Research on intelligent active disturbance rejection control algorithm for shock train leading edge of dual-mode scramjet

Abstract

To prevent scramjet inlet unstart, stringent control over the shock train's leading edge in the isolator is necessary. Therefore, this study proposes a fuel flow active control scheme combining an adaptive particle swarm optimization algorithm (APSO) and active disturbance rejection control (ADRC) to enhance the traditional control (such as proportional-integral-derivative, PID) system's stability and anti-interference capabilities in complex and uncertain environments. Within this context, a simple, semi-empirical mathematical model of a dual-mode scramjet is constructed. An ADRC controller is designed to counteract the nonlinearity and disturbance of the dual-mode scramjet. ADRC, not requiring an accurate mathematical model, utilizes its extended state observer to estimate all uncertain factors affecting the controlled object based on the relationship between the shock train's leading edge and the controller's output, treating them as unknown disturbances for compensation, thereby exhibiting strong anti-interference capabilities. In order to optimize the performance, the APSO is introduced to fine-tune the ADRC controller parameters. The APSO reduces the rise time of ADRC from 22.28 to 11.39 ms, and the adjustment time from 40.05 to 13.64 ms. The APSO effectively tunes the parameters of the ADRC controller, which ensures rapidity comparable to the PID and all-coefficient adaptive control (ACAC) in managing the shock train's leading edge. At the same time, ADRC has stronger anti-interference ability and adaptive ability than ACAC and PID. This research preliminarily verifies the feasibility and advancement of the ADRC for shock train leading-edge control in scramjet isolators.

Rapid Tracking Satellite Servo Control for Three-Axis Satcom-on-the-Move Antenna

“…These schemes will reduce the performance of the PID controller or increase the complexity of the PID controller. In addition, there is a contradiction between the "rapidity" and "overshoot" of the PID controller [19][20][21][22]; that is, if the system output response is made to converge quickly, the system will have a large overshoot; if the system overshoot is reduced to a small value or even zero, the convergence speed of the system output response will be reduced. In the servo control system of the SOTM antenna, if the system output response converges slowly, it may result in the antenna failing to adjust to the required direction before changes in the carrier's attitude and/or location occur, necessitating a readjustment of the antenna direction; if there is a significant overshoot, it could cause the SOTM antenna pointing to deviate from the target satellite.…”