Python 获取PID控制器的最后一个错误
我试图在Python上构建一个PID控制器。下面是到目前为止我的实现。虽然语法是连贯的,但这仍然是伪代码Python 获取PID控制器的最后一个错误,python,control-theory,Python,Control Theory,我试图在Python上构建一个PID控制器。下面是到目前为止我的实现。虽然语法是连贯的,但这仍然是伪代码 def PID(self, Kp, Ki, Kd, reference_velocity, vehicle_velocity, current_time, last_update_time): desired_velocity = 0 Kp = 0 Ki = 0 Kd = 0 error = refere
def PID(self, Kp, Ki, Kd, reference_velocity, vehicle_velocity, current_time, last_update_time):
desired_velocity = 0
Kp = 0
Ki = 0
Kd = 0
error = reference_velocity - vehicle_velocity
delta_time = current_time - last_update_time
proportional = Kp * error
integral = Ki * error
derivative = Kd * ((error - last_error) / (delta_time))
desired_velocity = proportional + integral + derivative
return desired_velocity
我试图通过我在这里已经给出的内容来找出
最后一个错误
,但我无法找出它。将错误或最后一个错误存储在函数外部作用域的容器中
errors = []
def PID(...):
...
errors.append(error)
return desired_velocity
然后,在函数中,可以使用检索最后一个错误
...
last_error = errors[-1]
或者,您可以将控制器设置为一个类,其实例由常量和起始参数初始化,并保留过去错误的记录(类似于列表的容器)。当前/下一个输出控制信号的计算将是一种可使用当前参数值调用的方法 使用你的算法——类似这样的
class PID:
def __init__(self,setpoint,t_now,Kp=0,Ki=0,Kd=0):
self.setpoint = setpoint
self.t_last = t_now
self.Kp = Kp
self.Ki = Ki
self.Kd = Kd
self.last_error = 0
def adjust(self,process,t_now):
error = process - self.setpoint
delta_time = t_now - self.t_last
proportional = self.Kp * error
integral = self.Ki * error
derivative = self.Kd * ((error - self.last_error) / (delta_time))
desired_process = proportional + integral + derivative
self.t_last = t_now
self.last_error = error
return desired_process
用法:
v_controller = PID(setpoint=66, t_now=0, Kp=.2, Kd=.1, Ki=1)
# or
#parameters = {'setpoint':66, 't_now':0, 'Kp':.2, 'Kd':.1, 'Ki':1}
#v_controller = PID(**parameters)
print(v_controller.adjust(66.1,1))
print(v_controller.adjust(66.2,2))
print(v_controller.adjust(65.9,3))
print('-------------')
parameters = {'setpoint':66, 't_now':0, 'Kp':.2, 'Kd':.1, 'Ki':1.5}
v_controller = PID(**parameters)
print(v_controller.adjust(66.1,1))
print(v_controller.adjust(66.2,2))
print(v_controller.adjust(65.9,3))
print('-------------')
parameters = {'setpoint':66, 't_now':0, 'Kp':1.25, 'Kd':.2, 'Ki':.5}
v_controller = PID(**parameters)
print(v_controller.adjust(66.1,1))
print(v_controller.adjust(66.2,2))
print(v_controller.adjust(65.9,3))
结果
>>>
0.12999999999999262
0.2500000000000043
-0.1499999999999929
-------------
0.17999999999998975
0.3500000000000057
-0.19999999999999005
-------------
0.1949999999999889
0.37000000000000666
-0.2349999999999895
>>>