Torque Measurement of High-Precision Reducer for Industrial Robot

Torque testing is crucial to improve the quality of high-precision reducers—the core component of industrial robots. Herein, a torque-measurement system for a novel vertical measuring instrument is designed. The distance from the torque transducers to the robot reducer is minimized to ensure the shortest measurement chain. The symmetrical system structure improves the overall rigidity, and error compensation can be performed easily. The characteristics of the torque measurement errors due to shaft bending and torsional deformations were also analyzed. A torque calibrator comprising two high-precision torque output systems was used to calibrate torque transducers in the measurement system. Reasonable and practical compensation models based on a backpropagation neural network were developed to accurately obtain the input and output torques of the reducer. As the torque-measurement precision of the reducer detector reached 0.1% over the entire torque range, the instrument can be used for accuracy measurement of the input and output torques of the robot reducer.