针对六维力/力矩传感器测量量程受限问题, 提出一种具有分载测量功能的预紧式Stewart结构六维力/力矩传感器。首先, 对比传统Stewart结构力/力矩传感器, 阐述了预紧式六维力/力矩传感器的结构特点和测量原理。然后, 完成了预紧式Stewart结构六维力/力矩传感器的结构设计。建立了传感器的有限元模型, 对模型进行了模态分析, 得到了传感器的前五阶固有频率和振型, 并确定了传感器的工作带宽为0～204 Hz。最后, 研究了传感器的静态标定原理, 并对传感器进行了静态标定实验, 得到了传感器的标定实验解耦矩阵。实验结果表明, 该预紧式Stewart结构六维力/力矩传感器的测力量程为0～3 000 N, 测力矩量程达0～300 N·m, 测量精度优于实际值的7.5%。传感器能够满足空间六维力/力矩的测量, 具有量程大、解耦计算简单、安装调试方便等优点。

A pre-stressed six-axis force/torque measurement method based on a Stewart platform was established to extend its measuring range. Compared to the traditional Stewart six-axis force/torque sensor, the principle of the pre-stressed Stewart six-axis force/torque measurement was analyzed. Then, structure design of the sensor was finished. By using the ANSYS software, a finite element model for the pre-stressed Stewart six-axis force/torque sensor was established. According to this model, the vibration modal was analyzed, and the natural frequencies and vibration modes were obtained. Finally, principle of the sensor calibration was analyzed, and the sensor coupling matrix was calculated according to the data of a static calibration experiment. Experimental results indicate that this pre-stressed Stewart six-axis force/torque sensor has the measuring ranges of 0～3 000 N for the force and 0～300 N·m for the torque, and its measuring accuracy is better than 7.5% of the actual data. It shows its advantages in wide measuring range, easy to decoupling and convenient for assembly.