Proportional control in hydraulics is widely utilized. The most widely used current types of proportional valves utilize solenoid technology. While this technology has been around for decades and has been proven an effective means of control, there is always a demand for improved performance of advancing technologies. Integrating piezoelectric devices as a means to control hydraulic systems helps advance control for hydraulic systems.

Piezoelectric stack devices have been used to control hydraulic systems with success. Advantages of these stacks include being relatively small with a high power to weight ratio, using less energy than solenoid operations, and being fast acting. The main disadvantage to these piezoelectric stacks is the small amount of displacement. This research focuses on the use of a piezoelectric linear motor to control a proportional regulator valve.

After a literature review was conducted, a mathematical model was developed to determine valve performance. The motor performance was tested under 4 loading conditions and the velocity curves were plotted for different velocities. The valve was printed using 3D printing and then tests were conducted to determine flow rates and pressures for the rapid prototyped proportional hydraulic regulator valve. It was found that a piezoelectric linear motor can be used as a means to control a proportional valve. However, the rapid prototyped design was determined to have drawbacks that hindered performance noticeably.


piezoelectric, piezo, digital, hydraulics, piezoelectric linear motor, digital hydraulic valve

Date of this Version



Mechanical Engineering Technology

Department Head

Dr. Vahid Motevalli

Month of Graduation


Year of Graduation



Master of Science

Degree Type

Directed Project

Advisor 1 or Chair of Committee

Henry Zhang

Advisor 2

Richard Mark French

Advisor 3

Bradley Harriger