用云台人脸追踪时舵机只会向上移动不会向下并且向右移动比向左移动灵敏是怎么回事

[iuby]

import sensor, image, time
from pid import PID
from pyb import Servo
pan_servo=Servo(1)
tilt_servo=Servo(2)
pan_servo.calibration(500,2500,500)
tilt_servo.calibration(500,2500,500)
red_threshold  = (13, 49, 18, 61, 6, 47)
pan_pid = PID(p=0.07, i=0, imax=90)
tilt_pid = PID(p=0.05, i=0, imax=90)
sensor.reset()
sensor.set_contrast(1)
sensor.set_gainceiling(16)
sensor.set_pixformat(sensor.GRAYSCALE)
sensor.set_framesize(sensor.QQVGA)
sensor.set_vflip(True)
from pyb import millis
from math import pi, isnan
class PID:
	_kp = _ki = _kd = _integrator = _imax = 0
	_last_error = _last_derivative = _last_t = 0
	_RC = 1/(2 * pi * 20)
	def __init__(self, p=0, i=0, d=0, imax=0):
		self._kp = float(p)
		self._ki = float(i)
		self._kd = float(d)
		self._imax = abs(imax)
		self._last_derivative = float('nan')
	def get_pid(self, error, scaler):
		tnow = millis()
		dt = tnow - self._last_t
		output = 0
		if self._last_t == 0 or dt > 1000:
			dt = 0
			self.reset_I()
		self._last_t = tnow
		delta_time = float(dt) / float(1000)
		output += error * self._kp
		if abs(self._kd) > 0 and dt > 0:
			if isnan(self._last_derivative):
				derivative = 0
				self._last_derivative = 0
			else:
				derivative = (error - self._last_error) / delta_time
			derivative = self._last_derivative + \
									 ((delta_time / (self._RC + delta_time)) * \
										(derivative - self._last_derivative))
			self._last_error = error
			self._last_derivative = derivative
			output += self._kd * derivative
		output *= scaler
		if abs(self._ki) > 0 and dt > 0:
			self._integrator += (error * self._ki) * scaler * delta_time
			if self._integrator < -self._imax: self._integrator = -self._imax
			elif self._integrator > self._imax: self._integrator = self._imax
			output += self._integrator
		return output
	def reset_I(self):
		self._integrator = 0
		self._last_derivative = float('nan')

import sensor, image, time

from pid import PID
from pyb import Servo

pan_servo=Servo(1)
tilt_servo=Servo(2)

pan_servo.calibration(500,2500,500)
tilt_servo.calibration(500,2500,500)

red_threshold = (13, 49, 18, 61, 6, 47)

pan_pid = PID(p=0.07, i=0, imax=90) #脱机运行或者禁用图像传输，使用这个PID
tilt_pid = PID(p=0.05, i=0, imax=90) #脱机运行或者禁用图像传输，使用这个PID
#pan_pid = PID(p=0.1, i=0, imax=90)#在线调试使用这个PID
#tilt_pid = PID(p=0.1, i=0, imax=90)#在线调试使用这个PID

sensor.reset() # Initialize the camera sensor.
sensor.set_contrast(1)
sensor.set_gainceiling(16)
sensor.set_pixformat(sensor.GRAYSCALE) # use RGB565.
sensor.set_framesize(sensor.QQVGA) # use QQVGA for speed.
sensor.set_vflip(True)
sensor.skip_frames(10) # Let new settings take affect.
sensor.set_auto_whitebal(False) # turn this off.
clock = time.clock() # Tracks FPS.

face_cascade = image.HaarCascade("frontalface", stages=25)

def find_max(blobs):
max_size=0
for blob in blobs:
if blob[2]*blob[3] > max_size:
max_blob=blob
max_size = blob[2]*blob[3]
return max_blob

while(True):
clock.tick() # Track elapsed milliseconds between snapshots().
img = sensor.snapshot() # Take a picture and return the image.

blobs = img.find_features(face_cascade, threshold=0.75, scale=1.35)
if blobs:
    max_blob = find_max(blobs)
    pan_error = max_blob[0]+max_blob[2]/2-img.width()/2
    tilt_error = max_blob[1]+max_blob[3]/2-img.height()/2

    print("pan_error: ", pan_error)

    img.draw_rectangle(max_blob) # rect
    img.draw_cross(int(max_blob[0]+max_blob[2]/2), max_blob[1]+int(max_blob[3]/2-img.height()/2)) # cx, cy

    pan_output=pan_pid.get_pid(pan_error,1)/2
    tilt_output=tilt_pid.get_pid(tilt_error,1)
    print("pan_output",pan_output)
    pan_servo.angle(pan_servo.angle()+pan_output)
    tilt_servo.angle(tilt_servo.angle()-tilt_output)