Cedrat Technologies, innovation in mechatronics

A design of a single phase step micro motor is presented. The rotor has been optimised to induce the greatest magnetic energy using film permanent magnets. A special study has been performed to select the most advantageous magnetisation direction and the structure has been chosen taking into account micro technologies characteristics and the present know-how available for realisation of prototypes. A scale 2 prototype has already been realised. Its special air gap tuning for film magnet test is presented, as well as first torque measurements.

A tool adaptor with built-in active vibration damping device to dynamically stabilize the turning process is presented in this paper. It can be used in standard CNC-lathes and allows the usage of off-the-shelf tool heads. The vibration compensation system is based on a multilayer piezoactuator that is in collocation with a piezoelectric force sensor. An analogue controller based on the integral force feedback method is used for active damping.

Piezo-electric motors have been successfully developed for various applications like autofocus drives in camera lenses and handling equipment for semiconductor production. Their high speed and accurate positioning capability, combined with a favourable holding torque in unpowered condition, make piezomotors also very attractive for actuation purposes in spacecraft mechanisms. The paper introduces a new concept of a versatile ultrasonic piezomotor. The testing campaign carried out on the designed rotating piezomotor has validated the vacuum compatibility and the lifetime of the motor in air.

Sandia National Laboratories has previously tested a capability to impose a 7.5 g-rms (30 g peak) radial vibration load up to 2 kHz on a 25 lb object with superimposed 50 g acceleration at its centrifuge facility. This was accomplished by attaching a 3,000 lb Unholtz-Dickie mechanical shaker at the end of the centrifuge arm to create a “Vibrafuge”. However, the combination of non-radial vibration directions, and linear accelerations higher than 50g’s are currently not possible because of the load capabilities of the shaker and the stresses on the internal shaker components due to the combined centrifuge acceleration.

Piezoelectric mechanisms are more and more used in space applications requiring precise positioning functions for scientific payloads or optical functions. Indeed, piezoelectric actuators are generally deemed of being good candidates for driving and control compact mechanisms.

Smart actuators and intelligent structures receive a considerable interest in the fields of Air & Space, to realise new functions or more efficient functions than passive structures. In these fields, there are needs for actuation means offering high mechanical energy density (product of stroke and force divided by the mass), a low power consumption, a resistance to severe environment (such as vibrations) as well as other case by case needs : High resolution (embedded active optics for cameras and telescopes), fast response (active control of structures shape, active damping of vibration)…

LA75B : A powerful electronic that makes APA sing higher in volume and larger in frequency.