Our bub has never slept in our bed (we have tried once or twice when she was sick but she just doesnt associate it with sleep) so I dont know if this method will work for you but its probably worth a shot.
There is a method called gradual withdrawal which is good for older bubs who often have a a stronger will and we used it to put our little one into a bed from her beloved cot at 21 - 22 months.
You have to put aside for a couple of weeks that evening time but its worth it. We started having to rock her to sleep and then put her int her bed as there was no way she would go near it! but after two nights we would just stroke her forhead or pat her off on the bed, then we would just do this for a couple of mins and sit on the floor firstly next to the bed then further (little by little) every night. Because it was a minimal change each night we didnt really have any tears, occaisionally a whinge, but no crying. It took time and you feel like a fool sitting there in the dark waiting for them to sleep. You make no eye contact or talking, I would say occaisionally that mummy was here. but the night we got out of the door and stood in the door way was great. Now we shut the the door say were here if you need me and walk away (we started about 5 weeks ago). We had the perfect little sleeper but we got her into a bed and then she got sick and everything changed. She started light sleeping too (not good with a new bub due in a few weeks) and we are using a white noise CD which has helped with the quality of her sleep and she now sleeps through anything again. we have used controlled comforting and it worked well in the past but there was no way she was going to take this time and this worked a treat. If you email karitane on their website they will give you help by email for free and you can call them 24 hours for clarification or support. They helped us work this out in a few emails and were very supportive in choosing what is right for us. They also have these kinds of methods on their websites if you just want a sticky at them.
Which ever way you go goodluck! now shes as happy as in her own bed runs to go there of a night and settles herself back if she does stir.
Bec, NsW, charlie 5, AJ almost 3