Tracking the information about your manuscript
Communicate with the editorial office
Query manuscript payment status Edit officeCollecting, editing, reviewing and other affairs offices
Managing manuscripts
Managing author information and external review Expert Information Expert officeOnline Review
Online Communication with the Editorial Department
Download Center
Page Views
Introduction of Aerospace Technology
Chinese Name:空天技术
English Name: Aerospace Technology
Publication cycle: Bimonthly
Language: Chinese
Director: China Aerospace Science and Industry Corporation Limited (CASIC)
Sponsor: Beijing HIWING Scientific and Technology Information Institute
Editor in chief: LIU Haifeng
An improved MPC-based flight control method for eVTOL tilt transition
Yang Biao;An improved MPC method is used to design the controller for stable flight control of eVTOL with distributed rotor tilt configuration. The eVTOL flight dynamics model of tilt configuration is established considering the tension variation characteristics during distributed rotor tilting. In order to realize the stable control of attitude, velocity, altitude and tilt angle during tilt flight, a tilt transition path tracking controller based on improved MPC method is proposed. Combined with the change of vehicle acceleration performance and tilt angular rate capability in different tilt stages, an adaptive cost function is designed to improve the stability and safety of tilt transition flight control. The simulation results show that the improved MPC method can effectively realize stable tilting flight control, and has better control accuracy and robustness than traditional PID control methods.
A research on 3-DOF trimming of tandem-wing tilt-duct eVTOL
Wu Di;Chen Jinghongju;Zhang Sidong;Li Weibo;Lu Zhenbo;To conduct dynamic modeling of a tandem-wing tilt-duct eVTOL, the trim point for steadylevel flight must first be determined. This study investigates the 3-DOF longitudinal trim process and its determining factors. Aerodynamic parameters are obtained through a combination of ducted-fan static thrust experiments and CFD simulations using the momentum source method. It is proposed that drag and pitching moment effects be considered when calculating the neutral point, and an analytical solution is derived using a binomial approach. Using the control variable method, the effects of freestream velocity, angle of attack, and front and rear duct thrusts on aerodynamic forces and moments are analyzed. Empirical fitting formulas are developed and presented in full expressions. Results show that the neutral point is sensitive to freestream velocity, highlighting the need for accurate determination in this configuration. The four factors' effects on the three aerodynamic forces generally exhibit second-order relationships.
Development of a sub-gram ultralight servo actuator for micro unmanned aerial vehicles
Lv Yafei;Li Fu;Wang Liang;As key actuators for achieving precise position control in small-scale mechanical and electronic systems, micro servos are widely applied in fields such as micro aerial vehicles(MAVs), precision optical pods, robotic joints, and portable communication terminals. To address the design challenges regarding torque density, dynamic response, and disturbance suppression in 0.5-gram class servos, an integrated scheme is proposed and implemented. This scheme is based on a coreless micro DC motor, a hybrid reduction mechanism combining a worm drive and a sectoral gear, an off-axis 3D Hall-effect sensor calibration system, and a 3.3 V single-voltage drive control circuit. Independent third-party testing results of the initial prototype show a rotation range of 149°, a torque density of 2.46 N·m/kg, a total mass of 0.617 g, a dynamic response time of approximately 76 ms, an overshoot of 4.6%, and a steady-state error of 0.8%. These results verify the feasibility and superiority of the design.
Control allocation strategy for tiltrotor UAV based on improved whale optimization algorithm
Chen Jinghongju;Mo Chongsen;Wu Di;Lu Zhenbo;Aiming at the strong nonlinearity and actuator saturation constraints encountered in the thrust vector control allocation of tiltrotor UAV, this paper proposes a control allocation strategy based on an improved whale optimization algorithm(IWOA). Firstly, a six-degree-of-freedom dynamic model of the tiltrotor UAV is established, and attitude and position controllers are designed. The whale optimization algorithm(WOA) is adopted to address the thrust vector control allocation problem. On this basis, three major improvements are implemented to the original WOA: Elite opposition-based learning is introduced to optimize the quality of the initial population; the convergence factor is adjusted to balance the global search and local exploitation capabilities of the algorithm; and the Lévy flight operator is integrated to strengthen the local exploitation performance. Finally, numerical simulation experiments are carried out to compare the proposed algorithm with allocation strategies based on conventional optimization algorithms. The results verify the feasibility and superiority of the presented algorithm for solving control allocation problems, which provides a reliable solution for high-performance maneuvering control of tiltrotor UAV.
Post-launch trajectory control method of vertical mounted fixed-wing aircraft
Xu Chenglong;Leng Jinyi;Yan Zheping;Lin lin;To address the problems of limited mounting configurations, low aerodynamic efficiency, restricted sub-UAV layout and payload capacity in conventional mother-child UAV systems, a mounting configuration is proposed in which the sub-UAVs are installed vertically on the outer sides of the carrier aircraft fuselage. The proposed layout provides more flexible combination configurations and improves the flexibility and spatial utilization efficiency of the system. To satisfy the higher requirements for attitude stability and trajectory tracking accuracy during the sub-UAV release process, a phased control architecture based on variable step-size model predictive control(MPC) is proposed. During the separation transition phase(Phase I), precise attitude tracking control of the preset roll angle is achieved. During the stable flight phase(Phase II), the control mode is switched to a high-precision trajectory tracking mode. Simulation results show that, in the presence of model linearization errors and atmospheric disturbances, the proposed multi-phase variable step-size MPC algorithm confines the trajectory tracking error to within 4.7m-a 51.6% reduction compared to conventional MPC algorithm. The robustness and effectiveness of the proposed method under complex operating conditions are thereby verified.
Research progress on key technologies of autonomous landing for shipborne vertical take-off and landing unmanned aerial vehicles
Liu Zhongchen;Peng Yiming;Hu Xionglong;Zhang Ming;Chen Xinmin;Wei Xiaohui;Shipborne vertical take-off and landing unmanned aerial vehicles (VTOL UAVs) offer significant advantages， including runway independence， excellent low-altitude and low-speed performance， stable hovering capability， and high mission flexibility. However， the autonomous landing process on naval vessels is characterized by a high accident rate and substantial risks， representing a critical phase in the maritime application of shipborne VTOL UAVs. This paper briefly outlines the technical characteristics distinguishing shipborne VTOL UAVs from their land-based counterparts. It analyzes the technical challenges encountered during the three phases of autonomous landing: return approach， descent and touchdown， and aircraft-ship locking. The study focuses on reviewing key technologies such as autonomous landing guidance， landing platform stabilization， and rapid aircraft-ship securing. Future development trends are also projected. Key directions for advancement include multi-source data fusion-based landing guidance technology， multifunctional integrated landing platform technology， and intelligent adaptive take-off and landing system integration technology.
[Downloads: 100 ] [Citations: 0 ] [Reads: 40 ] HTML PDF Cite this article
[Downloads: 7,602 ] [Citations: 101 ] [Reads: 160 ] HTML PDF Cite this article
Links
Chinese Library Classification
2022-03-24Beijing News Publication Bureau
2022-03-24Journal of Propulsion Technology
2021-11-25Tactical Missile Technology
2021-11-25Unmanned Systems Technology
2011-10-18Academic Misconduct Detection System
2011-10-18International Repository of Knowledge Resources
more..