Integration of the inverse dynamics with a reference model technique, and its application for the improvement of the helicopter flying qualities

• Published in: IOP conference series. Materials Science and Engineering 2020-05, Vol.868 (1), p.12016
• Main Authors: Mbikayi, Z, Efremov, A V, Efremov, E V
• Format: Article
• Language: English
• Subjects: Aerodynamics; Aircraft; Atmospheric models; Atmospheric turbulence; Couplings; Flight characteristics; Frequency ranges; Helicopters; Inverse dynamics; Simulation; Tracking; Uncertainty
• ISSN: 1757-8981; 1757-899X; 1757-899X
• DOI: 10.1088/1757-899X/868/1/012016

The application of inverse dynamics for the improvement of flying qualities is considered. It is shown that the use of the inverse dynamics in the control loop suppresses the dynamics of the aircraft considerably, leaving only the dynamics of the integral in almost the entire frequency range. The inverse dynamics however could not help in case of atmospheric disturbances or modeling uncertainties. A new scheme using a reference model and its inverse was presented to counter these effects. The results of the mathematical modeling showed that the inverse dynamics allow to improve the tracking performances and all other parameters of the pilot-aircraft system compared to the controller synthesized with feedback gains only. These results were confirmed using ground based simulation. These simulations showed that the use of the inverse dynamics based technique allowed to decrease the variance of error up to 60% during a tracking compensation task. The simulations also showed to that the addition of the reference model and its inverse proved to be able to reduce or suppress atmospheric turbulence, couplings between different control channels and effects of modeling uncertainties, while improving the tracking accuracy and decreasing the pilot workload, thus enhancing the flying qualities of the helicopter.