Week 4 January 27- January 31

Tony3dr · February 4, 2020, 11:07pm

Dronecode Test Team, Week 4 Report

PX4 Autopilot Flight Testing, by the Dronecode Test Team. Sponsored by Dronecode.

Summary

17 flights ([Link to log archive]
5 PR’s assigned
0 issue reported this week.

Vehicle Status

GitHub Pull Requests (Assigned / Tested)

mc_rate_control: publish angular acceleration setpoint #14035
sensors: move accel filtering to sensors/vehicle_acceleration #14033
Position Control Refactoring Part 6 #14017
[WIP]Hover thrust estimator #13981
board config: timer config simplifications #13871

https://github.com/PX4/Firmware/pull/14017

github.com/PX4/PX4-Autopilot

Hover thrust estimator (#13981)

master ← pr-hover-ekf

opened 04:38PM - 19 Jan 20 UTC

bresch

+823 -0

**Describe problem solved by this pull request** The hover thrust is an importa…nt parameter of the vehicle that is used during flight for altitude control and to detect landing. It needs to be set manually by the user ([MPC_THR_HOVER](https://dev.px4.io/master/en/advanced/parameter_reference.html#MPC_THR_HOVER)), and can trigger a crash if wrongly set. Furthermore, this parameter is constant, but In reality, the real hover thrust is not: - The battery voltage decreases during the flight -> requires more throttle if RPM isn't controlled by the ESC - The mass can change (e.g.: cargo drones, crop sprayers, ...) Finally, some vehicles with many possible payloads can have a different hover thrust at almost every takeoff. **Describe your solution** Given the current thrust and the measured vertical acceleration, it is possible to observe the hover thrust. This is done in this PR using a simple single-state EKF. The model is described and simulated [here](https://github.com/Auterion/Flight_Control_Prototyping_Scripts/pull/3). **Describe possible alternatives** Some logic that tries to detect a hover to set the hover thrust as the current thrust. A higher order model **Test data / coverage** Current state: SITL tests, the estimator converges to the correct value. When changing the mass during hover, the estimate follows quickly. **Additional context** https://github.com/Auterion/Flight_Control_Prototyping_Scripts/pull/3 TODO: - [x] unit tests! - [x] log the state and main important values (variance, innov, test ratio, ...) - use the estimated hover thrust in PositionControl and the LandDetector _edit: this will be done later_ - [x] check dynamic response (up/down motions) - [x] use unfiltered acceleration (edit: I'm using the acceleration in local frame from EKF2 and it seems to work quite well) - ~add thrust to acceleration dynamic model (first order filter should be enough)~ _edit: not required, the performance is good enough_ - [x] make sure it doesn't update during the ground contact phase fixes https://github.com/PX4/Firmware/issues/12439

https://github.com/PX4/Firmware/pull/13871

Topic	Replies	Views
Week 3 January 20- January 24 Flight Testing & Log Analysis	414	January 27, 2020
Week 5 February 3- February 7 Flight Testing & Log Analysis	448	February 11, 2020
Week 44 December 2- December 6 Flight Testing & Log Analysis	423	December 9, 2019
Week 42 November 18 - November 22 Flight Testing & Log Analysis	472	November 25, 2019
Week 2 January 13- January 17 Flight Testing & Log Analysis	305	January 20, 2020

Week 4 January 27- January 31

Dronecode Test Team, Week 4 Report

Summary

Vehicle Status

GitHub Pull Requests (Assigned / Tested)

Issues reported: 0

Related topics