Robson made 15 appearances for Oyonnax in the Top 14 last season after joining the French side in February 2015.
The 30-year-old had previously spent his entire career at Harlequins, where he made 146 Premiership appearances.
"I'm looking forward to the challenge of trying to win promotion back to the Premiership," he told the London Irish website.
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It is expected to fetch up to Â£1.2m as part of Christie's Post-War and Contemporary Art sale.
The controversial piece, shortlisted for the Turner Prize in 1999, gives a snapshot of Emin's life after a traumatic relationship breakdown.
It is being sold by art collector Charles Saatchi, who bought it for Â£150,000 in 2000.
After installing the bed at Christie's, Emin told BBC News arts correspondent Tim Masters what it still means to her 16 years on.
It feels different knowing that it's going to leave. Before, when I've installed it, there is a level of nostalgia each time. But this time I was really quite sad because I don't know where it's going.
It's quite scary, it's out of my control completely. Not that I'm a giant control freak. But I really care about the bed, and I really love it.
I realise being here today how much it means. It's always meant a lot to me, but I didn't realise how passionate I was about it.
The best possible result is that an amazing benefactor buys it and then donates it to a museum.
I have no idea where it's going to end up - or how much anyone is going to pay for it. There's never been anything like it for sale in an art auction before.
All the duvets were wrapped up, and everything was in airtight containers.  It looked like a crime scene or a scientific project.
Today when I took the duvet out, it was flat. And when I threw it on the bed, it didn't look right. So I fluffed it up, and it still didn't look right.
So I actually made the bed and got in and pushed the cover back so it had that natural feeling that a body has been into it.
It is strange because it still has that same smell that it had 16 years ago.
Obviously the stains and everything else are touching me, and it's like being touched by a ghost of yourself.
My American friends came to see me installing it this morning, and they saw the mattress and they went: "Tracey!"
I think people are so used to seeing it as an image that they forget that it's real.
When they see it for real, it still evokes these feelings inside them because you can see the trace of a human being in there.
It's like the self-portrait of someone that's gone. It's like a time capsule, and a lot of people relate to that in some way.
Pretty good. Especially being a woman and being part of art history. I'm pleased about that. If I never do anything else great and seminal again, like the bed, I've done it. And that makes me happy.
Now I can just get on with my life and do what's really important to me - and that's making art.
My Bed is being sold as part of Christie's Post-War and Contemporary Art sale on 1 July, which includes works by Francis Bacon, Peter Doig, Andy Warhol and Jackson Pollock.
Championship club London Irish have signed Oyonnax and former Harlequins lock George Robson on a one-year deal.
[NEXT_CONCEPT]
Tracey Emin's most famous artwork My Bed (1998), which features stained sheets, cigarette packets, and discarded condoms, is being auctioned in London on Tuesday.