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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 gyroscope values, as they change when I tilt the robot but not when the robot accelerates in X,Y or Z. But I want X and Y acceleration values for Ros2 robot_localization via ekf, how would I get that. Is that an issue with this driver, or a problem with MPU6050? Thanks I am a beginner.

Edit: I get the values described in the robot_localization wiki:

Acceleration: Be careful with acceleration data. The state estimation nodes in robot_localization assume that an IMU that is placed in its neutral right-side-up position on a flat surface will: Measure +9.81 9.81 meters per second squared for the Z Z axis. If the sensor is rolled +90 90 degrees (left side up), the acceleration should be +9.81 9.81 meters per second squared for the Y Y axis. If the sensor is pitched +90 90 degrees (front side down), it should read -9.81 9.81 meters per second squared for the X X axis.

But I don’t understand how this works. When I pitch the robot forward, it goes forward faster and faster in RViz. And when moving around it eventually drifts because of this. Why is linear_acceleration providing me angular values? Perhaps it is measuring the acceleration forces on the robot but this would change when the robot is pitch/rolled so how does the EKF properly control for changes in pitch and roll?

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  • $\begingroup$ Can you edit your question to provide the data that convinced you that the values are not what you're expecting? $\endgroup$
    – Tully
    Mar 17, 2023 at 18:08
  • $\begingroup$ @Tully I edited my comment. I’m getting the right values but have a hard time understanding how these values are used to determine position of the robot, if pitch and roll affects these values. $\endgroup$
    – Redstone
    Mar 21, 2023 at 3:37

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