Motion planning and control of an installation robot for attitude adjustment of arc parts in underground shield tunneling

The traditional assembly process of arc parts (box‐shaped pieces) in shield tunneling faces significant challenges, including outdated assembly techniques, low assembly precision, and slow construction progress. This study introduces a walk‐through assembling robot for arc parts (W‐ARa), inspired by the crawling behavior of spiders. W‐ARa consists of eight legs, 19 hydraulic cylinders, and a dual‐layer pose adjustment unit. Considering the structural characteristics of W‐ARa, a pose adjustment dynamics model is established, which maps the relationship between load poses, hydraulic cylinder displacements, and hydraulic oil pressures. Based on the developed mechanistic model, an optimal hierarchical pressure distribution strategy is proposed for hydraulic oil allocation, transitioning from an initial cylinder configuration to a target pose configuration. This strategy considers energy consumption, actuator efficiency, and structural constraints under heavy‐load conditions. To validate the effectiveness of the proposed planning algorithm, a synchronous control strategy based on linear active disturbance rejection control is developed to address the synchronization issues caused by strong coupling, nonlinearity, and internal‐external disturbances in the parallel hydraulic system.