Mechanisms
Categories
Stiff and soft stewart platforms for active damping and active isolation of vibrations
6 January 2002
As future astronomic missions will require more and more stringent resolution requirements, the high demand for an environment clean of vibrations and disturbance appears. This also leads to the need for high precision steering devices for fine pointing of sensitive optics with the highest possible accuracy. Several methods exist to reduce vibration levels: the first consists in isolating the sensitive system from the perturbation and the second in damping the structure vibration modes. Therefore, two Stewart platforms have been designed, manufactured and tested. The first is a soft hexapod that provides 6 degree-of-freedom (DOF) active isolation and the second is a stiff hexapod that provides active damping to whatever flexible payload attached/mounted to it. In addition, both hexapods have steering capabilities.
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
Magnetically actuated fast steering mirrors
19 June 2023
Free-Space Optics (FSO) for optical communication request new compact low-power high-stroke high-bandwidth Fast
Steering Mirrors (FSM). To address this need, CEDRAT TECHNOLOGIES has developed a Magnetically-actuated Fast
Steering Mirror called M-FSM, taking heritage of its MICA™ actuators. This FSM offers Rx Ry strokes larger than +/-
2° with a 250Hz bandwidth when tilting a 31mm diam mirror. Requested power is minimized leading to low heating.
Vibration tests have been performed to define first limits and conditions for the M-FSM to bear external vibrations. Large
bandwidth closed loop control is achieved using integrated eddy current sensor and a state feedback-based controller.
Super amplified piezo actuator
19 June 2023
MICROMEGA DYNAMICS is a spin-off company of the “Université Libre de Bruxelles” (ULB), Department of Mechanical Engineering and robotics of Pr PREUMONT. This department created in 1989, is specialized in the modeling and control of mechatronic systems and in the active control of vibrations.
Design and evaluation of a piezo xy stage
19 June 2023
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.
From the Test Benches to the First Prototype of the muFly Micro Helicopter
19 June 2023
The goal of the European project muFly is to build a fully autonomous micro helicopter, which is comparable to a small bird in size and mass. The rigorous size and mass constraints infer various problems related to energy efficiency, flight stability and overall system design. In this research, aerodynamics and flight dynamics are investigated experimentally to gather information for the design of the helicopter’s propulsion group and steering system. Several test benches are designed and built for these investigations
