Dynamic Performance Analysis of PID and Fuzzy Logic Controllers Applicable in Electrohydraulic Servo Actuator

Electrohydraulic servo actuators (EHSAs) are the main element of many hydraulic systems used for variety of applications. They are usually preferred because of their unique and flexible characteristics. However, to optimise their performance, these systems are usually accompanied with sophisticated control systems. Generally, there are different types of control systems or algorithms, and the choice of the suitable one is subjective and based on a trade-off between different system parameters. This paper presents a critical appraisal of two types of control algorithms, PID and Fuzzy logic, and investigates the relative performance of them when applied to EHSAs using the Moog 760 servo valve. The PID controller was design using Trial and Error and Ziegler-Nichols methods. It was concluded that a proportional P controller is suitable for controlling the system. The response of the P controller is fast, but it contains oscillation and this makes it nonsuitable for some aspects of applications. The Fuzzy controller was separated into Sugeno and Mamadani. Sugeno is more preferred than Mamdani to control EHSAs systems because it produces a faster response. The Fuzzy controller response has no oscillations and this is suitable for many important/high precision applications such as robotics and military systems.