Agricultural Robot Chassis: How to Deal With Special Scenes Such As Mud And Paddy Fields?

When ordinary robot chassis operate in soft terrain such as paddy fields and muddy swamps, they can easily sink, causing a low crop emergence rate. Maintaining the stable movement of the chassis and maintaining the soil structure has always been the core problem of agricultural robot design.

Traditional wheeled robots often have a slip rate of more than 60% and a sharp increase in energy consumption of 40% in fields with a moisture content of more than 35% due to their high ground pressure and insufficient adhesion. The advantage of the tracked robot chassis is that it expands the ground contact area, optimizes the pressure distribution, and controls the pressure below 18kPa. The parameter is equivalent to the pressure on the ground when humans stand on their feet.

Common problems and solutions for complex terrain

1. Muddy farmland and paddy fields:

The soil bearing capacity of muddy farmland and paddy fields is usually less than 50kPa, equivalent to the dilemma of humans falling into the snow when walking. The high ground pressure and insufficient adhesion often cause sinking and slipping, resulting in low operating efficiency and even soil structure damage. According to general data, when the ground pressure of the robot chassis exceeds the soil bearing limit, the traction resistance will increase by 3-5 times for every 1cm increase in sinking depth, resulting in more than 40% in equipment energy consumption.

The wheeled robot chassis often sinks due to excessive ground pressure (generally exceeding 50kPa), resulting in more than 40% in traction resistance. The tracked chassis controls the ground pressure below 18kPa (equivalent to the pressure of human feet standing) through the 30cm wide tracked design, effectively reducing the sinking depth to within 5cm (the sinking depth of the wheeled robot chassis reaches 15-20cm).

2. Mountainous areas and terraces:

Due to the characteristics of steep slopes, gullies, and broken fields, the wheeled robot chassis is often limited by instability of the center of gravity, uneven distribution of driving force, or insufficient obstacle crossing ability when operating in terraces with a slope of more than 15°.

Given the slope and complex terrain of mountain terraces, the tracked chassis can achieve a 30°-60° climbing ability (wheeled robot chassis is usually ≤20°) by optimizing the transmission system and track tooth design, adapting to complex terrain such as mountainous areas and terraces. Actual measurements of a mining project show that the climbing efficiency of the tracked robot chassis is 50% higher than that of the wheeled type.

When agricultural robots are working in mountainous areas, obstacles such as stones, tree roots, and gullies are common. The obstacle height that traditional wheeled robots can overcome is generally within 10 cm. The tracked chassis, using a heightened tracked frame design (ground clearance of 25 cm) and an active suspension system, can increase its obstacle-crossing capability to a 15 cm step or a 30 cm wide gully. 

3. Soil germination rate

When the wheeled robot chassis is operating, the soil is compacted, resulting in a lower crop germination rate (only 30%-40%), while the tracked chassis operation can maintain the soil structure, avoid the formation of the plow bottom layer, and ensure the crop growth environment, with a germination rate of 80%-90%. ‌

Soil compaction is a key factor affecting crop emergence rate. The tracked chassis uses a low-specific-pressure design and a pressure sensor array to monitor and optimize the ground pressure distribution in real time to avoid local high-pressure areas. The sowing robot equipped with this chassis reduces soil compaction by 22%, increases rice emergence rate by 18%, and corn emergence rate by 15%.

With the development of agricultural robot chassis, the tracked chassis is upgrading from a simple mobile platform to an environmental perception and energy distribution system. It can monitor soil reaction force in real time (measurement range 0-200N) through an integrated pressure sensor array, provide data feedback for fertilization and sowing operations, and promote the formation of "perception-decision-execution".