Robotic Force/Torque Sensor with Controlled Thermal Conduction

Abstract

A robotic force / torque (FT) sensor restricts the conduction of heat, generated by an attached tool, through the FT sensor body to a radial direction. Heat from the tool is channeled to the center of the FT sensor body by a thermally conductive member. Additionally, heat from the tool is insulated from portions of the FT sensor body other than its center by a thermally insulating member. Transducers, such as strain gages attached to the surfaces of deformable beams, are disposed at a substantially equal distance from the center of the FT sensor body. Accordingly, as heat conducts through the FT sensor body from the center radially outwardly, all transducers experience substantially equal thermal load at any given time. Embodiments of the present invention substantially eliminate thermal gradients across groups of transducers that are wired in differential circuit topologies, such as half-bridge or quarter-bridge, enhancing the ability of such circuits to reject a common-mode signal component caused by thermal changes to the FT sensor body or the transducers themselves. Elimination of thermal gradients in the FT sensor body, other than one in the radial direction, enhances the effectiveness of known temperature compensation techniques.

Description

[0001] Cross References to Related Applications [0002] This application claims priority to U.S. Patent Application No. 16 / 902,674, filed June 16, 2020, entitled "Robotic Force / Torque Sensor with Controlled Thermal Conduction," the disclosure of which is incorporated herein by reference in its entirety. technical field [0003] The present invention relates generally to force / torque sensors for robotic applications, and in particular to force / torque sensors having a predictable distribution of heat throughout the sensor body during operation. Background technique [0004] Robotics is a growing and increasingly important field in industrial, medical, scientific, aerospace and other applications. In many instances where a robotic arm or a tool attached to it comes into contact with a workpiece, the applied force and / or torque must be closely monitored. Therefore, force / torque sensors are an important part of many robotic systems. [0005] Many types of force / torque sensors ...

AI Technical Summary

Problems solved by technology

[0015] In general, these techniques work best when the temperature variation is uniform across the body of the force / torque sensor - which is rarely the case in practical applications

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