<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _reset_internal_state(self):
 """ Resets internal state of controller, except for the reset signal. """

        self.rotation = np.array([[-1., 0., 0.], [0., 1., 0.], [0., 0., -1.]])
        self.pos = np.zeros(3)  # (x, y, z)
        self.last_pos = np.zeros(3)
        self.grasp = False