# Simulation Model for Robotic Pick-Point Evaluation for 2-F Robotic Gripper
## 4 Results
### Simulation Time Evaluation  
Several tests were conducted to evaluate the time required for the simulations. We assessed the simulations running in a single batch mode and interactive mode by varying simulation time using Parallel Processing Toolbox. Next, 25 simulations were run in parallel, where all the input models (location and orientation of the object) were the same, and lastly, 25 different models were considered. The number of \(N_{\text{sim}}=25\) was selected due for the time required for subsequent simulations. The simulation time evaluation was performed based on the \"hygienic door opener\" model, described in the Section 4.2.  
Since there is no guarantee that MATLAB will use all the selected workers of the pool in a parallel cluster due to available system resources or possible model errors, we performed five runs for the specified simulation time. However, the average required time for the selected simulation time considers only the three shortest simulation time runs. MATLAB started with the default 12 workers, while this number usually dropped to 9 after executing 25 parallel simulations. The first test runs were performed on a workstation with the following setup: Intel i9-9900K processor, 64 GB DDR4 RAM, Gigabyte nVIDIA GTX 3070 OC, and \(1\) TB nVMe SSD.  
The results of these tests are presented graphically in Figure 11.  
Increasing the number of simulations from 25 to 250 does not scale linearly with the time required for the simulations. As seen from Figure 12, in the event of \(t_{\mathrm{sim}}=5\) s, the average time needed to complete 25 simulations is \(t=14.61\) s. However, when \(N_{\mathrm{sim}}=50\) and \(N_{\mathrm{sim}}=100\) simulations, the time required for a single simulation is \(t=13.62\) s and \(t=12.24\) s, respectively. However, it should be noted that the number of workers can drop significantly if more simulations are pending due to possible model errors. On the other hand, the time required for a single simulation also drops significantly with the increase in the total number of simulations.  
The time to run a single simulation (in the initial position and orientation) in both modes, normal simulation mode and \"ode3\" numerical integration method with simulation time \(t_{\mathrm{sim}}=3\) s and integration step \(T_{\mathrm{s}}=5\) milliseconds, is about \(t=53\) s in batch mode and about \(t=97\) s in interactive mode. It must be emphasized that the simulation may take different amounts of time for different pick-points due to the number of (contact) recalculations required.  
Under the same simulation conditions, we could run around 600 simulations in 45 min in a batch mode (around 100 simulations for interactive mode) using this function, which equates to around \(t=4.5\) s per simulation. This would allow us to run around 19,200 simulations in 24 h, almost 13 times the initial simulations. At the same time, we significantly exceeded our target for run-time per simulation.  
Figure 11: Time required for running 25 parallel simulations compared to simulation time (3–10 s) with the default number of workers (12). Source: own.