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pjrambo / VINS-Fusion-gpu

This repository is a version of VINS-Fusion with gpu acceleration. It can run on the Nvidia TX2 in realtime
GNU General Public License v3.0
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IMU noise values #13

Closed mmp52 closed 4 years ago

mmp52 commented 4 years ago

Hello,

What are the units of the white noise and random walk noise values that we should enter in the configuration file and how are they implemented correct the IMU measurements in this algorithm?

Thank you, Metin

tianxinyu0509 commented 4 years ago

@mmp52 Dear friend, I have used imu_utils to calibrate the imu noise, and my result file is as follows: %YAML:1.0 type: IMU name: imu2 Gyr: unit: " rad/s" avg-axis: gyr_n: 4.1189587602879753e-02 gyr_w: 1.6054253990019963e-03 x-axis: gyr_n: 3.8975737957935651e-02 gyr_w: 6.0272505562839460e-04 y-axis: gyr_n: 4.8037327855181083e-02 gyr_w: 2.8522800225796153e-03 z-axis: gyr_n: 3.6555696995522510e-02 gyr_w: 1.3612711187979793e-03 Acc: unit: " m/s^2" avg-axis: acc_n: 1.6350417082535498e-02 acc_w: 2.9525380783174891e-04 x-axis: acc_n: 1.6870862701912053e-02 acc_w: 2.8715983372116290e-04 y-axis: acc_n: 1.7901894586820004e-02 acc_w: 1.7848223656850905e-04 z-axis: acc_n: 1.4278493958874441e-02 acc_w: 4.2011935320557475e-04

It has the same name as the parameters in VINS. acc_n: 0.1 # accelerometer measurement noise standard deviation. gyr_n: 0.01 # gyroscope measurement noise standard deviation. acc_w: 0.001 # accelerometer bias random work noise standard deviation. gyr_w: 0.0001 So, I guess it is unit: " rad/s", unit: " m/s^2".

mmp52 commented 4 years ago

@tianxinyu0509 thank you for your answer

mmp52 commented 4 years ago

@tianxinyu0509 Thank you for your suggestion of imu_utils, I also have a question on it at here, about using an imu in 50 hz (rather than 200). Also I will use kalibr to justify my transformation matrix, right after finishing calibrating intrinsic parameters of my IMU with imu_utils. One final thing, did you record IMU for 2 hours or less, do you think recording it for 30 minutes will be enough?

tianxinyu0509 commented 4 years ago

@mmp52 Imu_utils says it takes 2 hours, so it's better to leave it there for 2 hours.Half an hour might be fine, but you'll need to change the time in the launch file to 30 minutes.