Raspi伺服抖动，在应该静止的时候来回移动

Question

(很抱歉格式化(我正在尝试编写一个opencv程序来跟踪红色。到目前为止，它还可以工作，但伺服系统会抖动，当物体静止并居中时，伺服系统会来回移动。我有一个470uf电容器和一个外部电源。任何能让它更顺利的帮助都是天赐之物！

''

from picamera.array import PiRGBArray 
from picamera import PiCamera
import time 
import cv2
import numpy as np
import RPi.GPIO as GPIO
import time

###SERVO SETUP###
servoPIN_x = 17
servoPIN_y = 18
GPIO.setmode(GPIO.BCM)
GPIO.setup(servoPIN_x, GPIO.OUT)
GPIO.setup(servoPIN_y, GPIO.OUT)
px = GPIO.PWM(servoPIN_x, 50)
py = GPIO.PWM(servoPIN_y, 50)
position_x = 7.5
position_y = 7.5
px.start(position_x)
py.start(position_y)
x_gain = 0.1#0.01 - 5.00
y_gain = 0.3#0.01 - 5.00
xon = True
yon = True
###CAMERA SETUP##
camera = PiCamera()
camera.resolution = (640, 480)
camera.framerate = 32
raw_capture = PiRGBArray(camera, size=(640, 480))
time.sleep(0.1)

###VIDEO CAPTURE LOOP### 
for frame in camera.capture_continuous(raw_capture, format="bgr", use_video_port=True):
#cv2 video init
image = frame.array
hsv_frame = cv2.cvtColor(image,cv2.COLOR_BGR2HSV)
#color parameters
low_red = np.array([161,155,84])
high_red = np.array([179,255,255])
#find color
red_mask = cv2.inRange(hsv_frame, low_red, high_red)#create black/white mask for all reds
contours,_ = cv2.findContours(red_mask,cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)#find different red contours
contours = sorted(contours, key=lambda x:cv2.contourArea(x), reverse=True)#sort contours from largest to smallest
#set line x/y var to center
x_medium=320
y_medium=240
#loop sets x/y_medium
for cnt in contours:
(x,y,w,h) = cv2.boundingRect(cnt)
y_medium = int((y+y+h)/2)
x_medium = int((x+x+w)/2)
cv2.rectangle(image,(x,y),(x+w,y+h),(0,255,0),2)
break
#draw lines
cv2.line(image,(x_medium,0),(x_medium,480), (0,255,0),2)
cv2.line(image,(0,y_medium),(640,y_medium), (0,255,0),2)
#cv2.imshow('mask', red_mask)
#show regular frame
cv2.imshow("Frame", image)
key = cv2.waitKey(1) & 0xFF
raw_capture.truncate(0)
#quit 
if key == ord("q"):
cv2.waitKey(1)
px.stop()
py.stop
break

#servoX travels to place postion_x in center frame
if not xon and x_medium != 320:
px.start(position_x)

if x_medium > 320:
position_x = position_x - x_gain

elif x_medium < 320:
position_x = position_x + x_gain
elif x_medium == 320:
position_x = position_x
xon = False
else:
position_x = 7.5

if xon:
px.ChangeDutyCycle(position_x)
else:
px.stop

px.stop()
py.stop()
cv2.destroyAllWindows()
exit(0)

''

Answer 1

在建造机器人时，我对这种伺服电机也有同样的问题。我使用另一个名为"；pigpio"；，以控制树莓派的引脚。从那时起，伺服系统不再无故移动。命令非常相似。看看：

http://abyz.me.uk/rpi/pigpio/