Cedrat Technologies, innovation in mechatronics

The new piezo actuators manufactured by Cedrat Technologies have been developed for the positioning control of space optics but they are spreading widely in various engineering fields such as precise positioning, intelligent control of shapes and generation or control of vibrations. Their ability for the control or active damping of vibrations has been successfully demonstrated at the lab scale in space applications. In a first case, the piezo actuators were used for both for the control of launching vibrations and the positioning control in orbit of a telescope mirror. In a second set of space applications, these piezo actuators have been successfully integrated in a space truss using active tendons for control of micro vibrations, as publicly released at the Industry Space Days (ISD2001, Noordwijk, 9-10 Mai 2001) and as presented in this paper.

Several classes of low voltage piezo actuators have been developed by CEDRAT TECHNOLOGIES to cover precise positioning needs and / or fast. This paper discusses the ability of these actuators to cover these needs and illustrates this through various applications (mechanisms, shock absorbers, valves) in the fields of instrumentation, space, aeronautics and automotive.

Implementation of 3D capabilities on ultrasonic imaging systems tantalizingly proves the high interest for this diagnosing modality. However, to become a clinical tool, 3D ultrasound has to spend further technological efforts in acquisition performance and probe size to deliver on the fly, quality volumetric images as well as current functionalities.

Existing piezo motors such as travelling wave motors present several technical limitations, they are not useable for linear drive, they cannot be easily adapted to specific rotational needs and the development of customised solution is expensive. The proposed Ultrasonic Piezo Drive (UPD) aims at overcoming these limitations. It is a shell-based stator using multilayered piezoceramics in d33 mode. Excited at only 1-10V, it produces an ultrasonic elliptical vibration large enough to direct drive any type of second body by friction. Tangential driving properties of UPD20 are typically in the range of 100-200mm/s max speed and 15-30N max force.

The ROSETTA/MIDAS space mission intends to analyze the dust resulting from the Wirtanen comet using an Atomic Force Microscope (AFM). To scan the dust, an extremely fine mechanism able to produce displacement’s accuracy in the sub-micrometer range with a limited mass, is required. The only technology which can meet this specification is the piezoelectric actuator associated to capacitive displacement sensors, which displays several advantages : solid state design, which means no friction, noise limited by the driving electronic, ...

The ROSETTA/MIDAS mission of the Europeans Space Agency (ESA) intends to study the dust collected from the Wirtanen comet using an Atomic Force Microscope (AFM). This instrument utilzes an XY piezoelectric stage to achieve precise positioning in two in-plane orthogonal directions, and a Z actuator to support the needles for the analyses of dust particles in the out-of-plane direction.