Bobby Brown -- Arrested for DUI ... Again

Bobby Brown was just arrested for DUI ... for the second time this year, TMZ has learned.

Law enforcement sources tell us, Brown was pulled over around 1AM when police observed the singer driving erratically on an L.A. street.

According to law enforcement sources, officers approached Brown's vehicle and detected a strong odor of alcohol -- at which point they asked Brown to get out of his car.

We're told Brown performed a field sobriety test, but didn't do very well -- so he was arrested on suspicion of DUI. He's currently being booked.

Brown was previously arrested for DUI in March and sought treatment for alcohol abuse issues over the summer. He also has a DUI conviction on his record from 1996.