Rotation and Position Control of a Cubic Object Using Airborne Ultrasound

The long-term goal of our research is to create a mid-air robot that can be driven using airborne ultrasound phased array devices placed in the surrounding environment. In this study, we developed a method to control the position and rotation of a cube-shaped object using airborne ultrasound. Multiple phased array devices synthesize focal points on the surface of a balloon to exert acoustic radiation force upon it. We constructed a prototype system and performed dynamic PID control based on visual feedback. Through experiments, we confirmed that it was possible to control the position and the rotation around the yaw axis of a cube-shaped object simultaneously. Our method is useful for long-duration midair robot applications such as 24-hour surveillance and all-day exhibitions.