{ "id": 332395, "title": "What is IMU data?", "url": "/competitions/smartphone-decimeter-2022/discussion/332395", "author_name": "", "post_date": "2022-06-21T13:47:11.185723Z", "votes": 3, "comment_count": 4, "views": 0, "content": "

In the data section,

\n
\n

[train/test]/[drive_id]/[phone_name]/device_imu.csv - Readings the phone's accelerometer, gyroscope, and magnetometer.
\n MessageType - which of the three instruments the row's data is from.
\n utcTimeMillis - The sum of elapsedRealtimeNanos below and the estimated device boot time at UTC, after a recent NTP (Network Time Protocol) sync.
\n Measurement[X/Y/Z] - [x/y/z]_uncalib without bias compensation.
\n Bias[X/Y/Z]MicroT - Estimated [x/y/z]_bias. Null in datasets collected in earlier dates.

\n
\n\n

It would be helpful if someone could tell me.

", "messages": [ { "id": "1828103", "postDate": "06/21/2022 13:47:11", "content": "

In the data section,

\n
\n

[train/test]/[drive_id]/[phone_name]/device_imu.csv - Readings the phone's accelerometer, gyroscope, and magnetometer.
\n MessageType - which of the three instruments the row's data is from.
\n utcTimeMillis - The sum of elapsedRealtimeNanos below and the estimated device boot time at UTC, after a recent NTP (Network Time Protocol) sync.
\n Measurement[X/Y/Z] - [x/y/z]_uncalib without bias compensation.
\n Bias[X/Y/Z]MicroT - Estimated [x/y/z]_bias. Null in datasets collected in earlier dates.

\n
\n\n

It would be helpful if someone could tell me.

", "rawMarkdown": "In the data section,\n> [train/test]/[drive_id]/[phone_name]/device_imu.csv - Readings the phone's accelerometer, gyroscope, and magnetometer.\n> MessageType - which of the three instruments the row's data is from.\n> utcTimeMillis - The sum of elapsedRealtimeNanos below and the estimated device boot time at UTC, after a recent NTP (Network Time Protocol) sync.\n> Measurement[X/Y/Z] - [x/y/z]_uncalib without bias compensation.\n> Bias[X/Y/Z]MicroT - Estimated [x/y/z]_bias. Null in datasets collected in earlier dates.\n\n- MessageType\nThis column contain \"UncalAccel\", \"UncalGyro\" and \"UncalMag\". So this is corresponds to each device.\n\n- Measurement[X/Y/Z]\nWhat does this column mean?　If it is an accelerometer value, what is the unit?　Please tell me where to refer.\n\n- Bias[X/Y/Z]MicroT\nWhat does this column mean?　What is \"Bias\"? \n\nIt would be helpful if someone could tell me.", "votes": null }, { "id": "1828827", "postDate": "06/22/2022 04:45:15", "content": "

Thank you for posting this topic.

\n

I am also trying to find out more about imu, but I am struggling to calculate the Euler angles.

\n

So far I am aware of the following
\nUnits are [m/s^2] for acceleration [rad/s] for angular velocity
\nGeomagnetic field is [μT].
\nhttps://developer.android.com/guide/topics/sensors/sensors_motion
\nhttps://developer.android.com/guide/topics/sensors/sensors_position#sensors-pos-orient

\n

Also, the XYZ coordinate system of the phone refers to the following.
\nhttps://developer.android.com/guide/topics/sensors/sensors_overview

\n

As for the bias, I initially tried to calculate the Euler angle without considering it, but it didn't work.
\nSo I am trying to calculate the Euler angle while referring to last year's competition, but I am one step away from the calculation.
\nhttps://www.kaggle.com/code/alvinai9603/predict-next-point-with-the-imu-data

\n

Please note that I am a beginner.

", "rawMarkdown": "Thank you for posting this topic.\n\nI am also trying to find out more about imu, but I am struggling to calculate the Euler angles.\n\nSo far I am aware of the following\nUnits are [m/s^2] for acceleration [rad/s] for angular velocity \nGeomagnetic field is [μT].\nhttps://developer.android.com/guide/topics/sensors/sensors_motion\nhttps://developer.android.com/guide/topics/sensors/sensors_position#sensors-pos-orient\n\nAlso, the XYZ coordinate system of the phone refers to the following.\nhttps://developer.android.com/guide/topics/sensors/sensors_overview\n\nAs for the bias, I initially tried to calculate the Euler angle without considering it, but it didn't work.\nSo I am trying to calculate the Euler angle while referring to last year's competition, but I am one step away from the calculation.\nhttps://www.kaggle.com/code/alvinai9603/predict-next-point-with-the-imu-data\n\nPlease note that I am a beginner.", "votes": null }, { "id": "1828962", "postDate": "06/22/2022 07:47:26", "content": "

Thank you for the useful information!
\nI will try to find out what you shared.

", "rawMarkdown": "Thank you for the useful information!\nI will try to find out what you shared.", "votes": null }, { "id": "1828969", "postDate": "06/22/2022 07:58:32", "content": "

Hosts are submitting.
\nPlease note that this year's imu data will not include orientaion data.

\n

https://www.kaggle.com/competitions/smartphone-decimeter-2022/discussion/323964

\n
\n

There is unfortunately no orientation sensor data as this sensor type was deprecated in Android 4.4W (API level 20). In addition to @queyrusi's implementation, Android has guidance on using accel and mag to compute the device's orientation, albeit via Android libraries.

\n
", "rawMarkdown": "Hosts are submitting.\nPlease note that this year's imu data will not include orientaion data.\n\nhttps://www.kaggle.com/competitions/smartphone-decimeter-2022/discussion/323964\n\n> There is unfortunately no orientation sensor data as this sensor type was deprecated in Android 4.4W (API level 20). In addition to @queyrusi's implementation, Android has guidance on using accel and mag to compute the device's orientation, albeit via Android libraries.", "votes": null }, { "id": "1838132", "postDate": "06/30/2022 08:32:57", "content": "

Bias is inherent bias in the sensor e.g. for Gyroscope if remain static will still not show zero, the values shown is additive bias to be subtracted from actual readings. For accelerometer if lets say your x axis is pointing down to earth center, it should display a value of 1g (9.81 m/s^2) if it is not displaying that, it has a multiplicative bias that need to be rectified.

", "rawMarkdown": "Bias is inherent bias in the sensor e.g. for Gyroscope if remain static will still not show zero, the values shown is additive bias to be subtracted from actual readings. For accelerometer if lets say your x axis is pointing down to earth center, it should display a value of 1g (9.81 m/s^2) if it is not displaying that, it has a multiplicative bias that need to be rectified.", "votes": null } ], "comments": [ { "id": 1828827, "author_name": "tyonemoto", "author_url": "", "post_date": "06/22/2022 04:45:15", "content": "

Thank you for posting this topic.

\n

I am also trying to find out more about imu, but I am struggling to calculate the Euler angles.

\n

So far I am aware of the following
\nUnits are [m/s^2] for acceleration [rad/s] for angular velocity
\nGeomagnetic field is [μT].
\nhttps://developer.android.com/guide/topics/sensors/sensors_motion
\nhttps://developer.android.com/guide/topics/sensors/sensors_position#sensors-pos-orient

\n

Also, the XYZ coordinate system of the phone refers to the following.
\nhttps://developer.android.com/guide/topics/sensors/sensors_overview

\n

As for the bias, I initially tried to calculate the Euler angle without considering it, but it didn't work.
\nSo I am trying to calculate the Euler angle while referring to last year's competition, but I am one step away from the calculation.
\nhttps://www.kaggle.com/code/alvinai9603/predict-next-point-with-the-imu-data

\n

Please note that I am a beginner.

", "votes": null, "replies": [ { "id": 1828962, "author_name": "watanabetakahiro", "author_url": "", "post_date": "06/22/2022 07:47:26", "content": "

Thank you for the useful information!
\nI will try to find out what you shared.

", "votes": null, "replies": [] }, { "id": 1828969, "author_name": "tyonemoto", "author_url": "", "post_date": "06/22/2022 07:58:32", "content": "

Hosts are submitting.
\nPlease note that this year's imu data will not include orientaion data.

\n

https://www.kaggle.com/competitions/smartphone-decimeter-2022/discussion/323964

\n
\n

There is unfortunately no orientation sensor data as this sensor type was deprecated in Android 4.4W (API level 20). In addition to @queyrusi's implementation, Android has guidance on using accel and mag to compute the device's orientation, albeit via Android libraries.

\n
", "votes": null, "replies": [] } ] }, { "id": 1838132, "author_name": "vv4zir", "author_url": "", "post_date": "06/30/2022 08:32:57", "content": "

Bias is inherent bias in the sensor e.g. for Gyroscope if remain static will still not show zero, the values shown is additive bias to be subtracted from actual readings. For accelerometer if lets say your x axis is pointing down to earth center, it should display a value of 1g (9.81 m/s^2) if it is not displaying that, it has a multiplicative bias that need to be rectified.

", "votes": null, "replies": [] } ], "raw_markdown_by_id": { "1828103": "In the data section,\n> [train/test]/[drive_id]/[phone_name]/device_imu.csv - Readings the phone's accelerometer, gyroscope, and magnetometer.\n> MessageType - which of the three instruments the row's data is from.\n> utcTimeMillis - The sum of elapsedRealtimeNanos below and the estimated device boot time at UTC, after a recent NTP (Network Time Protocol) sync.\n> Measurement[X/Y/Z] - [x/y/z]_uncalib without bias compensation.\n> Bias[X/Y/Z]MicroT - Estimated [x/y/z]_bias. Null in datasets collected in earlier dates.\n\n- MessageType\nThis column contain \"UncalAccel\", \"UncalGyro\" and \"UncalMag\". So this is corresponds to each device.\n\n- Measurement[X/Y/Z]\nWhat does this column mean?　If it is an accelerometer value, what is the unit?　Please tell me where to refer.\n\n- Bias[X/Y/Z]MicroT\nWhat does this column mean?　What is \"Bias\"? \n\nIt would be helpful if someone could tell me.", "1828827": "Thank you for posting this topic.\n\nI am also trying to find out more about imu, but I am struggling to calculate the Euler angles.\n\nSo far I am aware of the following\nUnits are [m/s^2] for acceleration [rad/s] for angular velocity \nGeomagnetic field is [μT].\nhttps://developer.android.com/guide/topics/sensors/sensors_motion\nhttps://developer.android.com/guide/topics/sensors/sensors_position#sensors-pos-orient\n\nAlso, the XYZ coordinate system of the phone refers to the following.\nhttps://developer.android.com/guide/topics/sensors/sensors_overview\n\nAs for the bias, I initially tried to calculate the Euler angle without considering it, but it didn't work.\nSo I am trying to calculate the Euler angle while referring to last year's competition, but I am one step away from the calculation.\nhttps://www.kaggle.com/code/alvinai9603/predict-next-point-with-the-imu-data\n\nPlease note that I am a beginner.", "1828962": "Thank you for the useful information!\nI will try to find out what you shared.", "1828969": "Hosts are submitting.\nPlease note that this year's imu data will not include orientaion data.\n\nhttps://www.kaggle.com/competitions/smartphone-decimeter-2022/discussion/323964\n\n> There is unfortunately no orientation sensor data as this sensor type was deprecated in Android 4.4W (API level 20). In addition to @queyrusi's implementation, Android has guidance on using accel and mag to compute the device's orientation, albeit via Android libraries.", "1838132": "Bias is inherent bias in the sensor e.g. for Gyroscope if remain static will still not show zero, the values shown is additive bias to be subtracted from actual readings. For accelerometer if lets say your x axis is pointing down to earth center, it should display a value of 1g (9.81 m/s^2) if it is not displaying that, it has a multiplicative bias that need to be rectified." }, "source": "meta" }