Project OLGA 1997 - 2000

At first sight, there is not much of a difference between this helicopter and the one used in 1996...

What has been done in the meantime?

• The onboard computer is a complete new design. Hardware and software have been customized to our needs regarding performance, real-time aspects, and interfaces.

• The onboard (electrical) power consumption has been reduced to 15 W, compared to 45 W beforehand.

• A substantial part of the I/O-handling is done using FPGAs (Field Programmable Gate Arrays), which gives the possibility of very fast reconfigurations.

• The software is written in Oberon SA. Oberon is a language developed at ETHZ; the compiler for the StrongArm chip has been contributed by Prof. N. Wirth.

• The navigation algorithms have been improved. The alignment phase is less critical than before due to additional states in the Kalman filter: the bias of the measured acceleration is estimated.

• Compared to the PD controllers used before, new multivariable designs (using H_inf methods) resulted in increased robustness of the closed loop.

• The trajectory to be flown may be defined in various ways: by predefined segments, by segments calculated on-line, or by using a "spaceball": kind of a joystick which measures forces and momentums

• Various environments have been developed for efficient data handling, identification, simulation, visualization, and trajectory generation.