Aerial robots

Mobile Robotics – Aerial Robots

Beginning fall 2008, the Mobile Robotics group at MCS lab explores aerial robotics with a first project on tracking SMAVs (small and micro aerial vehicles) in space.

Motivation: Autonomy for SMAVs becomes challenging since they are too small and lightweight to incorporate onboard sensors. It is true that technology is currently evolving to enable autonomous flight at small scales with miniature cameras, microelectronics, and lightweight advanced sensors based on micro-electromechanical systems (MEMS). However, their performance is not yet optimal: miniature accelerometers and gyroscopes are still highly sensitive to electromagnetic noise, especially when they are very close to the SMAV’s electric motors. Miniature cameras provide poor quality images due to the radio interference and vibrations in the SMAV. Independently of their performance, SMAVs have always a limited payload and autonomy is usually engaged in trade-offs.

Objective: A no-onboard-sensor approach that allows autonomous flight.

Solution: Fig. 1 shows the proposed solution. This platform consists of a Wii remote (Wiimote) controller and a video camera that track the 6 DoF motion of a SMAV. The combination of the Wiimote’s and video camera fields of view creates a virtual cube in which motion can be fully monitored (Fig. 2). This controlled space allows a vehicle to navigate autonomously with no onboard sensors. The Wiimote is responsible for tracking the 3 dimensional position (X, Y, Z) of the vehicle while the video camera is responsible for the vehicle’s orientation (pitch, roll, and yaw). The 6 coordinates obtained from both sensors are sent to a computer where they are compared to a target position. Position processing and correction are also carried out in the computer. Resulting commands are conditioned by an FPGA and sent to the vehicle via a radio transmitter.

Fig. 1: 6 DoF motion tracking platform for SMAVs with a Wiimote and a video camera.

Fig. 2: Virtual cube: total workspace combining a Wiimote and a video camera.

Contact: Héctor Vargas, Enrique Preza and Ramiro Velázquez