Robot Buddy Series by Alfred Slote

Science fiction story for younger readers. On Jack Jameson's 10th birthday, his family gives him a robot that can do everything Jack can do and more.

Traveling by VOYA-CODE, it takes Jack only a few seconds to get to the planet where his aunt lives, six million light years away. Jack has gone to Alpha I to help his aunt move to Earth. But Aunt Katherine is acting very strangely, not like herself at all. And Frank and Ruth Arbo, the couple who manage her fantastically wealthy mining company, seem downright sinister. What on Earth-or Alpha I — is going on?

Stranded on an unknown planet when their spaceship runs out of fuel, the Jameson family must rely on their robot to save their lives.

Jack Jameson and his robot twin, Danny One, must save the universe from a mad scientist.