A systematic procedure for the design of piezoelectric inchworm precision positioners

Design equations are developed and integrated into a computerized design tool in order to facilitate the creation of inchworm piezoelectric based positioners. Fundamental to the development of the design tool is the piezoelectric actuator and motor frame stiffness interaction and its influence on positioner performance. A generalized motor frame configuration for each of the motor subsystems is presented and used to generate key initial positioner frame geometry. An inchworm precision positioner is implemented based on the generalized motor frame and the computerized design tool and it is shown experimentally and through finite-element analysis that the design approach is effective for precision positioner design. The prototype of the inchworm positioner developed is shown to have a stiffness in the direction of motion of 88 N/μm, a maximum thrust of 150 N and a traversing speed of up to 20 mm/s.