Wednesday, August 26, 2009

New Quanser Quadrotor UAV

Last week we had some very exciting flight tests as our brand new Quanser Quadrotor UAV underwent some untethered flight tests and passed with flying colours. The design of our quadrotor is unique as the entire mechanism is enclosed within a protective carbon fiber cage (Patent Pending). Quanser's proprietary design ensures safe operation as well as opens the possibilities for a variety of novel applications. When seen for the first time the Quanser Quadrotor appears as a flying sphere. The cage is a crucial feature when you consider the potential consequences of flying multiple vehicles in close formation or in close quarters such as indoor laboratories. The carbon fiber frame provides protection against collision damage and if the helicopter should become unstable and fall to the ground, it will simply roll on its cage keeping the helicopter assembly safe.

The vehicle uses four 10-inch propellers and standard RC motors and speed controllers. The real brains of the vehicle lies in the Quanser Embedded Control Module (QECM), which is comprised of a Quanser HiQ Aero data acquisition card and a QuaRC-powered Gumstix embedded computer. The Quanser HiQ provides high-resolution accelerometer, gyroscope, and magnetometer IMU sensors as well as servo outputs to drive the motors. In addition to the high-resolution IMU sensors, the HiQ has 4 sonar inputs, 2 pressure sensors, a serial GPS input, analog inputs, and a USB camera input. The on-board Gumstix computer runs QuaRC (Quanser's realtime control software), which allows us to rapidly develop and deploy controllers designed in MATLAB Simulink. The controllers run on-board the vehicle itself and runtime sensors measurement, data logging and parameter tuning is supported between the host PC and the target vehicle.

The video below shows one of our recent flight tests. The quadrotor is flown with a human-in-the-loop and a stabilizing controller. The HiQ sensors are used in a stabilizing controller, which is needed to keep the vehicle stable during flight. The entire controller is designed in Simulink including the joystick used to fly the vehicle. As we fly the vehicle, sensor data is streamed back to the host PC so we can monitor everything from vehicle sensors to controller performance. We can tune our filters and controller parameters remotely from the host PC during flight and immediately see the changes in vehicle stability and responsiveness. Finally, when we are confident that our controller is sufficiently robust, we add disturbances to the vehicle and watch that it maintains stability (i.e., it doesn't crash!).

This vehicle was extremely challenging and fun to develop. Look for more on the Quanser Quadrotor in future posts and on our website!



Prashant said...

Hi Cameron. This is very impressive indeed! I like the idea of surrounding the quadrotor with a crystal lattice-like structure to prevent damage to the surroundings. Which GPS module do you use when operating outdoors? Is it the uBlox 5 by any chance?

Anonymous said...

Hello,i am really interested in what u guys were doing.Quad rotor flying untethered?that is totally impressive.I am currently doing a research on the same manner.However, i can't seem to find a resource on simulation in MATLAB.Do u mind helping me??

Cameron Fulford, Manager Control Systems Group, Quanser said...

Simulink is a great tool for simulation. The Qball comes with MATLAB Simulink models both for flying the vehicle and also for simulating the vehicle dynamics during a mission.