Euler Angles for Aircraft Autopilot and Autonomous Control

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Euler Angles for Aircraft Autopilot and
Autonomous Control (Prof. Hedricks lab)
Body-fixed axes (attached to aircraft)
t2
t1
t3
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3-2-1 Euler Axes Commonly Used for Aircraft
(roll)
(pitch)
North
t2
t1
t1
t2
t1
East
t3
t3
t3
t3
(yaw)
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Piccolo autopilot system (gyroscopes,
acceleromoters, internal MPC555 processor, etc.)
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Why Do We Care About Euler Angles?

• Attitude estimation is ESSENTIAL for flight
  control, either for a pilot or autopilot
  controller
• Sensing applications Attitude estimation tells
  us what direction our sensor are pointed

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Aircraft Flight Control Autopilot Mounting
Orientation
Q
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Aircraft Flight Control Autopilot Control Loops

• Control on Turn Rate
• Purpose To direct the heading of a vehicle. That
  is, want
• Control Algorithm
• Find the necessary bank angle to achieve the
  desired turn rate under level flight assumptions
  (this is a ME104 problem)
• 2) We must estimate the bank angle of the
  aircraft via integrating the gyro signals as well
  as using the GPS
• 3) Actuate aileron to achieve the desired
  estimate of the bank angle

Picture credit wikipedia and aerospace.web
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Aircraft Flight Control Autopilot Control Loops

• Control on Pitch Damper
• Purpose To maintain a level flight by dampening
  the phugoid mode of the aircraft
• Control Algorithm
• Estimate the pitch angle.
• 2) Actuate the elevator to maintain zero pitch
  angle thus achieving level flight.
• Recall that the turn rate controller assumes a
  level flight condition

Picture credit wikipedia and www.centennialofflig
ht.gov
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Sensing Applications Computer Vision and Tracking
Image coordinates
Transform image coordinates to absolute
coordinates (GPS)
Onboard video detects river
Attitude estimate
Mapping application
River location
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Piccolo Autopilot Sensor and Control Structure
Desired yaw rate Desired Altitude
Altitude Air speed
Thermometer
Bernoullis equations
Pressure sensors (static/dynamic)
Nested PID control loops
Actuator Commands
Accelerometers
Basis transformation, Filtering, and
numeric integration
Gyroscopes
Euler angles rates Position, velocity,
acceleration
GPS receiver
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Details of Euler Angle Estimation
GPS (Lat, Lon)
More estimation and filtering
Autopilot (nested PID loops)
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Questions?
(Or visit us in 2162 Etch.)