This Small Business Innovation Research Phase I project proposes the development of an ultrasonic three-dimensional (3D) rangefinder system for mobile gesture recognition. Optical gesture recognition has been introduced for gaming and will soon be launched for personal computer (PC) interaction, but optical gesture sensors are too large and power-hungry to be incorporated into tablets, smartphones, and smaller devices. The proposed 3D rangefinder uses an array of tiny piezoelectric ultrasound transducers which are built on a silicon wafer using microfabrication techniques. Custom electronics are used to control the transducers. In operation, the system emits sound into the air and receives echoes from objects in front of the transducer array. The system infers the location of the objects by measuring the time delay between transmission of the sound wave and reception of the echo. The system will be designed for incorporation into smartphones, tablets, and other mobile devices.
The broader impact/commercial potential of this project is to bring contextual awareness to everyday devices, which currently have very little idea about what is going on in the space around them. The proposed ultrasonic 3D rangefinder has the potential to be small and low-power enough to be left on continuously, giving the device a way to sense the physical objects surrounding it in the environment. While today's optical 3D ranging systems work across a small room and are capable of sufficient resolution, they are too large and power hungry to be integrated into battery-powered devices. Mobile contextual awareness will enable 3D interaction with smartphones and tablets, facilitating rich user interfaces for applications such as gaming and hands-free control in automobiles. Looking beyond the smartphone and tablet market, the proposed rangefinder would be well-suited for wearable devices that are too small or simply don't allow for a full-function touchscreen, such as head mounted displays and smart watches. These products currently have limited input options since the area available for buttons and touch-sensor inputs is only slightly larger than a finger. Ultrasonic contextual awareness has the potential to revolutionize the user interface for tiny consumer electronics.
This SBIR is aimed at developing a low-power ultrasonic gesture recognition chipset ready for integration into consumer devices. User interfaces are undergoing a revolution. The touchscreen has largely replaced the keypad in mobile devices. Low cost inertial sensors enabled a new generation of hands-on gaming with great success. 3D imagers such as the Microsoft Kinect have created a whole new type of gaming using gesture recognition, which allows a user to interact with a device through finger, hand, or body movements. This user interface technology is also expanding outside the gaming world into other common electronics such as PCs and a new generation of smart TVs. An area that has not yet seen a viable gesture recognition technology is mobile electronics, where strict power consumption and size requirements must be met. Chirp Microsystems builds ultrasonic rangefinders which work in a similar fashion to a bat's echolocation sense which the bat uses to navigate and hunt in a dark forest. Chirp's sensor emits a short sound at a pitch 10 times higher than humans can hear, and then times how long the echo takes to return. From the time of flight of the sound, the range to a target can be recorded. Multiple sensors allow the system to sense the 3D position of objects in the area around the sensor. Chirp’s ultrasonic 3D rangefinding technology enables gesture recognition in mobile devices and is well-positioned to take advantage of the large growth potential of this as-yet untapped market. During Phase I of this project, we achieved innovations in three areas: (1) sensor fabrication; (2) low power electronics to connect the sensor to a device; (3) building a 3D rangefinder prototype.
