A Mechatronic Active Force Control System for Real Time Test Loading of an Aircraft Landing Gear

Abstract

This paper describes an electronically controlled active force control system that was recently developed to provide real time loading for the tests of a landing gear. As the landing gear moves during the test, a force is generated on the landing gear in order to ensure that its dynamics is identical to that that would occur during its operation in an actual flight. Since landing gear deployment and retraction can occur at different environmental and flight conditions, the load profile that must be developed by the force control system depends on the simulated flight condition and is determined by an appropriate landing gear model. To attain accurate force control, a system was setup comprised of a servovalve controlled hydraulic actuator, force and position sensors, and a high rate digital controller implementing a complex adaptive control law. An excellent accuracy of the load control was eventually achieved for all load profiles occurring on the landing gear.