基于机器视觉的共轴双旋翼桨尖位移实时监测系统

Real-Time Monitoring System of Coaxial Twin Rotor Tip Displacement Based on Machine Vision

共轴双旋翼直升机风洞实验中,配平状态是不可预测或预知的,具有很高的风险性,为了保证实验的安全,开发了一种基于机器视觉测量方法的桨尖位移实时监测系统。根据实验的高转速、高风险的特点,采用高速相机实时采集桨尖图像,通过增加光照、优化相机参数等措施获得了清晰的图像。采用图像分割、目标检测等数字图像处理方法,获取了桨尖的实时位置,通过桨尖位置解算出上下桨尖距离。通过相机外部触发与同步,实现不同转速条件下,桨叶的识别和测量。基于Matlab软件平台开发了系统软件,实现了旋转状态下旋翼桨尖的图像采集、图像实时处理、数据实时显示等功能。在4 m共轴旋翼实验中,获取了悬停状态、前飞状态下的桨尖位移和桨尖距离数据,数据符合共轴双旋翼空气动力学理论。实验验证表明,该系统完全满足实验需求,对保障共轴旋翼实验的安全具有重要意义。

In the wind tunnel test of coaxial twin rotor helicopter,the trim state is unpredictable and has high risk.In order to ensure the safety of the experiment,a real-time monitoring system of propeller tip displacement based on machine vision measurement method is developed.According to the characteristics of high speed and high risk in the experiment,a high-speed camera is used to collect the real-time image of the propeller tip,and the clear map image is obtained by increasing illumination and optimizing camera parameters.The real-time position of the propeller tip is obtained by using image segmentation,target detection and other digital image processing methods,and the distance between the upper and lower propeller tips is calculated by solving the position of the propeller tip.Through the external trigger and synchronization of the camera,the identification and measurement of blades under different speeds are realized.Based on Matlab software platform,the system software is developed to realize the functions of rotor tip image acquisition,image real-time processing and data real-time display.In the 4 m coaxial rotor experiment,the data of tip displacement and tip distance in hover and forward flight are obtained,which are consistent with the aerodynamic theory of coaxial twin rotor.Through the experimental verification,the system fully meets the experimental requirements,which is of great significance to the safety of coaxial rotor experiment.