  System Identification of Hydraulic Actuators is critical for analyzing their
performance and designing a suitable Control System. Hydraulic actuators are
extensively used in many applications, ranging from flight simulators,
robotics, orthopaedic surgery, material testing, construction and many other
industrial types of machinery. In the aviation industry, hydraulic actuators
are currently being used in full flight simulators used for controlling the
position and orientation of the motion platform. Every actuator has its own
characteristics, therefore, the choice of excitation signals for System
Identification must take into account the dynamics of the actuator under
consideration. This work proposes the selection of excitation signals based on
bandwidth of the hydraulic actuator. Validation of the proposed selection is
done by performing system identification, obtaining a mathematical model and
comparing it with a nonlinear hydraulic actuator model designed in Simscape.
After validation, a nonlinear PID control has been tuned on the identified
model and tested on the nonlinear model. Extensive simulations have been run
and results show accurate mathematical modelling, as well as precise control
has been achieved through the proposed methodology.
