Sleep Help is a site devoted to spreading awareness of sleep health and wellness. They have created a resource specifically for helping children and adults with autism to get better sleep, available here:

Researchers have found that autism can affect the body’s ability to produce melatonin at the correct times, causing autistic children and adults to experience daytime fatigue and difficulty falling asleep at night. Sensory issues in the bedroom can also make it difficult to fall asleep and sleep well throughout the night. Their guide covers these issues in detail and gives some simple, non-prescription options for getting a better night’s sleep.