Fig. 1. Flow chart of pose estimation algorithm based on point pair features

Fig. 2. Diagram of point pair feature

Fig. 3. Diagram of building a Hash table

Fig. 4. Diagram of local coordinates

Fig. 5. Diagram of voting process

Fig. 6. Diagram of consistency adjustment of point cloud normal direction. (a) Original point clouds; (b) point cloud normal direction before adjustment; (c) point cloud normal direction after adjustment

Fig. 7. Diagram of gripping pose strategy adjustment. (a) Objects to be gripped; (b) top 5 proposed poses; (c) output poses

Fig. 8. Diagram of adjustment of angle deviation caused by rotational symmetry

Fig. 9. Diagrams of gripping system. (a) Simulation environment; (b) real environment

Fig. 10. Diagrams of pose estimation. (a) Simulation environment; (b) real environment

Fig. 11. Line charts of pose estimation results. (a) Simulation environment; (b) real environment