US Patent 9643077 Pitch-propelled vehicle

A method, system and apparatus for carrying a user including a board for supporting the user, a ground-contacting member coupled with the board, a motorized drive assembly coupled with the ground-contacting member and one or more sensors coupled with the drive assembly. In operation, the drive assembly adjusts the velocity of the ground-contacting member based on one or more distances of the board from a surface below the board as detected by the sensors. As a result, the system is able to maintain a desired velocity when ascending, descending or traversing uneven ground without the need for excessive and sometimes impossible tilting of the board.