Robinson, 27, is coming off a one-year stint with the Giants, where he was used as their primary nickel linebacker. He played 70 percent of their defensive snaps, the second most on the team.
Robinson has ties to Bengals linebackers coach Jim Haslett, who spent three seasons with Robinson as the Redskins' defensive coordinator.
Robinson was drafted by the Redskins in 2012 and spent four seasons there (the 2013 season was spent on injured reserve).
He had seven pass deflections in 2016.