Lu Wenbo, Xue Junpeng, Pu Wei, Chen Hongyang, Wang Kelei, Jia Ran
School of Aeronautics and Astronautics, Sichuan University, Chengdu 610065, China.
Robotic Satellite Key Laboratory of Sichuan Province, Chengdu 610065, China.
Sensors (Basel). 2024 Oct 9;24(19):6499. doi: 10.3390/s24196499.
The rotational speed vectors of the bearing balls affect their service life and running performance. Observing the actual rotational speed of the ball is a prerequisite for revealing its true motion law and conducting sliding behavior simulation analysis. To address the need for accuracy and real-time measurement of spin angular velocity, which is also under high-frequency and high-speed ball motion conditions, a new measurement method of ball rotation vectors based on a binocular vision system is proposed. Firstly, marker points are laid on the balls, and their three-dimensional (3D) coordinates in the camera coordinate system are calculated in real time using the triangulation principle. Secondly, based on the 3D coordinates before and after the movement of the marker point and the trajectory of the ball, the mathematical model of the spin motion of the ball was established. Finally, based on the ball spin motion model, the three-dimensional vision measurement technology was first applied to the measurement of the bearing ball rotation vector through formula derivation, achieving the analysis of bearing ball rolling and sliding characteristics. Experimental results demonstrate that the visual measurement system with the frame rate of 100 FPS (frames per second) yields a measurement error within ±0.2% over a speed range from 5 to 50 RPM (revolutions per minute), and the maximum measurement errors of spin angular velocity and linear velocity are 0.25 °/s and 0.028 mm/s, respectively. The experimental results show that this method has good accuracy and stability in measuring the rotation vector of the ball, providing a reference for bearing balls' rotational speed monitoring and the analysis of the sliding behavior of bearing balls.
轴承滚珠的转速矢量会影响其使用寿命和运行性能。观察滚珠的实际转速是揭示其真实运动规律并进行滑动行为模拟分析的前提条件。为了满足在高频高速滚珠运动条件下对自旋角速度进行精确实时测量的需求，提出了一种基于双目视觉系统的滚珠旋转矢量测量新方法。首先，在滚珠上布置标记点，并利用三角测量原理实时计算其在相机坐标系中的三维坐标。其次，根据标记点运动前后的三维坐标以及滚珠的轨迹，建立了滚珠自旋运动的数学模型。最后，基于滚珠自旋运动模型，通过公式推导将三维视觉测量技术首次应用于轴承滚珠旋转矢量的测量，实现了对轴承滚珠滚动和滑动特性的分析。实验结果表明，帧率为100 FPS（每秒帧数）的视觉测量系统在5至50 RPM（每分钟转数）的速度范围内测量误差在±0.2%以内，自旋角速度和线速度的最大测量误差分别为0.25°/s和0.028 mm/s。实验结果表明，该方法在测量滚珠旋转矢量方面具有良好的精度和稳定性，为轴承滚珠转速监测和轴承滚珠滑动行为分析提供了参考。
