光纤光栅六维测力仪耦合误差原位校准

In-Place Calibration for Coupling Error of Six-axis Dynamometer Based on Fiber Bragg Grating

不同于应变型测力仪,光纤光栅(Fiber Bragg Grating, FBG)六维测力仪采用结构型测力原理及光无源器件,耦合误差是其主要指标参数之一,且由于其应用场景限制,通常进行原位校准。文中分析了FBG六维测力仪的传感结构及原理,根据耦合误差模型,设计了无标准力源的原位校准装置,提出基于机械臂的耦合误差原位校准方法,实现了校准操作流程的简化和不确定度来源的控制。通过结合实际算例,分析了校准结果不确定度,验证了该方法的有效性。

Different from strain gauge dynamometers,six-axis dynamometer based on fiber Bragg grating(FBG)adopts the structural force measurement principle,and one of its main performance parameters is the coupling error.Due to the limitation of its application scenario,in-place calibration is usually performed.The sensing structure and principle of the FBG six-axis dynamometer are analyzed,and an in-place calibration device without a standard force source is proposed according to the coupling error model.An in-place calibration method based on a robot arm for coupling error is also established,in which the calibration process is simplified and the source of uncertainty is reduced.The uncertainty of calibration results is analyzed with a practical example,and the effectiveness of the method is verified.