# Electromagnetic Switching Multiple Grasping Modes Robot Hand
## 7 Conclusions  
In this paper, a switchable parallel fusion method is proposed, which integrates three basic grasping modes into a two-joint single source driving robot hand. Based on this method, the ESMGM robot hand uses a switchable CPS mechanism to realize the electromagnetic switching function between the conflicting parallel grasping and coupled grasping modes. The partial effective transmission mechanism divides the motion into two phases \begin{table}
\begin{tabular}{c c c} \hline \hline
**Parameters** & **Result/Range** & **Unit** \\ \hline Grasping object size & 0–220 & mm \\ Grasping force of parallel grasping mode & 0–45 & N \\ Grasping force of coupled grasping mode & 0–18 & N \\ Grasping force of self-adaptive grasping mode & 0–78 & N \\ Number of motors & 4 & / \\ Degree of freedoms & 8 & / \\ Period of parallel grasping mode & 0–2.8 & s \\ Period of coupled grasping mode & 0–1.2 & s \\ Period of idle-stroke phase & 0–5.2 & s \\ Period of self-adaptive grasping mode & 0–5.7 & s \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Universal grasping experiments parameter measurement results. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Scenario** & **Grasping Mode** & \(\mathbf{\alpha}/^{o}\) & \(\mathbf{\beta}/^{o}\) & \(\mathbf{f_{1}/N}\) & \(\mathbf{f_{2}/N}\) \\ \hline
1 & Parallel & \(42.25\pm 1.76\) & \(-42.39\pm 1.20\) & / & \(35.53\pm 1.89\) \\
2 & Coupled & \(25.32\pm 1.39\) & \(23.27\pm 1.50\) & / & \(11.69\pm 1.27\) \\
3 & PASA & \(13.96\pm 0.94\) & \(28.77\pm 1.42\) & \(7.28\pm 0.71\) & \(29.53\pm 2.35\) \\
4 & COSA & \(10.46\pm 1.07\) & \(32.58\pm 1.27\) & \(9.62\pm 1.80\) & \(25.53\pm 1.86\) \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Grasping force of the ESMGM hand during grasping experiments. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Gripper** & **DOFs Driven by One Motor** & **Grasping Modes** & **Adaptive to Object** & **Stroke/mm** & **Max. Grasping Force/N** \\ \hline Hosmer Split-Hook & \(1\) & \(1\) & no & 44 & 80 \\ Yale Hand & \(2\) & \(2\) & yes & 48 & 42 \\ APRL Hand & \(2\) & \(1\) & no & 38 & 80 \\ Roboita Hand & \(2\) & \(2\) & yes & 50 & 105 \\ Barret Hand & \(2\) & \(2\) & yes & 120 & 72 \\ ESMGM Hand & \(2\) & \(3\) & yes & 110 & 82 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Grasping performance of the ESMGM hand and other grippers. and ensures the grasping motion always ends with the self-adaptive grasping mode. The ESMGM robot hand not only achieves functional expansion but also guarantees its property advantages. The operator can choose the appropriate grasping mode before an operation, the switching is fast, and the functions are abundant. The kinematic analysis and contact forces analysis show that the ESMGM hand has not only ample motion space but also sufficient grasping force for the grasping of daily life objects and small workpieces in industry production. To verify the properties of the ESMGM hand, grasping experiments were performed. The results show that it is suitable for grasping objects with different shapes, positions, and sizes due to combining the advantages of the three basic grasping modes. However, through the comparison with various mainstream robot hands and grippers, it is found that although the ESMGM hand has achieved functional expansion, its performance under each grasping mode is not significantly better than other products. Firstly, due to the usage of gear sets, the size of the ESMGM robot hand is slightly larger than that of the human hand, which slightly hinders its dexterity. Secondly, elastic elements are used to realize the trigger and conversion mechanism of various grasping modes; thus, the maximal grasping forces are somehow limited. In future research, we should develop a more advanced mode integration method, more efficient transmission mechanism, and high-performance switching device to further improve the power and dexterity of the ESMGM robot hand.