Robot joint torque sensor

Abstract

The invention discloses a robot joint torque sensor. A traditional sensor is taken as an individual component and is arranged in a joint driving structure, which increases complexity and the cost of torque measurement. NPN silicon phototransistors and an infrared light emitting diode are fixed on a first planar torsion spring. A PCB signal processing circuit board carries out amplification and filtering processing on four voltage signals transmitted by the four NPN silicon phototransistors. Simulation voltages after filtering processing are converted into digital voltage signals. A least square method linear fitting algorithm is used to carry out linearity correction on the four digital voltage signals. And then, the four digital voltage signals after the linearity correction are calibrated and decoupled so that corresponding voltage values are converted into a torque value. In the invention, a hysteresis error and a temperature drift error are small, measurement precision is high, andsimultaneously, the influence of the torque sensor on joint flexibility is reduced.

Description

technical field [0001] The invention belongs to the technical field of a robot joint measuring torque sensor, in particular to an integrated torque sensor used for measuring the torque of a plane torsion spring at a robot joint. Background technique [0002] In a mechanical transmission system, torque is one of the important parameters reflecting the performance of the system. The drive unit used for the transmission at the robot joints—the double-layer planar torsion spring (application number 201611059925.9) can realize the flexibility of the joint drive and reduce the joint transmission stiffness. In the transmission process of the plane torsion spring, the information of torque and rotation angle borne by the plane torsion spring is an indispensable part of the robot joint drive control, and the force or torque sensor is a necessary sensor for sensing the torque information of the torsion spring. [0003] In the traditional sensor design, the sensor exists as a separate...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a planar torsion spring integrated optical sensor for the deficiencies of the prior art, which solves the problems of traditional sensors with large hysteresis errors and temperature drift errors, and low measurement accuracy, while reducing the influence of torque sensors on joint flexibility

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