The research of the influence of digital exchange in the stabilization system of the unmanned aerial vehicle on the dynamic characteristics of the steering actuator

• Main Author: S. V. Gryzin
• Format: Article
• Language: Russian
• Published: Moscow State Technical University of Civil Aviation 2019-10-01
• Series: Naučnyj Vestnik MGTU GA
• Subjects: unmanned aerial vehicle (uav); stability of the stabilization system; frequency responses of the electric actuator; the system "data interface steering actuator"; zero-order hold; pade approximation; frequency model; nonlinear model
• Online Access: https://avia.mstuca.ru/jour/article/view/1502

When designing a stabilization system for highly maneuverable unmanned aerial vehicles (UAVs), one of the relevant tasks is to impose requirements on the dynamic characteristics and control methods of the steering actuators, which will ensure the required stability margins of the stabilization system as part of the UAV control system. Currently, there is an increasing preference for microcontroller method of electric actuator control and digital exchange between the control system and the steering actuators. One of the reasons for the reduction of stability margins of the stabilization system is the delay introduced by the digital exchange between the elements of the stabilization system. In the process of solving the problem of transition to digital exchange between the elements of the stabilization system, a research was conducted of the influence of amplitude and phase distortions arising in the path "data transmission interface steering actuator" on the dynamic characteristics of the steering actuator. As an actuator of the stabilization system, the real electric drive used on highly maneuverable UAVs is considered. For this drive, extremely stringent requirements for bandwidth and phase delays are introduced, which complicates the problem of ensuring the stability of the stabilization system, taking into account the delays in the digital exchange. As a result of the research, a frequency model has been proposed that allows to estimate the minimum possible exchange rate in the path "data interface steering actuator", taking into account ensuring the required dynamic characteristics of the actuator. In the proposed model, the data transfer interface is represented as a zero-order hold, the transfer function of which is replaced by Pade approximations of the second order. In the course of the research, a comparison was made of the results obtained on the proposed model with the results of experiments on a real electric actuator and its complete nonlinear time model. The main advantage of the proposed frequency model is the simplicity of obtaining the transfer function of the path "data interface steering actuator". This allows at the initial stage of the research to quickly and accurately determine the minimum possible rate of exchange, which will ensure the fulfillment of the requirements imposed on the drive dynamics.