Moog FCS Offers Advanced Force Control Technology for Aircraft Structural Testing

Moog FCS is a recent addition to Moog, following the acquisition of FCS Control Systems by Moog in 2005. Originally formed from a division of the Fokker Aircraft Company, Moog FCS has a long history of providing hydromechanical and electromechanical control systems. The control technology was developed to provide high fidelity loading to flight control systems used in aircraft flight simulation applications. This flight control loading capability was soon developed and adapted for use in new applications such as full-scale static load and durability testing of aircraft structures, testing for product development in the automotive industry and even in haptic devices which are small robots designed to present to a human user the feeling of actually touching a virtual or remote world.

Aircraft structural testing is a demanding control application, as it requires the introduction of accurately controlled forces derived from hydraulic actuators, synchronously applied by up to two hundred actuators at a time. Hence, Moog FCS moved from “control loading” to “load control” applications.

Safety, when testing full-scale aircraft, is naturally very critical as the actuators can apply destructive loads to experimental aircraft worth many millions of dollars. The safety of Moog FCS’ testing systems is proven by the fact that no structure under test has ever been damaged by a faulty control system. This is due to extensive software safeguards and the fail-safe hardware architecture of the Moog FCS solution.

The heart of all high performance control systems supplied by Moog FCS is the control algorithm itself. This control algorithm adds to the standard PID loop controller a damping term. In physical terms, this can be thought of as a value proportional to velocity that is subtracted from the force summation point. The inclusion of this control parameter means the instability inherent on control loops with high gain can be damped and the result is faster step-response and improved system stability. The faster response results in shorter setup time and importantly allows customers to run the required fatigue flight spectra faster, thus saving time and money.

This technology is attracting major customers from around the world. The SmarTEST solution has been selected along with HBM data acquisition systems purchased through Moog FCS for the F35 JSF project and will be used to test all variants of the F35. This project, running for some 5 years in the delivery stage is worth over $14,000,000 USD. We have been awarded a contract with BAE systems in the UK for all their testing requirements and also have recently secured a 10 year contract with Airbus to supply them with their next generation testing solution for all tests in Germany, France, UK and Spain.

Author

Bob Barrett has 11 years experience of selling instrumentation normally constituting capital good on a business-to-business basis. He has worked for the last 7 years primarily in the Aerospace industry initially with HBM, selling data acquisition systems before moving to FCS to offer complete control, data acquisition and hydraulic turnkey solutions. He has a degree in Cybernetics and Control Engineering gained at Reading University and lives in the UK.