The present disclosure provides a method of generating a control signal to control a motion of a robot arm device by a brain-computer interface (BCI) apparatus and the BCI apparatus. The present method includes: measuring a first electroencephalogram (EEG) and extracting an abstract feature of the first EEG; determining one of a reaching control mode, a hand grasp/opening control mode, and a wrist rotation control mode based on the abstract feature of the first EEG; performing feedback of the determined control mode to a user; measuring an error-related potential as a second EEG; redetermining the control mode by re-extracting an abstract feature of the first EEG when the error-related potential exceeds a threshold value or measuring a third EEG when the error-related potential does not exceed the threshold value; extracting a result value by applying different feature extraction methods and different classification methods to the third EEG depending on the determined control mode; and supplying a control signal generated based on the result value to the robot arm device.
Brain computer interface (BCI) apparatus and method of generating control signal by BCI apparatus