Linear actuators
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Highly dynamic & high precision self balanced optical mechanism
19 June 2023
Ongoing developments of instruments reveal the need for fast and precise mechanisms [1]. These requirements are all the more significant when large payloads of hundreds grams, such as mirrors, optical plates, corner cubes or antennas are involved in the motion. Indeed, highly dynamic kinematics coupled with large inertia lead to parasitic reaction forces that interfere on the accurate measurement.
Hysteresis characterization in piezoceramic stack actuators and its influence on vibration and noise reduction in helicopters using actively controlled flaps
19 June 2023
In this study, a characterization of hysteresis in a piezoceramic stack actuator similar to those employed in an actively controlled flap (ACF) system is performed to assess the effects of hysteresis on system performance. The effect of unmodeled actuation hysteresis may significantly reduce vibration and noise reduction capabilities. A hysteresis model based on the classical Preisach model has been developed from experimental data.
Tunable proof mass based on a pendulum structure
6 January 2008
Proof mass dampers are currently used in aircraft structures, but are not active, which introduce performance limitations. Proof Mass Actuators based on spring-mass structures are an interesting technique for active vibration control, but it is difficult to design them for operation below 100 Hz, especially if high dynamic forces are required. The proof of concept of a Tunable Proof Mass Actuator (TPMA) based on a pendulum structure has been assessed into the Mesema FP6 EC project targeting an Helicopter application.
Dynamic strain limits of Amplified Piezo Actuators
19 June 2023
It is well known that the Amplified Piezo Actuators (APA) offer large strains in static conditions and at resonance. Because many applications as shakers, anti-vibration and motors would benefit also of large dynamic strain below resonance, the maximum strain of the APA has been theoretically and experimentally investigated in this wide frequency range. The tested actuator is the APA30uXS currently used in the SPA30uXS new inertial micro piezo motor.
Compact sensitive piezoelectric mass balance for measurement of unconsolidated materials in space
19 June 2023
In many in-situ instruments information about the mass of the sample could aid in the interpretation of the data and portioning instruments might require an accurate sizing of the sample mass before dispensing the sample. In addition, on potential sample return missions a method to directly assess the captured sample size would be required to determine if the sampler could return or needs to continue attempting to acquire sample.
Improvement of Linear and Rotative Stepping Piezo Actuators using design and control
19 June 2023
Stepping Piezo Actuators (SPA) are inertial piezo motors able to reach long stroke with important resolution. Previous work showed that large benefits in terms of speed and input current are taken from use of Amplified Piezo Actuators (APA®). The aim of this paper is to present new rotative configuration, advancements in maximal actuation force into thermal vacuum conditions and improvements using smart control.
