Transformational vehicle management systems

The US helicopter industry has been working on a multi-year joint cooperative research and development program in the Vehicle Management Systems area. This work has been carried out under the auspices of the Vertical Lift Consortium and funded jointly by NRTC and the participating companies. The first phase of this program was executed in 2009 and 2010 and included a total investment in excess of $2.0 million. The focus was on areas and technologies of broad interest to all participants which included Bell Helicopter, The Boeing Company and Sikorsky Aircraft Corporation along with Penn State University. Together, these tasks help to define technology gaps and launching points for the AMRDEC Transformational VMS program. The premise of this VLC TAJI project was that current handling qualities requirement documents (ADS-33-PRF, MIL-F-9490D) are based on present knowledge and vehicles, and are considered necessary but may not be sufficient to ensure excellent handling qualities for new vehicles. Therefore, there is a need to update and refine these documents for the future. The TVMS project contributed to this goal both by gathering additional handling qualities data on a variety of aircraft, and discussing the results across key U.S. rotorcraft industry and government partners. In a second joint project, conducted under the auspices of this program, the participants investigated the use of active rotors for gust alleviation, with an extra emphasis on shipboard operations. A stochastic model of the ship airwake was developed. The gust rejection compensators were evaluated in Simulink development models for the H-60 class helicopter by Penn State and CH-47 airframes, and in a PSU-GenHel non-linear simulation using CETI turbulence models. In all cases, the final controllers provided a significant reduction in the body rate and attitude excursions from trim when compared to cases without the gust rejection compensator.