quadrotor/motor_lag

A scenario of the Quadrotor model, from tools/trace/scenarios/quadrotor/motor_lag.hpp.

✓ pass

• The clang run (clang 18.1 optimized) matches the committed trace.
• The gcc run (gcc 13.3 optimized) matches the committed trace.

Shown on

These players show the same trace, with panels chosen to explain it:

• How quickly does a rotor follow its command? (How the Quadrotor Model Works)

Every channel

quadrotor/motor_lag: every channel 1× real time

World: z up · Body: x forward, y left, z up
Rotors (PX4 Quad X): 0 FR, 1 RL spin CCW · 2 FL, 3 RR spin CW

Thrust arrows: 1 N = 4 cm · Grid: 0.5 m · Body axes: x red, y green, z blue

Chase Behind Overview

position [m] x y z

velocity [m/s] x y z

rotor_speeds [rad/s] rotor 1 rotor 2 rotor 3 rotor 4 dashed: command

rotor_thrusts [N] rotor 1 rotor 2 rotor 3 rotor 4

total_thrust [N] total_thrust

t = 0.000 s / 0.400 s

Keys (with the player focused): Space play/pause · ← → one sample (Shift: ten) · Home/End · [ ] speed

0.4 s of the model/quadrotor scenario motor_lag.hpp, 201 samples every 0.002 s. The panels plot every channel that changes: position, velocity, rotor_speeds, rotor_thrusts, total_thrust, with setpoints dashed. 3 events are marked. Pass criteria: BB-V1 rotor_speed_error_vs_closed_form_max <= 0.0001 rad/s.

1. t = 0.050 s command +10 % on every rotor
2. t = 0.070 s one time constant later: 63 % of the step
3. t = 0.250 s command back to the hover speed

• ✓ passBB-V1 rotor_speed_error_vs_closed_form_max = 3.32e-6 rad/s (<= 1.00e-4), computed by the scenario harness

Block model/quadrotorScenario tools/trace/scenarios/quadrotor/motor_lag.hppSeed 0dt_sim 0.001 s · dt_trace 0.002 sgcc 13.3 optimizedGenerated at 2183adcFormat reflex-trace/1, checked by CI against a fresh run

Constant over the run

• attitude = [1, 0, 0, 0]
• body_rates = [0, 0, 0] rad/s
• roll_pitch_yaw = [0, 0, 0] rad
• weight = 9.807 N

All scenarios