A novel F-shaped linear guiding mechanism based compliant positioning stage with restricted parasitic motion

Abstract

Positioning stages are significant in precision technologies under higher demands of operation and manufacturing. The performance of the selected guiding mechanisms is a decisive factor affecting the positioning accuracy of the stage. To restrict the parasitic motions along the degrees of constraint during motion transmission, a piezo-actuated compliant positioning stage with novel F-shaped linear guiding mechanisms (FLGM) is developed in this paper to enable a precision motion. With a simple and compact structure, a single FLGM can generate an approximate straight-line motion and enhance the transverse stiffness. Four FLGMs are arranged symmetrically in parallel to theoretically eliminate the parasitic motions, bringing in the merits of a low coupling rate and a wide bandwidth in the working direction. A stack piezoelectric actuator embedded in a forward bridge-type displacement amplifier is utilized to drive the guided stage. Analytical modeling of its kinematic, static, and dynamic characteristics is mathematically established by utilizing the pseudo-rigid-body method, compliance matrix method, and Lagrange’s equation. Finite element analysis is conducted and a fabricated prototype is experimentally tested, validating the veracity of the analytical models. Experimental results show that the parasitic motion is constrained by the guiding mechanism effectively with a coupling rate below 0.95%, and a high natural frequency of 856.9 Hz is achieved simultaneously.