Please feel free to try and connect with the school psychologist who can help develop a student- school- home behavioral system. You also may wish to learn more about this here: http://www.nasponline.org
Consider the use of social stories and photography to make relatable connections from school to home, too!
Hi I teach kindergarten and I currently have a child with autism and a child with aspergers in my class. I use the 5 minute time out with a visual timer so the child can see how long the time will be and how much time is remaining. I place a chair in a place where I can still see the child and we use this as out time out chair. I also remove privileges when needed but also use positive reinforcement, encouragement, and rewards that the child would be interested in when he/she does something correctly. For example, putting sneakers on by themselves, completing work on time, playing or behaving correctly in social situations and play time..etc. I would recommend being consistent, calm and firm with the time out, also choose just one thing at a time as a focus behaviour, and gradually work in more as you move along. For children who suffer from autism and aspergers the world can seem very overwhelming so take it slow and be patient.
Its best to talk with parent and encourage them to maintain a behaviour chart at home.It's difficult to maintain a consistency without home support.You could also try using Home-School behavior management sheet.
I know it is tough getting an Asperger's child to understand that his actions have consequences, but they really do understand. My 8 year old son has Asperger's and I hear stories of how mean his teacher is everyday. She is not mean just frustrated. I use humor to break through my son's mind set. If he is having a melt down or refuses to see things my way or a siblings way I make a joke. Nothing grand just something that will shake him from frustration. It works every time. He is then out of his own head and free to listen to me. It just takes a second of my time and it puts me in a good mood too instead of me being angry. My son hates it when people are angry at him, he sees it as being mean and shuts down. As soon as he giggles I know he is ready to hear what I have to say.
Hope you can use this to enjoy your student as much as I enjoy my son now.