4. 追小球小车关于识别问题
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    • 追小球小车关于识别问题

    • H

      老师我想请问一下为啥我按照历程上传程序，追小球的时候，小球在左边它向右转呢 左右方向相反咋回事，但是如果换了电机接线的话 那就前后相反了

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    • 检查一下：

      car.run(100,100)向前走，
      car.run(100,0)左轮子转，右轮子不转。
      car.run(0,100)左轮子不转，右轮子转。

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      H
       2 条回复
    • H

      @kidswong999 在 追小球小车关于识别问题 中说：

      左轮子转，右轮子不转。

      对的呀 老师 这些都是对的

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    • H

      @kidswong999

      import sensor, image, time
import car
from pid import PID
sensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.QQVGA)
sensor.skip_frames(10)
sensor.set_auto_whitebal(False)
clock = time.clock() # Tracks FPS.
green_threshold   = (76, 96, -110, -30, 8, 66)  
size_threshold = 2000  
x_pid = PID(p=0.5, i=1, imax=100)   
h_pid = PID(p=0.005, i=0.1, imax=50) 

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()
    img = sensor.snapshot()
    blobs = img.find_blobs([green_threshold])
    if blobs:
        max_blob = find_max(blobs)
        x_error = max_blob[5]-img.width()/2
        h_error = max_blob[2]*max_blob[3]-size_threshold
        print("x error: ", x_error)
        '''
        for b in blobs:
            # Draw a rect around the blob.
            img.draw_rectangle(b[0:4]) # rect
            img.draw_cross(b[5], b[6]) # cx, cy
        '''
        img.draw_rectangle(max_blob[0:4])
        img.draw_cross(max_blob[5], max_blob[6])
        x_output=x_pid.get_pid(x_error,1)
        h_output=h_pid.get_pid(h_error,1)
        print("h_output",h_output)
        car.run(-h_output-x_output,-h_output+x_output)
    else:
        car.run(10,-10)

      这是main.py

      from pyb import Pin, Timer
inverse_left=False
inverse_right=False
ain1 =  Pin('P0', Pin.OUT_PP)
ain2 =  Pin('P1', Pin.OUT_PP)
bin1 =  Pin('P2', Pin.OUT_PP)
bin2 =  Pin('P3', Pin.OUT_PP)
ain1.low()
ain2.low()
bin1.low()
bin2.low()
pwma = Pin('P7')
pwmb = Pin('P8')
tim = Timer(4, freq=1000)
ch1 = tim.channel(1, Timer.PWM, pin=pwma)
ch2 = tim.channel(2, Timer.PWM, pin=pwmb)
ch1.pulse_width_percent(0)
ch2.pulse_width_percent(0)
def run(left_speed, right_speed):
    #if inverse_left==True:
    #	left_speed=(-left_speed)
    #if inverse_right==True:
    #	right_speed=(-right_speed)
    if left_speed < 0:
        ain1.low()
        ain2.high()
    else:
        ain1.high()
        ain2.low()
    ch1.pulse_width_percent(int(abs(left_speed)))
    if right_speed < 0:
        bin1.low()
        bin2.high()
    else:
        bin1.high()
        bin2.low()
    ch2.pulse_width_percent(int(abs(right_speed)))

      这是car.py

      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')

      这是pid.py

      感觉都是用的原来的 不知道为啥，前进还有原地旋转都没有问题 就是这个左右反了 小球在左边向右转，小球在右边向左转

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