Madgwick AHRS MATLAB 程序

以下是Madgwick AHRS MATLAB程序的示例代码：

function [q] = MadgwickAHRS(imuData, beta, sampleFreq)

% MadgwickAHRS - Madgwick's implementation of the AHRS algorithm
%
% Syntax:  [q] = MadgwickAHRS(imuData,beta,sampleFreq)
%
% Inputs:
%    imuData - 6xN matrix of IMU data. Rows 1-3 are accelerometer data
%              (in g), and rows 4-6 are gyroscope data (in rad/s).
%    beta - algorithm gain (default 0.1)
%    sampleFreq - sampling frequency (Hz)
%
% Outputs:
%    q - 4x1 quaternion representing the estimated orientation
%

if (nargin < 3)
    sampleFreq = 100;
end

if (nargin < 2)
    beta = 0.1;
end

q = [1; 0; 0; 0]; % initialize quaternion

for i = 1:size(imuData,2)
    accel = imuData(1:3,i);
    gyro = imuData(4:6,i);

    % normalize accelerometer data
    accelNorm = norm(accel);
    if (accelNorm == 0)
        continue;
    end
    accel = accel / accelNorm;

    % estimate the direction of gravity in the body frame
    v = [2*(q(2)*q(4) - q(1)*q(3)); ...
         2*(q(1)*q(2) + q(3)*q(4)); ...
         q(1)^2 - q(2)^2 - q(3)^2 + q(4)^2];
    
    % error between the estimated and measured direction of gravity
    error = cross(v,accel);
    
    % gyroscope units are radians/s so we need to convert to quaternion rate
    gyro = gyro / sampleFreq;
    
    % integrate the gyroscope data
    qDot = 0.5 * quatmultiply(q',[0 gyro])';
    
    % estimate the orientation quaternion
    q = q + (qDot - beta * [0 error'])';
    
    % normalize the quaternion
    q = q / norm(q);
end

end

该程序的输入是一个6xN的IMU数据矩阵，其中前三行是加速度计数据（以g为单位），后三行是陀螺仪数据（以rad/s为单位）。程序的输出是一个4x1的四元数，表示估计的方向。程序中的beta参数是算法增益，sampleFreq是采样频率（Hz）。