Week 3 January 20- January 24

Tony3dr · January 27, 2020, 5:50pm

Dronecode Test Team, Week 3 Report

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

Summary

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

Vehicle Status

GitHub Pull Requests (Assigned / Tested)

[DO NOT MERGE] IMU clipping testing #13837
navigator: add position setpoint reset helper with safe defaults #13969
sensors/vehicle_imu: incremental step towards multi-EKF #14004
[WIP]Hover thrust estimator #13981
[WIP] accel and gyro calibration loading cleanup #13446

https://github.com/PX4/Firmware/pull/13969#event-2970273221

github.com/PX4/PX4-Autopilot

sensors/vehicle_imu: incremental step towards multi-EKF (#14004#event-2969159333)

master ← pr-sensors__vehicle_imu

opened 01:26AM - 22 Jan 20 UTC

dagar

+611 -79

One of the missing pieces for running multiple estimators (an instance per IMU o…r more) is the current sensors module only provides the voted primary IMU message (sensor_combined). This pull request updates the sensors module to additionally launch a WorkItem per IMU (accel + gyro pair) that handles collecting the data, applying any corrections (thermal), board rotation (including level), then published as an instance of `vehicle_imu`. The ekf2 module has been updated to optionally subscribe to a specific `vehicle_imu` set by the parameter `EKF2_IMU_ID`, or continue using `sensor_combined`. The structure of this change is a bit weird, but it will enable further multi-ekf development and testing while the sensors module is refactored. ### Next steps 1. update ModuleBase to enable multiple instances of certain modules - https://github.com/PX4/Firmware/pull/12191 - update ekf2 to launch a configured number of instances - in multi-instance mode publish all messages to estimator_X_n equivalents 2. create ekf2_selector to subscribe to all estimators messages, select best, and republish system vehicle_local_position, vehicle_global_position, vehicle_attitude, and handle resets, jumps between estimators, etc 3. (optional) parameter instances, each EKF instance should have it's own set of parameters with minimal overhead. 4. (investigating) move actual IMU integration work to `VehicleIMU` WorkItems and run in a WQ thread per EKF 5. (investigating) various improvements to ensure each "IMU" consists of synchronized accel + gyro data - pair up accel + gyro from same physical device. In many cases we only need a single device id per IMU (mpu6000, icm20602, etc). - sensors that provide accel + gyro simultaneous could instead publish a `sensor_imu` message rather than rely on reassembling sensor_accel + sensor_gyro downstream ``` Console nsh> listener vehicle_imu TOPIC: vehicle_imu 2 instances Instance 0: vehicle_imu_s timestamp: 1218855875 (0.003490 seconds ago) timestamp_sample: 1218852526 accel_device_id: 3607306 gyro_device_id: 3672842 delta_angle: [0.0000, 0.0001, 0.0000] delta_velocity: [0.0001, -0.0001, -0.0393] dt: 3999 integral_samples: 4 integral_clip_count: 0 Instance 1: vehicle_imu_s timestamp: 1218868690 (0.002584 seconds ago) timestamp_sample: 1218865207 accel_device_id: 1442826 gyro_device_id: 2360330 delta_angle: [-0.0000, 0.0000, 0.0001] delta_velocity: [0.0008, 0.0013, -0.0400] dt: 3999 integral_samples: 4 integral_clip_count: 0 ```

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/13446#event-2978179123

Topic	Replies	Views
Week 4 January 27- January 31 Flight Testing & Log Analysis	421	February 4, 2020
Week 5 February 3- February 7 Flight Testing & Log Analysis	447	February 11, 2020
Week 1 January 6- January 10 Flight Testing & Log Analysis	382	January 13, 2020
Week 2 January 13- January 17 Flight Testing & Log Analysis	304	January 20, 2020
Week 42 November 18 - November 22 Flight Testing & Log Analysis	470	November 25, 2019

Week 3 January 20- January 24

Dronecode Test Team, Week 3 Report

Summary

Vehicle Status

GitHub Pull Requests (Assigned / Tested)

Issues reported: 0

Related topics