Design Of 3-dof Model Support Device And Control System In Wind Tunnel

The function of the wind tunnel model support device is to support and adjust the position and attitude of the aircraft model to achieve accurate measurement of the aerodynamic performance parameters of the aircraft.It is a core component of the wind tunnel test.The three-degree-of-freedom model support device designed in this paper can be applied to high-speed and heavy-load conditions,and can realize pitch,yaw and axial motion control when the rotation center is fixed.This paper first analyzes the significance of the development of the wind tunnel multi-degree-of-freedom model support device,and investigates the research status and deficiencies of the multi-degree-of-freedom model support device at home and abroad in terms of structure and motion mechanism.According to technical requirements,comparing the advantages and disadvantages of the three pre-designed model support devices and determining the mechanism scheme,the mechanical body,including the structural design of the base,yaw,pitch,axial,and locking mechanism,is completed.In this paper,the force analysis and modeling of the aerodynamic load on the device are carried out,and the nine extreme poses of the device under the maximum impact load are statically analyzed using ANSYS software to verify the safety of the structural strength;at the same time,ADAMS is used.The software performs dynamic simulation on six typical motion conditions,which verifies the correctness of the motion load analysis.Based on the kinematics and dynamics characteristics of the device,this paper uses MATLAB software to model and analyze the functional relationship between the motion angle of the mechanism and the driving displacement and driving force of the hydraulic cylinder,and complete the calculation and selection of the three-degree-of-freedom hydraulic cylinder,and The stability and strength of the piston rod of the hydraulic cylinder are calculated and verified.This paper has completed the schematic drawing of the hydraulic drive system,and optimized the design of various functional modules such as the oil source system,the actuator drive system,the locking mechanism drive system,the cooling system,and the oil monitoring system.At the same time,the hydraulic control components,The hydraulic power components and hydraulic auxiliary components have been calculated and selected.This paper has completed the design of control subsystems such as motion control system,oil source control system,and health management system,including key hardware selection,controller IO distribution,and control system software structure design.Compared with pure PID control algorithm,this paper proves the advancement of feedforward + PID control algorithm in hydraulic servo control through comparative analysis and simulation;and adopts trapezoidal speed planning combined with sliding average filter algorithm to achieve variable step movement and continuous change S-shaped trajectory planning for attitude angular motion.Combining the mechanical body and hydraulic drive module,trajectory planning module,control algorithm module,wind tunnel pneumatic load loading module,etc.,this paper builds a mechanical and electrical-hydraulic integrated physical closed-loop control simulation system based on Matlab/Simscape,and realizes the high-speed control of the model support device and precise control with dynamic accuracy better than ±0.05°.Finally,this article uses QT host computer development software to design,program and test the user login interface,health management interface,oil source monitoring interface,motion control interface,and three-dimensional real-time simulation subsystem of the measurement and control system.