Recently quadrotors have gained a lot of interest in research use for various reasons.
A quadrotor is a hovercraft that is lifted and propelled by four motors/propellers. Unlike regular helicopters, quadrotors do not require mechanically complicated variable-pitch mechanisms for their rotors. Instead, they use fixed-pitch propellers and therefore have only a minimum number of moving parts.

Stabilizing control of a quadrotor is achieved by varying the angular velocities of the rotors in accordance with an onboard control algorithm, creating thrust/torque and moving/rotating the quadrotor platform in the desired way. An inertial measurement unit (IMU) onboard the aircraft gives information about the quadrotor’s system states. Sensor data is fed into an attitude estimation algorithm to give accurate real-time attitude information.

Our quadrotor project started with a full-size quadrotor for outdoor use. We chose a processor platform based on the Arduino standard for implementation on our quadrotors. This ensures broad software and hardware support, easy implementation and low costs. We then designed miniature quadrotor airframes specifically for indoor lab use. Two identical airframes were completed and flight tested.

This design was reviewed and modified to provide an airframe that is both easier to manufacture, modular and that can stand up to the rigors of algorithm testing.

Parallel to flight testing, a six degree of freedom quadrotor simulator has been programmed in Matlab/Simulink. Parameters are chosen to exactly emulate the real system’s performance and can be used for controller tuning. Additionally, a quadrotor flying laboratory was established at the University of Illinois over the summer of 2011. A 24-camera motion capture system enables full three-dimensional motion tracking of several ground and air vehicles simultaneously. 

This research has the following objectives:

  • Implement robust and fault-tolerant control to deal with sensor and actuator failures without a complete loss of the aircraft
  • Test suitable outer-loop guidance algorithms for the position control of quadrotors
  • Test different approaches to quadrotor control to allow a simpler, more intuitive flight experience to untrained, beginning users

 

Contact:

Naira Hovakimyan
Jan Vervoorst
nhovakim (at) illinois (dot) edu
vervoors (at) illinois (dot) edu