High-level manager nodes within the MRS

ControlManager

• integrates the control and tracking part of the MRS UAV pipeline
• dynamically loads feedback controllers and reference trackers plugins
• subscribes to the estimated UAV state and provides it to all loaded trackers and controllers
• runs the iteration of the currently active controller and tracker with every received state estimator message
• outputs the attitude control command to the HW API
• provides constraints to trackers through a common interface
• allows in-mid-air switching of feedback controllers and reference trackers
• provides common services for
  • setting a reference
  • setting a trajectory reference
  • human-callable goto, goto relative, goto altitude, set heading and set relative heading
  • hover
  • emergency hover after which most of the provided services are disabled
  • emergency landing - switches to emergency controller and tracker and lands as fast as possible
  • failsafe landing - feedforward landing, only effective in small heights and low speeds
  • escalating failsafe - the measures escalate when calling it repeatedly
    1. emergency hover
    2. emergency landing
    3. failsafe landing
    4. disarm
  • transforming references and vectors between frames
  • verifying that references are inside of the allowed safety area
• provides safety routines for checking
  • position control error
  • tilt control error
  • yaw control error
  • estimator innovation error
  • missing estimator data
  • the validity of desired references
• allows controlling the UAV using a ROS-compatible joystick
• allows controlling the UAV using RC through our pipeline
  • the RC channels are picked up from HW API
  • a relative reference is generated for the active tracker
  • escalating failsafe can be triggered by a dedicated switch
• provides an obstacle bumper feature
  • has priority over user-provided references
  • for slow-flight only

UavManager

• handles takeoff from the high-level
  • checks for pre-condition which might result in takeoff failure
  • switches to the right tracker and controller for the takeoff
  • triggers takeoff
  • switches to the right tracker and controller after the takeoff
• handles a regular landing from the high-level
  • descends to a landing height (~2.0 m) using the currently active tracker and controller, given the current constraints
  • switches to the right tracker and controller for the landing
  • triggers the landing
  • monitors the thrust output and decides when the UAV touched the ground
• provides a land home feature
  • the UAV flies in the current altitude to its takeoff location and lands
• provides a land there feature
  • the UAV flies to the desired position at which it lands
• monitors exceeding the maximum altitude
  • triggers a priority descend if it exceeds the safety area ceiling
• monitors exceeding the maximum thrust
  • triggers a landing if it exceeds a limit
• provides a flight timer
  • triggers a landing if it exceeds a limit

ConstraintManager

• stores and provides sets of dynamics constraints for the trackers
• allows mapping each set of constraints to only some state estimators
• automatically switches to a fallback set of constraints if the current ones are not allowed
• provides a service for switching to a desired set of constraints

GainManager

• stores and provides sets of gains for the Se3Controller
• allows mapping each set of gains to only some state estimators
• automatically switches to a fallback set of gains if the current ones are not allowed
• provides a service for switching to a desired set of gains

EstimationManager

• provides the state estimation of the UAV
• dynamically loads default state estimator or custom user-made plugins
• publishes following topics:
  • the uav_state topic that is used for feedback control in ControlManager
    • velocities in uav_state are in the headed/frame_id frame!!
  • visualizable odom topic
    • velocities in odom are in the child_frame_id frame!! (follows the ROS convention for nav_msgs/Odometry msg)
  • current UAV height above terrain on topic height_agl (if available)
  • maximum height above terrain that the UAV can fly in (based on the current estimator used for control)
• provides common services for
  • switching of state estimator currently used in control feedback
• checks health of current state estimator and switches to a healthy one in case current estimator becomes unhealthy
• if no estimator is healthy, calls failsafe landing

TransformManager

• provides the following default TFs from the fcu frame (can be turned off/on or renamed by custom configs):
  • fcu_untilted_origin, world_origin, local_origin, stable_origin, fixed_origin, utm_origin, mapping_origin_tf (if a SLAM algorithm is running)
• publishes the delay of odometry produced by a SLAM algorithm (if available) on topic map_delay
• additionally can provide custom TFs from nav_msgs/Odometry topics by adding them to the tf_sources array in custom config
  • the msg can also be republished in another frame by adding the frame_id to the republish_in_frames array