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Force Stepping Piezo Actuator : a motorised solution for high resolution positioning and external forces resistance
19 June 2023
Typical holding force of piezo motors is defined by friction force, required to make motor move. However, increase of friction force is not inconsequent for motor performances in terms of speed, max motion force and lifetime (tribology). In this paper, a new motor, offering high resolution positioning and holding position when unpowered, is presented. Based on a Stepping Piezo Actuator [1] at its core, this new design decouples the outer forces from the most sensitive parts of the motor. This allows the motor to propose a high force/mass ratio and sustain even higher forces without supply. Results obtained on prototype are presented, giving the reader the benefits of proposed technology.
Compact, Lightweight, and Efficient Piezo-Actuation Chain for aeronautical applications
19 June 2023
Many past and on-going studies are focusing on the use of piezo-actuators for aeronautical applications. One of the trendiest topics is the use of such devices for active flow control in aircraft, in order to reduce fuel consumption and noise. However, the implementation of such systems in aircraft suffer a lack of maturity with respect to aeronautical constraints, which are: high efficiency, compactness, and lightweight. In general, the actuators are composed of ceramics integrated in a metallic shell, which makes them heavy. For driving the actuators, the power amplifiers employed are usually linear amplifiers, which have a poor efficiency, leading to bulky designs due to large heatsinks. This paper presents recent developments that have been made to cope with these issues in order to obtain a piezo-actuation chain suitable for aeronautical applications.
Contactless Position sensors for space mechanisms based on eddy current sensing
19 June 2023
For more than 20 years, CTEC has been involved in various space missions, delivering products designed for severe environment conditions (vibrations, shocks, vacuum, humidity, wide thermal range including cryogenic). Eddy current sensor (ECS) technology, using printed circuit board (PCB) for printed coils, provides both a good resolution/accuracy and a good robustness against temperature variations.These sensors are available commercially off the shelf (COTS).
Contactless Torque Sensors based on shaft torsion measurement, compatible with existing shafts
19 June 2023
The torque measurement usually comes from strain gauges bonded on a shatf. the main concern in this measurement is due to the fact that these gauges are also rotating and the integration of electronic on rotating parts is definitely a blocking point.
Control of magnetic actuators in electric contactors by current shapping
19 June 2023
Most of present electric contactors use magnetic actuators of reluctant type (so called electromagnets) that are supplied with a simple voltage source. The use of a reluctant actuator in this condition leads to a considerable force increase when the magnetic circuit is closing, which creates damaging rebounds of the electrical contacts. To have a better control of the closing dynamics, we develop an electric drive method to reduce impact speed and to improve the closing dynamics. In this method, the reluctant actuator structure is unchanged. The appropriate current shape to be injected into the actuator is determined using a calculation method.
Cryogenic piezo characterisation and integration For Fine Steering Tip/Tilt Mechanism
19 June 2023
High precision cryogenic applications are demanding domains that require precise knowledge of component performance. In the case of active components such as piezoelectric actuators, such knowledge includes stroke, capacitance and Coefficient of Thermal Expansion (CTE). These parameters are difficult to define with precision because of the combination of small displacements and low temperature sensor compatibilities. A high stability and low sensibility test bench is required to obtain such results
