Algorithm problem

masteriphone · November 15, 2023, 5:45pm

I don’t know why it wasn’t possible to redefine the direction of the accelerometer axis before, but now everything works.
As usual, if the acceleration axis is facing UP, then the force of gravity is directed DOWN and you just need to put a “-” in front of the acceleration value in the code:

github.com

rbv188/IMU-algorithm/blob/bd77afdb7018a46998ae74e12bcd763c5b6711b2/IMU-algorithm-master.ino#L41


      
            q_acc = quaternion_initialize(1.0,0.0,0.0,0.0);

            loop_start = millis();

          }

          void loop(){

            

            wx = 0.0005323*GyX;

            wy = 0.0005323*GyY;

            wz = 0.0005323*GyZ;

            

            delta = 0.001*(millis()-Start);

            fused_vector = update_fused_vector(fused_vector,AcX,AcY,AcZ,wx,wy,wz,delta);

            

            q_acc = quaternion_from_accelerometer(fused_vector.a,fused_vector.b,fused_vector.c);

            angles = quaternion_to_euler_angles(q_acc);

          

            Serial.print("A ");

            Serial.print(int(angles.yaw));Serial.print(" ");

            Serial.print(int(angles.pitch));Serial.print(" ");

            Serial.println(int(angles.roll));

          

            Start = millis();

I also found two options for calculating the roll angle from quaternion, in the source code there was the first option

result.roll = atan2(2*(q0*q1 + q2*q3),1 - 2*(q1*q1 + q2*q2))*180/3.14;
// result.roll = atan2f(q0*q1 + q2*q3, 0.5f - q1*q1 - q2*q2)*180/3.14;

and in the code you specified, there was a slightly different one.

But the result is not much different.
I'm looking for algorithms that will deal with changes in roll or pitch angles during sudden movements of the device.
Video1 and video2
And this video3 shows the operation of DCM from open source

github.com

pololu/minimu-9-ahrs-arduino/blob/master/MinIMU9AHRS/MinIMU9AHRS.ino

/*

MinIMU-9-Arduino-AHRS
Pololu MinIMU-9 + Arduino AHRS (Attitude and Heading Reference System)

Copyright (c) 2011-2016 Pololu Corporation.
http://www.pololu.com/

MinIMU-9-Arduino-AHRS is based on sf9domahrs by Doug Weibel and Jose Julio:
http://code.google.com/p/sf9domahrs/

sf9domahrs is based on ArduIMU v1.5 by Jordi Munoz and William Premerlani, Jose
Julio and Doug Weibel:
http://code.google.com/p/ardu-imu/

MinIMU-9-Arduino-AHRS is free software: you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by the
Free Software Foundation, either version 3 of the License, or (at your option)
any later version.

This file has been truncated. show original

The video shows that the algorithm successfully compensates for sideways jerks of the sensor, while the orientation angles remain stable.

Topic		Replies	Views
Determination of orientation in space (yaw, pitch, roll) exclusively by using a magnetometer Sensors	14	3857	March 10, 2024
Absolute angle from MPU6050 Sensors	3	231	October 1, 2025
Help with getting orientation from MPU 6050 under acceleration Sensors	1	306	September 4, 2023
Roll Pitch Yaw steady output Programming	13	715	October 3, 2025
Upgrading IMU (either code or hardware) General Guidance	4	195	March 8, 2026

Algorithm problem

Related topics