There's really not a whole lot you can do... Robot will beat the sh*t out of Ike off the stage, and on ground you're pelted by lasers and gyros and overall quicker tilts, jabs, and f/u smashes.
I think the direction is up to DI out of d-smash, and don't only shield the gyros when he's shooting them at you, but even while they're spinning on the floor, get rid of them by shielding them. Robot has a great glide toss that's a very good approach especially against slow people and he can glide toss right into a down or forward smash if you're not careful.
Remember that Robot's blind spots are below him and behind him. U-tilt and u-air can help. You can bait a d-air in which case he's wide open, but overall it's difficult to punish Robot, especially with Ike.
Just... try to space I guess. Double jump fairs, f-tilts, and when your up close jab like a mad man. Always, ALWAYS anticipate the laser/gyro. Lasers will happen with a 99.8% probability at the beginning of the match and when you've knocked Robot away and he's on the other side of the stage. The possibility of a gyro varies based on playstyle, but just remember that gyros and lasers are also R.O.B.'s killing moves. A full charged gyro or laser can take care of you around the 100-110%'s depending on where you are off the stage. This is especially troublesome for Ike because of how vertical or horizontal he needs to be in order to recover.