我是学数学的，不是学自动化的，啥啥的自动控制，啥啥的信号系统，我啥也不懂，在恶补。
最基本的一个pid控制器
代码语言：javascript复制import time
class PID:
"""PID Controller
"""
def __init__(self, P=0.2, I=0.0, D=0.0, current_time=None):
self.Kp = P
self.Ki = I
self.Kd = D
self.sample_time = 0.00
self.current_time = current_time if current_time is not None else time.time()
self.last_time = self.current_time
self.clear()
def clear(self):
"""Clears PID computations and coefficients"""
self.SetPoint = 0.0
self.PTerm = 0.0
self.ITerm = 0.0
self.DTerm = 0.0
self.last_error = 0.0
# Windup Guard
self.int_error = 0.0
self.windup_guard = 20.0
self.output = 0.0
def update(self, feedback_value, current_time=None):
"""Calculates PID value for given reference feedback
.. math::
u(t) = K_p e(t) K_i int_{0}^{t} e(t)dt K_d {de}/{dt}
.. figure:: images/pid_1.png
:align: center
Test PID with Kp=1.2, Ki=1, Kd=0.001 (test_pid.py)
"""
error = self.SetPoint - feedback_value
self.current_time = current_time if current_time is not None else time.time()
delta_time = self.current_time - self.last_time
delta_error = error - self.last_error
if (delta_time >= self.sample_time):
self.PTerm = self.Kp * error
self.ITerm = error * delta_time
if (self.ITerm < -self.windup_guard):
self.ITerm = -self.windup_guard
elif (self.ITerm > self.windup_guard):
self.ITerm = self.windup_guard
self.DTerm = 0.0
if delta_time > 0:
self.DTerm = delta_error / delta_time
# Remember last time and last error for next calculation
self.last_time = self.current_time
self.last_error = error
self.output = self.PTerm
(self.Ki * self.ITerm) (self.Kd * self.DTerm)
def setKp(self, proportional_gain):
"""Determines how aggressively the PID reacts to the current error with setting Proportional Gain"""
self.Kp = proportional_gain
def setKi(self, integral_gain):
"""Determines how aggressively the PID reacts to the current error with setting Integral Gain"""
self.Ki = integral_gain
def setKd(self, derivative_gain):
"""Determines how aggressively the PID reacts to the current error with setting Derivative Gain"""
self.Kd = derivative_gain
def setWindup(self, windup):
"""Integral windup, also known as integrator windup or reset windup,
refers to the situation in a PID feedback controller where
a large change in setpoint occurs (say a positive change)
and the integral terms accumulates a significant error
during the rise (windup), thus overshooting and continuing
to increase as this accumulated error is unwound
(offset by errors in the other direction).
The specific problem is the excess overshooting.
"""
self.windup_guard = windup
def setSampleTime(self, sample_time):
"""PID that should be updated at a regular interval.
Based on a pre-determined sampe time, the PID decides if it should compute or return immediately.
"""
self.sample_time = sample_time
import PID
import time
import matplotlib.pyplot as plt
import numpy as np
from scipy.interpolate import BSpline, make_interp_spline # Switched to BSpline
def test_pid(P=0.2, I=0.0, D=0.0, L=100):
"""Self-test PID class
.. note::
...
for i in range(1, END):
pid.update(feedback)
output = pid.output
if pid.SetPoint > 0:
feedback = (output - (1/i))
if i>9:
pid.SetPoint = 1
time.sleep(0.02)
---
"""
pid = PID.PID(P, I, D)
pid.SetPoint = 0.0
pid.setSampleTime(0.01)
END = L
feedback = 0
feedback_list = []
time_list = []
setpoint_list = []
for i in range(1, END):
pid.update(feedback)
output = pid.output
if pid.SetPoint > 0:
feedback = (output - (1/i))
if i > 9:
pid.SetPoint = 1
time.sleep(0.02)
feedback_list.append(feedback)
setpoint_list.append(pid.SetPoint)
time_list.append(i)
time_sm = np.array(time_list)
time_smooth = np.linspace(time_sm.min(), time_sm.max(), 300)
# feedback_smooth = spline(time_list, feedback_list, time_smooth)
# Using make_interp_spline to create BSpline
helper_x3 = make_interp_spline(time_list, feedback_list)
feedback_smooth = helper_x3(time_smooth)
plt.plot(time_smooth, feedback_smooth)
plt.plot(time_list, setpoint_list)
plt.xlim((0, L))
plt.ylim((min(feedback_list)-0.5, max(feedback_list) 0.5))
plt.xlabel('time (s)')
plt.ylabel('PID (PV)')
plt.title('TEST PID')
plt.ylim((1-0.5, 1 0.5))
plt.grid(True)
plt.show()
if __name__ == "__main__":
test_pid(1.2, 1, 0.001, L=50)
# test_pid(0.8, L=50)
测试用代码
