Fig. 1

Overall flowchart of berthing parameter estimation algorithm

Fig. 2

Comparison of effects of different filtering algorithms

Fig. 3

Point-to-plane error between two surfaces

Fig. 4

Schematic diagram of berthing distance and berthing angle during berthing process

Fig. 5

Flowchart of extracting berth frontline based on random sample consensus algorithm

Fig. 6

ROS-based berthing perception framework

Fig. 7

Simulation experiment environment and unmanned surface vessel

Fig. 8

Real-world experiment environment and unmanned surface vessel

Table 1

LIDAR data specifications

Fig. 9

Comparison of the trajectories obtained by three registration algorithms in simulation experiment

Fig. 10

Comparison of trajectories obtained by three registration algorithms in the real ship experiment

Fig. 11

Comparison of attitude Euler angles obtained by three registration algorithms in simulation experiments

Fig. 12

Comparison of attitude Euler angles obtained by three registration algorithms in real ship experiments

Fig. 13

Comparison of errors in x, y, and z directions for positions obtained by three methods in simulation experiments

Fig. 14

Comparison of errors in x, y, and z directions for positions obtained by three methods in real ship experiments

Fig. 15

Comparison of average attitude errors obtained by three registration algorithms in simulation experiments

Fig. 16

Comparison of average attitude errors obtained by three registration algorithms in real ship experiments

Fig. 17

Comparison between berth front point cloud extracted by MSAC algorithm and original point cloud

Fig. 18

Comparison of berth front extracted by MSAC algorithm with ground truth value

Fig. 19

Distance of the USV from the berth during the berthing process

Fig. 20

Berthing angle of USV during the berthing process

Fig. 21

Berthing distance error during berthing process

Fig. 22

Berthing angle error during berthing process