px4adrc

ROS2 PX4 quadrotor controller package using a dual-loop ADRC structure and direct motor actuation.

Features

• PX4-native NED and FRD control path
• Position loop driven by /fmu/out/vehicle_local_position
• Attitude state from /fmu/out/vehicle_attitude
• Attitude loop driven by /fmu/out/vehicle_angular_velocity
• Fixed Quad-X motor order for PX4 direct_actuator mode
• Per-motor thrust mapped to throttle using PX4 THR_MDL_FAC
• Continuous offboard requests after node startup
• Manual arm required before automatic takeoff
• Package-local FlatTrajectoryReference message and trajectory publisher

Motor Order

The controller uses this fixed PX4 direct-actuator order:

1. front-right, CCW
2. back-left, CCW
3. front-left, CW
4. back-right, CW

No runtime motor_output_map parameter is kept.

Flight Flow

1. Start the node.
2. The node continuously requests PX4 offboard mode.
3. Manually arm the vehicle.
4. The node performs automatic takeoff to the configured height.
5. After takeoff hold, the node publishes start_tracking=true on /mission/start_tracking.
6. The trajectory publisher starts emitting /px4adrc/reference.
7. The controller switches to tracking when a fresh reference arrives.

State Inputs

• /fmu/out/vehicle_local_position
• /fmu/out/vehicle_attitude
• /fmu/out/vehicle_angular_velocity
• /fmu/out/vehicle_status_v1

The controller requires valid vehicle_local_position XY/Z and VXY/VZ estimates before running control.

Reference Contract

• position_ned, velocity_ned, acceleration_ned, jerk_ned, snap_ned: PX4 world frame NED
• yaw, yaw_rate, yaw_acceleration: desired heading and heading derivatives in NED

Controller Parameters

Controller tuning lives in config/px4adrc.yaml:

• position_adrc.td_r
• position_adrc.eso_beta1/beta2/beta3/b0
• position_adrc.nlsef_k1/k2/alpha1/alpha2/delta
• attitude_adrc.attitude_eso_beta1/beta2/beta3/b0
• attitude_adrc.attitude_nlsef_k1/k2/alpha1/alpha2/delta

Notes

The node publishes both /fmu/in/actuator_motors and /fmu/in/vehicle_thrust_setpoint when using direct_actuator.