Stanford’s Biomimetics and Dexterous Manipulation Laboratory has developed another first: a quadrotor robot that can fly, climb, perch, and push off of objects.
Stanford Climbing and Aerial Maneuvering Platform, or SCAMP, leverages onboard sensors and computation to effectively maneuver on outdoor surfaces like brick or concrete.
Though it might not seem like it, SCAMP’s ability to perch is significant. The function allows the robot to roost on an object as long as necessary without wasting power, something that is of great concern when dealing with quadcopters. This would come in handy especially for long reconnaissance or data gathering missions.
SCAMP performs its perch by flying into a surface, with its tail making first contact. As soon as that contact is made—the impact with the surface sensed by accelerometers— the robot cranks up the power of its rotors. SCAMP’s tail plays the role of a swivel, as its body swings toward to the structure, attaching to it aerodynamically. Once the device finds its footing—through the help of rotors—the mission to perch is complete.
If the person operating SCAMP can’t land the robot exactly where they intended it to end up on a surface, its crawling skills can get it to that select spot. SCAMP’S climbing function involves its two feet, which alternate the responsibility of holding the load of the platform with each step. While one foot is completely gripped to the surface, the other grinds across it until it completes the step, at which point the foot that was completely affixed to the surface begins to drag.
Since different surfaces have a different feel—think glass compared to concrete—the lab gave SCAMP a climbing mechanism that ascents well up a variety of surfaces.
“The end result is a climbing mechanism that uses one high torque-density servo to drive long steps up the wall, and one even smaller servo to actuate motion towards and away from the wall,” described Morgan Pope, a Ph.D candidate in mechanical engineering at Stanford and a member of the lab, in an article he authored for the Institute of Electrical and Electronics Engineers.
Considering all of the elements that SCAMP might be crawling in, like rain or heavy wind, and the differences in surface texture, a misstep might occur from time to time during the crawl process. To rectify this mistake, onboard accelerometers detect when the robot missteps, and its rotors kick in to nudge SCAMP back toward the surface it had been climbing.
When it’s time for SCAMP to fly again, its two servos are moved so that a “takeoff spine” can be arranged. The load from the foot affixed to the surface is transferred to the spine, which impels SCAMP from that surface. As SCAMP is falling away from the surface, the rotors will begin to roll to levels they need to be at for flight.
[Via IEEE and Stanford’s Biomimetics and Dexterous Manipulation Lab]