Active damping of aircraft engine shafts using integral force feedback and piezoelectric stack actuators

Unbalance induced vibrations in an aircraft engine shaft are reduced with an active damping system based on piezoelectric stack actuators at the bearing locations. Investigations with a test rig aim at the replacement of squeeze film dampers in aircraft engines with a long-term perspective. In this article controller design using the integral force feedback approach is demonstrated and experimental results achieved from the test rig are presented. The test rig rotor has the characteristics of a 1:2 scaled low pressure shaft of an air-craft engine. For the control system treated in this article, actuator and sensor positions are chosen to be collocated since sensor placement close to the bearings is assumed to be a realistic scenario for an aircraft engine. Such collocated control systems have the advantage of robustness with respect to stability.