Questions tagged [imu]
Inertial Measurement Unit
60
questions with no upvoted or accepted answers
5
votes
2
answers
323
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 ...
- 191
3
votes
1
answer
262
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 ...
- 131
2
votes
0
answers
40
views
transform IMU reference to robot reference
I have an IMU rigidly attached to the end effector of a robotic arm. The goal is to compare the orientation of the IMU to the orientation of the robot arm. The 9-axis IMU data is used in a sensor ...
- 21
2
votes
0
answers
136
views
How to fuse IMU with encoders in EKF
Background
I have a car-like mobile robot (4 wheels, where the forward ones are steering wheels) and I want to estimate its pose and velocity assuming 2D planar motion. I'm trying to solve this ...
2
votes
1
answer
244
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
votes
0
answers
455
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
votes
0
answers
205
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 ...
- 21
2
votes
0
answers
534
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,...
- 21
1
vote
0
answers
28
views
How does IMU pre-integration work and how is it different from EKF?
My understanding is that IMU pre-integration is to get away from having to re-integrate the the IMU between key-frame intervals when doing bundle adjustment. The formulations I ave seen involve a ...
- 273
1
vote
0
answers
22
views
Compensate tractor's (vehicle's) tilts in the GNSS-IMU based system
I have the following setup: a tractor with a dual band antenna (from ublox) installed on the vehicle's symmetry axis on the roof (h=3m), approx. 1m ahead of the center of the rear axis (which I ...
- 11
1
vote
0
answers
433
views
robot_localization not fusing imu data
According to the documentation in : http://docs.ros.org/en/noetic/api/robot_localization/html/state_estimation_nodes.html
I was able to transform the imu data header fram from "imu_link" ...
- 11
1
vote
1
answer
229
views
How do you rotate positions from ENU-frame to body frame?
If positions are in the local frame of ENU (or ECEF - either works), how do you rotate that to the body frame of the device?
Logically, I thought that I could use the pitch, roll, and yaw angles of ...
user31870
1
vote
1
answer
55
views
IMU Senosr fusion algorithm of gyro and accelerometer during acceleration of vehicle
Hello so we have a car with 10 IMUs mounted at different locations of the car and the idea is the measure the centripetal force at each location of the car and compare it to each other. We also need ...
1
vote
0
answers
96
views
What exactly is meant by the "Bias instability over temperature range" specification on IMUs?
I'm trying to become educated on IMU specifications, and my understanding is that when comparing IMUs, the Gyros make the big difference. I am looking at the InertialLabs IMU-Nav-100:
https://...
- 11
1
vote
0
answers
373
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 ...
- 158
1
vote
0
answers
63
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 ...
- 111
1
vote
0
answers
37
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
0
answers
49
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
0
answers
61
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 ...
- 69
1
vote
0
answers
188
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
...
- 21
1
vote
0
answers
51
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 ...
- 111
1
vote
0
answers
870
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
vote
0
answers
46
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 ...
- 142
1
vote
0
answers
68
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 ...
- 71
1
vote
0
answers
105
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:
...
- 155
1
vote
0
answers
331
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. ...
- 71
1
vote
0
answers
137
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
vote
0
answers
207
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 ...
- 111
1
vote
0
answers
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 ...
- 21
1
vote
0
answers
537
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 ...
- 11
0
votes
0
answers
20
views
Why new/recommended MEMS IMU for AHRS for drones are 6-DOF instead of 9-DOF?
I'm developing an quadcopter as an DIY project.
I'm in nascent stage of development.
I've just finalized the design/working philosophy.
I'm planning to fuse data from 9-DOF (9-Axes) IMU + GNSS + ...
- 101
0
votes
0
answers
57
views
MPU6050 providing gyroscope values for linear acceleration
I am using this ROS2 driver to connect my MPU6050 to RPi 4 running ROS2 humble. It outputs an IMU message containing linear acceleration and angular velocity. The linear acceleration values seem to be ...
- 1
0
votes
0
answers
18
views
Do MEMS or optical gyroscope record Earth's rotational and revolutional angular velocities?
I am using a 3 axis gyroscope (Android device) to record angular velocities using a sensor data logger application.
When the device is placed stationary, the gyroscope recorded the following values:
...
- 43
0
votes
0
answers
65
views
Nonlinear continuous system function of IMU sensor fusion robot
For my robotics course I have to implement the nonlinear continuous system function for a mobile robot that is equipped with a GPS receiver and an IMU consisting of an accelerometer and a gyroscope. ...
- 1
0
votes
0
answers
145
views
IMU to Camera transformation
Suppose you are implementing SLAM or VIO system, you have your camera C and IMU and a coordinate transformation between them (R, T).
How do convert IMU measurements to camera accelerations and ...
- 273
0
votes
1
answer
51
views
Simulate GPS IMU With Quadcopter Swarm?
I have multiple drones work in swarm formation, i made the quadcopter model and the swarm one. Until now i have the swarm moving in a formation leader-follower and track a predefined trajectory based ...
0
votes
0
answers
23
views
Suggest me an IMU which is not affected by magnetic field
I am using IMU for platform stabilization (Stewart Platform). But the issue is that there is a strong changing magnetic field. And I think that it might affect the accuracy of IMUs. Any suggestions?
0
votes
0
answers
41
views
Question about 4-mecanum wheeled mobile robots
I'm trying to make a mobile robot with 4 mecanum wheels. The method that I've chosen is to fuse the sensors(encoder, imu) with EKF and use the SLAM algorithms(Gmapping, Cartographer, etc..). Right now ...
- 1
0
votes
0
answers
15
views
My LSM303 magnetometer values are stuck
My Raspberry Pi Pico is connected to a 9 DOF IMU like this one, Adafruit 9-DOF IMU Breakout - L3GD20H + LSM303, through an I2C connection.
For some reason, whenever I try and get values from the ...
0
votes
1
answer
144
views
Get rotation of IMU data snapshot
I received snippets of data of an IMU with 9 DoF in motion. For these I wanted to get their rotation by angles relative to the earth frame. My goal is to receive ...
0
votes
1
answer
93
views
How to perform time-offset calibration use GTSAM in Camera-IMU system?
Assume we have camera poses data and IMU data(which include gyr and acc data) with different timestamps, now I want to estimate this value, I known that this can be done in many ways(EKF,MSCKF), but I ...
- 1
0
votes
0
answers
13
views
Nao robot IMU data rates
I'm trying to stream data from the Nao's inertial unit in its trunk. However the update rate is quite slow ~ 1Hz. Is there any way to improve it? For reference, I issued the following command using ...
- 101
0
votes
0
answers
146
views
Mapping IMU readings from body frame to navigation frame
I'm trying to combine IMU displacements with the time of flight sensor readings in order to navigate through the indoor environment with a non-linear Kalman filter variant. In the graphic below, I ...
- 11
0
votes
0
answers
165
views
Uncontrolled drift of Visual Inertial Odometry
I'm trying to use the VINS-Fusion package to obtain odometry for a quadcopter. The primary sensor is an Intel Realsense D435i. I've calibrated the camera and IMU extrinsics using Kalibr. IMU ...
- 1
0
votes
1
answer
94
views
Compensation of sudden impacts/shocks in adaptive AHRS sensor fusion algorithms
Background
I have a 9-DOF MEMS-IMU and trying to estimate the orientation (roll, pitch and yaw) in scenarios (e.g. car crash) where sudden shocks (mainly linear) lead to high external accelerations ...
- 1
0
votes
1
answer
157
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 ...
- 101
0
votes
0
answers
93
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 ...
- 167
0
votes
0
answers
42
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 ...
- 1
0
votes
0
answers
183
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 ...
- 1
0
votes
0
answers
150
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 ...
- 113