Welcome to Raspbot V2 repository

5.Restricting

1. Learning Objectives

Previously, we used the four-way patrol module to patrol the line. Now we use this feature to surround the car with black lines, so that the car always moves in the circle we surround.

2. Experimental Preparation

1. The car wiring has been installed and installed correctly
2. Debug the four-way patrol module. The indicator light is on when it encounters a black line. The indicator light is off when it is not a black line.

3. Implementation Principle

The basic principle of infrared sensor patrol is to use the reflective properties of objects. Our experiment is to patrol the black line on a white background. When the infrared ray is emitted to the black line, it will be absorbed by the black line. When it is emitted to materials of other colors, it will be reflected back to the infrared receiving tube.

Through the four-way patrol module, we let the car turn left or right when it encounters a black line, and it can only go straight when it is all white. It can also be imagined as a kind of obstacle avoidance, with the obstacle being a black line.

4. Code analysis

Source code path:

/home/pi/project_demo/05.Comprehensive_gameplay/5.car_geofencing.ipynb

​x
import sys
import time

sys.path.append('/home/pi/project_demo/lib')
# Import Mecanum Car Driver Library
from McLumk_Wheel_Sports import *

speed = 25#25

try:
while True:
# Read line sensor data from I2C
track_data = bot.read_data_array(0x0a, 1)
track = int(track_data[0])

# Analyze the status of the line patrol sensor
x1 = (track >> 3) & 0x01
x2 = (track >> 2) & 0x01
x3 = (track >> 1) & 0x01 x4 = track & 0x01 """ X2 X1 X3 X4 | | | | elif lineL1 and not lineR1 and not lineR2: rotate_left(speed-10) time.sleep(1) # 00X1 elif not lineL1 and not lineL2 and lineR2: rotate_right(speed-10) time.sleep(1) # 10X1 elif lineL1 and not lineL2 and lineR2: rotate_right(speed-10) time.sleep(1) # 1X01 elif lineL1 and not lineR1 and lineR2: rotate_right(speed-10) time.sleep(1) # 0110 elif not lineL1 and lineL2 and lineR1 and not lineR2: rotate_right(speed-10) time.sleep(1) # 0111 elif not lineL1 and lineL2 and line R1 and lineR2: rotate_right(speed-20) time.sleep(1) # 1110 elif lineL1 and lineL2 and lineR1 and not lineR2: rotate_left(speed-20) time.sleep(1) # 1111 elif lineL1 and lineL2 and lineR1 and lineR2: move_forward(speed)

# Wait for a while before the next test
time.sleep(0.01)

except KeyboardInterrupt:
# Ensure that all motors stop when the user interrupts the program
stop_robot()
print("Ending")

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stop_robot()
# Cleaning up resources
del bot

5. Experimental results

We put the robot on a map surrounded by black lines, and make sure that the four-way patrol module of the robot is set to the indicator light when encountering black lines, and the indicator light is off when not black lines, and then run the program. After running the program, we can see that when the robot does not encounter a black line on the white map, it goes straight; when it encounters a black line on the edge of the map, it turns right or left, and always moves within the black circle.