Helicopter multi-frequency vibration active control method

Abstract

The invention discloses a method for actively controlling multi-frequency vibration of a helicopter, including system identification, collecting the control voltage of the actuator and the acceleration response at the controlled point, using the recursive least squares algorithm for system identification, and finally obtaining the discrete state space of the secondary channel Equation; feedback controller design, using the secondary channel discrete state space equation obtained in step 1 to carry out discrete predictive sliding mode feedback controller design; reference signal and error signal acquisition, according to the helicopter rotor characteristics and speed characteristics, extract the rotor excitation frequency, synthesize reference signal, and collect the vibration response error signal at the controlled point; the feedforward-feedback hybrid control algorithm iterates, and uses the reference signal and error signal obtained in step 3 to iterate the feedforward controller and the feedback controller to obtain the feedforward-feedback Feedback the mixed control voltage signal; output the control quantity; use the mixed control voltage obtained in step 4 as the input signal at the next moment, drive the actuator to produce the required response, and return to step 3.

Description

Technical field: [0001] The invention discloses an active control method for multi-frequency vibration of a helicopter, which belongs to the technical field of active vibration control of a helicopter. Background technique: [0002] When the helicopter is flying forward, the alternating force and moment generated by the rotor caused by the asymmetric airflow is the main vibration source causing the vibration of the helicopter, and only the vibration components with a frequency of NΩ (N is the number of blades, and Ω is the rotor speed) and its multiples It is transmitted to the fuselage through the rotor shaft, so that the fuselage structure is always in a rather harsh vibration environment. High vibration levels seriously affect the efficiency and comfort of drivers and passengers, and reduce the fatigue life of structures and the reliability of mechanical equipment. Certain measures must be taken to control the high level of vibration of the helicopter, which has become o...

AI Technical Summary

Problems solved by technology

However, this parallel structure still has the above-mentioned similar problems, and the weight coefficients of all control filters are updated by a single error signal containing multiple frequency components, which in turn will modulate multiple irrelevant vibration components in the error signal, Slow down the convergence process, reduce the adaptive ability, and may even cause the control to be invalid

The HHC algorithm commonly used in existing structural response active control systems is based on the linear quasi-static assumption, which is a method that can effectively reduce multi-frequency steady-state vibrations, but this also determines that its control interval is large and the update rate is slow, which is only applicable to In the case of low frequency, relatively stable external disturbance and little change in structural parameters

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