6 votes

Use data from gyroscope to calculate orientation

gyroscopes do not measure [dRoll ,...] they measure body rates. These are not the same things. There is a transformation matrix ( that I do not have on hand) that relates body rates to euler rates. ...
  • 1,823
6 votes
Accepted

Stabilising an inverted pendulum

There are lots of ways to solve this problem, which falls into the category of Control Engineering. There are two standard approaches: Classical Control: The control command has to be proportional ...
  • 1,258
5 votes

What does "6 degrees of freedom" mean?

Most "meters" of all varieties include up to three degrees of freedom simply to observe all three dimensions of reality we find ourselves in. That said, every object in our three space has three ...
  • 95
4 votes
Accepted

Angular velocities and rotation matrices

If your object $O$ has a different orientation from your global frame $S$, and you know what that difference in orientation is, you can create a 4x4 transform matrix between the two: $$ T = \left[ \...
  • 15.6k
4 votes
Accepted

Complimentary filter issues

There are quite a few things wrong here. I'll split them into two sections: technical errors, and coding warnings. Technical Errors: You are not calculating your angles from accelerometer readings ...
  • 15.6k
4 votes
Accepted

Is there a commercially available inertial gyro with electronic control?

The device you describe is known as a Control Moment Gyroscope (CMG). These devices are mostly used for attitude control in spacecraft, but are also commercially available.
3 votes

Is there a way to measure 3 axis orientation without a magnetometer?

Calibration procedures for magnetometers exist, to compensate for soft iron (nearby ferromagnetic objects) and hard iron (nearby magnetic fields) offsets, which skew the measurements. However, these ...
  • 550
3 votes

Filtering angular velocity spikes of a cheap Gyroscope

You gave the part number and protocol, but Can you provide a schematic for how this is installed in a circuit? Are you using the module or an individual chip? Is this all soldered together or is it ...
  • 15.6k
3 votes

Kalman filter model values or state space original value? Which values to use?

To apply Kalman filter successfully, you need two requirements namely the system must be linear (i.e. both the motion and observation models) and the noise to be Gaussian with zero mean and some ...
  • 2,429
3 votes
Accepted

How do I get MPU 6050 gyroscope data using "MPU6050_6Axis_MotionApps20.h" library

I went through the header files of the 12cdev lib and I figured it out. you have to first add the line VectorInt16 gyro; to your motion variables, then you add the line mpu.dmpGetGyro(&gyro, ...
3 votes

How to calculate Euler Angles from gyroscope output?

Using the Gyroscope First thing to note is that the gyroscope is reporting angular rates with respect to the sensor. So if the sensor is rotating with some rate, the data it's outputting will be in ...
3 votes

How to calculate Euler Angles from gyroscope output?

First you need to integrate the output from the gyro to get the actual X, Y and Z angles. angleX = gyroAngleX + gyroInputX angleY = gyroAngleY + gyroInputY ...
3 votes

How to calculate Euler Angles from gyroscope output?

Look into a complementary filter. It isn't the correct way to go out this but it will give you usable data for attitudes around level. It's also worth mentioning that you will not be able to track yaw....
  • 1,823
3 votes
Accepted

Simulate IMU (2D gyro and accelerometer) data

This is really simple. First of all, you need to understand how the sensor works. In other words, you need understand whether the measurements is coming from linear or nonlinear model. Second, what is ...
  • 2,429
3 votes

Stabilising an inverted pendulum

The theory that describes what you are looking for is call Control Theory. Search for the Nonlinear Systems textbook by Hassan Khalil for an excellent overview of the material--the inverted pendulum ...
  • 926
3 votes
Accepted

Localising a robot placed at an unknown position in a known environment

The problem is that you can't apply path planning until you know where the robot is in the global coordinate frame. There are many localization techniques, and each has its pros/cons; I have used ...
  • 926
3 votes
Accepted

Can I use a 3D gimbal system as a simplistic quadcopter IMU(3 axis accelerometer)?

A gimbal system will not replace an accelerometer. I assume by gimbal system you mean something like a Gyroscope, i.e. a device that has a fixed orientation allowing you to measure your orientation ...
3 votes

Compensation for IMU mounting misalignment

You need the transformation from the car to the IMU. You can get this by recording the IMU published attitude with the car in known orientations. You should be able to construct the IMU to car ...
  • 1,823
3 votes

angular velocity output of IMU

1) An inertial frame is one in which a free particle travels in a straight line at constant speed, or is at rest. Practically speaking, you usually check if a frame is inertial or not by ...
  • 331
3 votes

Data collected from ROS

As Ben noticed, you may want to elaborate on your question, but in general data collection in ROS is performed using tools from the rosbag package. As you'll find when you read the documentation, ...
  • 1,286
2 votes

How can I filter Gyroscopic data?

$1^\circ/s$ does not seem to be very catastrophic. The noise seems quite low. More interesting is if your euler angles are stable and drift-free. Then you can control the pitch and roll error based on ...
  • 3,004
2 votes

How to combine an accelerometer and a gyroscope to find robot location and orientation in 2D/3D space

Here's a pretty good overview of what holmeski is saying, and using multiple sensors in general for different applications. FWIW DARPA is, and has been looking into inertial sensors with enough ...
2 votes

How to combine an accelerometer and a gyroscope to find robot location and orientation in 2D/3D space

Look into nonlinear filters, particularly the unscented kalman filter (ukf). Using a ukf to fuse the data from a gyroscope and accelerometer will allow you to estimate orientation. However, these two ...
  • 1,823
2 votes
Accepted

How to choose the state space model for 1 axis gyroscope to implemnt a good kalman filter

Assuming the angular velocity is constant (i.e. $\dot{\theta}_{k+1} = \dot{\theta}_{k}$) It seems to me the state vector should look like this $$ \underbrace{ \begin{bmatrix} \theta_{k+1} \\ \dot{\...
  • 2,429
2 votes
Accepted

Structuring EKF to estimate pose and velocity with odometry inputs

Great question! Your intuition is correct. I would do this: Put the state $x$, and expected velocities at the current time $t$, $v $ as the vector to estimate. Use estimated velocities to predict ...
2 votes

Can a Jacobian matrix be used to derive joint angles from end-effector linear and rotational velocity (without a filter)?

Joint angles can be determined by looking at the gravity vector of each accelerometer. The paper Low-cost Accelerometers for Robotic Manipulator Perception by Morgan Quigley, Reuben Brewer, Sai P. ...
  • 5,770
2 votes
Accepted

Gyroscope - How can I remove low frequency component with a high pass filter only?

:UPDATED: This is the last update I'm going to make to this answer because I feel like you are repeatedly redefining your question. You have already designed a Butterworth filter that removes the DC ...
  • 15.6k
2 votes
Accepted

Quadrocopter problem with stability

You have far too much vibration reaching your sensors. Mount the board you're using with vibration damping mounts, this should solve most of your problem. An easy way to do this is to attach each ...
  • 1,823
2 votes

What does "6 degrees of freedom" mean?

n degrees of freedom of an object means it requires n unique parameters to completely define itself. For eg., a 3-DOF arm requires 3 joint parameters with which each and every position on the arm can ...
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