1 Al-Mustaqbal University College, Hillah, Iraq.

2 University of Technology, Baghdad, Iraq.

3 Al-Turath University College, Baghdad, Iraq.


The hydraulic system plays an important role in the design of many mechanical devices due to its high power to weight ratio. In this work, a theoretical study of a hydraulic stimulator was performed to conduct suspension tests in a quarter car in the laboratory. Due to high nonlinearity in the hydraulic systems, a robust controller based upon integral sliding mode (ISMC) with nonstandard backstepping was used to perform the tracking process of the hydraulic actuator to the required road profiles. The controller design divided into two parts: the first part deals with the generation of the ideal control force which satisfied all the tracking requirements by using ISMC. The second part of the controller is the replacing of the ideal control force with the actual hydraulic force with all parameters by using nonstandard backstepping control. The effectiveness of the exciter control system was performed by using two road profiles i.e. Bump road profile and random road profile.