Sensor systems; wireless power; sensing for robotics; ubiquitous computing; personal robotics
The Free-range Resonant Electrical Energy Delivery (FREE-D) wireless power system uses magnetically coupled resonators to efficiently transfer power across meter distances to an artificial heart, specifically a ventricular assist device (VAD) implanted in the human body. Previously, artificial heart pumps recieved power from a wire through the chest, limiting patient quality of life. The FREE-D system will cut down on cardiac patients' dangerous infections and improve quality of life.
WREL enables transfer of large amounts of power (up to 50W) over medium distances (1m, depending on coil size). Our key contribution is the development of adaptive tuning techniques that enable high efficiency power transfer, even as transmit-receive range, orientation, or load vary. With most wireless power systems, the farther the receiver is from the transmitter, the less power can be transferred. The WREL system has a "magic regime" in which efficiency does not fall with distance. We are currently working to power implanted medical devices using these techniques.
Hobbes is our PR2 Robot, from Willow Garage. It is a very capable mobile manipulation platform that allows us to test our newly developed technologies in a complete, fully functional robotic system, without having to build everything from scratch.
WISP, the Wireless Identification and Sensing Platform, is a family of sensors that are powered and read by UHF RFID readers. WISPs do not require batteries since they harvest their power from the RF signal generated by the reader. The WISP is an open source, open architecture EPC Class 1 Generation 2 RFID tag that includes a fully programmable 16 bit microcontroller as well as arbitrary sensors. Unlike the WISP, conventional RFID tags are black boxes that cannot execute arbitrary computer programs and do not support sensors. We have given WISPs to collaborators around the world.
Seashell Effect Pre-Touch Sensing is a new form of sensing used to help robots sense the shape and material of objects before they grasp. ''Pretouch'' refers to sensing modalities that are intermediate in range between tactile sensing and vision. The novel pretouch technique is effective on materials for which prior pretouch techniques fail. Seashell effect pretouch is inspired by the phenomenon of ''hearing the sea'' when a seashell is held to the ear and relies on the observation that the ''sound of the sea'' changes as the distance from the seashell to the head varies.
RF signals, such as TV broadcasts that used to be considered information-only, can now be treated as a power source, thanks to the continual improvements in the energy efficiency of microelectronics, a consequence of Moore's law. The image on the left shows a kitchen thermometer, with LCD display, being powered by RF signals from a TV tower 4km away. We have also developed a newer WARP sensor node that measures light level and received power and transmits the data on a short range (Zigbee-like) radio.
In 2006, our group became one of the first to demonstrate the control of a humanoid robot using a non-invasive brain computer interface (BCI). The system consists of a robot, an electrode cap for sensing brainwaves, and a graphical user interface for controlling the robot remotely. Our original research demonstrated that the BCI can be used to command a HOAP-2 humanoid robot to select and fetch desired objects from remote locations. We have more recently proposed a framework for adaptive hierarchical brain-computer interfacing that allows the user to teach a robot new behaviors on-the-fly.
The Sensor Systems Lab is working with the UW Applied Physics Lab on underwater wireless power transfer and communication. We are collaborating with David Dyer and Bob Michimoto to transmit power wirelessly via WREL at 1000m depths beneath sea-level to charge power base stations. Tests have shown that the power transmission gain decreases in seawater compared to air and even to fresh water. However, by modifying coil size and various parameters, this loss can be minimized.
Our mobile manipulation plaform, Marvin (developed while we were at Intel Labs Seattle), feeds itself by "smelling" its food, electricity. Marvin can detect the 60Hz emissions from ordinary unmodified electrical outlets and align its plug with the socket using just this signal -- computer vision is not used. This technique is fast, inexpensive, and lighting-independant: it works even in complete darkness!
We are investigating strategies for robot interaction with piles of objects and materials in cluttered scenes. In particular, interaction with unstructured sets of objects will allow a robot to explore and manipulate novel items in order to perform useful tasks, such as counting, arranging, or sorting even without having a prior model of the objects.