# The Current Development Status of Agricultural Machinery
## 3. Chassis Travel Mechanism System of Agricultural Machinery
### Wheeled Travel Mechanism  
Wheeled chassis provides smooth mobility, low energy consumption, and precise control over speed and direction, facilitating adaptation to diverse operational environments. These advantages not only reduce operator fatigue but also enhance operational precision and efficiency. Based on drive configurations, wheeled chassis can be categorized into: front-wheel drive (FWD), rear-wheel drive (RWD), and four-wheel drive (4 WD). These configurations exhibit excellent gradeability and tractive performance, thereby meeting the operational requirements of agricultural machinery in most environments. Wheeled agricultural machinery predominantly utilizes pneumatic rubber tires, which offer exceptional damping and vibration absorption capabilities. However, when operating on unpaved surfaces, inadequate traction at the wheel-ground interface often results in wheel slip, significantly undermining obstacle-crossing performance and terrain adaptability. This issue becomes particularly critical in hilly and mountainous regions, where unstable traction heightens the risk of lateral rollover. [PERSON] et al. [91] proposed a velocity-acceleration bivariate neural fuzzy friction model (NFFEM) that integrates fuzzy logic rules with radial basis function (RBF) neural networks. This approach overcomes the limitations of conventional single-variable velocity models, achieving a 94.55% reduction in positioning error for nonlinear friction models (NFNLFMs). The study introduces a novel paradigm for agricultural chassis development: (1) the dual-variable framework accurately captures wheel slip dynamics; (2) high-precision friction estimation optimizes traction control and energy consumption; and (3) the adaptive neural fuzzy mechanism enhances chassis trafficability and energy efficiency in complex farmland environments, \begin{table}
\begin{tabular}{p{42.7 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Type** & **Working Principle** & **Structural Features** & **Key Parameters** & **Performance Indicators** & **Typical Agricultural Application Scenarios** \\ \hline \multirow{8}{*}{Wheeled} & Frictional drive through tire-ground interaction with steering mechanism for directional control & Simple structure; diverse tire & Ground pressure: 50–150 kPa; configurations; optional & Max climbing angle: 25–32; energy consumption per unit mass: 2.5–3.8 kJ/kg\(\cdot\)km; traction efficiency: 60–75%; slip rate: 15–30% & Dryland farming in plains (e.g., John Deere 8R tractor), transport vehicles, and orchard management machines (narrow wheelbase design) \\  & Continuous ground contact via driven sprockets and track plates for pressure distribution & Multi-material track systems; logic-bearing; adjustment device & Ground pressure: 15–30 kPa; medium-bearing; speed range: 0–15 km/h & Max climbing angle: 35–42°; energy consumption per unit mass: 1.8–2.5 kJ/kg\(\cdot\)km; traction efficiency: 75–88%; slip rate: 5–15\% & Paddy field operations (e.g., Kubota PRO988Q) harvester), wetland framing, and slope orchards (slip resistance \(>\) 85\%) \\  & Electro-hydraulic coupling system combining front-wheel steering configuration and rear-track drive & Articulated chassis; hydraulic speed regulation; compliant & Ground pressure: 30–50 kPa; minimum turning radius: 2–4 m; speed range: 0–25 km/h & Max climbing angle: 32–38°; energy consumption per unit mass: 2.0–3.0 kJ/kg\(\cdot\)km; traction efficiency: 68–82%; slip rate: 8–20\% & Muddy terrain operations (e.g., Case Steiger Quadtrac), hill/mountainous transport, and silge harvesting (40\% traction enhancement) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Principles, characteristics, and applications of agricultural machinery chassis travel systems. providing an algorithmic foundation for intelligent anti-slip control systems in agricultural machinery. [PERSON] et al. [92] developed a dynamic model to address tractor rollover and stability issues in hilly terrain.