元器件材料清单：
树莓派 *1
arduino Nano *1
L298N电机驱动模块 *1
左右轮马达 各1
7.2V锂电池 （电机驱动供电）
充电宝 5V 2A （树莓派）
手机Micro USB线
Nano MINI USB Type B
快换接头 *1
杜邦线
超声波
USB摄像头
圆形车底盘
用杜邦线把，接口对应相连：
arduino Nano L298N电机驱动模块
5 IN1
6 IN2
9 IN3
10 IN4
GND GND
VIN +5V
arduino Nano 超声波模块
5V VCC
8 (EchoPin, INPUT)
7 (TrigPin, OUTPUT)
GND GND
UNO接USB供电，输出电流比较弱，可能无法驱动电机，需要 5V输入 端口，独立供电，
驱动模块5V输入 Nano
GND GND
+5V VIN
A 左轮马达
OUT1 马达 正极+ 红线
OUT 2 马达 负极- 黑线
B 右轮马达
OUT3 马达 正极+ 红线
OUT 4 马达 负极- 黑线
主电源 7.2V锂电池
+12V 正极+
GND 负极-
| 2:驱动直流电机
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||
如果要做电机调速，还可以让Arduino输出PWM波，而不是恒定的5V电平，达到控制速度的效果（本项目暂时没有用）。
代码：
（主要本例为圆形底盘，左轮马达由5、6控制正反转，右轮马达由9、10控制左右）
正转 反转 左转 右转 左单 右单
5 高 低 低 高 低 高
6 低 高 高 低 低 低
9 高 低 高 低 高 低
10 低 高 低 高 低 低
arduino Nano 代码：
int led = 13;
//float duration;
//float distance;
//int srfPin = 8;
const int TrigPin = 7; //发出超声波
const int EchoPin = 8; //收到反射回来的超声波
float cm; //因为测得的距离是浮点型的
void setup()
{
Serial.begin(9600);
pinMode(led, OUTPUT);
pinMode(9,OUTPUT);//右轮马达 正极+
pinMode(10,OUTPUT);//右轮马达 负极-
pinMode(5,OUTPUT); //左轮马达 正极+
pinMode(6,OUTPUT);//左轮马达 负极-
pinMode(TrigPin, OUTPUT);
pinMode(EchoPin, INPUT);
}
void loop()
{
delay(100); // wait for a second
if (Serial.available()>0)
{
char cmd = Serial.read();
//Serial.print(cmd);
Serial.print(cmd);
Serial.println();
switch (cmd)
{
case '1':
Forward();
break;
case '2':
Back();
break;
case '3':
Turn_left();
break;
case '4':
Turn_right();
break;
case '7':
Only_left();
break;
case '8':
Only_right();
break;
case '9':
Stop();
break;
case '6':
Measure();
default:
Stop();
}
}
//Measure();
//超声波循环测距，测试时可暂时屏蔽；case '6'只是单次测距
}
void Forward()
{
digitalWrite(9,HIGH);
digitalWrite(10,LOW);
digitalWrite(5,HIGH);
digitalWrite(6,LOW);
}
void Back()
{
digitalWrite(9,LOW);
digitalWrite(10,HIGH);
digitalWrite(5,LOW);
digitalWrite(6,HIGH);
}
void Turn_right()
{
digitalWrite(9,LOW);
digitalWrite(10,HIGH);
digitalWrite(5,HIGH);
digitalWrite(6,LOW);
}
void Turn_left()
{
digitalWrite(9,HIGH);
digitalWrite(10,LOW);
digitalWrite(5,LOW);
digitalWrite(6,HIGH);
}
void Stop()
{
digitalWrite(9,LOW);
digitalWrite(10,LOW);
digitalWrite(5,LOW);
digitalWrite(6,LOW);
}
void Only_left()
{
digitalWrite(9,HIGH);
digitalWrite(10,LOW);
digitalWrite(5,LOW);
digitalWrite(6,LOW);
}
void Only_right()
{
digitalWrite(9,LOW);
digitalWrite(10,LOW);
digitalWrite(5,HIGH);
digitalWrite(6,LOW);
}
void Measure()
{
/*
pinMode(srfPin, OUTPUT);
digitalWrite(srfPin, LOW);
delayMicroseconds(2);
digitalWrite(srfPin, HIGH);
delayMicroseconds(10);
digitalWrite(srfPin, LOW);
pinMode(srfPin, INPUT);
duration = pulseIn(srfPin, HIGH);
distance = duration/58;
Serial.println(distance);
delay(50); */
digitalWrite(TrigPin, LOW); //低高低电平发一个短时间脉冲去TrigPin
delayMicroseconds(2); // delayMicroseconds在更小的时间内延时准确
digitalWrite(TrigPin, HIGH);
delayMicroseconds(10);
digitalWrite(TrigPin, LOW); //通过这里控制超声波的发射
cm = pulseIn(EchoPin, HIGH) / 58.0; //将回波时间换算成cm
cm = (int(cm * 100.0)) / 100.0; //保留两位小数
Serial.print("Distance:");
Serial.print(cm);
Serial.print("cm");
Serial.println();
delay(50);
}
打开IDE，nano通过USB连接电脑；
选择匹配的 开发版 和 端口；
验证无误后，点击上传：
卸载设备，断电接线；
实物接线：
测试：
nano通过USB连接树莓派，启动树莓派：
通过VNC连接树莓派，启动自动驾驶程序：
cd /home/pi/Desktop/smart_car-master
python smart_raspberry.py
Ctrl+z暂停，kill +%1终止程序；
灯还亮，运行
python pixels.py
再Ctrl+c，LED灯即可熄灭；
测试：
原教程提供的镜像不适用于树莓派3B+，烧录 respeaker提供的镜像安装必要的服务即可正常运行程序：
本例应用的镜像：
下载链接：
https://v2.fangcloud.com/share/7395fd138a1cab496fd4792fe5?folder_id=188000207913
自行安装python-opencv，
本例源代码仅修改两处：
直接导入Image，出错，修改PIL.Image即可正常导入
nano通过USB接入，选USB0；
需要根据自己的硬件情况做相应修改；
最终代码：
#!/usr/bin/env python
import socket
import sys
import threading
import random
import os
import time
import struct
import serial
import cv
import cv2
import PIL.Image, StringIO
import numpy as np
from voice_engine.source import Source
from voice_engine.channel_picker import ChannelPicker
from voice_engine.doa_respeaker_4mic_array import DOA
from pixels import pixels
import datetime
port_serial="/dev/ttyUSB0"
sl = serial.Serial(port_serial,9600)
HOST = "0.0.0.0"
PORT = 9004
SOCK_ADDR = (HOST, PORT)
exit_now = 0
distance = 0
moving = False
last_movement_timestamp = datetime.datetime.now()
doa_valid = True
def exit_signal_handle(sig,stack_frame):
global exit_now
print "EXIT sig"
exit_now = 1
class serial_thread(threading.Thread):
def __init__(self):
threading.Thread.__init__(self)
def run(self):
self.running = True
while self.running:
try:
global distance
data=sl.readline()
#print "^^^^^^"
#print data
tmp = data.split("\r\n")[0]
if (":" in tmp ) and (";" in tmp):
distance_str = (tmp.split(":")[1]).split(";")[0]
distance = float(distance_str.decode("utf-8"))
#print str(distance)
#print "vvvvvv"
except:
print sys.exc_info()
def stop(self):
self.running = False
class doa_thread(threading.Thread):
def __init__(self):
threading.Thread.__init__(self)
def run(self):
global moving,last_movement_timestamp,doa_valid
src = Source(rate=16000, channels=4, frames_size=320)
ch1 = ChannelPicker(channels=4, pick=1)
doa = DOA(rate=16000)
src.link(ch1)
src.link(doa)
src.recursive_start()
self.running = True
while self.running:
try:
time.sleep(1)
current_timestamp = datetime.datetime.now()
if doa_valid == True and ((current_timestamp - last_movement_timestamp).seconds > 2):
position, amplitute = doa.get_direction()
if amplitute > 2000:
pixels.wakeup(position)
print amplitute,position
if position > 0 and position < 180:
pivot_right()
time.sleep(position/200)
stop()
elif position >= 180 and position < 360:
pivot_left()
position = 360 - position
time.sleep(position/200)
stop()
time.sleep(2)
else:
pixels.speak()
else:
pixels.think()
except:
print sys.exc_info()
src.recursive_stop()
def stop(self):
self.running = False
class movement_thread(threading.Thread):
def __init__(self, movement_type, quantity):
threading.Thread.__init__(self)
self.movement_type = movement_type
self.quantity = quantity
def run(self):
global moving, last_movement_timestamp
current_timestamp = datetime.datetime.now()
if (current_timestamp - last_movement_timestamp).seconds > 0.5:
moving = True
if self.movement_type == 1:
forward()
time.sleep(self.quantity/200)
stop()
elif self.movement_type == 2:
reverse()
time.sleep(self.quantity/200)
stop()
elif self.movement_type == 3:
pivot_left()
time.sleep(self.quantity/200)
stop()
elif self.movement_type == 4:
pivot_right()
time.sleep(self.quantity/200)
stop()
moving = False
last_movement_timestamp = datetime.datetime.now()
def forward():
string="1"
sl.write(string)
def reverse():
string="2"
sl.write(string)
def pivot_left():
string="3"
sl.write(string)
def pivot_right():
string="4"
sl.write(string)
def measure():
string="6"
sl.write(string)
def stop():
string="0"
sl.write(string)
def main():
global moving,last_movement_timestamp,doa_valid,distance
doa_th = doa_thread()
doa_th.start()
ser_th = serial_thread()
ser_th.start()
cap=cv2.VideoCapture(0)
ret=cap.set(3,320)
ret=cap.set(4,240)
#resize = 2
avg = None
while exit_now == 0:
ret, frame = cap.read()
frame = cv2.flip(frame,-1)
hsv = cv2.cvtColor(frame,cv2.COLOR_BGR2HSV)
lower_blue = np.array([100,50,50])
upper_blue = np.array([140,255,255])
mask = cv2.inRange(hsv,lower_blue,upper_blue)
if avg is None:
avg = mask.copy().astype("float")
continue
cv2.accumulateWeighted(mask,avg,0.5)
thresh = cv2.threshold(mask,25,255,cv2.THRESH_BINARY)[1]
kernel = np.ones((4,4),np.uint8)
thresh = cv2.erode(thresh,kernel, iterations = 1)
kernel = np.ones((13,13),np.uint8)
thresh = cv2.dilate(thresh, kernel, iterations = 1)
#cv2.imshow('thre',thresh)
(cnts,_) = cv2.findContours(thresh.copy(),cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_SIMPLE)
max_area = 0
rect_max = (0,0,0,0)
for c in cnts:
if cv2.contourArea(c) < 3000:
continue
if cv2.contourArea(c) > max_area:
max_area = cv2.contourArea(c)
rect_max = cv2.boundingRect(c)
#gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
#gray = cv2.equalizeHist(gray)
if max_area !=0:
doa_valid = False
(x,y,w,h) = rect_max
#cv2.rectangle(frame,(x,y),(x+w,y+h),(0,0,255),2)
x1 = x
y1 = y
x2 = x+w
y2 = y+h
x_mid = float((x1+x2)/2)
y_mid = float((y1+y2)/2)
print x_mid,y_mid,x1,x2
if x_mid > (160 + 30) and np.abs(x2-x1) < 150 :
mt = movement_thread(4,(np.abs(x_mid-160))/10)
mt.start()
elif x_mid < (160 - 30) and np.abs(x2-x1) < 150 :
mt = movement_thread(3,(np.abs(x_mid-160))/10)
mt.start()
else:
print "DB for cam"
#measure()
print "first:",str(distance)
#if distance > 450:
#print "not detected by sonar"
#mt = movement_thread(1,np.abs(80))
#mt.start()
#else:
if distance < 450:
#print "target detected by sonar:",str(distance)
if distance > 50:
print "too far, move forward"
mt = movement_thread(1,np.abs(distance-50)*1)
mt.start()
elif distance < 30:
print "too close, move backward"
mt = movement_thread(2,np.abs(distance-50)*1)
mt.start()
else:
print "DB for sonar"
else:
doa_valid = True
doa_th.stop()
doa_th.join()
ser_th.stop()
ser_th.join()
if __name__ == "__main__":
main()
参考链接：
原教程链接，硬件连接部分不够详细；本教程做相应补充；
https://blog.csdn.net/shukebeta008?t=1
基于声音和视频的人跟随自动驾驶汽车- smart_car 语音视频控制环境
https://blog.csdn.net/jacka654321/article/details/82493083
基于声音和视频的人跟随自动驾驶汽车- smart_car（PC控制）
https://blog.csdn.net/jacka654321/article/details/81951470
基于声音和视频的人跟随自动驾驶汽车- smart_car PC端 python环境搭建