The invention discloses an automatic identification and 
butt joint method for circular pipelines based on an intelligent hydraulic oil transfer arm technology, and the method comprises the steps: 1, rotating a two-dimensional 
laser scanner through an integrated holder to generate a 
pitch angle, and obtaining multi-view three-dimensional 
point cloud information of the circular pipelines; 2, establishing a disordered 
point cloud spatial index structure by utilizing a three-dimensional spatial grid, so that the data preprocessing speed is increased; 3, preprocessing the 
point cloud with the established data index structure so as to segment the three-dimensional point cloud of the whole scene into three-dimensional point cloud clusters representing different objects; 4, training the acquired point 
cloud data set, and continuously updating to form a time-phase 
invariant feature model 
library; and 5, completing self-identification of the circular pipelines in the port scene by utilizing themodel 
library and automatically butting the circular pipelines with the hydraulic oil transfer arm. Self-recognition of the circular pipelines and accurate 
butt joint of the circular pipeline and thehydraulic oil transfer arm can be achieved, and therefore a new step is developed towards an intelligent port.