Performance Testing of an Integrated Hybrid Actuator

Abstract

The piezoelectric-based hydraulic actuator is a hybrid device consisting of a hydraulic pump driven by piezoelectric stacks that is coupled to a conventional hydraulic cylinder

Study on flow distribution inside integrated hybrid actuator

“…However, the velocity did not increase after a certain frequency and it decreased slightly, as shown in Fig. 5, because of the unstable flow inside the actuator from the very high frequency and the increase of the pressure loss from the increase of the fluid inertia [8]. Also, the operation stopped at 350 Hz for 1000 V, since the electric signal of the piezo stack with a length of 60 mm and a diameter of 25 mm was blocked by the protection circuit which shut off the electric supply beyond the peak power.…”

“…The related equation of the axis movement can be derived by the force balance as follows: (9) A one-dimensional quasi-state analysis code was developed to solve Eq. (9) using the MATLAB program [8].…”

“…For example, if the mass m L works on the cylinder axis, then F. The friction F f is related to the force on the piston F and velocity V, using the symmetric Karnopp model [7]. (8) where the total force on the cylinder piston F = (P h -P l )A o -F ext , and F g and F d are the stop friction and kinetic friction, respectively. This friction occurs between the piston axis and the inner wall of the hydraulic cylinder from the seal for the o-ring of the cylinder.…”