Add PID controller implementation

Author: TahmidSwad

control_algorithms/__init__.py

@@ -1,16 +1,19 @@
 """
-A Proportional-Integral-Derivative (PID) controller is a control loop mechanism that calculates an error
-value as the difference between a desired setpoint and a measured process variable.
+A Proportional-Integral-Derivative (PID) controller
+is a control loop mechanism that calculates an error
+value as the difference between a desired setpoint
+and a measured process variable.
 
-It applies proportional, integral, and derivative corrections to minimize the error over time.
+It applies proportional, integral, and derivative
+corrections to minimize the error over time.
 
 Refer - https://en.wikipedia.org/wiki/PID_controller
 """
 
 
-class pid:
+class PID:
 
-    def __init__(self, Kp: float, Ki: float, Kd: float, setpoint: float = 0):
+    def __init__(self, kp: float, ki: float, kd: float, setpoint: float = 0):
         """
         Initialize the PID controller.
 
@@ -19,9 +22,9 @@ def __init__(self, Kp: float, Ki: float, Kd: float, setpoint: float = 0):
         :param Kd: Derivative gain
         :param setpoint: Desired target value
         """
-        self.Kp = Kp
-        self.Ki = Ki
-        self.Kd = Kd
+        self.kp = kp
+        self.ki = ki
+        self.kd = kd
         self.setpoint = setpoint
 
         self.integral = 0
@@ -39,14 +42,14 @@ def compute(self, measured_value: float, dt: float) -> float:
         self.integral += error * dt if error != 0 else 0
         derivative = (error - self.previous_error) / dt if dt > 0 else 0
 
-        output = (self.Kp * error) + (self.Ki * self.integral) + (self.Kd * derivative)
+        output = (self.kp * error) + (self.ki * self.integral) + (self.kd * derivative)
         self.previous_error = error
         return output
 
     def reset(self):
         """Reset the integral and previous error values."""
-        self.integral = 0
-        self.previous_error = 0
+        self.integral = 0.0
+        self.previous_error = 0.0
 
 
 if __name__ == "__main__":