精密球铰链在并联机构中应用广泛，但其在被动运动中，其回转方位及回转角无法自知。基于磁效应，提出一种霍尔传感器与永磁体组合的回转方位辨识及角度测量新方法。在球头上嵌入永磁体，在球窝上植入霍尔传感器阵列，当球头回转时，霍尔传感器阵列测量磁感应强度的变化，反解出角度信息。在完成理论建模、仿真计算和可行性试验的基础上，完成了嵌入式样机的研制。在实现信号冗余计算的基础上，优化了反解算法，基本实现了球铰链多维回转角度的实时测量。球铰链也从单纯的精密传动部件转变为集传动和感测为一体的综合智能部件。随研究的继续，其精度将有大幅提高，有望应用到精密工程中。
Precision ball hinges are widely employed in parallel mechanisms, but its rotation orientation and angle can not be known in its passive motion. Measurement of multi-dimensional angular displacement will be very of great significance in the prediction, feedback and control of motion errors of parallel mechanism. Based on the magnetic effect, a new method to identify the orientation and rotation angle with Hall sensors array matched by permanent magnet is proposed. The basic idea is embedding a permanent magnet in the ball head and several hall sensors are distributed in the ball socket. When the ball head carrying the permanent magnet rotates together, the Hall sensors array will detect the variation of magnetic induction intensity, and then the angle information can be calculated by mathematics model. An embedded prototype is developed after finishing the theoretical modeling, simulation calculation and feasibility experiment, the real-time measurement of the spherical hinge rotation angle has been realized and improved by optimizing the inverse algorithm and the signal redundancy calculation. Therefore, the ball hinge has evolved into an intelligent component integrated with transmission and sensing function. As the research continues, its accuracy will be greatly improved, and can be applied to precision engineering in the future.
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