Porter

For all functions involving grabbing square blocks, please use 30x30x30 mm wooden blocks. Non-standard sized objects may cause servo 6 to stall and become damaged.

1. Overview

The purpose of this experiment is to stack four colored blocks from bottom to top in the order of blue, green, red, yellow, then place them on the center cross block. After running the code, the robotic arm will sequentially grab the fourth layer block to the yellow area, the third layer block to the red area, the second layer block to the green area, and the bottom layer block to the blue area.

The block placement method is shown in the figure below:

After executing the code, the robotic arm will move the blocks to the corresponding positions. The final result is shown below:

2. Code

Code path:

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~/dofbot_ctrl/scripts/10.move_block.ipynb

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#!/usr/bin/env python3
#coding=utf-8
import time
from Arm_Lib import Arm_Device
​
# Create robotic arm object
Arm = Arm_Device()
time.sleep(.1)
​
from dofbot_utils.robot_controller import Robot_Controller
robot = Robot_Controller()

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# Define block grabbing function, enable=1: grab, =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, 135, 400)
    time.sleep(.5)
​
    
# Define robotic arm movement function, simultaneously controls servos 1-5 movement, 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))
        else :
            Arm.Arm_serial_servo_write(id, p[i], s_time)
        time.sleep(.01)
    time.sleep(s_time/1000)
​
# Robotic arm moves upward
def arm_move_up():
    Arm.Arm_serial_servo_write(2, 90, 1500)
    Arm.Arm_serial_servo_write(3, 90, 1500)
    Arm.Arm_serial_servo_write(4, 90, 1500)
    time.sleep(.1)

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# Define variable parameters for different positions
p_mould = robot.P_LOOK_AT
p_top = robot.P_TOP
p_Brown = robot.P_CENTER
​
p_Yellow = robot.P_YELLOW
p_Red = robot.P_RED
​
p_Green = robot.P_GREEN
p_Blue = robot.P_BLUE
​
p_layer_4 = robot.P_CENTER_4
p_layer_3 = robot.P_CENTER_3
p_layer_2 = robot.P_CENTER_2
p_layer_1 = robot.P_CENTER

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# Move the robotic arm to a ready-to-grab position
arm_clamp_block(0)
arm_move(p_mould, 1000)
time.sleep(1)

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# Move the fourth layer block to the yellow area
arm_move(p_top, 1000)
arm_move(p_layer_4, 1000)
arm_clamp_block(1)
arm_move(p_top, 1000)
arm_move(p_Yellow, 1000)
arm_clamp_block(0)
time.sleep(.1)
arm_move_up()
arm_move(p_mould, 1100)

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# Move the third layer block to the red area
arm_move(p_top, 1000)
arm_move(p_layer_3, 1000)
arm_clamp_block(1)
arm_move(p_top, 1000)
arm_move(p_Red, 1000)
arm_clamp_block(0)
time.sleep(.1)
arm_move_up()
arm_move(p_mould, 1100)

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# Move the second layer block to the green area
arm_move(p_top, 1000)
arm_move(p_layer_2, 1000)
arm_clamp_block(1)
arm_move(p_top, 1000)
arm_move(p_Green, 1000)
arm_clamp_block(0)
time.sleep(.1)
arm_move_up()
arm_move(p_mould, 1100)

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# Move the first layer block to the blue area
arm_move(p_top, 1000)
arm_move(p_layer_1, 1000)
arm_clamp_block(1)
arm_move(p_top, 1000)
arm_move(p_Blue, 1000)
arm_clamp_block(0)
time.sleep(.1)
arm_move_up()
arm_move(p_mould, 1100)

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del Arm # Release the Arm object

Open the program file from Jupyter Lab and click the "Run All Cells" button on the Jupyter Lab toolbar. You will see the porter function of the robotic arm in action.