Gadgetory

micro air vehicles capable of operating in constrained environments without the use of an external motion capture system are typically limited to slow and conservative flight as a consequence almost all of this research is done with rotorcraft in the hover regime in the robust robotics group in csail at MIT we've developed a fixed-wing vehicle capable of flying at high speeds through obstacles using only onboard sensors the vehicle is equipped with an inertial measurement unit and a laser range scanner all the computation for state estimation and control is done on board using an intel atom processor similar to what is found in a commercially available netbook we designed a custom airplane to carry the sensing and computation payload while still being able to maneuver in confined spaces our platform has a two-metre wingspan and weighs approximately 2 kilograms at any given time the laser can only see a two-dimensional picture of the environment laser scans are depicted with yellow points representing obstacles and blue representing free space even with a pre computed map individual 2d scans don't contain enough information to uniquely determine the 3d position velocity and orientation of the vehicle to overcome this difficulty we aggregate successive scans and combined laser information with the inertial measurement unit to perform state estimation another technical challenge is efficiently generating trajectories for the vehicle to follow the complicated vehicle dynamics create substantial computational difficulties in determining a path to fly from point A to point B to overcome this difficulty we use an approximate dynamics model that makes it easy to map the control inputs elevator rudder aileron and throttle to corresponding XYZ trajectories we start by connecting a set of high-level waypoints with line and arc segments we then use our approximate model to construct dynamically feasible paths by parameterizing an offset from this underlying trajectory here we demonstrate the accuracy and reliability of the system flying through a parking Raj in places the parking garage is less than 2.5 meters from floor to ceiling creating extremely tight tolerances for our 2 meter vehicle our algorithms allowed the vehicle to complete a 7 minute flight through the environment traveling at over 10 meters per second or 22 miles per hour covering almost 3 miles of distance and repeatedly coming within a few centimetres of obstacles