  The controller for a quadrotor working in severe environment is developed in
this study. Here, the severe environment indicates the temperature-varying air
near the volcano. The controller overcomes the intensively changing temperature
above the crater of the volcano which biases the nominal dynamics (25 Celcius).
The target Volcano is picked as Satsuma-iojima located in a tiny insular South
to the mainland of Japan. The temperature distribution is contributed from
previous research by Geological Survey of Japan. To guarantee that the control
signal is under the input saturation, a path planning method is developed.
Picking the eigenvalue for a system with a moving reference is a novel topic;
the method to develop a controller with specific requirement is created for the
first time. This method might be referred as a standard way for
designers/engineers in developing controller with a moving target/reference in
further study. In controlling part, a state feedback controller is designed to
stabilize the height of the quadrotor. The eigenvalue of the feedback
controller is picked based on the method developed in Chapter Path Planning.
And a PID controller is designed to control the attitude. The result of these
are verified in a simulator written in MATLAB. At last, a Kalman filter is
applied in height control to combine the measurement noise from IMU and laser
scanner and the system noise caused by the changing temperature. Another reason
for developing a Kalman filter is that IMU readout provides with acceleration.
While the velocity is not achieved by sensor directly. The result of height
control with a Kalman filter is verified in MATLAB Simulink.
