Files
brewpi/components/pid/pid.py
T

50 lines
951 B
Python

import numpy as np
class Pid:
def __init__(self):
# Integrator
self.yi = 0
# Differentiator
self.err = 0
# Auto windup
self.y_min = -1.0
self.y_max = 1.0
# Output
self.y = 0
@staticmethod
def params(kp, ki, kd, rho):
p = dict(kp=kp, ki=ki, kd=kd, rho=rho)
return p
def reset(self):
self.yi = 0
self.err = 0
def process(self, dt, params, err):
kp = params['kp']
ki = params['ki']
kd = params['kd']
rho = params['rho']
self.yi = rho*self.yi + ki*dt * err
yd = kd/dt*(err - self.err)
yp = kp * err
# Reset yi on error sign changes
if yp > self.y_max or yp <= self.y_min:
self.yi = 0
self.err = err
y = yp + self.yi + yd
self.y = max(self.y_min, min(self.y_max, y))
def get_y(self):
return self.y