Welcome to DOFBOT-Pi repository

Color Recognition Grab Blocks

1. Experiment Setup

Place the experiment setup according to the following: yellow blocks in the yellow area, red blocks in the red area, green blocks in the green area, blue blocks in the blue area.

2. Code Content

• Start Docker

After entering the main board desktop, open the terminal and run the following command to start the Dofbot corresponding container:

./Docker_Ros.sh

Then enter the following command in the docker terminal to start jupyter-lab,

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cd
jupyter-lab --allow-root

Then enter the main board's IP address plus :9999 in the browser,

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IP:9999         // Example: 192.168.1.11:9999

Code path: /root/Dofbot/6.AI_Visual/3.color_grab.ipynb

The following code content needs to be executed step by step according to the actual situation, cannot run all at once, running the last cell will directly exit the thread.

​x
#bgr8 to jpeg format conversion
import   enum
import   cv2
​
def   bgr8_to_jpeg(value, quality=75):
    return bytes(cv2.imencode('.jpg',   value)[1])

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# Import related modules
import   threading
import   time
from   Arm_Lib import Arm_Device
​
#   Create robotic arm object
Arm   = Arm_Device()
time.sleep(.1)

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# Camera component display
import   traitlets
import   ipywidgets.widgets as widgets
import   time
​
#   Thread function operation library
import   threading
import   inspect
import   ctypes
​
origin_widget   = widgets.Image(format='jpeg', width=320, height=240)
mask_widget   = widgets.Image(format='jpeg',width=320, height=240)
result_widget   = widgets.Image(format='jpeg',width=320, height=240)
​
#   Create a horizontal box container to place image widgets adjacent to each other
image_container   = widgets.HBox([origin_widget, mask_widget, result_widget])
#   image_container = widgets.Image(format='jpeg', width=600, height=500)
display(image_container)

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# Thread related functions
def   _async_raise(tid, exctype):
    """raises the exception,   performs cleanup if needed"""
​
    tid = ctypes.c_long(tid)
    if not inspect.isclass(exctype):
        exctype = type(exctype)
    res =   ctypes.pythonapi.PyThreadState_SetAsyncExc(tid, ctypes.py_object(exctype))
    if res == 0:
        raise ValueError("invalid thread   id")
    elif res != 1:
        # If the value of res is greater than 1, exception handling is required
          ctypes.pythonapi.PyThreadState_SetAsyncExc(tid, None)
     
def   stop_thread(thread):
    _async_raise(thread.ident, SystemExit)

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def   get_color(img):
    H = []
    color_name={}
    img = cv2.resize(img, (640, 480), )
    # Convert color image to HSV
    HSV = cv2.cvtColor(img,   cv2.COLOR_BGR2HSV)
    # Draw rectangle frame
    cv2.rectangle(img, (280, 180), (360,   260), (0, 255, 0), 2)
    # Extract H,S,V values from each row and column and put them into the container
    for i in range(280, 360):
        for j in range(180, 260):   H.append(HSV[j, i][0])
    # Calculate the maximum and minimum of H,S,V respectively
    H_min = min(H);H_max = max(H)
#     print(H_min,H_max)
   # Determine color
​
    if H_min >= 0 and H_max
    elif H_min >= 26 and H_max <= 34:   color_name['name'] = 'yellow'
    elif H_min >= 35 and H_max <= 78:   color_name['name'] = 'green'
    elif H_min >= 100 and H_max <= 124:   color_name['name'] = 'blue'
    return img, color_name

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#   Define variable parameters for different positions
look_at   = [90, 164, 18, 0, 90, 90]
p_top   = [90, 80, 50, 50, 270]
p_Yellow   = [65, 22, 64, 56, 270]
p_Red   = [118, 19, 66, 56, 270]
​
p_Green   = [136, 66, 20, 29, 270]
p_Blue   = [44, 66, 20, 28, 270]
p_gray   = [90, 48, 35, 30, 270]

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#   Define robotic arm movement function, control servos 1-6 simultaneously, p=[S1,S2,S3,S4,S5,S6]
​
def   arm_move_6(p, s_time = 500):
    for i in range(6):
        id = i + 1
        Arm.Arm_serial_servo_write(id, p[i],   s_time)
​
        time.sleep(.01)
​
    time.sleep(s_time/1000)
​
#   Define robotic arm movement function, control servos 1-5 simultaneously, p=[S1,S2,S3,S4,S5]
def   arm_move(p, s_time = 500):
    for i in range(5):
        id = i + 1
        if id == 5:
            time.sleep(.1)
            Arm.Arm_serial_servo_write(id,   p[i], int(s_time*1.2))
        elif id == 1 :
            Arm.Arm_serial_servo_write(id,   p[i], int(3*s_time/4))
        else:
            Arm.Arm_serial_servo_write(id,   p[i], int(s_time))
        time.sleep(.01)
    time.sleep(s_time/1000)
​
#   Define block clamping function, enable=1: clamp, =0: release
def   arm_clamp_block(enable):
    if enable == 0:
        Arm.Arm_serial_servo_write(6, 60,   400)
    else:
        Arm.Arm_serial_servo_write(6, 130,   400)
    time.sleep(.5)

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arm_move_6(look_at,   1000)
time.sleep(1)

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global   g_state_arm
g_state_arm   = 0
​
def   ctrl_arm_move(index):
    arm_clamp_block(0)
​
    if index == 1:
        print("黄色")
        number_action(index)
        put_down_block()
​
    elif index == 2:
        print("红色")
        number_action(index)
        put_down_block()
​
    elif index == 3:
        print("绿色")
        number_action(index)
        put_down_block()
​
    elif index == 4:
        print("蓝色")
        number_action(index)
        put_down_block()
​
    global g_state_arm
​
    g_state_arm = 0

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def   start_move_arm(index):
​
    # Start robotic arm control thread
    global g_state_arm
    if g_state_arm == 0:
        closeTid = threading.Thread(target =   ctrl_arm_move, args = [index])
        closeTid.setDaemon(True)
        closeTid.start()
        g_state_arm = 1

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#   Main process
import   cv2
​
import   numpy as np
​
import   ipywidgets.widgets as widgets
​
cap   = cv2.VideoCapture(0)
​
cap.set(3,   640)
​
cap.set(4,   480)
​
cap.set(5,   30)  #Set frame rate
​
cap.set(cv2.CAP_PROP_FOURCC,   cv2.VideoWriter.fourcc('M', 'J', 'P', 'G'))
​
#   image.set(cv2.CAP_PROP_BRIGHTNESS, 40) #Set brightness -64 - 64  0.0
​
#   image.set(cv2.CAP_PROP_CONTRAST, 50)     #Set contrast -64 - 64  2.0
​
#   image.set(cv2.CAP_PROP_EXPOSURE, 156)    #Set exposure value 1.0 - 5000  156.0
​
#   Default select red, the program will automatically switch colors based on the color detected in the box
​
#   Red range
​
color_lower   = np.array([0, 43, 46])
​
color_upper   = np.array([10, 255, 255])
​
#   #Green range
​
#   color_lower = np.array([35, 43, 46])
​
#   color_upper = np.array([77, 255, 255])
​
#   #Blue range
​
#   color_lower=np.array([100, 43, 46])
​
#   color_upper = np.array([124, 255, 255])
​
#   #Yellow range
​
#   color_lower = np.array([26, 43, 46])
​
#   color_upper = np.array([34, 255, 255])
​
#   #Orange range
​
#   color_lower = np.array([11, 43, 46])
​
#   color_upper = np.array([25, 255, 255])
​
def   Color_Recongnize():
​
    Arm.Arm_Buzzer_On(1)
​
    s_time = 300
​
    Arm.Arm_serial_servo_write(4, 10, s_time)
​
    time.sleep(s_time/1000)
​
    Arm.Arm_serial_servo_write(4, 0, s_time)
​
    time.sleep(s_time/1000)
​
    Arm.Arm_serial_servo_write(4, 10, s_time)
​
    time.sleep(s_time/1000)
​
    Arm.Arm_serial_servo_write(4, 0, s_time)
​
    time.sleep(s_time/1000)
​
    while(1):
​
        # get a frame and show Get video frame and convert to HSV format, use cvtColor() to convert BGR format to HSV format, parameter is cv2.COLOR_BGR2HSV.
​
        ret, frame = cap.read()
​
        frame, color_name = get_color(frame)
​
        if len(color_name)==1:
​
            global color_lower
​
            global color_upper
​
#             print ("color_name :",   color_name)
​
#             print ("name :",   color_name['name'])
​
            if color_name['name'] ==   'yellow':
​
                color_lower = np.array([26,   43, 46])
​
                color_upper = np.array([34,   255, 255])
​
                start_move_arm(1)
​
            elif color_name['name'] == 'red':
​
                color_lower = np.array([0,   43, 46])
​
                color_upper = np.array([10,   255, 255])
​
                start_move_arm(2)
​
            elif  color_name['name'] == 'green':
​
                color_lower = np.array([35,   43, 46])
​
                color_upper = np.array([77,   255, 255])
​
                start_move_arm(3)
​
            elif color_name['name'] ==   'blue':
​
                color_lower=np.array([100,   43, 46])
​
                color_upper = np.array([124,   255, 255])
​
                start_move_arm(4)
​
        origin_widget.value =   bgr8_to_jpeg(frame)
​
        #cv2.imshow('Capture', frame)
​
        # change to hsv model
​
        hsv = cv2.cvtColor(frame,   cv2.COLOR_BGR2HSV)
​
        # get mask Use inRange() function and the upper and lower bounds of the blue range in HSV model to get mask, the blue part in the original video in mask will be turned white, other parts black.
        mask = cv2.inRange(hsv, color_lower,   color_upper)
        #cv2.imshow('Mask', mask)
        mask_widget.value =   bgr8_to_jpeg(mask)
​
        # detect blue Perform bitwise AND operation between mask and original video frame, which will replace the white in mask with the real image:
        res = cv2.bitwise_and(frame, frame,   mask=mask)
        #cv2.imshow('Result', res)
        result_widget.value =   bgr8_to_jpeg(res)
​
        #       if cv2.waitKey(1) & 0xFF == ord('q'):
        #         break
        time.sleep(0.01)
    cap.release()
    #cv2.destroyAllWindows()

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# Start process
thread1   = threading.Thread(target=Color_Recongnize)
thread1.setDaemon(True)
thread1.start()

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# End process, this code segment only needs to be executed when ending
stop_thread(thread1)

You can place the blocks in front of the camera, the camera will detect the color of the blocks, and then place the blocks in the corresponding color area. The robotic arm will grab the blocks in the corresponding area to the middle area according to the detected color. Or you can first place the blocks in the corresponding color area, then find yellow, red, green, and blue color cards and place them in front of the camera, the robotic arm will grab the corresponding blocks according to the detected color and place them in the middle area.

Note: After grabbing each block, you need to remove the blocks in the middle area, otherwise it will block the next block placement.