A team of researchers at the University of Zurich, has developed a highly agile quadrotor drone that is able to avoid obstacles and carry out trajectory tracking. In their paper published in the journal Science Robotics, the group describes how they designed their drone, what they put into it and how well it worked when tested. Quadrotor drones can be very agile fliers, most particularly when they have a human pilot guiding their movements. Autonomous quadrotors, on the other hand, have suffered from agility issues, particularly when traveling at high speeds. In this new effort, the team in Switzerland has improved the agility of a quadrotor drone with their new design built using a variety of technologies.