小车无法脱机运行

bw1003002790

大佬，我格式化了还是不行呀，弄个追球小车，断开数据线就接上锂电池毫无反映呀，代码都弄到里面去的。

bw1003002790

大佬可以给个联系方式具体私聊吗？我QQ1003002790

yuan

请把你保存文件的具体步骤描述一下

bw1003002790

@yuan 先保存了一个 car.py 的代码文件在保存一个pid.py的文件最后保存小车运行的文件 main.py

bw1003002790

链接数据线和锂电池小车有反应断开其中一个就不行了

yuan

“先保存了一个 car.py 的代码文件在保存一个pid.py的文件 ”

怎么保存的？具体的步骤发一下

bw1003002790

先编写此代码

from pyb import Pin, Timer
inverse_left=False  #change it to True to inverse left wheel
inverse_right=False #change it to True to inverse right wheel

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(abs(left_speed))

    if right_speed < 0:
        bin1.low()
        bin2.high()
    else:
        bin1.high()
        bin2.low()
    ch2.pulse_width_percent(abs(right_speed))

``` 保存到FLASH里面 改名为car.py
在编写此代码

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')

接着编写此代码

Blob Detection Example

This example shows off how to use the find_blobs function to find color

blobs in the image. This example in particular looks for dark green objects.

import sensor, image, time
import car
from pid import PID

You may need to tweak the above settings for tracking green things...

Select an area in the Framebuffer to copy the color settings.

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

For color tracking to work really well you should ideally be in a very, very,

very, controlled enviroment where the lighting is constant...

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=0.05, 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() # Track elapsed milliseconds between snapshots().
img = sensor.snapshot() # Take a picture and return the image.

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]) # rect
    img.draw_cross(max_blob[5], max_blob[6]) # cx, cy
    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)

最后是如此显示
![0_1531728762292_@_SNM3RGHHPZ[VNY@HUMZPF.png](https://fcdn.singtown.com/d8c3377e-dfee-4793-8e0c-062df9e0118c.png)

bw1003002790

具体是按照追球小车的那三个代码来编的链接文本

yuan

你发的图片看不见。

你是怎么保存的，用的一键保存按钮？

bw1003002790

用工具里面的那个 "将打开的脚本保存到openmv cam" 保存的

yuan

断开数据线后，电池连接了吗？

bw1003002790

链接了的数据线和电池都链接的但是断了数据线后小车就不动了

yuan

首先，你要确保程序是正确的。

直接在IDE里运行小车的主程序。