The 30-year-old spent last season on loan with Stoke City.
Hendrie said: “I would have liked to stayed in the Premier League but this is a big club and the chance to work with the manager was a big attraction.
“I think I can learn a lot from him [Robson], he’ll give me great advice.
“I’ve gone a bit stale over the last couple of years but I’m really excited by this new challenge and I’m confident we can be up there challenging for promotion.”
