisation of a new differential steering concept. Veh Syst Dyn2022; 60(1): 73–95.
35.
ZhangJSunYGaoR. Optimal design of suspension parameters of flexible multibody vehicle model based on ADAMS software and improved genetic algorithms. In: Proceedings of the ASME 8th bienmial conference on engineering systems design and analysis, Turin, Italy, 4–7 July 2006, pp.77–82. ASME.
36.
CarusoMBregantLGallinaP, et al. Design and multi-body dynamic analysis of the Archimede space exploration rover. Acta Astronaut2022; 194: 229–241.
37.
WilkinsonADeGennaroA. Digging and pushing lunar regolith: classical soil mechanics and the forces needed for excavation and traction. J Terramechanics2007; 44(2): 133–152.
38.
WongJYReeceA. The prediction of rigid wheel performance based on the analysis of soil-wheel stresses: Part II. Performance of towed rigid wheels. The performance of towed rigid wheels. J Terramechanics1967; 4(2): 4.
