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Openmv云台寻找最大色块

代码是官方的代码,备注是自己加的,后续会改进
实验效果:

main.py:

import sensor, image, timefrom pid import PID
from pyb import Servopan_servo=Servo(1)# P7  底
tilt_servo=Servo(2)# P8 台
#s3 = Servo(3) # P9
pan_servo.calibration(500,2500,500)  #底  500-2500  中心值1500
tilt_servo.calibration(500,2500,500) #台red_threshold  = (9, 25, -28, -11, -33, 20)  #颜色阈值#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PIDsensor.reset() # 初始化摄像机传感器。
sensor.set_pixformat(sensor.RGB565) # 使用RGB565
sensor.set_framesize(sensor.QQVGA) # 速度使用QQVGA
sensor.skip_frames(10) # 让新设置生效。
sensor.set_auto_whitebal(False) # 关白平衡。。。。(导致每次开机都会自动搞出一个颜色,颜色识别会有问题)
clock = time.clock() # 跟踪FPS。赋值clock为现在的fps,超级低def find_max(blobs):max_size=0for blob in blobs:if blob[2]*blob[3] > max_size:max_blob=blobmax_size = blob[2]*blob[3]return max_blobwhile(True):clock.tick() #跟踪快照之间经过的毫秒数().img = sensor.snapshot() # 拍一张照片,然后返回图像。blobs = img.find_blobs([red_threshold])  #赋值blobs为找到红色像素的值if blobs:max_blob = find_max(blobs)          #找最大的色块#print("cx: ", max_blob.cx())             #打印X的的位置#print("cy: ", max_blob.cy())             #打印Y的的位置pan_error = max_blob.cx()-img.width()/2    #底的误差为最大色块所在的X轴-宽(宽固定=160  /2=80)我理解为取XY中心点tilt_error = max_blob.cy()-img.height()/2  #台的误差为最大色块所在的Y轴-高(120)#        print("pan_error: ", pan_error)             #打印底的偏差print("tilt_error: ", tilt_error)             #打印台的偏差'比如说现在X的距离是159 目标中心偏差159-img.width()/2=79'img.draw_rectangle(max_blob.rect()) # 矩形img.draw_cross(max_blob.cx(), max_blob.cy()) # cx, cy 交叉pan_output=pan_pid.get_pid(pan_error,1)/2    #底的转动=获取的PID值    get_pid(self, error, scaler)/2tilt_output=tilt_pid.get_pid(tilt_error,1)   #台的转动=获取的PID值    get_pid(self, error, scaler) 也可以除以2 走慢一点罢了'可以这样子理解,这个pid的函数是想使偏差=0'
#        print("pan_output",pan_output)print("tilt_output",tilt_output)pan_servo.angle(pan_servo.angle()+pan_output)    #底部舵机转动的角度为上一个角度+现在的输出(偏差)角度tilt_servo.angle(tilt_servo.angle()-tilt_output) #上面舵机转动的角度为上一个角度-现在的输出(偏差)角度  因为是倒转 所以是减print("tilt_servo.angle:",tilt_servo.angle())

官方PID算法:
pid.py

from pyb import millis
from math import pi, isnanclass 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_toutput = 0if self._last_t == 0 or dt > 1000:dt = 0self.reset_I()self._last_t = tnowdelta_time = float(dt) / float(1000)output += error * self._kpif abs(self._kd) > 0 and dt > 0:if isnan(self._last_derivative):derivative = 0self._last_derivative = 0else:derivative = (error - self._last_error) / delta_timederivative = self._last_derivative + \((delta_time / (self._RC + delta_time)) * \(derivative - self._last_derivative))self._last_error = errorself._last_derivative = derivativeoutput += self._kd * derivativeoutput *= scalerif abs(self._ki) > 0 and dt > 0:self._integrator += (error * self._ki) * scaler * delta_timeif self._integrator < -self._imax: self._integrator = -self._imaxelif self._integrator > self._imax: self._integrator = self._imaxoutput += self._integratorreturn outputdef reset_I(self):self._integrator = 0self._last_derivative = float('nan')

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