Navigation Functionalities for an Autonomous UAV Helicopter

Chapter 3
Simulation
3.1 Introduction
This chapter describes the simulation tool which has been used to develop
and test the control system for the RMAX helicopter. It is used to test the
helicopter missions both in the lab and on the field. The RMAX helicopter
simulator is implemented in the C language and allows testing of all the
control modes developed. Many flight-test hours have been avoided due
to the possibility of running, in simulation, the exact code of the control
system which is executed on the on-board computer during the actual flighttest.
In order to develop and test the helicopter control system a mathematical
model which represents the dynamic behavior of the helicopter
is required. The simulator described in this section is specialized for the
Yamaha RMAX helicopter in the sense that the model includes the dynamics
of the bare platform in addition to the Yamaha Attitude Control
System (YACS).
The YACS system stabilizes the pitch and roll angles of the helicopter,
the yaw rate and the vertical velocity. The reason why the YACS has been
used was to speed up the control development process and to shift the
focus toward development of functionalities such as the PFCM presented
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