*6.2. Multifaceted Edges Robotic Deburring Experiment*

In the second robotic deburring experiment, multifaceted edges deburring for an automobile steering booster housing were conducted on the improved experimental platform of the robot manipulator (shown in Figures 2b and 8a). The experimental object was an aluminum alloy casting automobile steering booster housing (shown in Figure 8b), and the experimental deburring object were multifaceted edges of the automobile steering booster housing, as shown in Figure 21, i.e., orifice edges (blue lines are showed in Figure 21) and facet edges (red lines are showed in Figure 20) on top facet, distal side facet and proximal side facet relative to the initial position of the robot manipulator, as shown in Figure 21a,b,c, respectively.

**Figure 21.** Experimental deburring of multifaceted edges for automobile steering booster housing: (**a**) top facet; (**b**) distal side facet; (**c**) proximal side facet.

A double-cutting arch round-head carbide rotary tool with the side cutting edge (shown in Figure 12c and its type—FX1020M06) was selected to conduct the deburring for multifaceted edges of automobile steering booster housing in the second experiment. In the multifaceted edges deburring experiment, the planned movement directions of the robotic deburring tool were clockwise and counterclockwise for orifice edges deburring and facet edges deburring, respectively.

Since burrs on multifaceted edges are very small, the entire allowance of each facet edge burrs could be deburred completely only once. Similarly, the proposed robotic deburring tool path planning method and the proposed robotic deburring process parameter control method were applied as in the first deburring experiment. Among them, the robotic spindle speeds for orifice edges deburring and facet edges deburring are selected to be 10,000 rpm and 8000 rpm, respectively; and the line speeds of the robotic feed for top facet edges deburring and other edges deburring were set to 30 mm/s and 20 mm/s, respectively. Note that these selected values for robotic spindle speeds and robotic feed speeds are not guaranteed to be very suitable as they are selected only according to limited past experiences. As mentioned above, the most appropriate way of selecting extremely suitable robotic deburring feed speed and tool spindle speed for specific deburring workpiece needs to refer to some related research issues for the technical details and be verified by a series of deburring experiments.

The detailed robotic experimental deburring for orifice edges and facet edges on the top facet, distal side facet and proximal side facet are shown in Figures 22 and 23, Figures 24 and 25, and Figures 26 and 27, respectively. Finally, experimental deburring results for multifaceted edges of the automobile steering booster housing are shown in Figure 28. And robotic experimental deburring results of target planning path and actual tool path of top facet, distal side facet and proximal side facet are shown in Figures 29–31, respectively (here, the blue line and the red line are the target planning path and the actual tool path, respectively). Deviation results of target planning path and actual tool path of robotic experimental deburring for top facet, distal side facet and proximal side facet are shown in Figures 32–34, respectively. In each deviation figure, the vertical axis indicates the magnitude of the deviation, and other two horizontal axes in the horizontal plane indicated the corresponding positions

of the target planning path in the deburring experiment (here, the blue line and the red line are the facet edges deburring deviation results and the orifice edges deburring deviation results, respectively). In addition, three figures in the form of plane polar coordinates illustrating deviation results of this experiment deburring for top facet, distal side facet and proximal side facet are shown in Figures 35–37, respectively. Among them, the maximum path deviations of top facet edge, distal side facet edge and proximal side facet edge were 0.97 mm, 1.13 mm and 1.21 mm, respectively. These robotic deburring results can satisfy the experimental deburring requirements.

It can be showed that the effectiveness of the proposed robotic deburring tool path planning method and the proposed robotic deburring process parameter control method were also verified in the second deburring experiment. Furthermore, the highly efficient and dexterous manipulation and deburring capacity of the robot manipulator for multifaceted deburring in one setup was totally demonstrated in the second deburring experiment. In addition, it should be noted that the proposed methods can be now only applied to soft material machining applications and low machining requirements due to the rigidity defect of the robot manipulator and lacking compensation for vibrations and/or chattering, although it had a very high level of dexterous manipulation and orientation reachability. There are still many meaningful research issues need to be conducted in the next step in order to improve the path accuracy of the robot manipulator, such as offline path correction, compensation for vibrations and/or chattering, high frequency oscillation suppression, structural rigidity improvement, calibration of the robot manipulator for dealing with nonnegligible dynamic effects which are caused by backlash of ball screws and robot manipulator structural deformations.

It is necessary to note that, when the end-effector tool of the robot manipulator is changed, like an abrasive belt or a fabric wheel, the robot manipulator can also conduct deburring, grinding and polishing for edges and surfaces of castings or other materials, such as parting line burrs, flash burrs, pouring risers burrs, and so forth.

**Figure 22.** Experimental deburring of orifice edges on top facet.

**Figure 23.** Experimental deburring of facet edges on top facet.

*Appl. Sci.* **2019**, *9*, 2033

**Figure 24.** Experimental deburring of orifice edges on distal side facet.

**Figure 25.** Experimental deburring of facet edges on distal side facet.

**Figure 26.** Experimental deburring of orifice edges on proximal side facet.

**Figure 27.** Experimental deburring of facet edges on proximal side facet.

**Figure 28.** Experimental deburring results for multifaceted edges of automobile steering booster housing: (**a**) top facet; (**b**) distal side facet; (**c**) proximal side facet.

**Figure 29.** Experimental deburring results of target planning path and actual tool path of top facet.

**Figure 30.** Experimental deburring results of target planning path and actual tool path of distal side facet.

**Figure 31.** Experimental deburring results of target planning path and actual tool path of proximal side facet.

**Figure 32.** Deviation results of target planning path and actual tool path of experimental deburring for top facet.

**Figure 33.** Deviation results of target planning path and actual tool path of experimental deburring for distal side facet.

**Figure 34.** Deviation results of target planning path and actual tool path of experimental deburring for proximal side facet.

**Figure 35.** Deviation results of target planning path and actual tool path of experimental deburring for top facet (polar representation): (**a**) facet edges deburring deviation; (**b**) orifice edges deburring deviation.

**Figure 36.** Deviation results of target planning path and actual tool path of experimental deburring for distal side facet (polar representation): (**a**) facet edges deburring deviation; (**b**) orifice edges deburring deviation.

**Figure 37.** Deviation results of target planning path and actual tool path of experimental deburring for proximal side facet (polar representation): (**a**) facet edges deburring deviation; (**b**) orifice edges deburring deviation.
