# Grasp Analysis for the Robot-Based Manipulation of Pre-Assembled Cables with Electrical Connectors
## 4 Results
### Grasp Analysis for High-Voltage Cables  
The results for three high-voltage cables made of copper with a cross-section of 50 mm\({}^{2}\) are shown in Figure 9 for each of the two grippers. Figure 8: Application scenario of interconnecting battery modules via high-voltage ECs. (**a**) gives an overview of the automatically generated scenario, in which three high-voltage cables are provided in a load carrier in order to interconnect four battery modules. (**b–d**) show the discrete time steps 1 (supply), 3, 5, 8, 11, and 15 (mounted state) of the trajectories along which the three cables are manipulated and consequently deformed. Cable 1 (**b**) and cable 2 (**c**) are mounted with a bend of 180 degrees around the same axis, and cable 3 (**d**) with two bends of 90 degrees each around two different axes. For each cable and each WP, the local curvature is color-coded individually (red: high, blue: low). At WPs 1 and 3, the cables are not color-coded, because their local curvature is close to zero here. The deformation begins after WP 4. For WPs 1-4, the required grasp force is zero since the cable is removed from the load carrier and manipulated solely vertically, and, therefore, does not undergo any deformation. From WP 5, the courses are strongly individual, especially when comparing the three cables. The correlation between the cable deformation and the required grasp force can be observed qualitatively using cable 2 as an example. Its deformation increases from WP 5 to WP 8 and then decreases again through WP 11; compare Figure 8c. This is reflected in the corresponding values for the required grasp force in Figure 9c,d. Moreover, qualitatively similar courses with different scaling of the four surface pairs are shown for one cable and one gripper. If we compare a planar surface with a non-planar one along the same  
Figure 9: Required grasp forces of the scenario shown in Figure 8 of the three different cables with two grippers each, differentiated for the four surface pairs of Figure 7. WP 1 represents the supply of a cable, and WP 15 is the mounted cable. WP 16\({}^{\circ}\) represents the superposition of WP 15 with the force for mating the plug to the socket. axial plug position, the planar surface requires a higher grasp force for almost every WP. Moreover, the closer a surface pair lies with respect to the CCI, the lower its required grasp force is. This can be seen when comparing surface pairs 1 with 3 and 2 with 4. With a few exceptions, surface pairs 3 and 4 require less grasp force. This can be explained by the lower leverage of the CCI to surface pairs 3 and 4 compared to 1 and 2. In addition, a qualitative comparison of two grippers reveals similar courses. In particular, this is the case for the predominant symmetrical deformations of cables 1 and 2, in which, primarily, a cable bending of 180 degrees occurs. However, cable 3 shows that asymmetrical deformations can amplify the variation in the grasp force courses, especially in the maximum values. If we compare cable 1 and cable 2, which, primarily, undergo bending deformations but have different lengths, similar courses apart from their scaling can be observed. For cable 1, significantly higher grasp force values result due to its much smaller bending radius. To analyze the superposition of the cable wrench in the mounted state and the mating force, the transition from WP 15 to 16* is observed. It can be noted that the impact of the mating force on the required grasp force depends on the characteristics of the cable wrench already acting in the mounted state. For example, the mating force has a stronger influence on the required grasp force for cable 2 than for cables 1 and 3. This is indicated by the increase from WP 15 to WP 16*. Solely considering the mating force while neglecting the cable wrenches is generally not allowed. Depending on the deformation, a multiple of the required grasp force may be necessary by the cable compared to the mating, as is the case for cables 1 and 3, for example.