# The Current Development Status of Agricultural Machinery
## 3. Chassis Travel Mechanism System of Agricultural Machinery
### Wheeled Travel Mechanism
By incorporating key parameters such as forward velocity (\(V_{f}\)), terrain slope (\(\theta\)), and wheel-ground friction coefficient (\(\mu\)), the research quantitatively analyzed the sensitivity of \(\mu\) to both slip stability indices and overall stability indices under varying slope and speed conditions. The results indicate that, in both dry and wet grassland conditions, slip-induced instability has a greater impact on overall stability than rollover instability, particularly under low-friction scenarios where variations in slope significantly increase the susceptibility to slip-induced instability. [PERSON] et al. [93] established a dynamics model of articulated tractors by employing a virtual pivot point to simulate the relative rotation between front and rear wheels, thereby deriving the conditions for lateral stability. [PERSON] et al. [94] developed a three-dimensional nonlinear dynamic model that incorporates critical rollover criteria based on abrupt changes in tire-ground contact forces, revealing how operational speed affects both working performance and lateral stability. [PERSON] et al. [95; 96; 97] conducted a systematic investigation into the influence of front tire configuration, counterweight distribution, and rear track width on lateral stability mechanisms. Their results demonstrated that an increased track width ratio enhances tire-ground contact stability, while a greater wheelbase ratio improves disturbance recovery capability, with no significant impact on vibration characteristics. [PERSON] et al. [98; 99] integrated a single-axis momentum flywheel system with an active steering system to dynamically adjust tractor posture, effectively reducing rollover risks. [PERSON] et al. [100; 101] proposed an active anti-roll control strategy based on single-gimbal control moment gyroscopes (SGCMGs) for slope steering scenarios. This method reduced the peak roll angle by 27% and shortened the response time by 35%, significantly expanding the vehicle's stability domain to meet lateral stability requirements. [PERSON] et al. [102] introduced an active steering control strategy incorporating a modified critical position-based lateral stability index (RCP) for compact tractors operating in complex terrain. In off-road conditions involving 20\({}^{\circ}\) slopes with soil subsidence and obstacles, vertical load redistribution was used to characterize frictional constraints, resulting in a 35.98% reduction in lateral instability duration and contributing to the theoretical foundation for active safety technologies in agricultural equipment. [PERSON] et al. [103] implemented an active steering system based on sliding mode control. The control algorithm was designed using variable structure theory, incorporating dynamic posture-dependent lateral stability indices to achieve adaptive torque distribution. Anti-rollover technologies for wheeled agricultural machinery mainly focus on four key areas: dynamic modeling, structural optimization, active and passive safety systems, and verification methodologies. Dynamic models allow for the quantitative assessment of stability boundaries, while parametric structural optimization improves the inherent anti-overturning capability. Furthermore, active control systems enable real-time regulation of stability performance. Existing research indicates that the integration of wheel-terrain interaction friction prediction algorithms with multi-modal control strategies can significantly reduce critical rollover risks. As smart agriculture continues to advance and autonomous driving technologies become more widely adopted, new challenges arise in the development of anti-rollover control systems. These challenges include enhancing motion control accuracy under complex wheel-terrain friction conditions, maintaining dynamic stability, and ensuring operational comfort during high-precision tasks.