代码是这样的

# Select an area in the Framebuffer to copy the color settings.
#from machine import I2C
#from vl53l1x import VL53L1X
import time

from pid import PID
from pyb import UART
import math
import json
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...


#i2c = I2C(2)
#distance = VL53L1X(i2c)
x_pid = PID(p=0.05, i=0.05, imax=100)
d_pid = PID(p=0.05, i=0.1, imax=50)

#uart1 = UART(3, 9600,timeout=1000)
uart1=UART(3, 9600)
uart1.init(9600, bits=8, parity=None, stop=1)
uart2=UART(1, 9600)
uart2.init(9600, bits=8, parity=None, stop=1)

List=list()
while(True):
#    clock.tick() # Track elapsed milliseconds between snapshots().
    List=[1]
    if uart1.any():
#        x_error =uart1.readline().decode()
        x_error = int(uart1.read().decode())
        print(x_error)
        SET=600


#        x_output=x_pid.get_pid(x_error,1)
#        print(x_output)
        if(x_error>=9999):
            a=len(List)
            D_24=0
            D_13=0
            List.append=("1")
            a=len(List)
            if(a>=3):
                FH = bytearray([57,168])
                uart2.write(FH)

                data = bytearray([27,27,27,27,60,5,60,5])   ###
                uart2.write(data)
                print(int(D_13),int(D_24))
        else:
            List=[0,]
            if(abs(x_error)>SET):

                x_output=d_pid.get_pid(x_error,1)


                D_24=-x_output   ###
                D_13=x_output  ###
                if((D_13)>=0):
                    a=5
                else:
                    a=60
                if((D_24)>=0):
                    b=5
                else:
                        b=60

#               FH = bytearray([168,168])
#               uart2.write(FH)
                D_13=abs(D_13)
                D_24=abs(D_24)
                if((D_13)>35):
                    D_13=35
                if((D_24)>35):
                    D_24=35

                FH = bytearray([57,168])
                uart2.write(FH)
                data = bytearray([int(D_13),int(D_24),int(D_13),int(D_24),a,b,a,b])   ###
                uart2.write(data)


#                print(int(D_13),int(D_24),a,b,a,b)


            else:
#               x_output=x_pid.get_pid(x_error,1)
#               print(x_output)
                theta_default=0.5*math.pi            #  0.5*3.14
#               l_threshold=100                     #####
                delta_theta_max=0.785
                a=delta_theta_max/SET
#               print(a)
#               x_output=x_pid.get_pid(x_error,1)
                delta_theta=a*x_error
#               d = distance.read()
#               print(d)

                k=30   ####
                D_14=k*(math.cos(theta_default+delta_theta)+math.sin(theta_default+delta_theta))
                D_23=k*(math.sin(theta_default+delta_theta)-math.cos(theta_default+delta_theta))
#                print(D_14,D_23)
                FH = bytearray([57,168])
                uart2.write(FH)
                data = bytearray([int(D_14),int(D_23),int(D_23),int(D_14),5,5,5,5])
                uart2.write(data)
                print(int(D_14),int(D_23),int(D_23),int(D_14),5,5,5,5)

会报错：AttributeError: 'NoneType' object has no attribute 'append'

@kidswong999 啊不是，不是这个意思，我是说咱们程序中pid代码返回的是占空比还是占空比的增量啊

小车pid代码是不是用问题

output += error * self._kp

既然用的是增量式pid，为什么是kp乘以error呢，根据增量式 PID 公式：
Pwm += Kp[e(k)-e(k-1)]+Ki*e(k)+Kd[e(k)-2e(k-1)+e(k-2)]
难道不应该是kp乘以error-self._last_error吗

为什么追小球的小车没有用微分控制，只用了p和i呢

那咱们的pid代码返回的是增量吗还是占空比啊

代码如下：

    if uart1.any():
        x_error = int(uart1.readline().decode())
        print(x_error)

我用下面这两种代码都接收不到，应该怎么办呢

    if uart1.any():
        x_error = uart1.read()
        print(x_error)

    if uart1.any():
        x_error = int(uart1.readline().decode())
        print(x_error)

增量式pid不是应该返回增量吗，为什么这个返回的是当前的占空比的

car.run(-h_output-x_output,-h_output+x_output)

当小车到达合适的距离而且左右也没有偏差的时候，h_error和x_error都为0，但由于是增量式pid，h_output和x_output都不为0，而且如果是从远处走向近处的话，h_output应该是小于0的啊，加上负号之后就成正值了，当到达设定的距离之后，h_outpu不为零，小车怎么会停下来呢