Piezomechatronic-based systems in aircraft, space, and defense applications

In Space & Defense fields, there is a trend for miniaturisation in active optics, fine instruments, robotic missions, microsatellites, UAVs, MAVs which directly impact on the design of actuators. A new generation of small and smart actuators such like piezoelectric (piezo) actuators, are responding to this trend, thanks to their capacity to offer high energy density and to support both extreme and various requirements. In Space vehicles, UAVs, missiles, military vehicles, etc., onboard place and available electric power can be very limited. For instance, a micro satellite often must operate all its instruments with less than 100W of power. As a result, allocated electric power per actuator is typically between 0.1 to 10W. This is also the case in small UAVs and in MAVs. Because of the high cost of embedded mass, space & military actuators need also to offer high output energy to mass ratio. One of the main difficulties is often the ability to withstand launching vibrations and shocks. Space environments add other constrains. A clear example is the vacuum conditions, which can induce difficulties to release the heat out off the actuator or for out gassing near optics. Other critical spacerelated environmental conditions include the thermal operation range required as well as the radiation-resistant requirements. In other situations, actuator strength to humidity is often an issue, especially for piezoelectric ceramics. Thus, the success of the application relies not only on design issues but also on material reliability. Specific actions at this level are needed to be undertaken to secure space projects. To cope with these issues and to illustrate the trend, the piezo actuators and mechanisms from Cedrat are presented. They have been initially developed and qualified to meet space requirements but logically found also applications in defense and micro aerial vehicle fields, for various micromechatronic functions. The paper presents typical applications and piezo mechatronic based system such like, piezo micro-scanning stage for IR camera resolution enhancement, piezo active flap on helicopter blade for noise reduction, micro amplified piezo actuator for tilting MAV rotor, hollow piezo actuator for external laser cavity tuning of a space LIDAR, in order to discuss the state-of-the-art performance and deduce further needs.