Children with Aspergers disorder are very likely to develop intense interests. Why not make use of some of your child's favorite things to help at homework time? For example, if your child has been asked to read 2 books each night, and he loves basketball, go to the library and help him check out books on basketball. He's more likely to look forward to reading time each night when he knows he'll be reading about his favorite thing. Incorporating student interest goes a long way in keeping a child's attention during homework time.
In addition to using student interest, consider a reward system for your child. This can be an extension of a reward system used at school, or it can be unique to the home setting. Whatever you choose, make sure it's concrete, and that rewards are frequent. Maybe a sticker with a picture of a favorite interest or 30 minutes of computer time after homework is complete. Use the child's favorite things to determine appropriate rewards.
Autism spectrum and homework issues don't have to be automatic. If parents and teachers work together, children with autism spectrum disorders can flourish, without tantrums and stress.