タイプエラー：繰り返し不可能なnumpy.float64オブジェクトと黒いオブジェクトの線検出をオンにできません

これは私が使用しているコードです。車両が高速で移動しているときにこのエラーが発生します。この問題を解決するにはどうすればよいですか。線として検出された領域の黒いオブジェクトに線を表示したいのですが、できませんでした。あなたもこれを手伝ってもらえますか？

import cv2
import numpy as np

def make_coordinates(image, line_parameters):
    slope, intercept = line_parameters
    y1 = image.shape[0]
    y2 = int(y1*(3/5))
    x1 = int((y1 - intercept)/slope)
    x2 = int((y2 - intercept)/slope)
    return np.array([x1, y1, x2, y2])

def average_slope_intercept(image, lines):
    left_fit = []
    right_fit = []
    if lines is not None:
        for line in lines:
            x1, y1, x2, y2 = line.reshape(4)
            parameters = np.polyfit((x1, x2), (y1, y2), 1)
            slope = parameters[0]
            intercept = parameters[1]
            if slope < 0:
                left_fit.append((slope, intercept))
            else:
                right_fit.append((slope, intercept))
        left_fit_average = np.average(left_fit, axis=0)
        #right_fit_average = np.average(right_fit, axis=0)
        print(left_fit_average, 'left')
        #print(right_fit_average, 'right')
        left_line = make_coordinates(image, left_fit_average)
        #right_line = make_coordinates(image, right_fit_average)
        return np.array([left_line])


def canny(img):
    gray = cv2.cvtColor(img, cv2.COLOR_RGB2GRAY)
    kernel = 5
    blur = cv2.GaussianBlur(gray, (kernel, kernel), 0)
    canny = cv2.Canny(blur, 50, 150)
    return canny


def display_lines(img, lines):
    line_image = np.zeros_like(img)
    if lines is not None:
        for line in lines:
            for x1, y1, x2, y2 in line:
                cv2.line(line_image, (x1, y1), (x2, y2), (255, 0, 0), 10)
    return line_image


def region_of_interest(canny):
    height = canny.shape[0]
    width = canny.shape[1]
    mask = np.zeros_like(canny)

    square = np.array([[(635,478),(0,478),(281,200)]
                       ])
    cv2.fillPoly(mask, square, 255)
    masked_image = cv2.bitwise_and(canny, mask)
    return masked_image

cap = cv2.VideoCapture(0)
while True:
    _, frame = cap.read()
    canny_image = canny(frame)
    cropped_canny = region_of_interest(canny_image)
    lines = cv2.HoughLinesP(cropped_canny, 2, np.pi / 180, 100, np.array([]), minLineLength=40, maxLineGap=5)
    averaged_lines = average_slope_intercept(frame, lines)
    line_image = display_lines(frame, averaged_lines)
    combo_image = cv2.addWeighted(frame, 0.8, line_image, 1, 1)
    cv2.imshow("result", combo_image)
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break
cap.release()
cv2.destroyAllWindows()

コードを実行すると、プログラムが表示するエラーは次のようになります。

/usr/lib/python3/dist-packages/numpy/lib/function_base.py:392: RuntimeWarning: Mean of empty slice.
  avg = a.mean(axis)
/usr/lib/python3/dist-packages/numpy/core/_methods.py:85: RuntimeWarning: invalid value encountered in double_scalars
  ret = ret.dtype.type(ret / rcount)
nan left
Traceback (most recent call last):
  File "/home/pi/Desktop/code.py", line 71, in <module>
    averaged_lines = average_slope_intercept(rotated, lines)
  File "/home/pi/Desktop/code.py", line 48, in average_slope_intercept
    left_line = make_coordinates(image, left_fit_average)
  File "/home/pi/Desktop/code.py", line 55, in make_coordinates
    slope, intercept = line_parameters
TypeError: cannot unpack non-iterable numpy.float64 object

私はopencvを初めて使用します。これを手伝っていただければ幸いです。