Apparatus and systems drive an infant carrier through space while providing soothing acceleration and/or sonic components. Infant-soothing swaying and vibrating mechanisms help to calm an upset infant and/or help the infant to fall asleep. Embodiments described herein include infant carriers capable of self-locomotion and/or platforms capable of self-locomotion with snap-in fasteners to accept an infant carrier. In some embodiments, a platform with an attached infant carrier travels along a track or monorail. In some embodiments, an infant carrier with wheels may be pulled by a toy providing the locomotion. Some embodiments incorporate a device controller with biofeedback mechanisms to adaptively pinpoint characteristics of soothing motions and sounds appropriate to a selected soothing task for a particular infant in a particular emotional state.