Having a set schedule is fine, but be willing to bend it occasionally. Make sure the work is addressed at a later time, and make sure the child knows the consequences if this is not done. Enthusiasm is contagious and limits halfhearted jobs on homework. Children pick up on their parents enthusiasm. When parents tell their children they should be interested in something but then show no interest themselves, the wrong message is being given.
Children are more likely to show interest in something in which their parents are involved.
It is also possible to encourage enthusiasm and interest through special clubs or outside resources.