Questions tagged [imu]

Inertial Measurement Unit

59 questions with no upvoted or accepted answers
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8
votes
1answer
7k views

Angle Random Walk vs. Rate Noise Density (MPU6050)

I’ve made a datalog from a MPU6050 (IMU: gyroscope and accelerometer) at 500Hz sample rate. Now I want to calculate the characteristics from the gyro to evaluate the sensor. For the gyro I’ve found ...
5
votes
1answer
267 views

Inferring joint orientation on multi-joint arm

Not a robotics question in the strictest sense, I guess, but related closely enough, I hope: I have an arm-like articulated two(-plus-one)-joint appliance that I want to use as a 3D input device. It ...
4
votes
1answer
414 views

MPU6050: Changing Gyro Output Range Throws off Positional Reading

I am using the MPU6050 in conjunction with an Arduino and Jeff Rowberg's i2cdev library, and my project requires that the gyro rate outputs be more precise than the default setting, which is 1/16.4 of ...
3
votes
2answers
1k views

Correctly calculating free acceleration given NED referenced orientation quaternion and sensor referenced acceleration data

I have a sensor outputting correct, calibrated North-East-Down referenced quaternions describing the orientation of the sensor. It also outputs raw, sensor referenced acceleration data, inclusive of ...
3
votes
1answer
180 views

How is the GPS fused with IMU in a kalman filter?

I've been trying to understand how a Kalman filter used in navigation without much success, my questions are: The gps outputs latitude, longitude and velocity. While the IMU outputs acceleration and ...
2
votes
2answers
148 views

GPS+IMU sensor fusion not based on Kalman Filters

Do you know any papers on or implementations of GPS + IMU sensor fusion for localization that are not based on an EKF (Extended Kalman Filter) or UKF (Unscented Kalman Filter)? I'm asking is because ...
2
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0answers
61 views

How to avoid gimbal with Quaternions

I'am working with an LSM6DSO32, so I'am starting with Kalman filter, everything works but with Euler angle I got gimbal lock I think... But if my pitch angle approach to 90° my roll angle jump and I ...
2
votes
1answer
122 views

Particle Filter for IMU tilt angle and bias estimation from Kalman Filter models

I understand the functioning of Particle Filters from the book Probabilistic Robotics and the robotics course provided by Cyrill Stachniss. I want to implement, from scratch, a particle filter to ...
2
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0answers
254 views

How to estimate yaw angle from magnetometer and gyroscope?

I'm using the MPU9250, it measures acceleration, magnetometer, gyro, etc. Complementary filter tutorial for this is here, however this tutorial does not have a magnetometer and I do, thus I thought I ...
2
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0answers
146 views

How to handle sensor data for a sensor-fusion algorithm

I am implementing the explicit complementary filter(see below) with a 9DOF MEMS sensors (accelerometer, magnetometer and gyroscope) for attitude estimation. Currently, the gyro and accel update rates ...
2
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0answers
496 views

How to properly calibrate a magnetometer in IMU for precise yaw?

EDIT: Moved to ElectricalEngineering StackExchange Community I'm using Sparkfun Razor IMU 9DOF sensor which incorporates accelerometer, gyroscope, and magnetometer, for giving the Euler's angles (yaw,...
1
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0answers
42 views

Why does AHRS system with Madgwick filter has so big drift?

I have an MPU9250 on my PCB and I use an AHRS system with a Madgwick filter to get yaw angle. I want to get very accurate and non-drifting yaw angle, but, for unknown reasons, I can't. I calibrated ...
1
vote
1answer
45 views

How to use Quaternion from IMU to get the transformation to inertial reference frame?

Im trying to get the Linear Velocity integrating the acceleration from IMu. I know there will be accumulated error due to integration bit before the integration I have to do couple of other steps. ...
1
vote
1answer
30 views

Sensor fusion in a metal heavy environment

I am trying to get heading information of a forklift. I've designed a small PCB for this purpose. This PCB has a 3 axis magnetometer and a 6 axis gyroscope-accelerometer (Z- axis looking towards the ...
1
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0answers
22 views

Digital compass precision in urban environment

I'm working on an application to compute the absolute heading (yaw) using the following hardware: WIT-Motion HWT905 IMU https://www.wit-motion.com/digital-inclinometer/witmotion-hwt905-ttl.html. It ...
1
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0answers
19 views

How do you derive the soft iron matrix for magnetometer calibration?

Can someone send reliable sources for how this is derived? I understand the diagonal values are for scale, but how do you determine all 6 values needed for this matrix? I would also like to normalize ...
1
vote
1answer
51 views

Drone lost traj recovery

So I am using slam algorithm to localize the drone which is gps denied . The input to the slam algo is imu data and a video . Now after the first run of the slam algorithm it creates the trajectory ...
1
vote
1answer
123 views

How to calculate the ground truth of your own simple dataset for testing your SLAM Algorithm?

I have tested my SLAM algorithm on EuRoC, TUM and KITTI Datasets. But I would like to test on my own custom dataset. Moreover, I already rectify how to make my own dataset in TUM dataset format, but I ...
1
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0answers
26 views

What could cause quaternion error to go up drastically when a gyroscope is rotated on more than one axis at a time?

Alright, I'm working on a small Arduino script that determines orientation using a a gyroscope and a quaternion. My hardware: LSM9DS1 IMU (Gyroscope, Accelerometer, Magnetometer) Teensy 4.0 My basic ...
1
vote
2answers
289 views

Sensor fusion of GNSS and IMU using UKF

I do have a land-based robot with an IMU and a GNSS receiver. From the IMU, I get the velocity and acceleration in both $x$ and $y$ directions. From the GNSS receiver, I get the latitude and ...
1
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0answers
34 views

Barometer altitude calculation

I want to calculate altitude using a barometer which is mounted in the proximity of a number of components which get quite hot and raise the localised temperature. The barometric pressure equation is ...
1
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0answers
100 views

Can someone help me understanding reference frames in OxTS data in KITTI Vision Benchmark dataset?

If anyone has worked with KITTI dataset, can you explain the reference frame used in roll pitch yaw values? I downloaded the raw data from this link: http://www.cvlibs.net/datasets/kitti/raw_data.php ...
1
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0answers
43 views

Intel Realsense Cameras for Object Avoidance and SLAM to go to destination

My goal is to make a UAV which can search an area while avoiding obstacles. I figured I would navigate using the SLAM and Intel Realsense D435i (a stereoscopic camera with an IMU built in), but all of ...
1
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0answers
489 views

Yaw, Pitch, Roll rate concepts and how to calculate them with an IMU

I need help understanding the difference from Y/P/R rate and the data that I can get from a gyroscope. I am using the raw readings of my IMU (MPU9250) and the Madwick Filter to calculate a quaternion ...
1
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0answers
23 views

Yaw from quaternion with non zero pitch

If IMU is gravity aligned, pitch is zero and yaw is unobservable. If IMU is not gravity aligned, pitch is non zero and yaw is observable. Question: given an input quaternion with non null pitch, how ...
1
vote
1answer
156 views

Complementary filter for gyroscope and accelerometer

I am trying to understand how the complementary filter works. I did some research and i found this: I am confused about the noise and drift before any filter is applied. I have 2 questions: In the ...
1
vote
1answer
251 views

Accelerometer and gyroscope noise and bias

I am doing an EKF (Extended Kalman Filter) to fusion Visual Odometry with IMU information. I am using a ROS package called ethzasl-msf (I am using the multi sensor fusion because then I have to add ...
1
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0answers
62 views

Kalman filter to fuse ultrasonic altitude sensor and accelerometer

I'm a little confused on how to set up the Kalman filter matrices to fuse an ultrasonic altitude sensor and accelerometer from IMU. I am trying to implement this for a quadcopter. And what I'm ...
1
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0answers
65 views

Writing IMU accelerometer data into as twist messages into cmd_vel

I am reading accelerometer data from the wiimote /wiimote/state topic. A sample of the data I'm working with is as follows: ...
1
vote
1answer
739 views

EKF implementation on odometry/IMU

I am applying Extended Kalman Filter for a mobile robot with IMU and odometry data. I am running simulation currently. However, I don't have suitable data for odo/IMU measurements to use. Where can I ...
1
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0answers
289 views

Is it my PID that is unstable or my physical system? (Quadcopter)

I've been working on this Arduino-MPU6050 quadcopter for a while now, and it looks like it's close to being finished. I have programmed it in rate mode, so the PID's control the rotational velocity. ...
1
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0answers
135 views

Using an AR.Drone's IMU to perform PDR

My task is simple: I want to move my drone manually around a room (IMPORTANT: I DO NOT WANT TO FLY IT) and I want to see its position update on a map using IMU data. I've attempted something in ROS ...
1
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0answers
202 views

Accelerometer, gyro, and magnetometer sensor fusion for material resource survey

As a hardware engineer, I have studied quite a lot on sensor spec such as Accel, Gyro and Magnetometer including custom made fluxgate. I have studied matrix and quadarion (complex number) and so on. I ...
1
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0answers
1k views

Orientation parameter for quadcopter with madgwick fusion algorithm

I recently decided to build a quadricopter from scratch using Arduino and now I'm faced with an orientation estimation problem. I bought a cheap 10DOF sensor with 3 axis magnetometer, 3 axis ...
1
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0answers
503 views

Fusion of GNSS position data and prefused 9-dof AHRS data

Bosch, FreeScale, InvenSense, ST and maybe others are releasing 9-dof AHRS platforms containing their own fusion software and outputting filtered/sane/fused data (attitude as quaternion and linear ...
0
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0answers
15 views

Creating a Kalman Filter model

I am trying to use a Kalman filter to estimate velocity and orientation of a drone using an IMU (accelerometer + gyro). However, I'm new to Kalman filters and thus struggling to create a model for ...
0
votes
1answer
29 views

GPS + IMU data and kinematics equations

I have the following data Longitudinal acceleration, $a_x^{IMU}$ Lateral acceleration, $a_y^{IMU}$ Vertical acceleration, $a_z^{IMU}$ Yaw angle, $\psi$ Yaw rate, $\dot{\psi}$ Latitude, $\rightarrow ...
0
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0answers
12 views

How should I learn about IMU datasheet specifications?

When comparing IMUs we should turn to datasheets and they contain lots of nomenclature and technical words that a layman does not know of. if someone wants to learn about them what or where should he/...
0
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0answers
28 views

Linear Velocity from robot_localization Package after IMU integration and and only one sensor (IMU) as sensor input

Im using the robot_localization robot_localizationto get the linear Velocity of underwater simulated ROV with Gazebo. In order to get the correct orientation of the linear (twist) component of the ...
0
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0answers
7 views

How to set up parameter in hector_localization stack to fuse IMU and Barometer (Pressure sensor)?

Im checking the hector_localization hector_localization stack, that provide the full 6DOF pose of a robot or platform. It uses various sensor sources, which are fused using an Extended Kalman filter. ...
0
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0answers
22 views

How to minimize the error integrating 3D angular velocity data obtained by the IMU to get linear velocity?

I have IMU sensor that gives me the raw data such as orientation, Angular and Linear acceleration. Im using ROS and doing some Gazebo UUV simulation. Furthermore, I want to get linear velocity from ...
0
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0answers
38 views

How do you convert the covariance matrix of a 3D rotation error-state to the covariance matrix of the corresponding quaternion?

I'd like to convert the covariance matrix of an error-state Kalman Filter that uses Euler angles to the corresponding covariance matrix of a quaternion state. I basically use this for standard INS-...
0
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0answers
24 views

Do you need to know the orientation between aircraft and IMU for IMU alignment?

I have a fixed wing aircraft and a MEMS IMU, but I am uncertain of the exact orientation between the IMU and aircraft. In the manual for the IMU, it recommends undergoing an alignment procedure prior ...
0
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0answers
38 views

Beginner needs help with Self-Balancing-Robot build

I'm looking for help on a 1st build self balancing robot, something that seemed pretty easy but not. I'm retired so have plenty of time but no real robot skills, electrical, mechanical yes. I have ...
0
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0answers
26 views

How to compute linear speed on scooter without gps and wheel odometry

My project is to be able to compute my linear speed on my scooter only with my IMU. I have a IMU build with my arduino which is in my backpack. I want first to compensate the acceleration measurement ...
0
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0answers
34 views

How is IMU noise dealt with between steps?

Direct integration of IMU will result in massive error incredibly quickly. What I am wondering is, how do you use an IMU over a small time intervals to aid in pose estimation? In particular, suppose ...
0
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0answers
35 views

When Implementing Madgwick filter for attitude estimation, the calculated Euler angles are drifting significantly. What could be the reason?

The Beta value is set according to the original report, which specifies for IMU B-0.033. and the sensor data acquisition and filter update is periodic at 200Hz. The angular velocity values from the ...
0
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0answers
46 views

IMU Vision Fusion using EKF

I am trying to track an object indoors using an IMU (only accel and gyroscope) and a visual marker. This is similar to IMU+GPS fusion, where GPS is effectively replaced by the position that my vision ...
0
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0answers
40 views

Find IMU's movement direction in x-axis

I have an IMU device with an accelerometer sensor and I fix that on top of the linear motion rail.so it can only move to the right or left (in the x-axis) side. How can I determine the direction (...
0
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0answers
37 views

MPU6050 Gyro rotaion always around Y axis

I am using an MPU6050 IMU. I did a small experiment having Z-axis pointing upwards. 1. Rotate 90deg around Z-axis (yaw) and back to the original position 2. Rotate 90deg around X-axis (roll) and back ...