Driving a Semiautonomous Mobile Robotic Car Controlled by an SSVEP-Based BCI

Figure 9

This chart presents exemplarily the BCI performance for subject 59 (optimal path with 100% accuracy). The top row shows the raw EEG signal acquired from channel (one of eight EEG electrodes). The remaining graphs show the SNR values during the whole experiment (dashed line represents the threshold for each command) for the four commands forward/up, turn left, turn right, and camera/drive; the stimulation frequencies for those commands were 6.67, 7.50, 7.06, and 6.32 Hz, respectively. The -axis, the same for all graphs, represents the total duration of the experiment (150 seconds). The marking above each graph represents the exact time of each classification; circled numbers below the -axis correspond to the task actions.