Comprehensive Engineering Frequency Domain Analysis and Vibration Suppression of Flexible Aircraft Based on Active Disturbance Rejection Controller

Abstract

The crash of an aircraft with an almost vertical attitude in Wuzhou, Guangxi, China, on March 21, 2022, has caused a robust discussion in the civil aviation community. We propose an active disturbance rejection controller (ADRC) for suppressing aeroelastic vibrations of a flexible aircraft at the simulation level. The ADRC has a relatively simple structure and it has been proved in several fields to provide better control than the classical proportional-integral-derivative (PID) control theory and is easier to translate from theory to practice compared with other modern control theories. In this paper, the vibration model of the flexible aircraft was built, based on the first elastic vibration mode of the aircraft. In addition, the principle of ADRC is explained in detail, a second-order ADRC was designed to control the vibration model, and the system’s closed-loop frequency domain characteristics, tracking effect and sensitivity were comprehensively analyzed. The estimation error of the extended state observer (ESO) and the anti-disturbance effect were analyzed, while the robustness of the closed-loop system was verified using the Monte Carlo method, which was used for the first time in this field. Simulation results showed that the ADRC suppressed aircraft elastic vibration better than PID controllers and that the closed-loop system was robust in the face of dynamic parameters.

Driving into the Dynamics−Leveraging the Direct-Quadrature-Zero Transform for Mechanical Systems

“…Referring to Fig. 1, the unitary vectors for the d and q components with respect to the α and β components can be defined as follows (12) The projection of the vector mαβ(t) onto the unit vectors of the d and q frames, i.e., and , can be understood through the concept of the dot product where md(t) represents the projection of mαβ(t) onto the axis, and mq(t) represents the projection onto the axis as can be seen as follows (13) Together, these projected components, md(t) and mq(t), constitute the new vector, mdq(t), within the dq reference frame [25], [31]. It is important to note that the positive angle θ(t) corresponds to a counter-clockwise rotation of the vector as it transitions to the new dq reference frame.…”

“…Vibration analysis, a core aspect of mechanical engineering, is dedicated to understanding the complex behavior of mechanical systems subjected to oscillations or vibrations due to external forces or displacements [1]. This field has deep significance in various sectors, including industry [2]- [6], automation [7]- [10], and aerospace [11], [12], as it provides a mechanism for designing, controlling, optimizing, and maintaining the performance, safety, and reliability of mechanical systems.…”

“…In discussing aerospace vibration, [12] focuses on flexible structures, describing their susceptibility to vibration and how that vibration can affect safety and performance. The article turns its attention to innovative solutions such as active disturbance rejection control, which is well suited to suppressing vibrations through active disturbance suppression.…”

Advanced Vibration-Based Fault Diagnosis and Vibration Control Methods

“…This Special Issue on “Advanced Vibration-Based Fault Diagnosis and Vibration Control Methods” includes twelve papers ranging across different methods used in the electrical and mechanical industries’ systems. The papers include a good literature review of the current new works on the verification of mechanical properties identification based on the impulse excitation technique and mobile device measurements [ 4 ], the method for bearing fault diagnosis under variable speeds based on envelope spectrum fault characteristic frequency band identification [ 5 ], the interface design of head-worn display applications for condition monitoring in aviation [ 6 ], color recurrence plots for bearing fault diagnoses [ 7 ], the failure mode detection and validation of a shaft-bearing system with common sensors [ 8 ], the strain response and buckling behavior of composite cylindrical shells subjected to external pressure with one end fixed and the other free of boundary conditions [ 9 ], the smartphone-based and data-driven superstructure state prediction method for highway bridges in service [ 10 ], the optimal control algorithm for stochastic systems with parameter drift [ 11 ], the nonlinear vibration control experimental system design of a flexible arm using interactive actuations from shape memory alloy [ 12 ], the design of an active vibration isolation controller with a disturbance observer-based linear quadratic regulator for optical reference cavities [ 13 ], the applicability of touchscreens in manned/unmanned aerial vehicle cooperative missions [ 14 ], and the engineering frequency domain analysis and vibration suppression of flexible aircraft based on an active disturbance rejection controller [ 15 ].…”

“…Elastic vibrations in flexible aircraft can reduce their service life, which may damage their mechanical structures at certain specific frequencies. Liu et al [ 15 ] presented an active disturbance rejection controller (ADRC) to suppress the aeroelastic vibrations of a flexible aircraft. They built a vibration model considering the first elastic mode of the flexible aircraft.…”