Inverted Pendulum

Simulation of inverted pendulum with PID controller and fuzzy controller

intsall:

• pygame
• box2d
• box2d-py
• scikit-fuzzy

four different control systems included:

• run Pendulum_PID.py for PID control loop
• run Pendulum_Fuzzy.py for fuzzy control loop
• run Pendulum_Fuzzy_PID.py for combination of fuzzy and PID control loop (runs smoother)
• run Pendulum_Fuzzy_PID_advanced.py for combination of two fuzzy controls to keep the pendulum in the middle

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PID control loop

PID control loop uses PID library from PyConSys

Following PID parameters are used in this example:

self._pid_control = PIDControl(105, 83, 28)  # kp, ki, kd

keyboard commands:

• n: create new world
• m: manual mode
• a: automatic mode

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fuzzy control loop

fuzzy control loop uses scikit-fuzzy

keyboard commands:

• n: create new world

Input fuzzy set:

Output fuzzy set:

Simple inference:

self.rule1 = ctrl.Rule(self.fuzz_pend1['dismal'], self.fuzz_motor['dismal'])
self.rule2 = ctrl.Rule(self.fuzz_pend1['poor'], self.fuzz_motor['poor'])
self.rule3 = ctrl.Rule(self.fuzz_pend1['mediocre'], self.fuzz_motor['mediocre'])
self.rule4 = ctrl.Rule(self.fuzz_pend1['average'], self.fuzz_motor['average'])
self.rule5 = ctrl.Rule(self.fuzz_pend1['decent'], self.fuzz_motor['decent'])
self.rule6 = ctrl.Rule(self.fuzz_pend1['good'], self.fuzz_motor['good'])
self.rule7 = ctrl.Rule(self.fuzz_pend1['excellent'], self.fuzz_motor['excellent'])
self.pendulum_ctrl = ctrl.ControlSystem([self.rule1, self.rule2, self.rule3, self.rule4, self.rule5, self.rule6, self.rule7])

Defuzzification:

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PID-Fuzzy combination control loop

Combination of fuzzy ans PID control loop, to get the control loop smoother.

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Combination of two fuzzy controls

This keeps the pendulum in the middle.

First fuzzy

• input: angle and angle speed
• output: motor1

angle

angle speed

motor1

Second Fuzzy

• input: position and speed
• output: output motor2

position

speed

motor2

fuzzy rules

motor = motor1 + motor2

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From the course "Mechatronische Systeme (Mechatronic Systems)", technical college SBS Herzogenaurach-Höchstadt.

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This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0. If a copy of the MPL was not distributed with this file, You can obtain one at https://mozilla.org/MPL/2.0/.

(c) 2020, Metin Karatas (m.karatas@sbs-herzogenaurach.de)