Mechanical and Civil Engineering Seminar

Multicopters are increasingly becoming part of our everyday lives, with current and future applications including delivery services, entertainment, and aerial sensing. These systems are expected to be safe and to have a high degree of autonomy -- this talk addresses three aspects thereof: failsafe strategies, fast trajectory generation, and state estimation.

The first part of the talk presents an actuator redundancy scheme for multicopters, allowing e.g. a quadrocopter to maintain controlled flight despite the complete failure of half its actuators. The related 'monospinner' will also be presented, which, with only one moving part, is potentially the world's mechanically simplest, controllable flying vehicle. Both the redundancy and the monospinner exploit coupling effects introduced when an asymmetric body rotates.

Then, a computationally light-weight strategy for generating quadrocopter motion primitives is presented. This trajectory generation can evaluate and compare on the order of one million motion primitives per second on a standard laptop computer. These motion primitives are designed to be fast to compute and verify (at the expense of optimality), while being flexible with respect to initial and final states. This allows to encode highly dynamic tasks with complicated end goals, such as catching a thrown ball.

The final part of the talk will present some work on state estimation, using ultra-wideband radios. These robust and light-weight radios can measure distances to one-another sufficiently accurately to act as distance beacons, and can serve as the basis for alternative localization systems.