How to detect circle together with aruco marker?

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I am building a robot soccer system using aruco marker as the robot id. The aruco marker already can be detected now i'm having problem to detect the ball. I am using Hough Circle Transform to detect the circle. I am having problem when I combined the aruco code with the hough circle code.

This is the code for hough circle transform

 #ifndef BALL_HPP
 #define BALL_HPP

 #include <vector>
 #include <opencv2/aruco.hpp>
 #include <opencv2/opencv.hpp>

 class Ball
 {  
 private:

  public:
Ball(){}
~Ball(){}

inline cv::Mat Run( cv::Mat input )
{
    cv::Mat gray;
    cv::Mat bw;
    std::vector<cv::Vec3f> circles;

    /// Convert it to gray
    cvtColor( input, gray, CV_BGR2GRAY );

    /// Reduce the noise so we avoid false circle detection
    cv::GaussianBlur( gray, gray, cv::Size( 9, 9 ), 2, 2 );
    // medianBlur( gray, gray, 5 );

    // Threshold
    threshold( gray, bw, 150, 255, 0 );

    // return bw;

    /// Apply the Hough Transform to find the circles
    cv::HoughCircles( bw, circles, CV_HOUGH_GRADIENT, 1, bw.rows / 8, 200, 60, 0, 0 );

    /// Draw the circles detected
    for( size_t i = 0; i < circles.size(); i++ )
    {
        cv::Point center( cvRound(circles[i][0]), cvRound(circles[i][1] ) );
        int radius = cvRound(circles[i][2]);

        // std::cout << radius << std::endl;

        // circle center
        cv::circle( input, center, 3, cv::Scalar( 0, 255, 0 ), -1, 8, 0 );

        // circle outline
        cv::circle( input, center, radius, cv::Scalar( 0, 0, 255 ), 3, 8, 0 );
    }

    return input;
}
 };

#endif // BALL_HPP