Presentation given during ICRA 2013 to accompany the following paper: C. Papachristos, K. Alexis, A. Tzes “Model Predictive Hovering-Translation Control of an Unmanned Tri-TiltRotor”, IEEE International Conference on Robotics and Automation, ICRA 2013, Karlsruhe, Germany
1. University of Patras
Laboratory of
Automation & Robotics
ETH Zurich
Autonomous
Systems Lab
Christos Papachristos Kostas Alexis
University of Patras
Laboratory of
Automation & Robotics
Anthony Tzes
C. Papachristos, K. Alexis, A. Tzes
5. Rigid-Body Dynamics
Newton-Euler Formulation
Roll
Pitch
Yaw
Longitudinal
Lateral
Vertical
Actuation Subsystem Dynamics
–
Frequency Domain Identification
Augmented Linear Model around Hovering
Compact Representation of Rigid-Body + Actuator Dynamics
Generalized Hovering Operating Point
Actuators Control Inputs
Rigid-Body States (Rotation & Translation)
Actuator States (Rotors Thrust & Angles)
C. Papachristos, K. Alexis, A. Tzes
6. 1.6 GHz Atom MCU
Cortex-M3 ARM
100 Hz AHRS
Sonar
Optic Flow Camera
Rotor RPM Encoders
High-Update Rate ESCs
800 W Main Motors
High-Torque Servos
Ubuntu Linux OS
Matlab Real-Time
Workshop
OpenCV
Specifications
Software
Mechanical
CAD-based Design
C. Papachristos, K. Alexis, A. Tzes
7. State Estimation – Control Computation – Communications
Control Computation
AHRS
Measurements
Low-Level Interfacing
Almost Real-Time
Execution Control
Wireless
Communications
Vision - Optical Flow
Camera Model-based
Rotation-Compensated
Translational States Estimation
Optical Flow + IMU
C. Papachristos, K. Alexis, A. Tzes
8. Attitude Controller: Gain-Scheduled P-D-dD
Roll Tracking Response
&
FD-Identified Closed-Loop Roll Model
Translation Controller: Constrained Model Predictive Control
State, State setpoint
Control Input Move Input, Input
Setpoint
Gain Scheduling provides
Improved Tracking Response
Without Violating Constraints:
State & Control Input Constraints
accounting for limitations based on
dynamics & mechanical limitations
of the UAV (i.e. Adverse Reaction
Moment during Rotor-Tilting)
C. Papachristos, K. Alexis, A. Tzes
10. Hovering Setpoint
Go-and-Return
Maneuvers
Z – step
Y – step
X – step
By employing Rotor-
Tilting
Faster Longitudinal
Dynamics
are Achieved
Video Results corresponding to Illustrated Datasets
C. Papachristos, K. Alexis, A. Tzes
11. Current Work: Exploitation of Yet-Unexplored Capabilities of Reconfigurable UAVs
Mock-Up: Desired UAV Path: Heavy Obstacle Blocking Doorway Entrance
Rotor-Tilting
gives
Full Longitudinal
Actuation
C. Papachristos, K. Alexis, A. Tzes
Push
Heavy Obstacle
(5kg)
Aside