What are the difficulties in the structural design of the four-way shuttle? How should they be solved?

Four-way vehicle rack is a kind of automated storage rack. It uses the longitudinal and lateral movement of the four-way vehicle and the transfer of the elevator to achieve the purpose of storage automation. The four-way vehicle is also called a four-way shuttle vehicle. It can move horizontally and vertically along the predetermined track load to realize the storage and retrieval of goods to the shelf. The equipment can realize automatic storage and retrieval, automatic lane change and layer change, and automatic climbing. It can also be transported and driven on the ground. It is a three-dimensional warehouse system that integrates automatic stacking, automatic transportation, unmanned guidance and other functions. The four-way shuttle vehicle has many components and modules, compact structure, complex frame, many gaps and holes on the structural components, and many stress concentration and design weaknesses. So what are the difficulties in the structural design and analysis of the four-way vehicle in the four-way shuttle vehicle automated three-dimensional warehouse?

1. Finite element analysis is needed, especially the driving stability analysis of the whole vehicle is currently only based on the working condition simulation test, and it cannot be systematically studied in theory.

The movement vibration of the whole vehicle is mainly concentrated in the drive and hydraulic parts. The axles and bearings are most likely to cause vibration fatigue damage. This is mainly because the rails configured in the steel rack have joints and installation deviations. The rack structure also has a certain elastic deformation. The contact stiffness between the wheel and the track is large, which is easy to cause wheel-rail contact vibration and vehicle body vibration. At present, rubber-coated wheels and other measures are often used to optimize the resonance of the wheel group.

High-capacity battery technology

Battery technology is one of the key technologies that affect the application of four-way shuttles. Because the pallet unit cargo stored and transported by the four-way shuttle is heavy, the power consumption per unit running distance is large, and the working time that can be fully charged each time has become a bottleneck for the widespread application of the four-way shuttle. Effectively monitoring the health status and charging and discharging performance of the lithium battery of the four-way shuttle is also one of the key technologies to ensure the full automation of the pallet four-way shuttle automated dense storage system. However, high-performance and high-capacity batteries are expensive, which makes the manufacturing cost of the four-way shuttle high. 

--- By Zita Jian

3rd July 2024