Virtual instruction set

Hello.

I am thinking about simulating robots in a virtual world, and they would have an embedded computer that controls their movement.

I would like to know which instruction set architecture to simulate on said computers. Also, if I use an instruction set already supported by common compilers, will I be able to compile C code and load the resulting binaries on these virtual robots ?

Thank you.

Is there any particular reason why an instruction set would be required? Just define an interface which the robots must obey to interact with the environment and leave the implementation to those writing the robot software (they can write it in any language and use any compiler as long as they can interface with your API/ABI). Unless, you're going for something more integrated and more "artificial life"-kind of virtual world.