# Questions tagged [imu]

Inertial Measurement Unit

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### 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
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### Optical flow inputs

I'm reading how the optical flow of my quadcopter works. The output of the optical flow that interests me is the linear (horizontal) velocity: $v_x$ and $v_y$. Here (page 10) it says that it fuses the ...
• 171
1 vote
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### 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 ...
• 111
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### Does Vehicle Yaw angle measures same at every point on it? If not, how to translate yaw rotation to COG of the vehicle from different point?

I am using an IMU to measure the yaw rotation angle of a car. I need to translate the rotation measured to COG of the vehicle. I can ignore roll and pitch as I am driving it on a flat surface. So, ...
348 views

### How does sensor fusion help in robot localization

Good day... Sorry for bigner quesion, but really I need some friendly explanation rather than long reference I have 9 dof mpu9250 imu and gps. I found some source that calculate euler angle in ardunio ...
139 views

### IMU based joint angle measurement

Let us assume we have a two 2-DoF robot. Both axes rotate around x. And the goal is to measure the joint angle values with the roll value from IMUs attached on each link. However, the problem is that ...
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### Catching drift from IMU with if...else

recently I tried to measure yaw angle with MPU6050 and MahonyAHRS algorithm. As expected, the yaw angle consistently drifts. But I could see that the changes caused by the drift are much smaller ...
• 314
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### 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 ...
758 views

### How to get position (X Y values) from a USB optical mouse

I want to use an optical mouse to measure displacement in X and Y direction of my robot. I'm using Ubuntu mate 18.04 on raspberry pi and wrote the following python code : ...
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1 vote
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### 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 ...
• 171
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### Is the information on the following link logical?

I cannot comment on the original answer, so I had to ask like this. I am trying to learn IMU's, accelerometers, gyros etc. for a while. So I came across with this answer below, https://engineering....
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### Gyro yaw drift compensation

I'm looking for some kind of filter, algorithm which will allow me to compensate gyro yaw drift using heading of magnetometer. My project requires only yaw measurments and both sensors are flat. Is ...
212 views

### What is required to get the roll, pitch and yaw of an aerial vehicle?

TL, DR : What is the method(in terms of sensors and algorithm) to get the roll, pitch and yaw of an aircraft at any instant. I am planning to build a hobby aircraft. I am so confused about which kind ...
• 153
492 views

### MPU6050 gyroscope giving wrong measure

i am trying to make an angle meter, using the UNO and MPU6050, following joop brokking video tutorials, when utilizing the accelerometer, the results are fine, however when i try to use gyroscope ...
42 views

### Differences between strapdown inertial navigation and motion models

In a state estimation scheme with a simple IMU/GNSS setup using EKF, I have always thought the prediction step would be done using a motion model and all sensor measurements would be incorporated via ...
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### Integreation Method In Dr with 3 Sources

I'm searching a navigation method to find my location while dead reckogning (gps signals jammed) with an imu and gsm based navigation results. In short i have 3 sources: Gsm Based Navigation ( gives ...
1k views

### How to read data from the VN100 IMU on Ubuntu?

Hi I have a VectorNav VN100S Development kit, which has VN100 IMU unit. I want to set it up with Ubuntu 16.04 and ROS Kinetic, but unable to read anything from the VN-100. So far I have been ...
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1 vote
1k views

### Aliexpress bought BNO055 UART connection

I bought a BNO055 module from Aliexpress which is shown in the picture below. I am able to read the IMU data in an Arduino nano from this BNO055 via an I2C connection. Now, I want to connect it to a ...
• 13
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### IMU and encoder fusion

I'm trying to simulate data fusion for a 4-wheeled mobile robot using ekf and am using IMU and wheel encoders as sensors,where IMU measures linear acceleration and angular velocity and encoder ...
1 vote
1k views

### Navigation - GPS + IMU; how to make it more accurate?

Currently, I am trying to navigate a small robot car to point A from my current position. The car has a GPS sensor and a BNO055 IMU(Gyro + Mag + Acc). I know the GPS co-ordinates of point A. Using the ...
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1 vote
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
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### 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
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### How to accurately navigate from one GPS coordinate to another using just GPS & IMU? [duplicate]

I'm looking for ways to accurately navigate from one GPS location to another. I have a GPS sensor and an IMU. I can calculate the distance with the help of GPS I believe and with the help of ...
• 11
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### Sensor fusion to calculate joint angles between segments of a robot arm using IMU data

I have an IMU attached to each of the segments of a robotic arm, which gives me accelerometer and gyroscope data. My goal is to first of all improve the quality of the sensor readings and subsequently ...
• 99
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### 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 ...
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1 vote
3k views

### Convert local coordinates of a moving IMU to global coordinates

I am trying to compare the performance of an IMU in motion against an optical tracking system. The IMU has an accelerometer and a gyroscope and gives output in the local IMU coordinate frames. The ...
154 views

### Quaternion error in one degree of freedom

I would like to control a system which orientation I measure with as quaternion based EKF in one degree of freedom. Obviously the simplest thing would be to convert the quaternion estimate to euler ...
241 views

### How to get starting location of robot using IMU Sensor (without using gps)

i have one robot, i have to get the initial location of that robot. then when we move the robot from that location, and when we give the command like "HOME" then it should go that initial location. ...
1k views

### How is the IMU used in the PixHawk?

Looking at 3DR's Pixhawk hardware on GitHub the FMU and IMU are treated as different pieces of hardware. On the schematics for the FMUs (example) there is limited reference to the IMU. So, is the IMU ...
1 vote
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: ...
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### what is the algorithm to get position (Linear displacement and linear velocity ) using IMU (Like MPU6050)?

So I have been working on a drone project for a very long time, now I decided to work on Kalman filter which is used widely nowadays like Ardupilot. I looked at the source code so basically understand ...
68 views

### Which algorithms to locate a static 3D object relative to a moving camera/IMU?

I am using typical setup with camera and IMU as found on a smartphone. Using this, I would like to estimate the relative pose between the camera and an object (for simplicity, let's say a cube). The ...
227 views

### Discontinuities in IMU data in pitch only

I am having a problem with pitch measurements with Bosch BNO055 IMU. The device is rotated on a relatively stable rotating spindle and does a revolution on a circle around 10cm radius. It is upright ...
2k views

### Position Tracking using IMU

I am working on a robot tracking application, where our main tool (a camera) for locating the x & y position of the robot is working on a quite low frequency. Therefore, I am looking for ways to ...
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### How does structural/installation errors have to be modelled in a gyroscope IMU?

I have the model for a gyroscope from an IMU given by $$\omega_{meas} = (I-S)\omega_{true} + \beta + v$$ $S$ is the scaling and misalignment of the sensor, which I understand is a parameter I get ...
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1 vote
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### How to do IMU and camera "sensor fusion" tracking?

I have some 50ms latency cameras at hand and a 800Hz IMU (gyro+accelerometer+magnetometer). I would like to know how exactly how I should do a sensor fusion of such an IMU and camera to fix the ...
• 143
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### How reliable are IMUs for a long usage (6 hours) rotation (only) tracking?

I know they are bad for positional tracking and drift from actual position over time but would like to know what is the situation with rotation only. I know Oculus DK1 used ordinary off-the-shelf ...
• 143
2k views

### angular velocity output of IMU

I am reading the paper On-Manifold Preintegration for Real-Time Visual-Inertial Odometry. There is one paragraph about IMU model. I have two questions. The first one: An IMU commonly includes a 3-...
• 273
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### measurement model of the accelerometers in IMU

I am new to IMU. About the measurements from IMU, different materials give different explanations. From the link: https://www.it.uu.se/edu/course/homepage/systemid/vt14/tokp2.pdf Here the b maybe ...
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### Practicality of using magnetometer inside AUV

I have an AUV with a 12 inch diameter, 29 inch long capsule. Inside the capsule sits an Intel NUC computer, an NVIDIA Jetson GPU, an Arduino Mega, a Sparton IMU (9 DOF) as well as a custom voltage ...
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1 vote
982 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 ...
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1 vote
331 views

### IMU oriented wrongly. How to correct it to get correct values?

We have used an SMC-108 IMU sensor in a hydrographic survey. This was our first time using this sensor. While processing the data, we noticed that the roll, pitch, and heave values were not right. ...
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### Find IMU based on previous works [closed]

I'm building a quadrotor robot and my supervisor has asked me to make a report of the IMU modules used in previous works, I couldn't find such reports however. Does anyone know how to find such ...
740 views

### MPU6050 inconsistent Gyro data

I'm using an MPU6050 for a custom flight controller and I am facing an issue when reading the values from the IMU. The data shown below represents the angular velocity in the y-axis. When the angular ...
166 views

### GPS/ 1GYRO - 2D + ACCEL+GPSEKF

I am trying to integrate GPS and IMU but as a first step I am trying to use just 1d gyro and 2d accelerometer to work. Below is my model - State model and propagation So, my question is .. after ...
356 views

### How to compute the observation matrix for a Kalman Filter?

If my state vector is just a representation of the error state of a quaternion represented as $[\delta \bf{q} ]$ which is a 3x1 vector and my external update is from an accelerometer, how would I ...
121 views

### Self balancing roboter IMU issue

I build a self-balancing robot, at least that what i should have been. now i have tried implementing a complementary filter which combines gyro and accelerometer data, but the problem is that the ...
2k views

### Yaw from accelerometer? No! So what do these equations actually mean?

note: I'm just a day or so into the use of inertial measurements and trying to learn everything at once, this may be a noob question (it's my first here). I have seen this image of "Figure 8" in ...
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### I fused a GPS and IMU and I am wondering if my results make sense

I am trying to fuse a ublox M8 (https://www.u-blox.com/sites/default/files/products/documents/u-blox8-M8_ReceiverDescrProtSpec_(UBX-13003221)_Public.pdf) with a MicroStrain IMU (http://www.microstrain....
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