Variable rotor speed control for an integrated helicopter/engine system

Abstract

A modified sequential shifting control algorithm is proposed for changing the helicopter rotor's speed in a large variation and providing continuous output power to the rotor. Two turbo-shaft engines and two multi-speed gearboxes, coordinating with the rotor, facilitate a wide rotor speed variation and provide continuous torque to the rotor. In the process of shifting, a new control scheme is proposed to design turbo-shaft engines' power turbine speed controller which is robust linear matrix inequality control, combined with active disturbance rejection control torque feed-forward compensation, so as to weaken engines' torque disturbance in rotor speed variation process. In the end, some numerical simulations are carried out to verify the feasibility of the shifting algorithm, based on the integrated helicopter/engine system model which can simulate auto-flight tasks of the real system. The simulation results show that the turbo-shaft engine's torque disturbance has little influence on engine power turbine speed in the process of torque shifting, and the rotor speed can perform large and rapid speed changes smoothly.

Design and Optimization of Low Impact Shift Control Strategy for Aviation Transmission Power System Based on Response Surface Methodology

“…By integrating (17) in the span direction, the required torque generated in the rotor can be obtained as follows:…”

“…In existing studies, the collective pitch of the main rotor is generally used as the cross-linking parameter of the flight control system to reduce the interference of the main rotor load on the turboshaft engine [15,16]. To ensure the continuous power output of the turboshaft engine, a sequential torque control method was adopted in [17], and a power turbine speed controller with linear matrix inequality control, and torque feed-forward compensation was designed to track the turbine speed and weaken the torque fluctuation in the process of rotor speed change. In a previous study [18], neural networks were used for rotor demand torque prediction to reduce the power turbine speed overshoot by more than 20%.…”

Simulation and semi-physical verification of fuel metering unit model for turboshaft aeroengine

“…19,20 Currently engine control systems are evolving from traditional hydromechanical control to digital control. [21][22][23] In 1989, a research program for development of ''numerical propulsion system simulation'' was announced, 21 which prompts gradual substitution of object-oriented modeling for process-oriented modeling. 24 For a fuel delivery system, a stepping motor was adopted to move and modulate the metering valve (MV).…”