一种机器人谐波减速器内嵌扭矩传感器的研制

Development of a built-in torque sensor in harmonic drive gears for robots

针对模块化可重构机器人对关节扭矩测量的需求,研制了一种内嵌于谐波减速器的扭矩传感器。基于二阶纹波模型,对谐波减速器的柔轮进行了应力应变分析。提出了一种基于矢量抵消原理的扭矩传感器设计方法,设计了一种基于三矢量抵消的扭矩传感器,使一、二阶纹波及更多阶纹波甚至所有其他高阶纹波都通过矢量叠加而抵消,且通过使用冗余应变片提高测量精度。分析了系统的输出与扭矩的关系,并进行了传感器误差分析。研制了扭矩传感器物理样机和测试平台,并进行了加载测试,结果表明,研制的扭矩传感器具有较高的灵敏度和精度,精度与波发生器的转动有相关性。

To meet the demand of joint torque measurement for a modular reconfigurable robot, a built-in torque sen- sor in harmonic drive gear was developed. Based on the two-order ripple model, the stress and strain of the flexspline in the harmonic drive gear were analyzed. A vector-added-and-cancelled-out-principle based torque sensor design method was proposed, and a three-vector-added-and-cancelled-out-based torque sensor was designed. The torque sen- sor cancels out the first order, the second order, and even all the other higher order ripples through ripple vector addi- tion. The redundant stain gauges were employed to improve the measurement accuracy. The relationship between the output signal and the input torque was obtained, and the error analysis was given. A torque sensor prototype and a test bed were developed;and the loading experiments were conducted. The experimental results show that the torque sen- sor possesses high sensitivity and accuracy, and the accuracy has correlation with the wave generator rotation.